Role of exogenous melatonin on adriamycin-induced changes in the rat heart.

Aim: The protective effect of melatonin on adriamycin (ADM)-induced car - diotoxicity was investigated in the rat heart. Melatonin is a pineal hormone with free radical scavenging activity on oxidants; therefore it may decrease the ADM-induced oxidative stress and cardiotoxicity so that therapeutic efficacy might be enhanced. Materials and Methods: Wistar rats in 4 groups were treated with saline (control), mela - tonin (MEL), adriamycin (ADM) and melatonin plus adriamycin (MEL+ADM). Results: Adriamycin given at a single dose of 15 mg/kg significantly increased lipid peroxida - tion products as measured by thiobarbituric acid reactive substances (TBARS). Melatonin (5 mg/kg bw) given 2 days before and 7 days after ADM treatment reduced TBARS level. Adri - amycin significantly reduced superoxide dismu - tase activity which was elevated by melatonin treatment. Additionally, ADM significantly in - creased catalase enzyme activity while mela - tonin normalized the ADM induced alteration in activity of catalase. Conclusions: The combined use of ADM and melatonin reduces the threat of cardiomyopathy. Melatonin seems to hold promise as a therapeu - tic treatment and can be recommended as an adjunct in antitumor therapy as a safe and effec - tive protection against acute ADM-induced car - diotoxicity.