Cardioprotective effects of rosuvastatin and carvedilol on delayed cardiotoxicity of doxorubicin in rats

CONTEXT: Doxorubicin is widely used anti-neoplastic drug but has serious cardiotoxicity. Long-term cardioprotective effects of statin and carvedilol against delayed cardiotoxicity of doxorubicin was not well elucidated. OBJECTIVE: To evaluate long-term cardioprotective effects of co-administered rosuvastatin and carvedilol against chronic doxorubicin-induced cardiomyopathy (DIC) in rats. METHODS: Sixty-one rats were assigned to six groups: group I, control; group II, doxorubicin only (1.25 mg/kg, bi-daily, I.P.); group III, doxorubicin + rosuvastatin (2 mg/kg/day, P.O.); group IV, doxorubicin + rosuvastatin(10 mg/kg/day, P.O.); group V, doxorubicin + carvedilol (5 mg/kg/day, P.O.); group VI, doxorubicin + carvedilol (10 mg/kg/day, P.O.). Drugs were administered for 4 weeks (by week 4) and rats were observed without drugs for 4 weeks (by week 8). RESULTS: After 4 weeks discontinuation of drugs (week 8), group III showed higher +dP/dt (p = 0.058), lower -dP/dt (p = 0.009), lower left ventricular (LV) tissue malondialdehyde (MDA; p = 0.022), and less LV fibrosis (p = 0.011) than group II. Group IV showed similar results to group III. However, in group V and VI, carvedilol failed to reduce LV dysfunction, elevation of troponin or myocardial fibrosis, although group V showed lower LV tissue MDA (p = 0.004) than group II. DISCUSSION AND CONCLUSIONS: Myocardial injury and LV systolic/diastolic dysfunction at week 8 was alleviated by co-administered rosuvastatin, but not by carvedilol. It is unclear whether the cardioprotective effect of rosuvastatin is attributed to a suppression of oxidative stress induced by doxorubicin, because carvedilol did not exhibit a cardioprotective effect despite its antioxidant effects.