ARTICLE | doi:10.20944/preprints202006.0023.v1
Subject: Chemistry, Analytical Chemistry Keywords: Nymphaea lotus L.; stamen; ultrasound-assisted extraction; macroporous resin (MPR) purification; in vitro; in cellulo; antioxidant; flavonoids
Online: 4 June 2020 (03:59:58 CEST)
Nymphaea lotus L. is the medicinal plant that has long been used as food, cosmetic and traditional medicines in Africa and Asia since the ancient time. Its flavonoids and other interesting phytochemical compounds from rhizome, leaf, and the whole flowers have been reported in the previous published researches. However, stamens, which are essential for reproductive functions, may also represent new alternative sources of potential antioxidant flavonoids as investigated in this study. The innovative green chemistry method i.e. ultrasound-assisted extraction (USAE) as well as macroporous resin (MPR) purification procedure were employed in this current research. The optimal ultrasound-assisted extraction condition is 90 % (v/v) aqEtOH with 34.65 khz ultrasonic frequency and 46 minutes of extraction time. Comparing with heat reflux extraction (HRE) conventional method, the significant gain of 1.35 total flavonoids content was obtained using optimized USAE conditions, jumping to 2.80 when this USAE associated with MPR purification. Not only in vitro cell free antioxidant activity of N. lotus stamen extracts, but also in cellulo antioxidant investigation using yeast model showed the same trend to indicate that the best antioxidant flavonoid can be found in USAE coupled with MPR purification. Moreover, the key antioxidant genes expression in yeast model such as SIR2 and SOD2 were also expressed at the highest level in yeast cell treated with the extract from USAE together with MPR purification. Consequently, it can be seen that the USAE combined with MPR purification can help to enhance the flavonoids antioxidant potential of the stamens extract from this medicinal species.
ARTICLE | doi:10.20944/preprints202204.0103.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Monochoria angustifolia; Monochoria hastata; Flavonoid; Antioxidant mechanism; Natural populations; Phytochemical profile; Traditional herbal medicine; Phytopharmaceutical
Online: 12 April 2022 (04:08:17 CEST)
Plants of the genus Monochoria have long been utilized in food, cosmetics, and traditional herbal treatment. Thailand has the highest species diversity of this genus and a new member, Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum has been recently described. This plant is called “Siam Violet Pearl” as a common name or “ไข่มุกสีม่วงแห่งสยาม” as its vernacular name in the same meaning in Thai language. Despite their importance, few researches on Monochoria species have been conducted. This study, thus, provided the results to fill in this gap by: i) determining flavonoids phytochemical profiles of 25 natural populations of M. angustifolia covering the whole floristic regions in Thailand, and ii) determining antioxidant activity using various antioxidant assays to investigate the probable mechanism. The results revealed that M. angustifolia presented a higher flavonoid content than the outgroup, M. hastata. Our results also revealed that flavonoids might be used to investigate Monochoria evolutionary connections and for botanical authentication. The various antioxidant assays revealed that M. angustifolia extracts preferentially act through a hydrogen atom transfer antioxidant mechanism. Pearson correlation analysis indicated significant correlations emphasizing that the antioxidant capacity is most probably the result of a complex phytochemical combinations rather than of a single molecule. Altogether, these results showed that this new species provide an attractive alternative starting material with phytochemical variety and antioxidant potential for the phytopharmaceutical industry.
