Grape seed proanthocyanidin extract protects human lens epithelial cells from oxidative stress via reducing NF-кB and MAPK protein expression

PURPOSE Oxidative damage induced by H₂O₂ treatment can irreversibly damage the lens epithelium, resulting in cell death and cataract. Grape seed extract (GSE) is a widely consumed dietary supplement that has the capability to scavenge oxidants and free radicals. GSE contain 70%-95% standardized proanthocyanidins. The study described herein investigated the protective effect of Grape seed proanthocyanidin extract (GSPE) on H₂O₂-induced oxidative stress in human lens epithelial B-3 (HLEB-3) cells and the possible molecular mechanism involved. METHODS HLE-B3 cells exposed to different doses of H₂O₂ were cultured with various concentrations of GSPE and subsequently monitored for cell viability by the 4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptosis rate and ROS generation were detected by flow cytometric analysis. Expression of NF-кB/P65 and mitogen activated protein kinase (MAPK) proteins were measured by western blot. RESULTS GSPE clearly reduced H₂O₂ induced cell apoptosis and reactive oxygen species (ROS) generation and protected HLEB-3 cells from H₂O₂ induced oxidative damage. GSPE depressed H₂O₂-induced activation and translocation of NF-кB/p65. GSPE also depressed H₂O₂-induced phosphorylation of the p38 and c-Jun N-terminal kinase (JNK) proteins of the MAPK family at various time points studied. CONCLUSIONS GSPE could be useful in attenuation of H₂O₂-induced oxidative stress and the activation of NF-кB and MAPK signaling in HLE-B3 cells, which suggests that GSPE has a potential protective effect against cataractogenesis.