Pterostilbene from Vitis coignetiae protect H2O2-induced inhibition of gap junctional intercellular communication in rat liver cell line

In this study, we identified various stilbenoids derived from Vitis coignetiae and investigated the protective effect of the main component, pterostilbene, against the inhibition of gap junctional intercellular communication (GJIC) induced by H2O2 in WB-F344 rat liver epithelial cells. We analyzed seven kinds of stilbenoids, pterostilbene, astringin, piceid, vitisin, rhaponticin, resveratrol, and rhapontigenin, using DAD/UV HPLC. Total stilbenoid content was 127.37 ± 19.29 mg/100 g dry weight. Pretreatment with 0.5, 1.0, and 5.0 μM pterostilbene for 24 h was shown to recover GJIC blocked by 500 μM H2O2. Pretreatment with pterostilbene prevented the inhibition of GJIC via the down-regulation of connexin43 phosphorylation by the inactivation of ERK1/2 and p38 MAP kinase. Our results suggest that pterostilbene may be a functional chemopreventative agent and that dietary exposure of pterostilbene would be helpful for improving health.