ARTICLE | doi:10.20944/preprints202004.0429.v1
Subject: Life Sciences, Biochemistry Keywords: Aging; Almond; Chlorogenic acid; Lipid peroxidation; Mitochondria; 8-Oxo-guanine; Oxidative stress; Protein carbonylation; Sirtuin; Superoxide dismutase; Yeast
Online: 24 April 2020 (08:54:52 CEST)
Almond (Prunus dulcis (Mill.) D.A.Webb) is one of the largest nut crops in the world. Recently, phenolic compounds, mostly stored in almond skin, have been associated with much of the health-promoting behavior associated with their intake. The almond skin enriched fraction obtained from cold-pressed oil residues of the endemic Moroccan Beldi ecotypes is particularly rich in chlorogenic acid. In this study, both almond skin extract (AE) and chlorogenic acid (CHL) supplements, similar to traditional positive control resveratrol, significantly increased the replicative life-span of yeast compared to the untreated group. Our results showed that AE and CHL significantly reduced the production of reactive oxygen and nitrogen species (ROS/RNS), most likely due to their ability to maintain mitochondrial function during aging, as indicated by the maintenance of normal mitochondrial membrane potential in treated groups. This may be associated with the observed activation of the anti-oxidative stress response in treated yeast, which results in activation at both gene expression and enzymatic activity levels for SOD2 and SIR2, the latter being an upstream inducer of SOD2 expression. Interestingly, the differential gene expression induction of mitochondrial SOD2 gene at the expense of the cytosolic SOD1 gene confirms the key role of mitochondrial function in this regulation. Furthermore, AE and CHL have contributed to the survival of yeast under UV-C-induced oxidative stress, by reducing the development of ROS / RNS, resulting in a significant reduction in cellular oxidative damage as evidenced by decreased membrane lipid peroxidation, protein carbonyl content and 8-oxo-guanine formation in DNA. Together, these results demonstrate the interest of AE and CHL as new regulators in the replicative life-span and control of the oxidative stress response of yeast.
REVIEW | doi:10.20944/preprints202103.0130.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Rivea hypocrateriformis (Desr.) Choisy; Traditional medicines; Phytochemistry; Biological activity; Pharmacology
Online: 3 March 2021 (11:46:16 CET)
Rivea hypocrateriformis (Desr.) Choisy is a robust woody climbing shrub of the genus Rivea which is found in India, Nepal, Sri Lanka, Pakistan, Bangladesh, Myanmar and Thailand. R. hypocrateriformis is a promising medicinal herb with enormous helpful and wellbeing advancing impacts. R. hypocrateriformis has been utilized as a customary medication for a long time to treat rheumatic pain, fever, urogenital problem, snake bite, cough, piles, malaria, and skin disease. Apart from the traditional uses its leaves and young shoots are cooked and eaten as a vegetable and for preparation of bread with millet flour. This review comprehensively summarizes the up-to-date information on the botanical characterization, distribution, traditional uses, phytochemistry, pharmacology and toxicity study of R. hypocrateriformis. Phytochemical investigation has been revealed that alkaloids, glycosides, coumarins, flavonoids, xanthones, stilbenes, and other organic compounds are contained in R. hypocrateriformis. Crude extracts and isolated compounds have exhibited numerous pharmacological activities such as anovulatory effect, antifertility activity, antiarthritic, antimicrobial, anticancer, antioxidant, hepatoprotective, antilithiatic, antimitotic. R. hypocrateriformis is a promising restorative spice with monstrous remedial and wellbeing advancing impacts. Along these lines, further investigations on the bioactive mixtures and systems of R. hypocrateriformis are justified. Extra clinical and toxicological examinations are expected to assess its wellbeing.
