INTRODUCTION: The majority of case-control epidemiological studies have shown that diet rich in polyphenols, of which fresh vegetables and fruit are rich, is inversely associated with gastric cancer (GC) risk. However, interventional studies failed to demonstrate any significant change in the risk of GC and no convincing claims can be made with regard to the mechanism through which polyphenols exert their protective effect.. AIMS AND METHODS: Aim of this study was to evaluate the protective effect of polyphenol extracts on oxidative stress-induced damage in GC cell lines. Cell viability was evaluated by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay in well differentiated GC cell line MKN28 after oxidative stress induced by xanthine oxidase (XO) (25–100 mU/ml) in the presence of its substrate xanthine (X) (1 mM) for 2hours with and without a 3 hour-pre-treatment with green tea, apple and olive polyphenol extracts. Green tea and apple polyphenol extracts, whose main component is catechin, was used at following concentrations:10-8M;10-7M; 10-6M; 10-5M; 10-4M while olive polyphenol extract, whose main component is hydroxytyrosol, was used at following concentrations: 0.625 μg/ml, 1.25 μg/ml;2.5 μg/ml;5 μg/ml;10 μg/ml.All experiments were performed in triplicate. RESULTS: X-XO induced a significant dose-dependent reduction in cell viability (p<0.0001). The concentration of X (1 mM) and XO (75 mU/ml), which led to a 60% decrease in cell viability, was selected for further experiments. Pre-treatment with green tea, apple and olive polyphenol extracts significantly prevented X-XO induced damage to MKN 28 cells [max fold increase in cell viability >2.168 (p< 0.0001 ); >2.032 (p <0.0001); >1.886 (p <0.0001) vs X-XO, respectively]. CONCLUSIONS: Green tea, apple and olive polyphenol extracts prevent oxidative stress-induced damage in GC cell lines.
File in questo prodotto:
Non ci sono file associati a questo prodotto.