ARTICLE | doi:10.20944/preprints201910.0178.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: essential oils; Bartonella henselae; persisters; stationary phase; antimicrobial activity
Online: 16 October 2019 (05:18:55 CEST)
Bartonella henselae is a fastidious Gram-negative intracellular bacterium which can cause cat scratch disease, endocarditis in humans and animals as well as other complications, leading to acute or chronic infections. The current treatment for Bartonella infections is not very effective due to antibiotic resistance and also persistence. To develop better therapies for persistent and chronic Bartonella infections, in this study, with the help of SYBR Green I/PI viability assay, we performed a high-throughput screening of an essential oil library against stationary phase B. henselae. We successfully identified 32 essential oils that had high activity, including four essential oils extracted from Citrus plants, three from Origanum, three from Cinnamomum, two from Pelargonium and two from Melaleuca, as well as frankincense, ylang ylang, fir needle, mountain savory (winter), citronella, spearmint, elemi, vetiver, clove bud, allspice and cedarwood essential oils. The minimal inhibitory concentration (MIC) determination of these 32 top hits indicated they were not only active against stationary phase non-growing B. henselae but also had good activity against log phase growing B. henselae. The time-kill curve by drug exposure assay showed 13 active hits, including essential oils of oregano, cinnamon bark, mountain savory (winter), cinnamon leaf, geranium, clove bud, allspice, geranium bourbon, ylang ylang, citronella, elemi and vetiver, could eradicate all stationary phase B. henselae cells within 7 days at the concentration of 0.032% (v/v). Two active ingredients, carvacrol and cinnamaldehyde, of oregano and cinnamon bark essential oils, respectively, were shown to be very active against stationary phase B. henselae such that they were able to eradicate all the bacterial cells even at the concentration ≤ 0.01% (v/v). Our finding of active essential oils may help to develop more effective treatments for persistent Bartonella infections.
ARTICLE | doi:10.20944/preprints202002.0435.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: encapsulated essential oils; coccidiosis vaccine; growth performance; broiler chickens; gut health
Online: 28 February 2020 (13:04:42 CET)
The present study was conducted to evaluate encapsulated essential oils as an alternative anticoccidial in coccidiosis vaccine challenged broiler chickens. A total of 600 day-old male broiler chicks were provided with no-added corn-soybean meal-based control diet or diets that contained either salinomycin or EO at 60 and 120 mg per kg of diet. On day 21, half of the control groups were orally challenged with a coccidiosis vaccine at 25 times higher than the recommended vaccine dose. During 22 to 28 days (i.e., one-week post coccidiosis vaccine challenge), the challenged chickens had decrease (P < 0.05) in body weight gain and feed intake but increase in feed conversion ratio compared with the non-challenged, naïve control chickens. However, dietary EO significantly counteracted (P < 0.05) coccidiosis vaccine-induced depression in body weight gain and feed intake. Increasing dietary EO linearly decreased (P < 0.05) the concentrations of the volatile fatty acids. Dietary SAL and EO affected gut morphology in chickens at 20 days posthatch. Increasing dietary EO linearly (P = 0.073) increased serum catalase activity. Collectively, our study shows that dietary EO increased coccidiosis vaccine-induced growth depression and altered gut physiology in broiler chickens.
REVIEW | doi:10.20944/preprints201610.0009.v1
Subject: Chemistry, Organic Chemistry Keywords: Essential(s) oils; monoterpenes; insecticidal activity; antimicrobial activity; acaricide activity; herbicidal activity
Online: 4 October 2016 (16:08:09 CEST)
Several plant species produce mixtures of odorous and volatile compounds known as essential oils (EOs). These mixtures play important roles in nature and have been utilized by man for pharmaceutical and agrochemical purposes. There are more than 3000 EOs reported in the literature with approximately 300 having commercial use, including the oils from Eucalyptus species. Such oils are rich in monoterpenes and have found applications as pharmaceuticals, agrochemicals, food flavorants and in the perfume industry. Such applications are related to their diverse biological and organoleptic properties. In view of their importance, we review in this article up to date information concerning chemical composition and biological activities of essential oils from different species of Eucalyptus. Among the 900 species and subspecies of the Eucalyptus genus¸ we examined 68 species. The studies associated with these species were conducted in 27 countries. We have focused on the antimicrobial, acaricide, insecticide and herbicide activities, hoping that such information will contribute in the advances of the research in this field. It is also intended that the information herein described can be useful in the rationalization of the use of Eucalyptus EOs as components for new pharmaceutical and agrochemical applications as well as food preservatives and flavorants.
ARTICLE | doi:10.20944/preprints201904.0012.v1
Subject: Biology, Plant Sciences Keywords: antimicrobial activity; essential oils; Salvia officinalis; Sudan
Online: 1 April 2019 (13:15:06 CEST)
This study aimed to screen the antibacterial activity of essential oils from different parts (leave and stem) of Salvia officinalis against some Gram positive and Gram negative bacteria using agar disc diffusion test, then the extracts were prepared by hydro distillation to extract the essential oils. Maceration and hexane extraction by Soxhlet were used to obtain crude extracts from the leave and stem. Essential oils from the leaves and the ethyl acetate extract of the leaves showed higher antimicrobial activity, while hexane extract of leaves and stems showed moderate antibacterial activity. In contrast the essential oil from the stems showed very low antibacterial activity. It was observed that the results gram positive bacteria (staphylococcus aureus) was more sensitive than Gram negative (Echerichia coli).
ARTICLE | doi:10.20944/preprints202011.0586.v1
Subject: Chemistry, Analytical Chemistry Keywords: chemical composition; antioxidant; Citrus; essential oils; Principal Component Analysis.
Online: 23 November 2020 (14:19:03 CET)
Citrus essential oils (EOs) have various bioactivities like antioxidants, with many applications. Antioxidant activities depend on the chemical compositions of the EOs, which are affected by climate, soil, and geographical region. Thus, investigations on chemical compositions and antioxidant activities of Citrus EOs in different countries are valuable. In this study, we distilled EOs from peels of Indonesian-grown Citrus, including C. nobilis, C. limon, C. aurantifolia, C. amblycarpa, and Citrus spp.Chemical compositions of EOs were analyzed using Gas Chromatography-Mass Spectrometer (GC-MS), whereas the antioxidant activities were determined by employing 2,2-diphenyl-2-picrylhydrazyl (DPPH) method. Furthermore, principal component analysis (PCA) was applied to elucidate the main contributing compounds for antioxidant activity. The results show that all EOs possess unique chemical characteristics, with limonene as the majority constituent. For antioxidant activities, C. limon and C. amblycarpa EOs are the two strongest, IC50 values below 7.00 μL/mL. PCA approach suggests that -terpinene mainly contributes to the high antioxidant activities of C. limon and C. amblycarpa. Moreover, o-cymene, thymol, p-cymene, and α-pharnesene may also be responsible for the antioxidant activity of C. limon EO. These results are valuable information for the applications of Citrus EOs as antioxidant sources.
BRIEF REPORT | doi:10.20944/preprints201902.0146.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: lesser mealworm; essential oils; repellency; spatial preference; locomotor activity
Online: 18 February 2019 (08:42:56 CET)
The main scope of the presented paper is an assessment of the potential repellent effect of selected essential oils (EOs) against Alphitobius diaperinus, which can cause economic losses in storages and poultry industry. Due to development of pesticide resistance in A. diaperinus populations, as well as an attempt to limit extensive usage of potentially harmful pesticides in food-related industries, there is a strong need for development of alternative methods of management of A. diaperinus infestations. Because of cost-effectiveness, availability and low vertebrate toxicity EOs are promising agents in pest management. In presented paper four of-the-shelf EOs: mint, vanilla, lemon and citronella (and their mixtures) were tested as a potential repellents. Moreover, novel preference assay providing an extended analysis of preference and the locomotor response was used. The most effective EOs were, respectively: citronella and lemon. EOs mixtures were generally more repellent than single EOs, with lemon and vanilla 1:1 mixture acting as the strongest repellent. Few of tested EOs caused significant alterations in locomotor activity, although direct relation wasn’t observed. In conclusion, EOs can be potentially used as a repellent agents in A. diaperinus management. Additionally, data on locomotor activity may lead to better design of pull-push strategies in pest management.
ARTICLE | doi:10.20944/preprints202002.0278.v1
Subject: Chemistry, Organic Chemistry Keywords: Chemotypes; Tephrosia vogelii; pesticidal activity; Sitophilus zeamais; essential oils
Online: 19 February 2020 (11:39:01 CET)
Chemical variability in the components of T. vogelii essential oils from eastern Uganda was identified using principal component analysis (PCA) and Agglomerative hierarchical clustering (AHC). Based on the profiles of the compounds of farnesene family three chemotypes were found: farnesol (chemotype 1), springene (β- Springene and α-Springene) and the β-Farnesene were distinctive in chemotype 2 and a mixed variety of farnesol and the Springene. In the three cases, alkybenzenes; o-xylene, m-xylene and ethylbenzene were significant components in the oil. 1,4-dihydroxy-p-menth-2-ene, 5,9-undecadien-2-one, 6,10-dimethyl, and 3-cyclohexen-1-carboxaldehyde,3,4-dimethyl were other prominent constituents. The yields of the essential oils did not vary significantly however the chemical composition varied with harvesting time during the rainy and dry seasons. In choice repellency tests, chemotype 1 and chemotype 2 were more active against Sitophilus zeamais than mixed chemotype. Farnesol was found to be effective only at a higher concentration as a repellent against S. zeamais. However, further study that aims to optimize and standardize the varieties and harvesting period needed for recommendation to smallhold farmers.
ARTICLE | doi:10.20944/preprints201810.0236.v1
Subject: Biology, Other Keywords: essential oils; drug resistant microorganisms; antimicrobial activity; antifungal activity; medicinal plants
Online: 11 October 2018 (11:51:16 CEST)
Antimicrobial resistance (AMR) is a recurring global problem, which constantly demands new antimicrobial compounds to challenge the resistance. It is well known that essential oils (EOs) have been known for biological activities including antimicrobial properties. In this study, EOs from seven aromatic plants of Asir region of southwestern Saudi Arabia were tested for their antimicrobial efficacy against four drug resistant pathogenic bacterial isolates (Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Streptococcus typhimurium) and one fungal isolate (Candida albicans). Chemical compositions of EOs were determined by Gas chromatography-Mass Spectrometry (GC-MS). The results revealed that EOs from Mentha cervina, Ocimum basilicum and Origanum vulgare proved most active against all isolates with inhibitory zone range between17 to 45 mm. The lowest minimum inhibitory concentration (MIC) of 0.025mg/ml was observed for Staph. aureus and Streptococcus pyogenes with EO of Origanum vulgare. All the three EOs showed significant anti candida activity. Together form the results the EOs from Mentha cervina, Ocimum basilicum and Origanum vulgare demonstrated a significant antimicrobial efficacy against drug resistant microorganisms.
ARTICLE | doi:10.20944/preprints201809.0568.v1
Subject: Chemistry, Organic Chemistry Keywords: essential oils; VOCs; GC-MS SPME; electronic nose; nanowire gas sensors; ANOVA.
Online: 28 September 2018 (13:22:44 CEST)
Essential oils are mixtures of compounds obtained from plants, including flowers, roots, bark, leaves, seeds,peel, fruits, wood, that have risen up in the last decades thanks to their beneficial properties as antibacterial, antifungal and anti-inflammatory agents. The aim of this study was to characterize and analyze 13 different commercial essential oils with two different techniques. The first is GC-MS, coupled with SPME, thanks to which 204 different VOCs have been identified. The results show that a total of 95 compounds was found only in one oil, while the others were found with different frequencies in many of them. The most represented class is that of terpenes, as widely reported in literature. The second technique is based on an array of chemical gas sensors. This system was used to investigate whether sensors are able to identify these products. It turned out that basil, cinnamon and carnation are the most identifiable oils with different number and typology of sensors, especially tin oxide and copper oxide nanowires, while cayeput and thyme are more mistakable samples. Thanks to this detailed study, it has been possible to reach and obtain novel insights for the future development of this type of research.
