Protective Effects of an Ancient Chinese Kidney-Tonifying Formula against H₂O₂-Induced Oxidative Damage to MES23.5...

Oxidative damage plays a critical role in the etiology of neurodegenerative disorders including Parkinson's disease (PD). In our study, an ancient Chinese kidney-tonifying formula, which consists of Cistanche, Epimedii, and Polygonatum cirrhifolium, was investigated to protect MES23.5 dopaminergic neurons against hydrogen peroxide- (H₂O₂-) induced oxidative damage. The damage effects of H₂O₂ on MES23.5 cells and the protective effects of KTF against oxidative stress were evaluated using MTT assay, transmission electron microscopy (TEM), immunocytochemistry (ICC), enzyme-linked immunosorbent assay (ELISA), and immunoblotting. The results showed that cell viability was dramatically decreased after a 12 h exposure to 150 μM H₂O₂. TEM observation found that the H₂O₂-treated MES23.5 cells presented cellular organelle damage. However, when cells were incubated with KTF (3.125, 6.25, and 12.5 μg/ml) for 24 h after H₂O₂ exposure, a significant protective effect against H₂O₂-induced damage was observed in MES23.5 cells. Using ICC, we found that KTF inhibited the reduction of the tyrosine hydroxylase (TH) induced by H₂O₂, upregulated the mRNA and protein expression of HO-1, CAT, and GPx-1, and downregulated the expression of caspase 3. These results indicated that KTF may provide neuron protection against H₂O₂-induced cell damage through ameliorating oxidative stress, and our findings provide a new potential strategy for the prevention and treatment of Parkinson's disease.