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Chemical & Pharmaceutical Bulletin 2020Black tea accounts for 70-80% of world tea production, and the polyphenols therein are produced by enzymatic oxidation of four tea catechins during tea fermentation.... (Review)
Review
Black tea accounts for 70-80% of world tea production, and the polyphenols therein are produced by enzymatic oxidation of four tea catechins during tea fermentation. However, only limited groups of dimeric oxidation products, such as theaflavins, theasinensins, and theacitrins, have been isolated from black tea and chemically characterized. This is largely because of the complexity and heterogeneity of the oxidation products. To determine structures and production mechanisms of uncharacterized black tea polyphenols, in vitro model fermentation experiments using pure catechins and polyphenol oxidase have been applied, and basic oxidation mechanisms have been established. Contemporary methods, such as LC-MS, are also effective to identify catechin oxidation products in black tea. Despite ongoing efforts, almost 60% of the solids in black tea infusion remain uncharacterized. These compounds include the so-called thearubigins, which are a heterogeneous mixture of uncharacterized catechin oxidation products with oligomeric structures. This review summarizes the current knowledge of the production mechanisms of representative black tea polyphenols and presents recent progress in characterization of thearubigins.
Topics: Molecular Structure; Polyphenols; Tea
PubMed: 33268645
DOI: 10.1248/cpb.c20-00295 -
Nutrients Aug 2018Recent evidence has suggested that polyphenol-rich foods intake may be associated with decreased risk of chronic diseases. The Special Issue "Effects of Polyphenol-Rich...
Recent evidence has suggested that polyphenol-rich foods intake may be associated with decreased risk of chronic diseases. The Special Issue "Effects of Polyphenol-Rich Foods on Human Health" comprised 64 peer-reviewed papers on the most recent evidence regarding the dietary intake of polyphenols and polyphenol-rich foods, as well as their effect toward the prevention and treatment of non-communicable diseases. Original contributions and literature reviews demonstrated the potential protective effects of polyphenol-rich foods and their extracts toward cardiovascular diseases, certain cancers, and neurodegenerative diseases, mostly through anti-oxidant and chemo-preventive properties.
Topics: Diet; Food Analysis; Humans; Polyphenols
PubMed: 30110959
DOI: 10.3390/nu10081089 -
Frontiers in Immunology 2022Polyphenols, commonly found in various plants, have attracted enormous attention due to their potential pharmacological activity, especially antitumor activity dependent... (Review)
Review
Polyphenols, commonly found in various plants, have attracted enormous attention due to their potential pharmacological activity, especially antitumor activity dependent on immune function. In recent years, the development of nanomedicine can counteract the low bioavailability of polyphenols and improve the effect of tumor treatment. Among them, metal-phenolic networks (MPNs), which utilize various metal ions and phenolic ligands for coordination binding, have now become candidates for polyphenol-based nanomedicine treatment of tumors. In this mini-review, we described the classification of polyphenols and their mechanisms in antitumor immune responses, and provided suggestions for the next steps of treating tumors with polyphenols.
Topics: Humans; Polyphenols; Immunomodulation; Neoplasms; Nanomedicine; Immunity
PubMed: 36505462
DOI: 10.3389/fimmu.2022.1041138 -
Nutrients Feb 2020Polyphenols are a class of well-known bioactive compounds widely distributed in the plant kingdom and abundant in plant foods and derived food products [...].
Polyphenols are a class of well-known bioactive compounds widely distributed in the plant kingdom and abundant in plant foods and derived food products [...].
Topics: Diet; Humans; Plant Extracts; Polyphenols
PubMed: 32028558
DOI: 10.3390/nu12020400 -
International Journal of Molecular... Nov 2017Polyphenols are a group of plant metabolites with potent antioxidant properties, which protect against various chronic diseases induced by oxidative stress. Evidence... (Review)
Review
Polyphenols are a group of plant metabolites with potent antioxidant properties, which protect against various chronic diseases induced by oxidative stress. Evidence showed that dietary polyphenols have emerged as one of the prominent scientific interests due to their role in the prevention of degenerative diseases in humans. Possible health beneficial effects of polyphenols are measured based on the human consumption and their bioavailability. Lentil (; Family: Fabaceae) is a great source of polyphenol compounds with various health-promoting properties. Polyphenol-rich lentils have a potential effect on human health, possessing properties such as antioxidant, antidiabetic, anti-obesity, anti-hyperlipidemic, anti-inflammatory and anticancer. Based on the explorative study, the current comprehensive review aims to give up-to-date information on nutritive compositions, bioactive compounds and the health-promoting effect of polyphenol-rich lentils, which explores their therapeutic values for future clinical studies. All data of in vitro in vivo and clinical studies of lentils and their impact on human health were collected from a library database and electronic search (Science Direct, PubMed and Google Scholar). Health-promoting information was gathered and orchestrated in the suitable place in the review.
Topics: Antioxidants; Diet; Humans; Lens Plant; Oxidative Stress; Polyphenols; Seeds
PubMed: 29125587
DOI: 10.3390/ijms18112390 -
The Journal of Nutritional Biochemistry Oct 2017Paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated enzyme involved in the protection of low-density lipoprotein and HDLs against lipid peroxidation.... (Review)
Review
Paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated enzyme involved in the protection of low-density lipoprotein and HDLs against lipid peroxidation. Several studies documented the capacity of polyphenols to stimulate PON1 transcription activation. The objective of the present review is to provide the main evidence about the role and the potential mechanism of action of polyphenols and polyphenol-rich foods in the modulation of PON1 gene expression and activity. A total of 76 in vitro and in vivo studies were included in the review. Overall, while evidence obtained in vitro is limited to quercetin and resveratrol, those deriving from animal models seem more convincing for a wide range of polyphenols but only at pharmacological doses. Evidence from human studies is promising but deserves more substantiation about the role of polyphenol-rich foods in the regulation of PON1 activity and expression. Research focused on the understanding of the structure-activity relationship of polyphenols with PON1 and on the mechanisms at the base of PON1 modulation is warranted. Well-designed human intervention studies are encouraged to corroborate the findings of polyphenols also at physiological doses.