ARTICLE | doi:10.20944/preprints201909.0121.v1
Subject: Life Sciences, Biochemistry Keywords: Tomato borer; essential oil; GC-MS profile; larvicidal effects
Online: 11 September 2019 (13:21:03 CEST)
This study aimed to determine the Gas Chrommatography (GC)-Mass Spectrometry (MS) profiles and insecticidal activity of essential oils (EOs) from Thymus vulgaris (Thyme) and Cymbopogon citratus (Lemongrass) against the invasive and devastating pest, Tuta absoluta (T. absoluta) through contact and fumigation routes. We found out that thyme oil was predominantly constituted of Thymol (22.16%), α-Pinene (15.35%) and p-Cymene (13.54%) whilst Neral (21.41%), Geranial (21.36%) and β-Myrcene (9.74%) were the major constituents of lemongrass oil. Lemongrass oil exhibited higher insecticidal efficiency irrespective of application mode with 50% lethal dose (LD50) values of 35.8 and 72.2 µL.L-1air on contact and fumigation routes, respectively. Lemongrass oil also lengthened pupal duration at all tested doses irrespective of application routes. The overall responses of Lemongrass oil surpassed that of the reference insecticide (Lynx®: Lambda-cyhalothrine; Acetamipride). Thus, the recorded data clearly showed the acute and long-term insecticidal effects of the studied EOs, though a greenhouse and open field trials are required prior to the validation of this approach as remediation measure for Integrated Pest Management (IPM) for tomato borer control in Cameroon and elsewhere.
ARTICLE | doi:10.20944/preprints201705.0132.v1
Subject: Biology, Plant Sciences Keywords: Pittosporum tobira (Thunb.) Aiton; Essential oils (EOs); Headspace solid-phase microextraction (HS-SPME); Gas chromatography-mass spectrometry (GC-MS); Anticancer activity
Online: 17 May 2017 (13:08:12 CEST)
Background: Pittosporum tobira (Thunb.) Aiton is an aromatic medicinal plant widely cultivated in the world. However, the essential oils (EOs) from P. tobira flowers for anti-cancer potential is still not systematically studied. The present aim to elucidate the phytochemical composition of the EOs and to explore mechanism of anticancer action. Methods: The EOs were extracted and analyzed by headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). Volatile components were identified according to Kovats retention index (KI) and NIST database. The anti-neoplasm mechanisms of the EOs was comprehensively investigated in lung carcinoma A549 and H460 cells. Results: A total of 47 secondary metabolites representing 94.18% of the EOs were successfully identified: monoterpenes and sesquiterpenes were the dominant terpenoids. The EOs exhibited antiproliferative activity on A549 and H460 lung carcinoma cells. Hoechst 33324 fluorescent staining indicated the typical characteristics of apoptosis and induced cycle phase arrest. AnnexinV/PI staining revealed that the number of apoptotic cells was increased. Furthermore, the EOs also induced the caspase-mediated mitochondrial apoptosis pathway. Conclusions: Findings suggest that the full-scale chemical composition and first characterization of anticancer activities of the EOs, it could be used for integrative natural anti-cancer agents in health care should be pay more attention.
ARTICLE | doi:10.20944/preprints201807.0542.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Mentha x piperita; Mentha x arvensis; essential oils; heat stress; antibacterial activity; monoterpenes
Online: 27 July 2018 (14:04:14 CEST)
Heat stress affects the yield of medicinal plants and can reduce biomass and/or metabolite production. In order to evaluate the effect of heat-induced stress on the essential oil production in Mentha x piperita L. var. Mitcham (Mitcham mint) and Mentha x arvensis var. piperascens Malinv. ex L. H. Bailey (Japanese mint), we studied the chemical composition of the oils of the two mint species under different heat shock stress in growth chambers. The antibacterial activity of the essential oils was also evaluated; microscopic observation (fluorescence and electron transmission) was used to assess the effect of the tested samples on bacterial growth. The results obtained shed light on the mint essential oils composition and biological activity in relation to heat stress.
ARTICLE | doi:10.20944/preprints202011.0412.v1
Subject: Biology, Anatomy & Morphology Keywords: Process; ontological category; life concept; essential feature
Online: 16 November 2020 (10:49:11 CET)
Although increasing knowledge about biological systems has advanced exponentially in recent decades, it is surprising to realize that the very definition of Life keeps presenting theoretical challenges. Even if several lines of reasoning seek to identify the essence of life phenomenon, most of these thoughts contain fundamental problem in their basic conceptual structure. Most concepts fail to identify necessary and sufficient features to define life. Here, we analyzed the main conceptual framework regarding theoretical aspects supporting life concepts, such as (i) the physical, (ii) the cellular and (iii) the molecular approaches. Based on ontological analysis, we propose that Life should not be positioned under the ontological category of Matter. Yet, life should be better understood under the top-level ontology of “Process”. Exercising an epistemological approach, we propose that the essential characteristic pervading each and every living being is the presence of organic codes. Therefore, we explore theories in biosemiotics in order to propose a clear concept of life as a macrocode composed by multiple inter-related coding layers. Therefore, we suggest a clear distinction between the concept of life and living beings, a distinction that is not evident in theoretical terms. From the proposed concept, we suggest that the evolutionary process is a fundamental characteristic for life’s maintenance but not to its definition. The current proposition opens a fertile field of debate in astrobiology, biosemiotics and robotics.
ARTICLE | doi:10.20944/preprints202003.0455.v1
Online: 31 March 2020 (10:16:13 CEST)
Background: COVID-19, a member of corona virus family is spreading its tentacles across the world due to lack of drugs at present. Associated with its infection are cough, fever and respiratory problems causes more than 15% mortality worldwide. It is caused by a positive, single stranded RNA virus from the enveloped coronaviruse family. However, the main viral proteinase (Mpro/3CLpro) has recently been regarded as a suitable target for drug design against SARS infection due to its vital role in polyproteins processing necessary for coronavirus reproduction.Objectives: The present in silico study was designed to evaluate the effect of Eucalyptol (1,8 cineole), a essential oil component from eucalyptus oil, on Mpro by docking study.Methods: In the present study, molecular docking studies were conducted by using 1-click dock and swiss dock tools. Protein interaction mode was calculated by Protein Interactions Calculator.Results: The calculated parameters such as RMSD, binding energy, and binding site similarity indicated effective binding of eucalyptol to COVID-19 proteinase. Active site prediction further validated the role of active site residues in ligand binding. PIC results indicated that, Mpro/eucalyptol complexes forms hydrophobic interactions, hydrogen bond interactions and strong ionic interactions.Conclusions: Therefore, eucalyptol may represent potential treatment potential to act as COVID-19 Mpro inhibitor. However, further research is necessary to investigate their potential medicinal use.
ARTICLE | doi:10.20944/preprints201902.0218.v1
Online: 25 February 2019 (08:50:48 CET)
Abstract: In this study the essential oils of Salvia officinalis growing in Sudan, were obtained by hydrodistillation and analyzed by Gas chromatography mass spectrometer, forty tow compounds were identified. The essential oil composition of S.officinalis found that it had many important compounds. The detected main compounds were oxygenated monoterpenes followed monohydrocarbone, squiterpenes and other compounds. The main essential oil constituents were α-terpineol (33.07%), camphor (11.57%), α-pinene (8.96%) camphene (5.09%) β-cymen (5.40 %) caryphyllene (3.76%) β-myrcene (3.65%) β-menth1-en-b-ol (3.45%) bomeol (3.38%) β-pinene (2.74%) Epiglobulol (2.59%) 1,8 Cineol (2.24%) and trans-β- terpinyl butanone(2.00% ).
ARTICLE | doi:10.20944/preprints201806.0386.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: essential oil; Psoralea corylifolia; cytotoxicity; encapsulation; solubilisation
Online: 25 June 2018 (12:00:52 CEST)
Babchi (Psoralea corylifolia) oil is an important essential oil used in several traditional medicines to cure various disorders. This phytotherapeutic agent possesses number of pharmacological activities including antibacterial, antifungal, antioxidant, anti-inflammatory, immunomodulatory and antitumor. However, volatile nature, poor stability and solubility of babchi oil (BO) restrict its pharmaceutical applications. Hence, the aim of the present work was to encapsulate this oil in β-cyclodextrin nanosponges (NS) in order to overcome above limitations. To fabricate nanosponges, β-cyclodextrin was crosslinked with diphenyl carbonate in different molar ratios viz.1:2, 1:4, 1:6, 1:8 and 1:10. The blank nanosponges were loaded with babchi oil using freeze-drying method. Particle size of the babchi oil loaded nanosponges was found to lie between 200-500 nm, with low polydispersity index. Further, zeta potential, Fourier transform infrared spectroscopy, X-ray diffraction, thermal analysis and electron microscopy were carried out for characterization of babchi oil nanosponges. Results obtained from spectral analysis ascertained the formation of inclusion complexes. Additionally, solubilisation efficiency of the babchi oil was checked in distilled water and found enhanced by 4.95 times with optimized β-cyclodextrin nanosponges. The cytotoxicity study was carried out by MTT assay using HaCaT cell lines. A significant improvement in photostability of essential oil was also observed by inclusion in nanosponges. Lastly, the optimized formulation was tested for antibacterial activity using Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Hence, encapsulation of BO in nanosponges resulted in efficacious carrier system in terms of solubility, photostability as well as safety of this oil along with handling benefits.
ARTICLE | doi:10.20944/preprints202209.0191.v1
Subject: Biology, Plant Sciences Keywords: Acinetobacter baumannii; Etlingera elatior; antibiofilm activity; essential oil
Online: 14 September 2022 (04:37:05 CEST)
The current study investigates the antibiofilm properties of essential oil extracted from the Flower of a Zingiber plant used in traditional medicines. EO from Etlingera elatior (Jack) R. M Smith tested against one of the critical nosocomial pathogens, Acinetobacter baumannii. The antibiofilm studies of Flower essential oil (FEO) by crystal violet staining method exhibited maximum inhibition of 80% at a concentration of 0.7% oil. The biochemical assays and microscopic analysis showed that the FEO significantly reduced extracellular polymeric substance production. Furthermore, FEO reduced the survival rate of A. baumannii in human blood. The chemical composition of extracted FEO was analyzed by Gas chromatography- Mass spectrometry. Dodecanal, 1-dodecanol, and alpha-pinene were identified as the major compounds. Concerning previous research, our study is the first investigation of the antibiofilm property of E. elatior flower oil. More detailed studies are required to identify the compound responsible for biofilm inhibition and its mode of action against A. baumannii biofilms.
ARTICLE | doi:10.20944/preprints202204.0146.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Essential medicines; affordability; NCD prevention; oral healthcare; access
Online: 15 April 2022 (10:46:26 CEST)
Background: Fluoride toothpaste (FT) has recently been included in the World Health Organization’s (WHO) Model List of Essential Medicines. Whereas it is essential for preventing dental caries, its current affordability around the globe remains unclear. This study aimed to analyse the affordability of FT in as many as possible countries worldwide. Methods: A standardized protocol was developed to collect country-specific information about the characteristics of the cheapest FT at a common point of purchase. 82 members of the WHO Global Oral Health Network of Chief Dental Officers (CDOs), directors of WHO Collaborative Centres and other oral health experts collected data using mobile phone technology. The Fluoride Toothpaste Affordability Ratio (FTAR) was calculated as the price associated with the recommended annual consumption of FT, relative to the daily wage of the lowest-paid unskilled government worker (FTAR >1 = unaffordable spending on fluoride toothpaste). The daily expenditure per capita of the poorest 15% of the income distrubition was used as the main proxy of the daily wage, using World Bank data. Alternatively, we used the daily minimum wage as a proxy of the daily wage. Stratified descriptive statistics were undertaken with respect to different World Bank Income Groups and WHO Regions. Results: There are significant discrepancies in the affordability of FT across 78 countries. FT was strongly affordable in high-income countries, relatively affordable in upper middle-income countries, and strongly unaffordable in lower middle-income and low-income countries. The affordability of FT across WHO Regions was dependent upon the economic mix of WHO Regions’ member states. Conclusion: FT is still unaffordable for many people, particularly in low-resource settings. Health policy members should develop better strategies to address and improve the universal affordability of FTs, for the incidence of dental caries to be reduced at a global level.
REVIEW | doi:10.20944/preprints202108.0386.v1
Subject: Life Sciences, Biotechnology Keywords: Clove essential oil; biological activity; chemical composition, extraction.
