Curcuma kwangsiensis Extracts Produced Antioxidant Effects Against Injury Induced by H2O2 on PC12 Cells

The radix of Curcuma kwangsiensis S. G. Lee & C. F. Liang (Zingiberaceae) is a traditional medicine in China, and used for treating qi stagnation and blood stasis. Previous chemical study showed it is rich in sesquiterpenoids and diarylheptanoids, similar to those in Curcuma longa L., which showed obviously protective effects against oxidative damage. However, the antioxidant and underlying mechanism of C. kwangsiensis has not been studied yet. In current study, the antioxidant activities of C. kwangsiensis extracts (ECWs), including 95 % EtOH extract (HCECW), 75 % EtOH extract (MCECW), methanol extract (MECW), dichloromethane extract (DECW) and petroleum ether extract (PECW), and their possible mechanisms, were studied on the model of H2O2-induced PC12 cell damage in vitro. The results showed different concentrations (1, 10, 50 µg/mL) of HCECW, MCECW and DECW could increase damaged PC12 cell viability significantly. In the extract-treated groups, the release rate of LDH significantly decreased, while SOD, CAT, and GSH markedly increased. In the meantime, the intracellular Ca2+ and cell apoptosis decreased significantly, while MMP increased and apoptosis morphology was clearly improved. Compared with the model group, they produced effects on up-regulating of Bcl-2, down-regulating of Bax and Caspase-3. Further, the chemical analysis of those five extracts by UPLC-DAD-Q-TOF-MS showed their major constituents were sesquiterpenoids and diarylheptanoids, indicating both of them presented in ECWs are antioxidant substances in this plant. This study provided an experimental basis for the future development of antioxidants from the genus Curcuma.