Protective effect of flos puerariae flavonoid on adriamycin-induced toxic myocarditis / 中国生化药物杂志

ABSTRACT

Objective To investigate the protective effect of flos puerariae flavonoid on adriamycin (ADR)-induced toxic myocarditis and its mechanisms from morphological,biochemical and molecular levels.Methods 96 healthy Kunming male mice were randomly divided into 6 groupsnormal control group,ADR model control group,ADR+low dose of flos puerariae flavonoid group(50 mg/kg),ADR +middle dose of flos puerariae flavonoid group(100 mg/kg),ADR +high dose of flos puerariae flavonoid group(200 mg/kg),and Vit E positive control group(40 mg/kg),16 in each group.The drugs were orally administered for consecutive 15 d and the model of toxic myocarditis was induced by intraperitoneal injection of ADR(3 mg/kg)in mice from day 2,one time every other day,for 7 times Colorimetry was used to measure the changes of marker enzymes about myocardial injury and inducible nitric oxide synthase(iNOS)activity in serum and tissue;immunohistochemical method was adopted to detecte the expression of myocardial apoptosis related proteins Bax and bcl-2;HE staining was conducted to observe the pathological changes of cardiac structure.Results Compared with normal control group,ADR(3 mg/kg,ip,7 times)induced the elevation of serum creatine kinase (CK),lactate dehydrogenase (LDH),aspartate transaminase(GOT)and iNOS activity increased significantly in mice(P<0.01).Meanwhile myocardial superoxide dismutase(SOD)activity decreased, and the malondialdehyde(MDA)content increased(P<0.01).Myocardial cell apoptosis in mice increased significantly,and the apoptosis rate was(40.5 ± 5.2)%;the expressions of Bax and Bcl-2 were significantly increased(P<0.01),However,the Bcl-2/Bax ratio decreased.The flos puerariae flavonoid (50,100,200 mg/kg,ig,15 d)and Vit E positive control group could reverse the changes induced by ADR,decrease serum CK,LDH,GOT and iNOS activities,increased myocardial SOD activity,lower MDA content and the expression of bax protein,and elevated Bcl-2/Bax ratio,in a dose-dependent manner.Light microscopy confirmed that flos puerariae flavonoid significantly alleviated the changes of myocardial microstructure.Conclusion ADR could induce myocardial cell apoptosis and lead toxic myocarditis in experimental mice.The flos puerariae flavonoid has protective effect on ADR-induced myocardial injury and the mechanism may be related to elevating myocardial SOD activity and anti-lipid peroxidation,inhibiting the expression of Bax protein and adriamycin-induced cardiomyocyte apoptosis.