Online: 18 August 2021 (14:19:49 CEST)
Clove (Syzygium aromaticum L. Myrtaceae) is an aromatic plant widely cultivated in tropical and subtropical countries, rich in volatile compounds and antioxidants such as eugenol, β-caryophyllene, and α-humulene. Clove essential oil has received considerable interest due to its wide application in the perfumery, cosmetic, health, medical, flavoring, and food industries. Clove essential oil has relevant biological activities to human health, including antimicrobial, antioxidant, and insecticide. This review describes the effect of the extraction method (hydrodistillation, steam distillation, ultrasound-assisted extraction, microwave-assisted extraction, cold pressing, and supercritical fluid extraction) on the chemical composition of essential oil and its correlation with their biological activities. Likewise, are summarized the main compounds and their reported biological activities. Furthermore, the main applications in clove essential oil in the food industry are presented. Finally, this review presents the new biological activities such as anti-inflammatory, analgesic, anesthetic, antinociceptive and anticancer, which are beneficial for human health. This review aims to compile the effect of different methods of extracting clove essential oil on chemical composition, food applications, as well as a current description of biological activities of interest to human health. Biological activities have increased interest in research into this essential oil and its future applications in the food or pharmaceutical industry.
ARTICLE | doi:10.20944/preprints202012.0210.v1
Subject: Life Sciences, Biochemistry Keywords: antibiotic resistance; antibiotic alternatives; heavy metals; essential oils
Online: 9 December 2020 (09:44:37 CET)
Antimicrobial resistance (AMR) represents a growing crisis in both human and veterinary medicine. We evaluated the use of two categories of antibiotic alternatives – heavy metals and essential oils – in beef cattle, and their effects on gram-negative and gram-positive bacteria. In this randomized controlled field trial, we measured the impact of supplemental zinc and menthol on antimicrobial resistance among commensal enteric bacteria of feeder cattle. Fecal suspensions were plated onto plain- and antibiotic-supplemented MacConkey and m-Enterococcus agar for quantification of total and antimicrobial-resistant Escherichia coli and Enterococcus spp., respectively. Temporal effects on overall E. coli growth were significant (P< 0.05); however, there were no significant effects on antibiotic-supplemented agar. Zinc was associated with significant increases in growth on erythromycin-supplemented m-Enterococcus agar. Cattle fed zinc exhibited significantly higher macrolide resistance among fecal enterococci isolates.
REVIEW | doi:10.20944/preprints201810.0487.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: bioactivity; essential oils; polyphenols; preclinical; rosmarinic acid; terpeniods
Online: 22 October 2018 (10:09:22 CEST)
Perilla frutescens (L.) Britt. (PF) is an annual herbal medicinal, aromatic, functional food and ornamental plant that belongs to the mint family, Lamiaceae. The origin of perilla traces back to East Asian countries (China, Japan, Korea, Taiwan, Vietnam and India), where it has been used as a valuable source of culinary and traditional medicinal uses. Leaves, seeds and stems of P. frutescens are used for various therapeutic applications in folk medicine. In the absence of comprehensive review regarding all aspects of perilla, thus this review aims to present an overview pertaining to the botanical drug, ethnobotany, phytochemistry and biological activity. It was found that the taxonomic classification of perilla species is quite confused, and the number of species is vague. Perilla has traditionally been prescribed to treat depression-related disease, anxiety, asthma, chest stuffiness, vomiting, cough, cold, flus, phlegm, tumour, allergy, intoxication, fever, headache, stuffy nose, constipation, abdominal pain, indigestion, analgesic, anti-abortive agent, and sedative. Until now, 271 natural molecules have been identified in perilla organs including; polyphenols, flavonoids, essential oils, triterpenes, carotenoids, phytosterols, fatty acids, tocopherols and policosanols. In addition to solvent extracts, these individual compounds (rosmarinic acid, perillaldehyde, luteolin, apigenin, tormentic acid, isoegomaketone) have attracted researchers' interest for pharmacological properties. Its bioactivity showed antioxidant, antimicrobial, anti-allergic, antidepressant, anti-inflammatory, anticancer, neuroprotection activity. Although the results are promising in preclinical studies (in vitro and in vivo) as well, clinical studies are insufficient, therefore further study needs to be done to validate its therapeutic effects and to ensure its safety and efficacy.
ARTICLE | doi:10.20944/preprints201809.0338.v1
Subject: Chemistry, Food Chemistry Keywords: Ocimum spp.; essential oil; aromatic profiles; Thai food
Online: 18 September 2018 (09:47:32 CEST)
The research objectives of this study are to analyse the volatile compositions of different basil types available in Thai markets and to descriptively determine their aromatic qualities. Essential oils were hydro-distillated from fresh leaves of 2 Holy basil (Ocimum sanctum) varieties namely, white and red and other basil species, including Tree basil (O. gratissimum), Sweet basil (O. basilicum var. thyrsiflorum) and Lemon basil (O. citriodorum). Oil physicochemical characteristics and volatile chromatograms from Gas Chromatography-Mass Spectrometry (GC-MS) were used to qualitatively and quantitatively describe the chemical compositions. Methyl eugenol, estragole and eugenol were among the major chemicals found in the essential oils of these basil types. Classification by Principal Component Analysis (PCA) advised that these Ocimum spp. samples are grouped based on either the distinctive anise, citrus aroma (estragole, geranial and neral) or spice-like aroma (β-methyl eugenol, caryophyllene and α-cubebene). The essential oil was also used for descriptive sensorial determination by five trained panelists, using the following developed terms: anisic, citrus, herb, spice, sweet and woody. The panelists were able to differentiate essential oil of white Holy basil from red Holy basil based on the intensity of the anisic attribute, while the anise and citrus scents were detected as dominant in the Lemon basil, Tree basil and Sweet basil essential oils. The overall benefit from this research was the elucidation of aromatic qualities from Thai common Ocimum species in order to assess their potential as the raw materials for future food research and development.
ARTICLE | doi:10.20944/preprints202207.0105.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: Melaleuca armillaris; essential oil; erythromycin; Staphylococcus aureus; synergism; mastitis
Online: 7 July 2022 (04:05:55 CEST)
Staphylococcus aureus frequently causes subclinical mastitis around the world with high impact in milk industry and public health. Essential oils (EO) are recognized antimicrobials that can be synergistic with antibiotics. The main objective of this study was evaluating the essential oil (EO) of Melaleuca armillaris as an adjuvant of erythromycin (ERY) for the alternative treatment of bovine mastitis caused by S. aureus. The Minimum Inhibitory and Bactericidal Concentrations (MIC and MBC) of EO, ERY, and its combinations were established against S. aureus at different pHs (7.4, 6.5 and 5.0), emulating extra and intracellular conditions. Sensible (N=3) and resistant (N=3) strains to ERY and S. aureus ATCC 29213 as control were used. Math models were applied to described the antibacterial activity of EO and combinations EO-ERY. The EO was bactericidal against all the strains independently of the pH with a slightly improvement in acid conditions. The synergism between EO and ERY was estimated by the Fractional Inhibitory Concentration Index (FIC) and by mathematical modeling of the bacterial killing data. Synergism was observed with ERY, where combinations had bactericidal activity also even with pH modification. M. armillaris EO is an interesting adjuvant for ERY, being a promissory option for further analysis of intracellular efficacy against S. aureus.
ARTICLE | doi:10.20944/preprints202204.0200.v1
Subject: Social Sciences, Library & Information Science Keywords: citation distribution; impact factor distribution; essential randomness; Sibuya distribution.
Online: 21 April 2022 (09:37:01 CEST)
A toy model for the distribution of the impact factor (IF) of a journal is proposed. The model demonstrates the presence of a heavy tail for the IF distribution, which occurs due to some random non-scientific circumstances. Therefore, the use of IF as an indicator of the quality of scientific papers seems to be inadequate.
REVIEW | doi:10.20944/preprints202106.0500.v1
Subject: Life Sciences, Biochemistry Keywords: anticancer; antimicrobial; antioxidants; cancer signalling; citral; Cymbopogon; essential oil
Online: 21 June 2021 (10:31:35 CEST)
The prominent cultivation of lemongrass relies on the pharmacological incentives of its essential oil. The lemongrass essential oil (LEO) has a significant amount of citral (mixture of geranial and neral), isoneral, isogeranial, geraniol, geranyl acetate, citronellal, citronellol, germacrene-D, and elemol in addition to numerous other bioactive compounds. These components confer various medicinal activities to LEO including antifungal, antibacterial, antiviral, anticancer, and antioxidant properties. These attributes are commercially exploited in pharmaceutical, cosmetics, and food preservations industries. Furthermore, the employment of LEO in the treatment of cancer opens a new vista in the field of therapeutics. Although different LEO components have shown promising anticancer activities in vitro, these effects have not been assessed yet in humans. Further studies on the anticancer mechanisms exerted by lemongrass components are required. The present review intends to provide a timely discussion on the relevance of lemongrass extracts in cancer and health treatment, and in food industry applications.
ARTICLE | doi:10.20944/preprints202206.0417.v1
Subject: Materials Science, Nanotechnology Keywords: lecithin; ginger oil; essential oil; nano-lipid; drug delivery system
Online: 30 June 2022 (08:00:31 CEST)
Lipid nanoparticles have an interesting part of drug delivery system. In this study, the modification of the convention nano-lipid based soybean lecithin was demonstrated. Ginger oil derived Zingiber officinale was used along with lecithin, cholesterol and span 80 to fabricate nano-lipid (GL nano-lipid) using thin-film method. Through TEM and confocal microscope, GL nano-lipid exposes the liposome- like morphology. The average size of the resultant nanoparticles was 249.1nm with monodistribution (PDI= 0.021). The ζ-potential of GL nano-lipid was negative as similar to as prepared nano-lipid based lecithin. GL nano-lipid express the highly stable over 60 days of storage at room temperature in term of size, ζ-potential. A shift of pH value from alkaline to acid was detected in lecithin nano-lipid, while with the incorporation of ginger oil, pH value of nano-lipid dispersion was around 7.0. Furthermore, due to the rich of shogaol-6 and other active compounds in ginger oil, the GL nano-lipid is endowed with intrinsic antibacterial feature. In addition, the sulforhodamine B (SRB) assay and live/dead imaging revealed the excellent biocompatibility of GL nano-lipid. Notably, GL nano-lipid was capable to carry the hydrophobic agents as curcumin and perform a pH-dependent release profile. A subsequent characterization are a suitable potential for drug delivery system.
REVIEW | doi:10.20944/preprints202102.0377.v1
Subject: Chemistry, Analytical Chemistry Keywords: limonene; green extraction; essential oil; citrus processing waste; p-cymene
Online: 17 February 2021 (10:39:24 CET)
A renewable cyclic monoterpene obtained from citrus peel, limonene is widely used as a fra-grance, nutraceutical ingredient, antibacterial, biopesticide, and green extraction solvent. Indus-trial demand largely exceeds supply. After reviewing recent advances in the recovery of limonene from citrus peel and residues with a particular attention to benign-by-design extractive processes, we focus on the latest results in its dehydrogenation to p-cymene via heterogeneous catalysis.
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: essential fatty acid semi carbazide; ID50; IL-4; IL-12
Online: 18 February 2020 (11:15:32 CET)
Bacterial infections are world-wide problem and resistant bacteria is increasing globally that lead to treatments failure. Thus, it is important to find new techniques that are effective for the treatment antibiotic-resistant microorganisms. Green medicine used for the medication of different bacterial infection. Therefore , the study aimed to evaluate the immunomodulatory activity of essential fatty acid semi carbazide (EFASC) compounds extracted from flaxseed to eradicate resistance pathogens . Crud extracts of Linum usitatissimum was extracted by hexane for extraction of EFASC. The results of LD50 appear that a live suspension of E.coli was 0.49×107 ,while HK E.coli was 108 , 125 mg /ml were the optimum dose in stimulate immune response of EFASC which gave maximum dose of total WBC , Neutrophil and Monocyte count. The immunomodulatory activity appear that E.coli + EFASC released moderate levels of IL-4 . HK E.coli release higher IL-4 lead to increase the hypersensitivity and hyper responses of immune system. HK + EFASC immunogen revealed moderate increased in IL-12 mean level 0.99 pg /ml, HK bacteria recorded 1.49 pg/ml, while the mean of EFASC revealed no significant different compare with control. An effective protection was observed in immunized groups with HK E.coli and EFASC challenged with 100 of LD50 of a live E.coli.
