Studies On Neuroprotective Activities Of Flavonoids Extracts From Cuscuta Chinensis

Cuscuta chinensis Lam, a member of the scammony, has been used as one of the primary Chinese tonic herbs with a history of thousands of years. It functions in tonifying both kidney-yang and yin, preserving essence, preventing frequent micturation, improving vision and arresting diarrhea.The direct oxidative stress model was simulated by using PC12 cells injured by H2O2. The effects of the flavonoids extract from Cuscuta chinensis (CF) on cell viability was investigated by MTT assay. The morphological changes were observed by hoechst 33258 staining assay, and the apoptosis rate of PC 12 cells was detected by propidium iodide stain flow cytometry (FCM). The ability of clearing the free radicals generated by DPPH was also investigated. The results indicated that CF could increase the cell viability, decrease the apoptosis rate. CF could dose-dependently clear the DPPH radicals.The apoptotic model of Parkinson's disease in vitro was made by rotenone-induced cytotoxicity in SH-SY5Y cells. The neuroprotective effect of CF was investigated using this model. The results showed that cell viability decreased, the apoptotic rate was increased significantly after the treatment of rotenone for 24 h. Further mechanism investigation showed that the treatment of rotenone caused increase of cellular reactive oxygen species (ROS), decrease of mitochondrial membrane potential (MMP), the decrease of GSH and Bcl-2. It was suggested that the rotenone induced damage involved the enhancement of cellular oxidative stress which led to the decrease of MMP, the depleting of cellular GSH, and the apoptosis of cells. The neuroprotective effect was observed pre-treatment with CF. It was shown that CF could attenuate the changes caused by treatment with rotenone. Compared with group treated with rotenone, the CF protective group showed higher cell viability, sustained cell mitochondrial potential (MMP), higher level of Bcl-2 and GSH, lower level of cell ROS, lower level of apoptosis cell rate. The protective effects of CF against rotenone-induced cell death may be ascribed to its antioxidative and free radical scavenging properties via diminishing the generation of ROS and sustained the MMP. These data indicated that CF might provide a useful therapeutic strategy for the treatment of progressive neurodegenerative disease such as Parkinson's disease.