Topics: Animals; Aryldialkylphosphatase; Food; Humans; Polyphenols; Structure-Activity Relationship
PubMed: 28623808
DOI: 10.1016/j.jnutbio.2017.06.002 -
Molecules (Basel, Switzerland) Jul 2020This review deals with hydrogels as soft and biocompatible vehicles for the delivery of plant-derived (poly)phenols, compounds with low general toxicity and an... (Review)
Review
This review deals with hydrogels as soft and biocompatible vehicles for the delivery of plant-derived (poly)phenols, compounds with low general toxicity and an extraordinary and partially unexplored wide range of biological properties, whose use presents some major issues due to their poor bioavailability and water solubility. Hydrogels are composed of polymeric networks which are able to absorb large amounts of water or biological fluids while retaining their three-dimensional structure. Apart from this primary swelling capacity, hydrogels may be easily tailored in their properties according to the chemical structure of the polymeric component in order to obtain smart delivery systems that can be responsive to various internal/external stimuli. The functionalization of the polymeric component of hydrogels may also be widely exploited to facilitate the incorporation of bioactive compounds with different physicochemical properties into the system. Several prototype hydrogel systems have been designed for effective polyphenol delivery and potential employment in the treatment of human diseases. Therefore, the inherent features of hydrogels have been the focus of considerable research efforts over the past few decades. Herein, we review the most recent advances in (poly)phenol-loaded hydrogels by analyzing them primarily from the therapeutic perspective and highlighting the innovative aspects in terms of design and chemistry
Topics: Biocompatible Materials; Biological Availability; Drug Delivery Systems; Humans; Hydrogels; Polymers; Polyphenols
PubMed: 32708833
DOI: 10.3390/molecules25143254 -
Archives of Biochemistry and Biophysics Apr 2016Population studies have shown a strong association between dietary intake of polyphenols and reduced risk of cardiovascular disease. These associations have been... (Review)
Review
Population studies have shown a strong association between dietary intake of polyphenols and reduced risk of cardiovascular disease. These associations have been confirmed to some extent by intervention studies which have shown improvements in vascular function and blood pressure with certain polyphenols or food extracts rich in polyphenols. The mechanisms involved in the bioactivity of dietary polyphenols is still under active investigation. It is unlikely that polyphenols act as antioxidants in vivo. Evidence suggests that dietary polyphenols or their metabolites act as signalling molecules and can increase nitric oxide bioavailability and induce protective enzymes. This review will outline some of the key issues in dietary polyphenol research that suggest mechanistic insights into the action of these bioactive compounds. There are a number of issues that remain to be resolved in bridging the gap between observational studies and intervention trials using food extracts or pure polyphenol compounds.
Topics: Antioxidants; Biological Availability; Diet; Humans; Oxidative Stress; Polyphenols; Signal Transduction
PubMed: 27095227
DOI: 10.1016/j.abb.2015.11.014 -
Molecules (Basel, Switzerland) Jul 2023Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases that play important roles in a variety of diseases, including cancer, cardiovascular disease,... (Review)
Review
Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases that play important roles in a variety of diseases, including cancer, cardiovascular disease, diabetes, obesity, and brain diseases. Dietary polyphenols are thought to have a variety of beneficial effects on these diseases characterized by inflammation. Clinical studies have demonstrated that MMPs are in most cases upregulated in various inflammatory diseases, including osteoarthritis, rheumatoid arthritis, inflammatory bowel disease, and Alzheimer's disease. Studies using patient-derived human samples, animal studies, and cellular experiments have suggested that polyphenols may be beneficial against inflammatory diseases by suppressing MMP gene expression and enzyme activity. One important mechanism by which polyphenols exert their activity is the downregulation of reactive oxygen species that promote MMP expression. Another important mechanism is the direct binding of polyphenols to MMPs and their inhibition of enzyme activity. Molecular docking analyses have provided a structural basis for the interaction between polyphenols and MMPs and will help to explore new polyphenol-based drugs with anti-inflammatory properties.
Topics: Animals; Humans; Molecular Docking Simulation; Polyphenols; Antioxidants; Anti-Inflammatory Agents; Matrix Metalloproteinases
PubMed: 37513300
DOI: 10.3390/molecules28145426 -
Biomolecules Jun 2022Nutraceuticals have been receiving increasing attention in the last few years due to their potential role as adjuvants against non-communicable chronic diseases... (Review)
Review
Nutraceuticals have been receiving increasing attention in the last few years due to their potential role as adjuvants against non-communicable chronic diseases (cardiovascular disease, diabetes, cancer, etc.). However, a limited number of studies have been performed to evaluate the bioavailability of such compounds, and it is generally reported that a substantial elevation of their plasma concentration can only be achieved when they are consumed at pharmacological levels. Even so, positive effects have been reported associated with an average dietary consumption of several nutraceutical classes, meaning that the primary compound might not be solely responsible for all the biological effects. The in vivo activities of such biomolecules might be carried out by metabolites derived from gut microbiota fermentative transformation. This review discusses the structure and properties of phenolic nutraceuticals (i.e., polyphenols and tannins) and the putative role of the human gut microbiota in influencing the beneficial effects of such compounds.
Topics: Dietary Supplements; Gastrointestinal Microbiome; Humans; Microbiota; Polyphenols; Tannins
PubMed: 35883431
DOI: 10.3390/biom12070875