Several lines of evidence suggest that besides antioxidant also prooxidant properties are crucially involved in cytotoxic and protective activities of the major green tea catechin epigallocatechin-3-gallate (EGCG) in vitro (Elbling et al., 2011). Furthermore recent data suggest that EGCG induces oxidative stress also in vivo (Li et al.
View Article and Find Full Text PDFCoffee is among the most frequently consumed beverages worldwide and epidemiological studies indicate that its consumption is inversely related to the incidence of diseases in which reactive oxygen species (ROS) are involved (liver cirrhosis, certain forms of cancer and neurodegenerative disorders). It has been postulated that antioxidant properties of coffee may account for this phenomenon. To find out if consumption of paper filtered coffee which is the most widely consumed form in Central Europe and the US protects humans against oxidative DNA-damage, a controlled intervention trial with a cross-over design was conducted in which the participants (n=38) consumed 800ml coffee or water daily over 5 days.
View Article and Find Full Text PDFThe beneficial health effects of (-)-epigallocatechin-3-gallate (EGCG), the main catechin of green tea, have been attributed to complex interactions with a focus on antioxidative properties. Susceptibility to autoxidation and production of cytotoxic reactive oxygen species (ROS), mostly H(2)O(2), have been suggested to occur in vitro but also in vivo. In this study, we address whether autoxidation-derived H(2)O(2) may be involved in the cytoprotective effects of EGCG.
View Article and Find Full Text PDFScope: Coffee is among the most frequently consumed beverages. Its consumption is inversely associated to the incidence of diseases related to reactive oxygen species; the phenomenon may be due to its antioxidant properties. Our primary objective was to investigate the impact of consumption of a coffee containing high levels of chlorogenic acids on the oxidation of proteins, DNA and membrane lipids; additionally, other redox biomarkers were monitored in an intervention trial.
View Article and Find Full Text PDFStilbenes comprise a group of polyphenolic compounds, which exert inhibitory effects on various malignancies. The aim of this study was to evaluate the antitumor effects of a previously unreported stilbene derivative-3,3',4,4',5,5'-hexahydroxystilbene, termed M8-on human melanoma cells. Cell-cycle analysis of the metastatic melanoma cell line M24met showed that M8 treatment induces G(2)/M arrest accompanied with a dose- and time-dependent upregulation of p21 and downregulation of CDK-2 and leads to apoptosis.
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