Bergenin alleviates H2O2-induced oxidative stress and apoptosis in nucleus pulposus cells: Involvement of the PPAR-γ/NF-κB pathway

Bergenin is a C-glucoside of 4-O-methyl gallic acid with a variety of biological activities, such as antioxidant and anti-inflammatory. Herein, we investigated the involvement of bergenin in the protective effect against H2O2-induced oxidative stress and apoptosis in human nucleus pulposus cells (HNPCs) and the underlying mechanisms. HNPCs were cotreated with various concentrations of bergenin and 200 mu M H2O2 for 24 h. Cell viability was detected by Cell Counting Kit-8 and lactate dehydrogenase release assays. Reactive oxygen species (ROS) was evaluated utilizing 2',7'-dichlorofluorescein-diacetate. Superoxide dismutase (SOD) and catalase (CAT) activities and glutathione (GSH) levels were measured to assess oxidative stress. Apoptosis was evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling and caspase-3/7 activity assays. Expression of protein was determined by western blotting. Results indicated that treatment with bergenin significantly alleviated H2O2-induced viability reduction and ROS overproduction in HNPCs in a dose-dependent manner. Bergenin alleviated H2O2-induced oxidative stress in HNPCs by increased activity of superoxide dismutase and level of glutathione peroxidase. H2O2-induced apoptosis and activity of caspase-3/7 were also suppressed by bergenin treatment in HNPCs. Western blotting showed that H2O2-induced decrease in expression of peroxisome proliferator-activated receptor gamma (PPAR-gamma) and increase in nuclear factor kappa B (NF-kappa B) were inhibited by bergenin. However, the inhibitory effect of bergenin on H2O2-induced viability reduction, oxidative stress and apoptosis were noticeably abrogated in PPAR-gamma knockdown HNPCs. In conclusion, our results indicated that bergenin alleviates H2O2-induced oxidative stress and apoptosis in HNPCs by activating PPAR-gamma and suppressing NF-kappa B pathway.

Automated summary

Our study demonstrated that bergenin alleviated H2O2-induced oxidative stress and apoptosis in HNPCs by reducing ROS production, increasing antioxidant enzyme activities, and modulating PPAR-gamma and NF-kappa B pathways.