Inhibition of rosmarinic acid on the apoptosis of vascular smooth muscle cells induced by hydrogen peroxide / 中国药理学通报

ABSTRACT

Aim To investigate the effects of rosmarinic acid on H2O2-induced apoptosis in rat VSMCs and its related mechanisms. Methods Flow cytometry was used to determine apoptotic rate of VSMCs. nuclear staining by acridine orange for morphologic change,MTT assay for cell viability and Western blot for expression of Bcl-2,Bax, fas and FasL. Results After being treated by H2O2(0,250,500,750 ?mol?L-1),apoptotic rate of VSMCs was 3.71%?0.56%,17.6%?6.92%,34.9%?2.55 %, and 85.6%?5.22% by FACS analysis,and VSMCs appeared nuclear condense and nuclear fragmentation after being treated by 500 ?mol?L-1 H2O2 for 24 hours,which were typical morphological changes of apoptosis. ① VSMCs treated with 500 ?mol?L-1 H2O2 for 24 hours had a significantly decrease on cell viability compared with control,and the apoptosis rate was increased to 35.7%?1.33%; Bcl-2 protein expression decreased,Bax protein expression increased, Bcl-2/Bax protein ratio decreased and Fas receptor and Fas ligand expression also increased.② Pre-incubation with rosmarinic acid(10, 20, 40 ?mol?L-1)for 30 min enhanced the cell viability, and decreased the apoptotic rate to 31.1%?1.38%,21.2%?1.18%,13.6%?0.51% in a dose-dependent manner. Moreover, Bcl-2/Bax protein ratio increased and Fas and FasL expression decreased. Conclusions ① Rosmarinic acid antagonizes H2O2-induced apoptosis of VSMCs. ② The antagonism of rosmarinic acid on apoptosis may be correlated with an increase Bcl-2/Bax protein ratio and a decrease expression of Fas and FasL protein.