Abstract:

Abstract:Objective
To observe the effect of Ciwujianoside B(C-B) on apoptosis induced by hydrogen peroxide (H₂O₂) in cardiomyocytes and the expressions of its related regulating proteins,and clanify  the inhibitory effect of C-B on apoptosis induced by injury of oxidative stress in cardiomyocytes.Methods The neonatal rat cardiomyocytes were primary cultivated and the cells which beat autonomously well were randomly divided into normal control group,H2O2 group,100  mg•L^-1 C-B group and 200  mg•L^-1 C-B group.The cardiomyocytes were exposed to 200  μmol•L^-1H₂O₂ for 120 min to induce apoptosis.The morphological changes of cardiomyocytes were observed by microscope,the survival rate was detected by MTT.The apoptotic rate was analyzed by  flow cytometry labelled with AnnexinⅤ-FITC. The activity of Caspase-3 was detected by spectrophotometric method.The expressions of Caspase-3,PARP,Bcl-2 and Bax proteins were determined by immunoblotting.Results Compared with normal control group,the injuried cardiomyocytes were seen and the survival rate was decreased significantly (P<0.001),the apoptotic rate and Caspase-3 activity were increased (P<0.001 or P<0.01);the expressions of Caspase-3,Bax and the degradation of PARP were raised,and the expression of Bcl-2 was decreased in 200  μmol•L^-1H₂O₂ group.Compared with 200  μmol•L^-1H₂O₂ group,the injuried changes of cardiomyocytes were reduced,the survival rates were significantly increased (P<0.05 or P<0.01),the apoptotic rates were decreased (P<0.001);the activities of Caspase-3 were decreased significantly  (P<0.05 or P<0.01);the expressions of Caspase-3 and Bax were decreased,the degradation of PARP was attenuated,and the expressions of Bcl-2 were increased in 100 and 200  mg•L^-1 C-B groups.Conclusion C-B can obviously inhibit the apoptosis induced by H₂O₂ in cardiomyocytes,its mechanism may be related to the regulation of the expressions of the apoptosis-related  proteins Caspase-3,Bax and Bcl-2.

Key words: acanthopanax senticosus saponins;hydrogen peroxide;cardiomyocytes;apoptosis