ARTICLE | doi:10.20944/preprints202009.0285.v1
Subject: Biology, Plant Sciences Keywords: Antioxidants; Biological System; Caffeic Acid; Callus culture; Chicoric Acid; Phenolics; Plant in vitro Cultures; Rosmarinic Acid; Thai Basil
Online: 13 September 2020 (12:18:48 CEST)
Thai basil is a renowned medicinal plant and a rich source of bioactive antioxidant compounds having several health benefits, with actions to prevent of cancer, diabetes and cardiovascular disease. Plant cell and tissue culture technologies can be routinely established as an important, sustainable and low-cost biomass source for the production of high-value phytochemicals. The current study aimed at developing an effective protocol for the production of Thai basil leaf derived callus cultures with sustainable and high production of biomass and antioxidants as an alternative of leaves production. MS basal medium with various concentrations of plant growth regulators (PGRs) compatible with nutraceutical applications (i.e., gibberellic acid (GA3) and 6-benzylaminopurine (BAP) either alone or in combination with naphthalene acetic acid (NAA)) were evaluated. Among all tested PGRs, the combination BAP:NAA (5 mg/L:1 mg/L) yield maximum biomass accumulation (fresh weight (FW): 190 g/L and dry weight (DW): 13.05 g/L) as well as enhanced phenolic (346.08 mg/L) production. HPLC quantification analysis indicated high productions of chicoric acid (35.77 mg/g DW) and rosmarinic acid (7.35 mg/g DW) under optimized callus culture conditions. Antioxidant potential was assessed using both in vitro cell free and in vivo cellular antioxidant assays. Maximum in vitro antioxidant activity DPPH (93.2 % of radical scavenging activity) and ABTS (1322 µM Trolox equivalent antioxidant capacity) was also observed for the extracts from callus cultures grown on optimal conditions. In vivo cellular antioxidant activity assay confirmed the effective protection against oxidative stress of the corresponding extract by the maximum inhibition of ROS and RNS production. Compared to commercial leaves, callus extracts showed higher production of chicoric acid and rosmarinic acid associated with higher antioxidant capacity. In addition, this biological system also has a large capacity for continuous biomass production, thus demonstrating its high potential for possible nutraceutical applications.
ARTICLE | doi:10.20944/preprints202101.0204.v1
Subject: Biology, Plant Sciences Keywords: Antioxidant; Anti-inflammatory; Chitosan; Flavonoids; Phenolics; Silybum marianum
Online: 11 January 2021 (15:59:31 CET)
Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S marianum were exploited for their in vitro potency to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension culture was maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 g/L fresh weight (FW) and 17.7 g/L dry weight (DW) productions. Chitosan treatment resulted in an overall increase in the accumulation of flavonoids, phenolic compounds and silymarin. High accumulation levels of silybin B, silydianin and silybin A were recorded by HPLC analysis. The corresponding extracts displayed interesting antioxidant and anti-inflammatory capacities. In particular, high ABTS antioxidant activity (741.5 μM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan. On the opposite, highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 %), secretory phospholipase A2 (sPLA2, 33.9 %) and 15-lipoxygenase (15-LOX-2, 31.6 %) enzymes involved in inflammation process were measured in extracts obtained in presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation of the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.
ARTICLE | doi:10.20944/preprints201907.0252.v1
Subject: Chemistry, Applied Chemistry Keywords: Silybum marianum; silymarin; flavonolignans; ultrasound-assisted extraction; design of experiement; antioxidant; anti-aging
Online: 23 July 2019 (09:51:35 CEST)
Silybum marianum (L.) Gaertn. (aka milk thistle) constitute the almost exclusive source of silymarin, a mixture of different flavonolignans, and is thus considered as a unique model for their extraction. The present research deals with ultrasound-assisted extraction (UAE) of S. marianum flavonolignans and their quantification using LC system. The optimal conditions for UAE were: aqueous EtOH 54.5% (v/v) as solvent, applying an ultrasound frequency of 36.6 kHz during an extraction time of 60 min at 45°C with a liquid to solid ratio of 25:1 ml/g DW. Following optimization, the extraction method was validated according to international standards of the association of analytical communities (AOAC) in order to ensure its precision and accuracy for the quantitation of the individual silymarin components. The efficiency of UAE was compared with maceration protocol of the same duration. The optimized and validated conditions allowed highest extraction yields of flavonolignans in comparison to maceration. The antioxidant capacity of the extracts was confirmed by the CUPRAC assays and inhibition of advanced glycation end products. The skin anti-aging action was also confirmed toward the strong in vitro inhibition capacity of the obtained extract against collagenase and elastase enzymes. The procedure presented here allows a green efficient extraction and quantification of the main flavonolignans from the fruits of S. marianum with attractive antioxidant and anti-aging activities for future cosmetic applications.