ARTICLE | doi:10.20944/preprints202207.0214.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Adiantum capillus-veneris L.; Chemical compounds; Antioxidant; Antimicrobial; Essential oil; DPPH
Online: 14 July 2022 (11:32:37 CEST)
Background: The use of medicinal plants and their effective compounds as natural sources that have antioxidant properties, has been considered by researchers. Antioxidants are compounds that effectively inhibit the reaction of oxygen and nitrogen-free radicals with biomolecules in a variety of ways, reducing damage or preventing cell death, cardiovascular diseases, and cancers. Objective: In this study, chemical compounds of Adiantum capillus-veneris essential oil were used to evaluate its antioxidant and antimicrobial activity using water distillation and gas chromatography. Methods: The whole plant was dried at room temperature at 25 ° C and the distillation method with water with modifications was used using a Clevenger device for essential oil extraction. Gas chromatography-mass spectrometry (GC/MS) was used to identify the resulting essential oil compounds and the antioxidant and antibacterial activity of the essential oil was evaluated. Results: The most important chemical constituents of Adiantum capillus-veneris essential oil were carvone (33.00%), carvacrol (15.05%), hexadecanoic acid (7.02%), hexahydrofarnesyl acetone (4.25%) and n-nonanal (4.2%). The antibacterial activity of Adiantum capillus-veneris essential oils (mg/ml) was calculated and the highest antibacterial activity was determined by Staphylococcus aureus (8.23±1.07), Streptococcus pyogenes (12.46±1.62), and Diphtheroid (11.37±1.36) at a concentration of 100 mg/ml of essential oils. Conclusion: The results of the present study showed that the essential oil of Adiantum capillus-veneris prevented the growth of three pathogenic bacteria. This antibacterial property is due to the presence of flavonoid compounds in Adiantum capillus-veneris has the capacity for therapeutic and medical uses.
ARTICLE | doi:10.20944/preprints202102.0061.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Staphylococcus aureus; Melaleuca armillaris; essential oil; Gompertz model; Sigmoid model; antibacterial
Online: 1 February 2021 (16:02:30 CET)
Essential oils (EO) are a great antimicrobial resource against bacterial resistance in public health. Math models are useful describing the growth, survival, and inactivation of microorganisms against antimicrobials. We evaluated the antimicrobial activity of M. armillaris EO obtained from plants placed in the province of Buenos Aires (Argentina) against Staphylococcus aureus. Minimum Inhibitory and Bactericidal Concentrations were close and decreased slightly acidifying the medium from pH 7.4 to 6.5 and 5.0. This result was also evidenced by applying a sigmoid model, where the time and EO concentration necessaries to achieve 50% of the maximum effect decreased when medium was acidified. Moreover, at pH 7.4, applying the Gompertz model, we found that subinhibitory concentrations of EO decreased the growth rate and the maximum population density, and increased the latency period respect to the control. Additionally, we established physicochemical parameters for quality control and standardization of M. armillaris EO. Mathematical modelling allowed us to estimate key parameters in the behavior of S. aureus and Melaleuca armillaris EO at different pHs. This is interesting in situations where the pH changes are relevant, such as the control of intracellular infections in public health or the development of preservatives for food industry.
ARTICLE | doi:10.20944/preprints202008.0015.v1
Subject: Materials Science, Nanotechnology Keywords: Metal oxide nanoparticles; Bioaccumulation; Recommended Dietary Allowances; Daily Values; Essential nutrients
Online: 2 August 2020 (11:18:19 CEST)
Understanding potential uptake and biodistribution of engineered nanoparticles in soil-grown plants is imperative for toxicity and risk assessment considering the oral exposure of edibles by humans. Herein, we assessed potential influence of particle size (25, 50, and 250 nm) and concentration (0, 50, 100, 200, and 500 mg/kg-soil) of Copper oxide nanoparticles (CuONPs) on: (1) the root system architecture, and the physicochemical attributes of soil at the soil-root interface, (2) leading to Cu transport and accumulation in root, stem, leaf and seed in soybean (Glycine max cv Kowsar) grown for entire lifecycle of 120 days, and compared with soluble Cu2+ ions and water-only controls, and (3) performed a comparative assessment of total seed Cu levels in soybean with other valuable food sources for Cu intake and discussed its human health implications. Our findings showed particle size- and concentration-dependent influence of CuONPs on Cu uptake and tissue distribution in root, stem, leaf and seed in soybean. Alterations in root architecture (root dry weight, root length, root volume, and root area) were dependent on the Cu compound type, Cu concentrations, and their interactions (p<0.05), except for root density. Concentration-response relationships for all three sized CuONPs, and Cu2+ ions, were linear. CuONPs and Cu2+ ions had inhibitory effects on root growth and development. Overall, soybean responses to smallest size CuONPs-25 nm were higher for all parameters investigated compared to two larger sized CuONPs (50 nm, 250 nm) or Cu2+ ions. Cu uptake/bioaccumulation differed among soybean tissues in the order: root > leaf > stem > seed. Despite reduced root architecture and seed yield, our smallest size CuONPs-25 nm led to increased total seed Cu uptake compared to the larger sized CuONPs and Cu2+ ions tested. Our findings also suggest that soil amendment by CuONPs, more so by the smallest size CuONPs-25 nm, could significantly improve nutritional Cu value in soybean seed as reflected by % Daily Values (DV), and are rated “Good” to “Very Good” according to the “World’s Healthiest Foods” rating. However, until the potential toxicity and risk from consumption of soybean seed is characterized in humans, caution should be exercised when the Cu fortified seeds are used for daily human consumption when addressing Cu deficiency and associated illnesses, globally.
ARTICLE | doi:10.20944/preprints202208.0126.v1
Subject: Chemistry, Applied Chemistry Keywords: Eugenol; Essential oils; Nanoencapsulation; Biopesticides; Insecticides; Odorant binding proteins; Inverted virtual screening
Online: 5 August 2022 (14:43:22 CEST)
The eugenol derivative, ethyl 4-(2-methoxy-4-(oxiran-2-ylmethyl)phenoxy)butanoate 1, with promising insecticidal capability was encapsulated in liposomal formulations of egg-phosphatidylcholine/cholesterol (Egg-PC:Ch) 70:30 and of 100% dioleoylphosphatidylglycerol (DOPG). Compound-loaded Egg-PC:Ch liposomes exhibit small hydrodynamic diameters (below 100 nm), high encapsulation efficiency (88.8% ± 2.7%), higher stability and a more efficient compound release, being chosen for assays in Sf9 insect cells. Compound 1 elicited a loss of cell viability up to 80% after 72h of incubation. Relevantly, encapsulation maintained the toxicity of compound 1 towards insect cells, while it lowered toxicity towards human cells, thus showing the selectivity of the system. Structure based inverted virtual screening was used to predict the most likely targets and molecular dynamics simulations and free energy calculations were used to demonstrate that this molecule can form a stable complex with insect odorant binding proteins and/or acetylcholinesterase.
ARTICLE | doi:10.20944/preprints202204.0236.v1
Subject: Life Sciences, Biochemistry Keywords: biorefining; by-products; enzymatic hydrolysis; essential fatty acids; green-extraction; lipids; sustainability
Online: 26 April 2022 (10:37:03 CEST)
The main intention of the present work was to investigate the ability of cellulose-degrading enzymes (C-DE) to release fatty acids (FAs) from complex matrices of cereal by-products during enzymatic hydrolysis (EH). For this purpose, three types of cereal bran (CB), i.e., wheat, rye, and oat were used as a lignocellulose substrate for three commercially available hydrolytic enzymes, i.e., Viscozyme L, Viscoferm, and Celluclast 1.5 L. The yield and composition of FAs after EH was assessed and confronted with the yield obtained after either conventional Soxhlet extraction or alkaline-assisted hydrolysis (A-AH) with 10% KOH in 80% MeOH and subsequent liquid-liquid extraction. The experimental results demonstrated that up to 6.3% and 43.7% higher total FAs yield can be achieved within EH of rye bran using Celluclast 1.5 L than by A-AH and Soxhlet extraction, respectively. However, the application of Viscoferm for EH of wheat bran ensured up to 7.7% and 13.4% higher total FAs yield than A-AH and Soxhlet extraction, respectively. The concentration of essential linolenic acid (C18:3) in lipids extracted after EH of rye bran with Celluclast 1.5 L was up to 24.4% and 57.0% higher than in lipids recovered by A-AH and Soxhlet extraction, respectively. In turn, the highest content of linolenic in wheat bran lipids was observed after EH with Viscoferm and Viscozyme L, ensuring 17.0 and 13.6% higher yield than after A-AH, respectively. SEM analysis confirmed substantial degradation of CB matrix promoted by the ability of C-DE to act specifically on 1,4-β-D-glycosidic bonds in cellulose and on 1,2-α-,1,3-α-, and 1,5-α-L- arabinofuranoside and 1,4-β-D-xylosidic bonds in arabinoxylans, arabinans, and other arabinose-containing hemicelluloses. Structural alteration in cells integrity greatly contributed to the release of bound FAs and their better transfer into the extraction solvent. It has been shown that the proposed process of EH can be used for the efficient release of FAs from the CB matrix more sustainably and with a safer profile, thereby representing the further sustainable production of FAs for certain purposes.
ARTICLE | doi:10.20944/preprints202203.0354.v1
Subject: Chemistry, Medicinal Chemistry Keywords: insecticides; semi-synthetic pesticides; eugenol derivatives; alkoxy alcohols; essential oils; nanoencapsulation biopesticides
Online: 28 March 2022 (06:12:52 CEST)
A new set of alkoxy alcohols were synthesised by reaction of eugenol oxirane with aliphatic and aromatic alcohols. These eugenol derivatives were evaluated against their effect upon the viability of the insect cell line Sf9 (Spodoptera frugiperda).The most promising compounds, 4-(3-(tert-butoxy)-2-hydroxypropyl)-2-methoxyphenol and 4-(2-((4-fluorobenzyl)oxy)-3-hydroxypropyl)-2-methoxyphenol were submitted to in silico assays to predict possible targets. Thought an Inverted Virtual Screening approach, 23 common pesticide targets were screened and the top 2 targets predicted were further evaluated through molecular dynamics simulations and free energy calculations. In addition, these to eugenol derivatives were subjected to encapsulation and release assays using liposome-based nanosystems of egg phosphatidylcholine/cholesterol (7:3), with encapsulation efficiencies higher than 90% and release profiles well described by both Korsmeyer-Peppas and Weibull models.
REVIEW | doi:10.20944/preprints202010.0635.v1
Subject: Medicine & Pharmacology, Allergology Keywords: DBS; Tremor; Essential Tremor; Parkinson’s disease; Multiple Sclerosis; Stroke; Trauma; Holmes tremor
Online: 30 October 2020 (10:21:14 CET)
Tremor is a prevalent symptom associated with multiple conditions, including Essential Tremor (ET), Parkinson’s disease (PD), multiple sclerosis (MS), stroke, and trauma. The surgical management of tremor evolved from stereotactic lesions to deep-brain stimulation (DBS), which allowed safe and reversible interference with specific neural networks. This paper reviews the current literature on DBS for tremor, starting with a detailed discussion of current tremor targets (Vim, Raprl, caudal Zi, Vo and STN) and continuing with a discussion of results obtained when performing DBS in the various aforementioned tremor syndromes. Future directions for DBS research are then briefly discussed.
