A preliminary study of the protective effects of daidzein against cardiotoxicity induced by doxorubicin

Objective To explore the protective effect of daidzein against myocardial injury induced by doxorubicin and related mechanisms. Methods SD rats were randomly divided into four groups: a Ctrl group, a Daid group, a Dox group and a Daid+Dox group. After intervention for six weeks, the ratio of heart weight to body weight and body length to tail length of the rats were measured. The activity of serum lactate dehydrogenase (LDH) and creatine kinase (CK) were detected by colorimetry. The structure of myocardial tissue and expression of Caspase-3 protein were detected by H-E staining and immunohistochemistry. Then, the dihydroethidium (DHE) staining was used to measure the expression of DHE fluorescence in rate cardiomyocytes H9C2 in different groups. Their levels of Caspase-3 were examined by Western blot. Results Compared with the Ctrl group, Dox treatment increased the ratio of heart weight to body weight and decreased the ratio of body length to tail length, without statistical difference between the two groups (P>0.05). The activities of LDH and CK were enhanced in the Dox group, compared with those in the Ctrl group (P<0.01), while the above indexes in the Daid+Dox group were significantly lower than those in the Dox group (P<0.01). The Dox group presented disordered and disintegrated myocardial fibers, and increased apoptosis, while the above conditions were significantly improved in the Daid+Dox group. Furthermore, the fluorescence expression of DHE and the expression of Caspase-3 protein were significantly enhanced after DOX treatment, while the above changes were reversed in the Daid+Dox group (P<0.01). Conclusions Daidzein can inhibit oxidative stress and reduce cell apoptosis against cardiotoxicity induced by doxorubicin.