ARTICLE | doi:10.20944/preprints201903.0007.v1
Subject: Life Sciences, Biotechnology Keywords: Silybum marianum L.; Light regimes; Melatonin; Antioxidant; Phenolics; Flavonoids; Silymarin; Anti-inflammatory
Online: 1 March 2019 (12:20:03 CET)
Silybum marianum L. is a well-known medicinal herb, primarily used in liver protection. Light strongly affects several physiological processes along with secondary metabolites biosynthesis in plants. Herein, S. marianum was exploited for in vitro potential under different light regimes in the presence of melatonin. The optimum callogenic response occurred in combination of 1.0 mg/L α-naphthalene acetic acid and 0.5 mg/L 6-Benzylaminopurine under photoperiod. Continuous light associated with melatonin treatment increased total flavonoid content (TFC), total phenolic content (TPC) and antioxidant potential, followed by photoperiod and dark treatments. The increased level of melatonin has a synergistic effect on biomass accumulation under continuous light and photoperiod, while adverse effect was observed under dark condition. More detailed phytochemical analysis showed maximum total silymarin content (11.92 mg/g DW) when placed under continuous light + 1.0 mg/L melatonin. Individually, the level of silybins (A and B), silydianin, isolsilychristin and silychristin was found highest under continuous light. Anti-inflammatory activities were also studied and highest percent inhibition was recorded against 15-LOX for cultures cultivated under continuous light (42.33%). The current study helps to better understand the influence of melatonin and different light regimes on silymarin production as well as antioxidant and anti-inflammatory activities in S. marianum callus extracts.
ARTICLE | doi:10.20944/preprints202004.0319.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: almond; antioxidant; by-products; chlorogenic acid; design of experiment; phenolic acids; ultrasound-assisted extraction
Online: 19 April 2020 (04:06:15 CEST)
Almond (Prunus dulcis (Mill.) D.A.Webb) is one of the most important nut crops both in terms of area and production. Over the last decades, an important part of the beneficial actions for health associated with their consumption was attributed to the phenolic compounds, mainly accumulated in almond skin. Interestingly, after cold-pressed oil extraction, most of these antioxidant phenolic compounds are retained in a skin-enriched by-product, so-called almond cold-pressed oil residue. In Morocco, ranked fifth producer in the world, this production generates an important part of this valuable byproduct. In the present study, using a multivariate Box-Behnken design, an ultrasound-assisted extraction (USAE) method of phenolic compounds from Moroccan almond cold-pressed oil residue was developed and validated. Response surface methodology resulted in the optimal extraction conditions: the use of aqueous EtOH 53.0% (v/v) as green solvent, applying an US frequency of 27.0 kHz for an extraction duration of 29.4 min. The present USAE allowed substantial gains in terms of extraction efficiency compared to conventional heat reflux extraction. Applied to 3 different local Beldi genotypes growing at 3 different experimental sites, the optimal USAE conditions led to a total phenolic content of 13.86 mg/g dry weight (DW). HPLC analysis revealed that the main phenolic compounds from this valuable byproduct were: chlorogenic acid followed by protocatechuic acid, p-hydrobenzoic acid and p-coumaric acid. The accumulation of these phenolic compounds appeared to be more dependent on the genetic background than on the environmental impact here represented by the 3 experimental culture sites. Both in vitro cell free and cellular antioxidant assays were performed, and revealed the great potential of these extracts. In particular, correlation analysis evidenced the prominent roles of chlorogenic acid, protocatechuic acid and p-hydrobenzoic acid. To summarize, the USAE method presented here is a quick, green, simple and efficient validated USAE for the possible valorization of antioxidant phenolic compounds from Moroccan almond cold-Pressed oil residues, making it possible to generate extracts with attractive antioxidant activities for future nutraceutical and/or cosmetic applications.