ARTICLE | doi:10.20944/preprints201911.0189.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: protein; plant-based protein; whey protein; essential amino acids; leucine, healthy men
Online: 16 November 2019 (00:58:01 CET)
This study assessed bio-equivalence of high-quality, plant-based protein blends versus Whey Protein Isolate (WPI) in healthy, resistance-trained men. The primary endpoint was incremental area under the curve (iAUC) of blood essential Amino Acids (eAAs) 4 hours after consumption of each product. Cmax and Tmax of blood leucine were secondary outcomes. Subjects (n=18) consumed three plant-based protein blends and WPI (control). Analysis of Variance model was used to assess for bio-equivalence of total sum of blood eAA concentrations. The total blood eAA iAUC ratios of the three blends were: [90% CI]: #1: 0.66 [0.58-0.76]; #2: 0.71 [0.62-0.82]; #3: 0.60 [0.52-0.69], not completely within the pre-defined equivalence range [0.80-1.25], indicative of 30-40% lower iAUC versus WPI. Leucine Cmax of the three blends was not equivalent to WPI, #1: 0.70 [0.67-0.73]; #2: 0.72 [0.68-0.75]; #3: 0.65 [0.62 – 0.68], indicative of a 28-35% lower response. Leucine Tmax for two blends were similar to WPI (#1: 0.94 [0.73-1.18]; #2: 1.56 [1.28-1.92]; #3: 1.19 [0.95-1.48]). The plant-based protein blends were not bio-equivalent. However, blood leucine kinetic data across the blends approximately doubled from fasting concentrations whereas blood Tmax data across two blends was similar to WPI. This suggests evidence of rapid hyperleucinemia, which correlates with a protein’s anabolic potential.
ARTICLE | doi:10.20944/preprints201802.0147.v1
Subject: Social Sciences, Economics Keywords: access to care; Burkina Faso; generic essential drugs; nursing staff; Trivariate Probit
Online: 23 February 2018 (05:26:19 CET)
This study uses data from the pilot project "Community Monitoring for Better Health and Education Services Delivery Project'' in Burkina Faso, to model the joint impact of generic essential drugs and nursing staff supplies constraints on access to primary health care in the country. The results show that statistical endogeneity of supply side constraints are present in the standard univariate probit specification of access to care. However, when accounted for, the resulting Trivariate Probit model shows that although shortages of generic essential drugs supply do not seem to constitute a significant barrier to access in Burkina Faso, shortages in nursing staff supply do. In fact, the likelihood of primary care access is reduced by 85.5% among those that reported having experienced a shortage in nursing staff, while paradoxically increasing by 60.3% among those that reported having experienced a shortage in generic essential drugs. A potential explanation for these findings is that overall the health care needs in the three surveyed regions in the country were more linked to primary health care services consumption from nurses, although further research would be important to clearly elucidate the position of health goods such as generic essential drugs.
ARTICLE | doi:10.20944/preprints201801.0055.v1
Subject: Life Sciences, Biotechnology Keywords: orange peel essential oil; green extraction; liquid whole eggs; biopreservation; shelf-life
Online: 8 January 2018 (09:22:37 CET)
A possible way to valorize citrus peels, which are byproducts of the juice extraction industry, is to use them as natural biopreservatives. In this paper we present early results from a compared Solvent Free Microwave Extraction (SFME) with Hydro-Distillation (HD) and Cold Pressing (CP) of essential oils (EOs) using fresh orange peel (Citrus sinensis L. var. Valencia late), a by-product in the production of orange juice in Algeria. The EOs were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). All extracted C. sinensis EOs were chemotype limonene (94.64 to 95.48%). SFME is performed without added any solvent or water. SFME increases EO yield and eliminate wastewater treatment, resulting in a great progress in terms of time and cost efficiency. In its second part, the present study was conducted to evaluate “in vitro”, the antioxidant activities of Solvent Free Microwave (SFM) extracted orange EO by using the DPPH• (2,2-di-phenyl-1-picrilhydrazyl) free radical scavenging assay. The ability of orange EO to scavenge the free radical DPPH• was high, exceeding 80%. The result of the DPPH assay gives an IC50 range value of 89.25 μg/mL (0.09 mg/mL) for the studied sample. Accordingly to the scientific literature, C. sinensis EO tested in the present study presented strong antioxidant activity, when looking to its values of AAI = 1.12 μg/mL. The feasibility of biopreservation used EOs as an alternative to synthetic techniques for liquid whole egg (LWE) stored under commercial retail conditions was investigated. The orange EO extracted by SFM was screened for its antibacterial and antioxidant activities in LWE at concentrations of 0.1, 0.3 and 0.5%. The TBA-RS results showed that the EO treatments significantly (p < 0.05) reduced the lipid oxidation in LWE. The long term oxidative, microbial and organoleptical stability of the LWE during display was positively influenced by orange EO treatments. Therefore, the results obtained here confirm that EO treatment as a promising technology to extend the commercial shelf-life of liquid egg products during retail/display.
REVIEW | doi:10.20944/preprints201711.0102.v1
Subject: Biology, Plant Sciences Keywords: Zingiber; ginger; essential oil; rhizome; herbal remedies; traditional healing systems; food preservatives
Online: 16 November 2017 (04:38:52 CET)
Plants of the genus Zingiber (Family Zingiberaceae) are widely used throughout the world as food and medicinal plants. They represent very popular herbal remedies in various traditional healing systems; in particular, rhizome of Zingiber spp. plants has a long history of ethnobotanical uses because of a plethora of curative properties. Antimicrobial activity of rhizome essential oil has been extensively confirmed in vitro and attributed to its chemical components, mainly consisting in monoterpene and sesquiterpene hydrocarbons such as α-zingiberene, ar-curcumene, β-bisabolene and β-sesquiphellandrene. In addition, gingerols have been identified as the major active components in the fresh rhizome, whereas shogaols, dehydrated gingerol derivatives, are the predominant pungent constituents in dried rhizome. Zingiber spp. may thus represent a promising and innovative source of natural alternatives to chemical food preservatives. This approach would meet the increasing concern of consumers aware of the potential health risks associated with the conventional antimicrobial agents in food. This narrative review aims providing a literature overview on Zingiber spp. plants, their cultivation, traditional uses, phytochemical constituents and biological activities.
ARTICLE | doi:10.20944/preprints202207.0037.v1
Subject: Earth Sciences, Environmental Sciences Keywords: remote sensing; satellite; altimetry; water level; water inland; essential climate variable; database; hydrology
Online: 4 July 2022 (08:02:24 CEST)
Surface water availability is a fundamental environmental variable to implement effective climate adaptation and mitigation plans, as expressed by scientific, financial and political stakeholders. Recently published requirements urge the need for homogenised access to long historical records at a global scale, together with the standardised characterisation of the accuracy of observations. While satellite altimeters offer world coverage measurements, existing initiatives and online platforms provide derived water level data. However, these are sparse, particularly in complex topographies. This study introduces a new methodology in two steps 1) teroVIR, a virtual station extractor for a more comprehensive global and automatic monitoring of water bodies, and 2) teroWAT, a multi-mission, interoperable water level processor, for handling all terrain types. L2 and L1 altimetry products are used, with state-of-the-art retracker algorithms in the methodology. The work presents a benchmark between teroVIR and current platforms in West Africa, Kazakhastan and the Arctic: teroVIR shows an unprecedented increase from 55% to 99% in spatial coverage.A large-scale validation of teroWAT results in an average of unbiased root mean square error ubRMSE of 0.638 m on average for 36 locations in West Africa. Traditional metrics (ubRMSE, median, absolute deviation, Pearson coefficient) disclose significantly better values for teroWAT when compared with existing platforms, of the order of 8 cm and 5% improved respectively in error and correlation. teroWAT shows unprecedented excellent results in the Arctic, using a L1 products based algorithm instead of L2 one, reducing the error of almost 4 m on average. To further compare teroWAT with existing methods, a new scoring option, teroSCO, is presented, measuring the quality of the validation of time series transversally and objectively across different strategies. Finally, teroVIR and teroWAT are implemented as platform-agnostic modules and used by flood forecasting and river discharge methods as relevant examples. A review of various applications for miscellaneous end-users is given, tackling the educational challenge raised by the community.
ARTICLE | doi:10.20944/preprints202102.0560.v1
Subject: Biology, Anatomy & Morphology Keywords: Trachymene incisa; Apiaceae; Chemotype; -Selinene; Bicyclogermacrene; -Bisabolene; -Pinene; -Caryophyllene; Essential oil; Chemical composition.
Online: 24 February 2021 (17:10:21 CET)
Trachymene incisa subsp. incisa is an Australian endemic taxon that varies greatly in the abundance and length of the leaf trichomes. The essential oil composition of five populations of this subspecies, three corresponding to the typical glabrous form and two of the particularly hairy variant, has been analyzed in an attempt to determinate if that variability is also reflected in their composition. The oils have been extracted by hydrodistillation and analysed by Gas Chromatography (GC) and Gas Chromatography coupled to Mass Spectrometry (GC-MS). The essential oils of T. incisa subsp. incisa were characterized by the high amount of sesquiterpenes that were the major fraction. The sesquiterepene hydrocarbons were significantly higher in the hairy variant in comparison to the glabrous one. According to the main compound three different chemotypes were found: I.- -selinene + bicyclogermacrene and II.- -bisabolene + -pinene for the typical glabrous variant and III.- bicyclogermacrene + -caryophyllene for the hairy variant.
REVIEW | doi:10.20944/preprints202009.0276.v1
Subject: Biology, Plant Sciences Keywords: Citral; essential oil; integrated pest management; insect-repellent; lemongrass; MEP pathway; mevalonate pathway
Online: 13 September 2020 (11:30:41 CEST)
Lemongrass (Cymbopogon flexuosus) is an aromatic perennial grass grown extensively for its essential oil. Lemongrass oil is chiefly a mixture of various cyclic and acyclic bioactive monoterpenes. We reviewed lemongrass oil and its biosynthesis in the present chapter along with its biochemical composition. Furthermore, we attempted to explore both the possible routes for essential oil biosynthesis in lemongrass, i.e. mevalonate and non-mevalonate pathways and how these pathways interwind with each other. Lemongrass oil has high commercial potential in medicinal, cosmetic, food and energy industries. Regarding the pharmacological properties, a wide array of biological activities has been observed in lemongrass oil such as antimicrobial, insecticidal, analgesic and anti-cancer properties as well as its efficacy as insect-repellent. The later sections were dedicated for the analysis of insecticidal property of the lemongrass oil and the mechanism working behind this phenomenon where it was observed that in addition to synergistic effects, various components of lemongrass oil can also induce specific neurotoxic and cytotoxic responses in the insects.
ARTICLE | doi:10.20944/preprints202007.0748.v1
Subject: Chemistry, Applied Chemistry Keywords: Rosmarinus officinalis L.; surface and subsurface drip irrigation; bentonite; Hundz conditioner; essential oil
Online: 31 July 2020 (13:43:12 CEST)
A relevant improvement of the cultivar conditions of Rosmarinus officinalis L. in desert areas was achieved by a specific combination between irrigation system and soil conditioner. A drastic reduction of water employment was obtained without affect the quality of the plants, determined by monitoring growth parameters and essential oil characteristics. In particular, the effect of surface and subsurface drip irrigation systems and different soil conditioners on growth parameters, yield, and essential oil constituents of rosemary plant was assessed. Field experiments at the Agricultural Research Station (Al-Adlya farm), SEKEM group Company, El-Sharkiya Governorate, Egypt, conducted over the two seasons revealed the effectiveness of the subsurface irrigation system in obtaining better performances, especially in terms of water saving. The combination of subsurface irrigation and the conditioner Hundz soil with bentonite showed the maximum mean values of growth characters compared with other soil amendments during both seasons. The possibility to employ a water-saving irrigation system as the subsurface one without any drawback in the resulting plants was also explored in terms of molecular composition. GC-MS analysis of the essential oil extracted from plants growth under different irrigation conditions revealed a comparable composition in both cases. The goodness of the most performing system was also confirmed by the comparable yield of the essential oil.
REVIEW | doi:10.20944/preprints201906.0107.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: dementia, behavioural and psychological symptoms of dementia, neuropsychiatric symptoms, aromatherapy, bergamot essential oil.
Online: 12 June 2019 (15:33:17 CEST)
Ageing of the world population makes of dementia a challenge for health systems worldwide. The cognitive disturbance is a serious but not the only issue in dementia; behavioural and psychological syndromes known as neuropsychiatric or behavioural and psychological symptoms of dementia remarkably reduce the quality of life of patients. Rising evidence is unraveling the pathophysiology of these symptoms in which all the neurotransmitter systems in the Central Nervous System (CNS) are implicated, with a pivotal role of alterations of the glutamatergic neurotransmission. Pharmacological agents for the treatment of these disorders endowed with efficacy and safety are not available yet; aromatherapy provides the best evidence in the control of agitation, the most resistant symptom. Basic research effort demonstrates that the essential oil of bergamot induces anxyolitic-like effects, devoid of sedation, typical of benzodiazepines, with noteworthy advantage for demented patients. People suffering from dementia often cannot verbalize pain, thus resulting unrelieved and contributing to agitation. Bergamot essential oil provides extensive evidence of analgesic properties independent from the route of administration. Among other mechanisms, modulation of autophagy, a process involved in neuropathic pain, seems to be implicated in the analgesic activity of bergamot essential oil. These data, together with the reported safety profile form the rational basis for bergamot as a neurotherapeutic to be trialed for the control of behavioural and psychological symptoms of dementia.
