Ethyl acetate extract of Wedelia chinensis inhibits tert-butyl hydroperoxide-induced damage in PC12 cells and D-galactose-induced neuronal cell loss in mice

Background: Wedelia chinensis is traditionally used as a hepatoprotective herb in Taiwan. The aim of this study was to evaluate the neuroprotective potential of W. chinensis. Methods: An ethyl acetate extract of W. chinensis (EAW) was prepared and analyzed by HPLC. The neuroprotective potential of EAW was assessed by tert-butylhydroperoxide (t-BHP)-induced damage in PC12 cells and D-galactose-induced damage in mouse cortex. Results: EAW exhibited potent radical scavenging property and highly contained luteolin and wedelolactone. EAW decreased t-BHP-induced reactive oxygen species (ROS) accumulation, cytotoxicity and apoptosis in PC12 cells. EAW and its major constituents blocked t-BHP-induced cytochrome C release and Bcl-2 family protein ratio change. EAW and its major constituents increased the endogenous antioxidant capacity evaluated by the binding activity assay of nuclear factor E2-related factor 2 (Nrf2) to antioxidant response element (ARE) and nuclear translocation of Nrf2 respectively in PC12 cells. Finally, EAW inhibited D-galactose-induced lipid peroxidation, apoptosis and neuron loss in the cerebral cortex of mice. Conclusion: These results demonstrate that W. chinensis has neuroprotective potential through blocking oxidative stress-induced damage and that luteolin and wedelolactone contribute to the protective action.