REVIEW | doi:10.20944/preprints202306.2260.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: epicatechin; skeletal muscle; muscular atrophy; catechins; myogenic regulatory factors
Online: 30 June 2023 (14:49:48 CEST)
Epicatechin has been described as a polyphenol compound that promotes skeletal muscle restructuring, by expressing muscle regulation factors, activation of satellite cells and modulation of the main pathways associated with catabolism. However, the literature shows contrasting results of therapeutic effects and treatment protocols. Thus, the aim of this systematic review was to analyze the current literature addressing the molecular mechanism and clinical protocol of epicatechin on skeletal muscular atrophy in humans and animals. A search was conducted in PubMed/MEDLINE, Embase, Web of Science, and Cochrane Library databases. The qualitative analysis showed a prevalence of the inhibitory action of epicatechin in myostatin expression and atrogenes FOXO, MAFbx and MuRF1. Epicatechin showed positive effects on increased follistatin and on the activation of the myogenic regulatory factors (Myf5, MyoD and myogenin). In addition, the studies evidenced the impact of epicatechin on the mitochondrias' biosynthesis in muscle fibers, activation of the signaling pathway of AKT/mTOR protein synthesis, and improvement of skeletal musculature performance, particularly when associated with physical training. Epicatechin showed promising clinical applicability through beneficial results under conditions that negatively affect the skeletal musculature. However, there is no protocol standardization allowing to draw more specific conclusions on its therapeutic use.
ARTICLE | doi:10.3390/sci2020031
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Khechechuri pear; Adjara region; phenolic compounds; catechins; flavonoids; antioxidant activity
Online: 9 May 2020 (00:00:00 CEST)
An endemic pear species spreads in one region of western Georgia, Adjara, called Khechechuri. Pears are dietary source of bioactive components such as polyphenols and triterpenic acid. In addition to its gastronomic value, the aim of the article was to examine and compare phenolic compounds, flavonoids, catechins, phenolic acids, and antioxidant activities in five species of Khechechuri collected from various regions in Adjara region: Adjaristskali, Merisi, Dandalo, Shuakhevi, and Khulo. Five fruit parts, the skin, edible pulp, the whole pear (skin + pulp), juice and the pomace were analyzed and the results were compared. Our study revealed that the amount of total phenolic content found in the skin of West Georgian pear types was as much as 4650 mg/kg. Also, the pear pomace showed significant amount of total phenolic content in all species of Khechechuri. In addition, in all species of Khechechuri pears, flavonoids were found, except in the fruit juice.
REVIEW | doi:10.20944/preprints201703.0239.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: green tea catechins; prostate cancer; chemoprevention; metabolism; nanoparticles; epigenetic; proteostasis
Online: 31 March 2017 (12:46:15 CEST)
Green Tea Catechins (GTCs) are a family of chemically related compounds usually classified as antioxidant molecules. Epidemiological evidences, supported by interventional studies, highlighted a more than promising role for GTCs in human Prostate Cancer (PCa) chemoprevention.In the last decades many efforts have been made to gain new insights into the mechanism of action of GTCs. Now it is clear that GTCs anticancer action can no longer be simplistically limited to their direct antioxidant/pro-oxidant properties. Recent contributions to the advancement of knowledge in this field have shown that GTCs specifically interact with cellular targets including, cell surface receptors, lipid rafts and endoplasmic reticulum, modulate gene expression through direct effect on transcription factors or indirect epigenetic mechanisms, interfere with intracellular proteostasis at various levels. Many of the effects observed in vitro are dose and cell context dependent and take place at concentration that cannot be achieved in vivo.Poor intestinal absorption together with an extensive systemic and enteric metabolism influence GTCs bioavailability through still poor understood mechanisms. Recent efforts to develop delivery systems that increase GTCs overall bioavailability, by mean of biopolymeric nanoparticles, represent the main way to translate preclinical results in a real clinical scenario for PCa chemoprevention.
REVIEW | doi:10.20944/preprints202305.2065.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Green Tea Catechins (ECGC); andrographolide; curcumin; Skin photoprotection; Skin permeation; Oxidative stress; Antimicrobial; Cosmetic and dermatologic formulations
Online: 30 May 2023 (07:27:36 CEST)
Here we have chosen to highlight the main natural molecules extracted from camellia sinensis, andrographis paniculata and curcuma longa that may possess antioxidant activities of interest for skin protection. The molecules involved, in the antioxidant process are respectively catechins derivatives, in particular EGCG, andrographolide and its derivatives as well as various curcuminoids. These plants are generally used as beverages for camellia sinensis (tea tree), as dietary supplements or as spices. The molecules they contain are known for their diverse therapeutic activities, including anti-inflammatory, antimicrobial, anti-cancer, antidiabetic and dermatological treatment. Their common antioxidant activities and therapeutic applications are widely documented, but their use in cosmetic is more recent. In this review, we will endeavor to compile the cosmetic uses of these natural molecules of interest, the various structural modulations reported, with the aim of improving their bioavailability as well as establishing their different mechanisms of action.
ARTICLE | doi:10.20944/preprints202308.1493.v1
Subject: Medicine And Pharmacology, Pharmacy Keywords: silver nanoparticles; chlorhexidine; conjunction; complexation; surface functionalization; nano-scaled drug delivery; antimicrobial synergism; antiviral activity; Camellia sinensis catechins; green synthesis
Online: 22 August 2023 (09:52:09 CEST)
This study explored the potential synergism within chlorhexidine-silver nanoparticles conjugates against Influenza type A, Staphylococcus aureus, Escherichia coli, and Candida albicans. Silver nanoparticles (SN) were obtained by the reduction of silver ions with green tea total phenolic extract and conjugated with chlorhexidine (Cx). The particles were characterized by UV-Vis and FTIR spectroscopies, dynamic light scattering, X-ray diffraction, and transmission electron microscopy. A stable negatively-charged nano-silver colloid (ζ=-50.01) was obtained with an average hydrodynamic diameter of 92.34 nm. In the presence of chlorhexidine, the spectral data and the shift of the zeta potential to positive values (ζ=+44.59) revealed the successful sorption of the drug onto the silver surface. The conjugates (SN-Cx) demonstrated potentiation in the effects against S. aureus and C. albicans, and synergism against E. coli with minimal inhibitory concentrations of SN 5.5 µg/mL+Cx 8.8 µg/mL. The SN showed excellent, increasing with time, virucidal properties, and low toxicity. The coupling of the cationic chlorhexidine with nano-silver, however, did not reduce its intrinsic cytotoxicity on various cell lines (MDCK, BJ, and А549). The newly-synthesized antimicrobial agent presented with an extended and promising therapeutic spectrum and needs to be further evaluated on relevant to the designated route of administration three-dimensional cell models (e.g., nasal, bronchial, dermal, ocular, etc.).