Potent Effects of Flavonoid-Rich Extract from Rosa laevigata Michx Fruit against Hydrogen Peroxide-Induced Damage in PC12 Cells via Attenuation of Oxidative Stress, Inflammation and Apoptosis

Oxidative stress-induced neuronal death has an important role in the pathogenesis of neurodegenerative disorders. The effects and mechanisms of action of the total flavonoids (TFs) from Rosa laevigata Michx fruit against hydrogen peroxide (H2O2)-induced oxidative injury in PC12 cells were investigated in this study. The results demonstrated that the TFs protected against cell apoptosis, DNA and mitochondrial damage caused by H2O2 based on single cell gel electrophoresis, in situ terminal deoxynucleotidyltransferase dUTP nick end labeling (TUNEL), flow cytometry and transmission electron microscope (TEM) assays. In addition, the TFs notably decreased cytochrome C release from mitochondria into the cytosol and intracellular Ca2+ levels, and diminished intracellular generation of reactive oxygen species (ROS). Furthermore, the TFs inhibited the phosphorylation levels of JNK, ERK and p38 MAPK as well as down-regulated the expressions of IL-1, IL-6, TNF-α, Fas, FasL, CYP2E1, Bak, caspase-3, caspase-9, p53, COX-2, NF-κB, AP-1, and up-regulated the expressions of Bcl-2 and Bcl-xl. In conclusion, these results suggest that the TFs from R. laevigata Michx fruit show good effects against H2O2-induced oxidative injury in PC12 cells by adjusting oxidative stress, and suppression of apoptosis and inflammation, and could be developed as a potential candidate to prevent oxidative stress in the future