REVIEW | doi:10.20944/preprints201810.0737.v1
Subject: Biology, Horticulture Keywords: allelopathy; bioherbicides; corn gluten meal; essential oils; mustard seed meal; pathogens; plant extracts
Online: 31 October 2018 (07:50:29 CET)
Over the last five decades, weed management systems have relied primarily on synthetic herbicides. Due to the concerns over the potential impact of chemicals on human health and the environment, efforts are being made to reduce the heavy reliance on synthetic herbicides. To reduce the use of synthetic herbicides, the use of natural products such as essential oils, plant extracts, allelochemicals, agricultural by-products, and some microbes are gaining attention because of their short environmental half-life and low toxicity. They are a good alternative to synthetic herbicides, especially in organic agriculture, since they focus on environmental protection, and ecological stability. Most of the commercially available natural herbicides are non-selective and require careful application in order to preserve the cash crops. Although many studies in this direction have been undertaken, the use of these natural products is still not common because of their cost the difficulties in their synthesis due to their complex structure, cost effectiveness, poor performance, and rapid degradation. When used singly, these natural herbicides do not perform as well as the chemical herbicides. An integrated approach may provide better results. Using a combination of natural herbicides may be more effective than using just one.
ARTICLE | doi:10.20944/preprints201608.0111.v1
Subject: Life Sciences, Other Keywords: Erigeron floribundus; essential oil; antimicrobial; NadD; Trypanosoma brucei; cytotoxicity; antioxidant; limonene; caryophyllene oxide
Online: 10 August 2016 (12:36:57 CEST)
Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in the Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD), a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%), caryophyllene oxide (12.4%) and limonene (8.8%). The E. floribundus oil showed a good activity against Staphylococcus aureus (IZD of 14 mm, MIC of 512 µg/mL). Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL), with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (TEAC= 411.9 μmol TE/g).
ARTICLE | doi:10.20944/preprints202009.0703.v1
Subject: Chemistry, Analytical Chemistry Keywords: açaí; total polyphenol; total anthocyanin; antioxidant; elemental analysis; essential elements; biological activity; wound healing
Online: 29 September 2020 (09:14:48 CEST)
Chemical composition analysis of açaí extracts revealed higher levels of total polyphenol content in purple açaí samples for both commercial (4.3 – 44.7 gallic acid equivalents mg/g) and non-commercial samples (30.2 – 42.0 mg/g) compared to white (8.2 – 11.9 mg/g) and oil samples (0.8 – 4.6 mg/g). The major anthocyanin compounds found in purple açaí samples were cyanidin-3-glucoside and cyanidin-3-rutinoside with total concentrations in the range of 3.6 – 14.3 cyanidin-3-glucoside equivalents mg/g. The oligomeric proanthocyanidins were quantified in the range of 1.5 – 6.1 procyanidin B1 equivalents mg/g. Moreover, açaí presented significant levels of calcium, magnesium, manganese, iron, zinc and copper, essential minor and trace elements, in comparison with other berries. All of the açaí extracts at 50 μg/mL potently inhibited the release of reactive oxygen species in lipopolysaccharide-stimulated RAW 264.7 macrophage cells, but none inhibited the release of nitric oxide. Furthermore, all the açaí samples demonstrated potential as wound healing agents due to the high levels of migration activity in human fibroblast cells.
ARTICLE | doi:10.20944/preprints202102.0011.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Elderly with dementia; needs; utilization; essential care service package; long-term care system; health policy
Online: 1 February 2021 (11:24:37 CET)
Alzheimer’s disease and related dementias (ADRD) remain a public health challenge in developing counties. We developed a needs-based essential care service package (ECSP) for care planning of persons living with dementia (PLWD) using a cross-sectional survey among PLWD in institutions in six cities in China (n= 1,299). Face-to-face interviews were conducted with caregivers of PLWD by trained staff between 2018 and 2019. Care service needs and utilization by the level of cognitive impairment were summarized. The average age of PLWD was 80.7 years. 76% of participants had severe cognitive impairment. The needs-based ECSP with 30 service items would be sufficient in supporting care services of PLWD in China, of which seven items are core care. The selection plan for ECSP at different levels is designed as “General Care Services + Selective Care Services”, in which service items for low-, mid-and high-level care for PLWD are 7+3, 7+6, and 7+10, respectively. The findings provide the first large-scale data on service needs and utilization of PLWD in mainland China. The ECSP for PLWD advanced in the paper was a practicable and effective quantitative management means. It is deserved to application in a large scale.
ARTICLE | doi:10.20944/preprints201908.0137.v1
Subject: Life Sciences, Microbiology Keywords: essential oils; Mentha x piperita; “Mentha of Pancalieri”; azoles; antifungal activity; yeasts and dermatophytes; synergism
Online: 12 August 2019 (04:52:43 CEST)
The promising antimicrobial activity of essential oils (EOs) led researchers to use them in combination with antimicrobial drugs in order to reduce drug toxicity, side effects, and resistance with single agents. In Pancalieri (Turin, Italy), there is a local production of Mentha x piperita worldwide known as “Mentha of Pancalieri”. The EO from this Mentha is considered as one of the best peppermint EO in the world. In our research, we assessed the antifungal activity of “Mentha of Pancalieri” EO either alone or in combination with azole drugs (fluconazole, itraconazole, ketoconazole) against a wide panel of yeast and dermatophyte clinical isolates. The EO was analyzed by GC-MS and its antifungal properties were evaluated by MIC/MFC parameters, according to the CLSI guidelines, with some modifications. The interaction of peppermint EO with azoles was evaluated through the chequerboard and isobologram methods. Results suggest this EO exerts a fungicidal activity against yeasts, and a fungistatic activity against dermatophytes. Interaction studies with azoles indicate mainly synergistic profiles between itraconazole and peppermint EO vs. Candida spp., Cryptococcus neoformans and Trichophyton mentagrophytes. Peppermint of Pancalieri EO may act as a potential antifungal agent and may serve as a natural adjuvant for fungal infection treatment.
Subject: Life Sciences, Microbiology Keywords: essential oil; Mentha pulegium; Mentha suaveolens; Listeria monocytogenes; Salmonella enterica; antioxidant; sub-lethally injured bacteria
Online: 5 May 2019 (12:05:03 CEST)
The essential oils (EOs) obtained from aromatic plants are rich in natural compounds with interesting biological effects. The aim of this study was to evaluate the chemical composition of EOs of Mentha pulegium (MP-EO) and Mentha suaveolens (MS-EO) collected from Morocco, and their antioxidant properties and antibacterial activity against Salmonella enterica and Listeria monocytogenes. The EOs were extracted by hydro-distillation, while the chemical compositions were determined by GC-MS. The antioxidant activity was evaluated by DPPH and FRAP assay. Antibacterial activity was tested with disc diffusion assay; determination of minimum inhibitory concentration, minimum bactericidal concentration and the evaluation of sub-lethally injured cell were also performed. The results of chemical composition showed the presence of compounds not still reported in EOs obtained from these plants. MS-EO was characterized by the best antioxidant and antibacterial activity vs S. enterica and L. monocytogenes respect to MP-EO. The EOs tested in this study were rich in compounds with interesting activities and they could be applied in the medical fields, as well as in food industries as natural preservatives against tested food borne pathogens.
ARTICLE | doi:10.20944/preprints202006.0228.v1
Subject: Biology, Horticulture Keywords: crop genetics; Solanum tuberosum; abiotic stress; phenylpropanoids; essential amino acid; transcriptome; small RNA; comparative genomics; nutrition
Online: 18 June 2020 (09:15:21 CEST)
Potato is among one of the most important food crops, yet maintaining plant productivity in this drought-sensitive crop has become a challenge. Competition for scarce water resources and the continued effects of global warming exacerbate current constraints on crop production. While plants’ response to drought in above-ground tissues has been well documented, the regulatory cascades in developing tubers have been largely unexplored. Using the commercial Canadian cultivar ‘Vigor’, plants were subjected to a drought treatment under high-tunnels causing a 4 ℃ increase in canopy temperature when compared to the well-watered control. Tubers were sampled for RNAseq and metabolite analysis. Approximately 2600 genes and 3898 transcripts were differentially expressed by at least four-fold in drought-stressed potato tubers, with 75 % and 69 % being down-regulated respectively. A further 229 small RNAs were implicated in gene regulation during drought. The comparison of protein homologues between Solanum tuberosum L. and Arabidopsis thaliana L. indicates that downregulated genes are associated with phenylpropanoid, carotenoid, and patatin biosynthesis. This suggests that there may be nutritive implications to drought stress occurring during the potato tuber bulking phase in sensitive cultivars.
ARTICLE | doi:10.20944/preprints201904.0235.v1
Subject: Chemistry, Analytical Chemistry Keywords: Essential and toxic elements, blood, urine, children, ICP-MS, reaction/collision cell (ORS technology), internal standard
Online: 22 April 2019 (11:03:17 CEST)
The authors determined mass concentrations of 12 elements (As, Cd, Cr, Cu, Mn, Ni, Pb, Se, Sr, Tl, V, Zn) in blood and urine taken from 100 rural children living in unremarkable condition in the West Ural region of the Russian Federation. We applied inductively coupled plasma mass spectrometry in conformity with Methodical Guidelines 4.1. 3230-14 (FR.1.31.2014.17064) designed by us and detailed in the paper. The article contains setting parameters for Agilent 7500cx quadrupole inductively coupled plasma mass spectrometer . The authors present grounds for an optimal scheme of samples preparation which helps to eliminate "matrix" effect and explain why it is advisable to use reaction/collision functioning mode as it enables interference overlaps suppression.To prepare whole blood samples for analysis, we used acid dissolution in concentrated nitric acid followed by centrifugation. The arithmetic mean (AM) of element content in blood amounted to 0.34 µg/l (As); 0.39 µg/l (Cd); 6.41 µg/l (Cr); 866.11 µg/l (Сu); 13.73 µg/l (Mn); 5.86 µg/l (Ni); 23.65 µg/l (Pb); 87.43 µg/l (Se); 33.54 µg/l (Sr); 0.04 µg/l (Tl); 0.16 µg/l (V); 4713.48 µg/l (Zn). The validity of the results was confirmed by means of SERONORM TM Whole Blood L2 standard samples (Norway). Urine samples were directly analyzed after 1/10 (V/V) dilution with 1% nitric acid solution. The arithmetic mean of element content of urine corresponded to 18.99 µg/l (As); 0.12 µg/l (Cd); 1.91 µg/l (Cr); 13.28 µg/l (Сu); 0.96 µg/l (Mn); 1.84 µg/l (Ni); 0.83 µg/l (Pb); 22.55 µg/l (Se); 239.09 µg/l (Sr); 0.16 µg/l (Tl); 0.68 µg/l (V); 270.56 µg/l (Zn). The validity of the results was confirmed by analyzing the SERONORM TM standard urine samples (Norway). Regional differences from levels found in other countries included higher concentrations of Cr, Mn and Ni in blood and lower levels of Se and Zn levels in West Ural children. Urine concentrations of West Ural children showed higher levels of As and Sr.
