Influence of steroidal glycosides from Cynanchum auriculatum on antioxidant indicators in H2O2-damaged PC12 cells

The root of Cynanchum auriculatum Royle ex Wight is a traditional Chinese medicine, which is rich in C₂₁ steroidal glycosides by phytochemistry research. In this study, the antioxidant effect of 27 C₂₁ steroidal glycosides isolated from the root of C. auriculatum by our group was evaluated using the H₂O_2-treated PC12 cells. As the result, all tested compounds altered the activities of lactate dehydrogenase, superoxide dismutase, catalase and glutathione peroxidase at concentrations as low as 1 μM in H₂O_2-treated PC12 cells. They also decreased the levels of intracellular reactive oxygen species and Ca²⁺. Further, the correlation between their structural features described by molecular descriptors and the indicators of bioactivity was analyzed by partial least squares analysis, displaying those six bio-indicators were positive correlated with 13 molecular descriptors and providing some guidance for further study of relationships between steroid structure and antioxidant activity.