Apple polyphenols extract has a positive effect on vascular oxidative stress and endothelium function. - GreenMedInfo Summary

SCOPE: We aimed examining apple polyphenols' effect on uricemia and endothelial function in a sample of overweight subjects.

METHODS AND RESULTS: This was a two-phases study. In vitro experiment aimed to evaluate apple polyphenols' ability to lower uric acid in comparison with allopurinol. In vivo study consisted in a randomized, double-blind, parallel placebo-controlled clinical trial involving 62 overweight volunteers with suboptimal values of fasting plasma glucose (100mg/dL≤FPG≤125mg/dL), randomized to 300mg apple polyphenols or placebo for 8 weeks. Apple polyphenols extract inhibited xanthine oxidase activity, with an IC50 = 130±30 ng/mL; reducing uric acid production with an IC50 = 154±28 ng/mL. During the trial, after the first 4 weeks of treatment, FPG decreased in the active treated group (-6,1%,P<0,05), while no significant changes were observed regarding the other hematochemistry parameters. After 4 more weeks of treatment, active-treated patients had an improvement in FPG compared to baseline (-10,3%,P<0,001) and the placebo group (P<0,001). Uric acid (-14,0%,P<0,05 vs baseline; P<0,05 vs placebo) and endothelial reactivity (0,24±0,09,P = 0,009 vs baseline; P<0,05 vs placebo) significantly improved too.

CONCLUSION: In vivo, apple polyphenols extract has a positive effect on vascular oxidative stress and endothelium function and reduce FPG and uric acid by inhibiting xanthine oxidase, as our in vitro experiment attests. This article is protected by copyright. All rights reserved.