Subject: Biology, Anatomy & Morphology Keywords: Wild Edible Plants; antimicrobial effect; Mediterranean plant; Gram+ bacteria; Gram- bacteria; extraction protocols; bioactive compounds; essential oils
Online: 21 July 2021 (10:05:22 CEST)
Introduction. Bacterial resistance to antibiotics is estimated to cause the major number of deaths by 2050 if we do not find strategies to slow down the rise of drug resistance . Reviews on Mediterranean Wild Edible Plants (MWEPs) with antimicrobial properties are scarce in the mean databases (Pubmed, Scopus and WoS). Hence, we proceeded to a new review of the studies on MWEPs. Methods. We used Wild Edible Plant and Antimicrobial as keywords. We only included the Mediterranean plants, and studies in non-Mediterranean countries, but for plants growing in Mediterranean basin. Exclusion criteria were the document type, studies not concerning plant, plants not edible, not antimicrobial properties, or totally out of topic. Results. Finally, the number of studies reviewed, starting from one hundred and ninety-two, was thirty-eight (19,8%), concerning the antimicrobial properties of seventy-four MWEPs species, be-longing to twenty-five Families. Fifty-seven (77%) out of seventy-four species, proved to be antimicrobial with a stringent threshold selection. Conclusions. The studies are still very heterogeneous. We still know too little about MWEPs properties, but what we already know seriously recommends continuing.
Subject: Biology, Anatomy & Morphology Keywords: Fennel; Semi-natural habitat; Interspersion and juxtaposition index (IJI); Insecticides – Insect abundance and richness – Essential oil yield
Online: 12 April 2021 (12:43:39 CEST)
Agricultural landscapes are more and more characterized by intensification and habitat losses. Landscape composition and configuration are known to mediate insect abundance and richness. In the context of global insect decline, and despite 75% of crops being under insect’s dependence, there is still a gap of knowledge about the link between pollinators and aromatic crops. Fennel (Foeniculum vulgare) is an aromatic plant cultivated in South of France, for its essential oil which is of great economic interest. Using pan-traps, we investigated the influence of the surrounding habitats at landscape scale (semi-natural habitat proportion and vicinity, landscape configuration) and local scale agricultural practices (insecticides and patch size) on fennel-flower-visitor abundance and richness and their subsequent impact on fennel essential oil yield. We found that fennel may to be a generalist plant species. We did not find any effect of intense local management practices on insect abundance and richness. Landscape configuration and the proximity to semi-natural habitat were the main drivers of flying insect’s family richness. This richness positively influenced fennel essential oil yield. Maintaining a complex configuration of patches at the landscape scale are important to sustain insect diversity and crop yield.
ARTICLE | doi:10.20944/preprints202008.0623.v1
Subject: Life Sciences, Microbiology Keywords: Leptospermum scoparium; Cryptomeria japonica; Mānuka; Sugi; Essential oils; Natural products; Secondary metabolites; Antimicrobials; Gas chromatography – Mass spectrometry
Online: 27 August 2020 (14:13:24 CEST)
This study evaluated the antimicrobial activity of Leptospermum scoparium (Mānuka) and Cryptomeria japonica (Sugi) essential oils and assessed the effect of seasonal chemical variation on the oils’ antimicrobial efficacies. Plate based assays were conducted to elucidate the oils’ spectrum of in vitro antimicrobial activity and to determine the oils’ minimum inhibitory concentrations (MIC) as a measure of antimicrobial efficacy. Gas chromatography – mass spectrometry was adopted to chemically profile oils distilled in different seasons. The resultant compositional information in conjunction with MIC data was used to evaluate the effect of seasonal variation on the oils’ antimicrobial efficacy. Both Mānuka and Sugi essential oils were active against all classes of target microorganisms. However, limited activity was observed against Gram-negative bacteria. The oils displayed consistent chemotypic characteristics regardless of the time of distillation. Nonetheless, there were quantitative differences in compound abundance in both essential oils. Significant differences in the MIC of Sugi essential oil was observed against target microorganisms as a result of seasonal variation in constituent abundances while Mānuka essential oil’s antimicrobial efficacy was unaffected. This study demonstrates that seasonal chemical variation is an important quality assurance parameter to consider for future application of essential oils as antimicrobial agents in consumer products.
ARTICLE | doi:10.20944/preprints201810.0337.v1
Subject: Earth Sciences, Geophysics Keywords: essential climate variables (ECV); climate change initiative (CCI); Greenland ice sheet; mass budget; cryosphere; sea level rise
Online: 16 October 2018 (07:53:22 CEST)
The Greenland ice sheet is a major contributor to sea level rise, adding an estimated 0.47 +/− 0.23 mm/yr to global mean sea level between 1991 and 2015 (van den Broeke et al., 2016). Making sea level rise projections for the future and understanding the processes controlling current observed rates of sea level rise are crucially dependent on understanding the present-day state of the ice sheet. Here, we provide an overview of the current state of the mass budget of Greenland based on satellite gravimetry and remote sensing observations of surface elevation change, ice sheet velocity and calving front positions. We also combine these essential climate variables with a regional climate model (RCM) output from an ice sheet model (ISM) to gain insight into poorly understood ice sheet dynamical and surface mass processes. On average from 1992 to 2017 the ice sheet in some locations has lost up −2.65 m/yr in elevation based on ESA Radar altimetry analysis. Calving fronts have retreated all around Greenland since the 1990s and in only two out of 28 study locations have they remained stable. The locations of grounding lines at 5 key glaciers with floating ice tongues have remained stable over the observation period. However a detailed case study at Petermann glacier with an ice fracture model shows the sensitivity of these floating ice shelves to future climate change. GRACE gravimetric mass balance (GMB) data allows us to tie together disparate lines of evidence showing that Greenland has lost about 265 +/− 25 Gt/yr of ice over the period 2002 to 2015. RCM and ISM simulations show that surface mass processes dominate the overall Greenland ice sheet mass budget except for areas of fast ice sheet flow but marked differences between models and between models and observations indicate that not all processes are captured accurately, indicating areas of greater uncertainty and directions of future research for future sea level rise projections.
REVIEW | doi:10.20944/preprints201804.0060.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: volatile renewable resources; microbial infection; secondary plant metabolites; antimicrobial essential oils; biologically-active polymers; plasma-assisted technique
Online: 5 April 2018 (03:32:08 CEST)
The persistent issue of bacterial and fungal colonization of artificial implantable materials and decreasing efficacy of conventional systemic antibiotics used to treat implant-associated infections has led to the development of a wide range of antifouling and antibacterial strategies. This article reviews one such strategy where inherently biologically active renewable resources, i.e. secondary plant metabolites (SPMs) and their naturally occurring combinations (i.e. essential oils) are used for surface functionalization and synthesis of polymer thin films. With a distinct mode of antibacterial activity, broad spectrum of action and diversity of available chemistries, secondary plant metabolites present an attractive alternative to conventional antibiotics. However, their conversion from liquid to solid phase without significant loss of activity is not trivial. Using select examples, this article shows how plasma techniques provide a sufficiently flexible and chemically reactive environment to enable the synthesis of biologically-active polymer-coatings from volatile renewable resources.
REVIEW | doi:10.20944/preprints202102.0455.v1
Subject: Medicine & Pharmacology, Allergology Keywords: essential oils; water extracts; ethanol extracts; periodontal bacteria; Candida; natural antimicrobials; natural anti-inflammatory; Sardinian plants; pharmaceutical plants
Online: 22 February 2021 (10:53:13 CET)
There is an increasing interest in revisiting plants for drug discovery proving scientifically their role as remedies. Pistacia lentiscus (PL) is a wild-growing shrub rich in terpenoids, which are pharmacological appealing. The more recurrent components in the oil are represented by α-pinene, terpinene, caryophyllene, limonene, and myrcene. High concentration of polyphenols enriches the extracts. PL-extracts showed in vitro and in animal model strong anti-inflammatory and anti-oxidative activities. The anti-inflammatory activity mainly occurs due to inhibition of NF-kB pathway or directly toward the proinflammatory cytokines, or arachidonic acid cascade against COX-2 and LOX. The antimicrobial activity of PL essential oil and extracts includes among others Staphylococcus aureus, Escherichia coli, periodontal bacteria and Candida sp.. In conclusion, the biological properties, and particularly the anti-inflammatory and anti-microbial capacity, propose PL as a new safe pharmaceutical agent.
ARTICLE | doi:10.20944/preprints201812.0175.v1
Subject: Life Sciences, Biotechnology Keywords: Abies Alba Mill.; antioxidant activity; coniferous trees; essential oils; flavonoids; food preservation; green extraction; hydrodynamic cavitation; nutraceutics; polyphenols
Online: 17 December 2018 (07:07:56 CET)
Extracts from parts of coniferous trees have received increased interest due to their valuable bioactive compounds and properties, useful for plenty of experimental and consolidated applications, in fields comprising nutraceutics, cosmetics, pharmacology, food preservation, and stimulation of plant growth. However, the variability of the bioactive properties, the complexity of the extraction methods, and the use of potentially harmful synthetic chemicals, still represent an obstacle to the spreading of such valuable natural compounds. Hydrodynamic cavitation is emerging as a promising innovative technique for the extraction of precious food components and by-products from waste raw material of the agro-food production chain, which can improve processing efficiency, reduce resource consumption, and produce healthy, high-quality products. In this study, a process based on controlled hydrodynamic cavitation was applied for the first time to the production of aqueous solutions of silver fir (Abies Alba Mill.) needles with enhanced antioxidant activity. The observed levels of the in vitro antioxidant activity, comparable or higher than those found for reference substances, pure extracts, and other water extracts and beverages, highlight the very good potential of the HC process for the creation of solvent-free, aqueous solutions endowed with bioactive compounds extracted from silver fir needles.
ARTICLE | doi:10.20944/preprints202208.0511.v1
Subject: Biology, Plant Sciences Keywords: Zingiber cassumunar Roxb.; essential oils; microencapsulated products; antibacterial activity; agricultural pathogens; foodborne pathogens; gram-positive bacteria; gram-negative bacteria
Online: 30 August 2022 (07:02:54 CEST)
Zingiber cassumunar Roxb. is a powerful medicinal plant that has been used as traditional medicine to cure respiratory problems, pain, and inflammation in China, Indonesia, Thailand and other Asian countries by using the crude extracts. The objective of this research is to identify phytochemical composition of Z. cassumunar Roxb. and to analyze antibacterial activity of crude extract, purified compounds, and their microencapsulated products of Rhizome Z. cassumunar Roxb. Identification of phytochemical composition in crude extract of rhizome Z. cassumunar Roxb. was achieved by chromatography-mass spectrophotometer. The major phytochemical composition in crude extract of Z. cassumunar Roxb. is essential oils, including terpinen4-ol (37.7%), β-pinene (20.8%), and (E)-1-(3,4-dimethoxyphenyl)but-1-ene (13.3%). Crude extract of Z. cassumunar Roxb. was purified with silica gel flash column chromatography, resulting two purified compounds. The antibacterial activity of crude extract, purified compounds, and their microencapsulated products of Rhizome Z. cassumunar Roxb. were evaluated against agricultural and foodborne pathogens by using disc agar diffusion and broth microdilution techniques. All of the samples studied (crude extracts, purified compounds, and microencapsulated of Z. cassumunar Roxb.) were effective against all the bacteria. Based on the results of the disc-diffusion assay suggested that amongst the samples studied, purified compounds (compound 1 and 2) and microencapsulated purified compounds (compound 1 and 2) exhibited more effective against all the bacteria compared to the crude extracts. Antibacterial activity of the rhizome of Z. cassumunar Roxb. was contributed mainly by the essential oils components as the active compounds. Gram-negative bacteria (X. oryzae, X. translucens, Pseudomonas spp, E. coli, and S. typhimurium) appeared to the most resistant to the crude extracts, purified compounds, and microencapsulated of Z. cassumunar Roxb. compared to the gram-positive bacteria (S. aureus, B. cereus, and L. monocytogenes). Microencapsulated of the tested samples (crude extract, purified compound 1, and purified compound 2) of the rhizome Z. cassumunar Roxb. exhibited high antibacterial activity with no significantly different with the tested samples without microencapsulation. These results suggest potential antibacterial properties of Z. cassumunar Roxb., which useful for agricultural plant health, food preservation, natural therapies, and pharmaceuticals.
REVIEW | doi:10.20944/preprints202105.0618.v1
Subject: Keywords: active packaging; bio-based polymers; bioeconomy; essential oil; food waste; natural additives; permeability; plant extracts; shelf life; sustainable packaging
Online: 25 May 2021 (15:28:12 CEST)
Abstract: The promotion of sustainable packaging is part of the European Green Deal and plays a key role in the EU’s social and political strategy. One option is the use of renewable resources and biomass waste as raw materials for polymer production. Lignocellulose biomass from annual and perennial industrial crops and agricultural residues are a major source of polysaccharides, proteins, and lignin, and can also be used to obtain plant-based extracts and essential oils. Therefore, these biomasses are considered as potential substitute for fossil-based resources. Here, the status quo of bio-based polymers is discussed and evaluated in terms of properties related to packaging applications such as gas and water vapor permeability as well as mechanical properties. So far, their practical use is still restricted due to lower performance in fundamental packaging functions that directly influence food quality and safety, the length of shelf life and thus the amount of food waste. Besides bio-based polymers, this review focuses on plant extracts as active packaging agents. Incorporating extracts of herbs, flowers, trees, and their fruits is inevitable to achieve desired material properties that are capable to prolong the food shelf life. Finally, the adoption potential of packaging based on polymers from renewable resources is discussed from a bioeconomy perspective.
ARTICLE | doi:10.20944/preprints202005.0199.v1
Subject: Keywords: SARS-CoV-2; COVID-19; CADD; virtual screening; approved drugs; drug repurposing; essential targets; molecular docking; molecular dynamics simulations
Online: 11 May 2020 (13:14:18 CEST)
The emergence of SARS/MERS drug resistant COVID-19 with high transmission and mortality has recently been declared a deadly pandemic causing economic chaos and significant health problems. Like all coronaviruses, SARS-CoV-2 is a large virus that has many druggable components within its proteome. In this study, we focused on repurposing approved and investigational drugs by identifying potential drugs that are predicted to effectively inhibit critical enzymes within SARS-CoV-2. We shortlisted seven target proteins with enzymatic activities known to be essential at different stages of the virus life cycle. For virtual screening, the energy minimization of a crystal structure or modeled protein was carried out using Protein Preparation Wizard (Schrödinger LLC, 2020-1). Following active site selection based on data mining and COACH predictions, we performed a high-throughput virtual screen of drugs (n=5903) that are already approved by worldwide regulatory bodies including the FDA, using the ZINC database. Screening was performed against viral targets using three sequential docking modes (i.e. HTVS, SP and XP). Our in-silico virtual screening identified ~290 potential drugs based on the criteria of energy, docking parameters, ligand and binding site strain and score. Drugs specific to each target protein were further analyzed for binding free energy perturbation by molecular mechanics (prime MM-GBSA) and pruning the hits to the top 32 candidates. A top lead from each target group was further subjected to molecular dynamics simulation (MDS) using the Desmond module to validate the efficacy of the screening pipeline. All of the simulated hit-target complexes were predicted to strongly interact and with highly stable binding. Thus, we have identified a number of approved and investigational drugs with high likelihood of inhibiting a variety of key SARS-CoV-2 proteins. Follow-up studies will continue to identify inhibitors suitable for combination therapy based on drug-drug synergy to thwart resistance. In addition, the screening hits that we have identified provide excellent probes for understanding the binding properties of the active sites of all seven targets, further enabling us to derive consensus molecules through computer-aided drug design (CADD). While infections are expanding at a rampant pace, it must be recognized that resistance will grow commensurately through either genetic shift and/or genetic drift to all small molecule drugs identified. Vaccines should provide a more permanent solution through prevention, but resistivity is still a possible scenario. Nevertheless, a persistent multi-target drug development program is essential to curb this ongoing pandemic and to keep reemergence in check.
ARTICLE | doi:10.20944/preprints202002.0452.v1
Subject: Keywords: neurodegeneration; Parkinson's disease; essential tremor; Deep Brain stimulation; Levodopa; Virtual Reality; Oculus Rift; Medical Virtual Reality; Tremor stabilization; Equalizers
Online: 29 February 2020 (03:56:19 CET)
Multidisciplinary neurotechnology holds the promise of understanding and non-invasively treating neurodegenerative diseases. In this preclinical trial on Parkinson's disease (PD), we combined neuroscience together with the nascent field of medical virtual reality and generated several important observations. First, we established the Oculus Rift virtual reality system as a potent measurement device for parkinsonian involuntary hand tremors (IHT). Interestingly, we determined changes in rotation were the most sensitive marker of PD IHT. Secondly, we determined parkinsonian tremors can be abolished in VR with algorithms that remove tremors from patients' digital hands. We also found that PD patients were interested in and were readily able to use VR hardware and software. Together these data suggest PD patients can enter VR and be asymptotic of PD IHT. Importantly, VR is an open-medium where patients can perform actions, activities, and functions that positively impact their real lives - for instance, one can sign tax return documents in VR and have them printed on real paper or directly e-sign via internet to government tax agencies. Lastly, we generated a technical framework wherein movements in the real world can be measured side-by-side with those in virtual reality. With this framework, we observed anecdotal evidence of parkinsonian tremors being reduced in real life when our algorithms abolished digital hand tremors in VR.
ARTICLE | doi:10.20944/preprints202108.0275.v1
Subject: Social Sciences, Microeconomics And Decision Sciences Keywords: Healthcare Priority-setting; Health Technology Assessment; Essential Health Packages, Low to Middle Income Countries; Equity; Efficiency; Evidence-Informed Decision Making
Online: 12 August 2021 (13:14:51 CEST)
There is a systematic exclusion of gender-based violence, safe abortion, reproductive cancers, infertility services, comprehensive sexuality education, sexuality services, and STI’s other than HIV in essential health packages in LMICs. To accelerate progress on sexual reproductive health (SRH), the Guttmacher–Lancet Commission proposed the adoption of these interventions into an essential health package of SRH services that should be universally available. In this commentary, we use a healthcare priority-setting processes lens to review the importance of these services for universal health coverage. We isolate inherent challenges in social value judgments for terminal, process and content evidence for their healthcare priority-setting. We then advance promising emerging practical examples from low to middle-income countries on evidence-informed decision-making processes. We recommend capacity development through regional support, generating equity and efficiency evidence and strengthening political and publicly acceptable processes to institutionalise and operationalise evidence-informed decision-making.
ARTICLE | doi:10.20944/preprints201806.0408.v1
Subject: Earth Sciences, Geophysics Keywords: surface albedo; remote sensing; geostationary satellites; climate data records; essential climate variables; near real-time; operational processing; climate; land surface modeling
Online: 26 June 2018 (10:31:10 CEST)
Land surface albedo determines the splitting of downwelling solar radiation into components which are either reflected back to the atmosphere or absorbed by the surface. Land surface albedo is an important variable for the climate community and therefore was defined by the Global Climate Observing System (GCOS) as an Essential Climate Variable (ECV). Within the scope of the Satellite Application Facility for Land Surface Analysis (LSA SAF) of EUMETSAT, a near-real time (NRT) daily albedo product was developed in the last decade from observations provided by the SEVIRI instrument on board the geostationary satellites of the Meteosat Second Generation (MSG) series. In this study we present a new collection of albedo satellite products based on the same satellite data. The MSG Ten-day ALbedo (MTAL) product incorporates MSG observations over 31 days with a frequency of NRT production of 10 days. The MTAL collection is more dedicated to climate analysis studies compared to the daily albedo that was initially designed for the weather prediction community. For this reason, a homogeneous reprocessing of MTAL was done in 2018 to generate a Climate Data Record (CDR). The resulting product is called MTAL-R and has been made available to the community in addition to the NRT version of the MTAL product which has been available for several years. The retrieval algorithm behind the MTAL products comprises three distinct modules: one for atmospheric correction, one for daily inversion of a semi-empirical model of the bidirectional reflectance distribution function, and one for monthly composition that also determines surface albedo values. In this study the MTAL-R CDR is compared to ground surface measurements and concomitant albedo products collected by sensors on-board polar-orbiting satellites (SPOT-VGT and MODIS). We show that MTAL-R meets the quality requirements if MODIS or SPOT-VGT are considered as reference. This work leads to 14 years of production of geostationary land surface albedo products with a guaranteed continuity in the LSA SAF for the future years with the forthcoming third generation of European geostationary satellites.
REVIEW | doi:10.20944/preprints201710.0006.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: essential fatty acids; ascorbic acid; glutathione; aging; parkinson’s disease; alzheimer’s disease; senescence; nervous system; growth factors; neuroprotection; docosahexaenoic acid; α-linolenic acid.
Online: 2 October 2017 (08:59:13 CEST)
Polyunsaturated fatty acids (PUFAs) and antioxidants are important mediators in the central nervous system (CNS). Lipid derivatives may be used to generate endocannabinoids or prostanoids derived from arachidonic acid, which attenuates excitotoxicity in quadripartite synapses with a focus in astrocytes and microglia; on the other hand, antioxidants, such as glutathione (GSH) and ascorbate, have been shown to signal through transmitter receptors and protect against acute and chronic oxidative stress, modulating the activity of different signaling pathways. Several authors have investigated the role of these nutrients in young and senescent brain, as well as in degenerative conditions such as Alzheimer’s and Parkinson's diseases. Through literature review, we aimed to highlight recent data on the role of fatty acids, antioxidants and physical activity in physiology and in molecular mechanisms of brain senescence. Data indicate the complexity and essentiality of endogenous/dietary antioxidants for maintenance of the redox status and control of neuroglial signaling under stress. Recent studies also indicate that omega-3 and -6 fatty acids act in a competitive manner to generate mediators for energy metabolism, feeding behavior, plasticity and memory mechanisms throughout aging. Finding pharmacological or dietary resources that mitigate or prevent neurodegenerative affections continues to be a great challenge and require additional efforts from researchers, clinicians and nutritionists in the field.
REVIEW | doi:10.20944/preprints202001.0330.v1
Subject: Life Sciences, Molecular Biology Keywords: fatty acyl desaturase; Δ6 - desaturase; long-chain polyunsaturated fatty acid; LC-PUFA; ω3; ω6; EPA; DHA; AA; essential fatty acid; health; fish; transgene
Online: 28 January 2020 (04:39:09 CET)
Fatty acid desaturase 2 (Fads2) is the key enzyme of long chain polyunsaturated fatty acid (LC-PUFA) biosynthesis. Endogenous production of these biomolecules in vertebrates, if present, is insufficient to meet demand. Hence, LC-PUFA are considered as conditionally-essential. At present however, LC-PUFA are globally-limited nutrients due to anthropogenic factors. Attention of research is given therefore to find ways to maximize endogenous LC-PUFA production especially in production species, whereby deeper knowledge on molecular mechanisms of enzymatic steps involved is being generated. This review first briefly informs about the milestones in the history of LC-PUFA essentiality exploration before it focuses on the main aim – to highlight the fascinating Fads2 potential to play roles fundamental to adaptation to novel environmental conditions. Investigations are summarized, which elucidate the evolutionary history of fish Fads2 providing an explanation for the remarkable plasticity of this enzyme in fish. Further, structural implications of Fads2 substrate specificity are discussed and some relevant studies performed on organisms other than fish are mentioned in cases when such studies have so far not been conducted on fish models. The importance of Fads2 in the context of growing aquaculture demand and dwindling LC-PUFA supply is depicted and a few remedies in the form of genetic engineering to improve endogenous production of these biomolecules are outlined.
ARTICLE | doi:10.20944/preprints201806.0155.v1
Subject: Earth Sciences, Space Science Keywords: essential climate variables; climate data records; earth observation satellites; quality assurance; traceability; user requirements; climate applications; surface albedo; LAI; FAPAR; NO2; HCHO; CO
Online: 11 June 2018 (11:24:59 CEST)
Data from Earth Observation (EO) satellites are increasingly used to monitor the environment, understand variability and change, inform evaluations of climate model forecasts and manage natural resources. Policy makers are progressively relying on the information derived from these datasets to make decisions on mitigating and adapting to climate change. These decisions should be evidence based, which requires confidence in derived products as well as the reference measurements used to calibrate, validate or inform product development. In support of the European Union’s Earth Observation Programmes Copernicus Climate Change Service, the Quality Assurance for Essential Climate Variables (QA4ECV) project fulfilled a gap in the delivery of climate quality satellite derived datasets by prototyping a robust, generic system for the implementation and evaluation of Quality Assurance (QA) measures for satellite-derived ECV climate data record products. The project demonstrated the QA system on six new long-term, climate quality ECV data records for surface Albedo, Leaf Area Index, FAPAR, NO2, HCHO and CO. Provision of standardized QA information provides data users with evidence-based confidence in the products and enables judgement on the fitness-for-purpose of various ECV data products their specific applications.