Cisplatin is a potent chemotherapeutic agent, widely used in treatment of cancer. Melatonin, body hormone secreted by the pineal gland, has anti inflammatory and antioxidant characters. This study was done to evaluate the protective role of melatonin on cisplatin-induced hepatotoxicity in rats.

Materials and Methods: Forty rats were divided into four groups : group I(control group) in which, the animals received no drug), group II ( melatonin group) receiving melatonin (4mg/kg i.p. for 10 days), group III (cisplatin group) receiving (single dose of 7 mg/kg), and group IV (melatonin/cisplatin group) receiving melatonin for 10 days+ cisplatin with a single dose on the 5th day of experiment. Drugs were given by intraperitoneal injection. At the end of experiment, blood samples were obtained from the tails of animals for biochemical study then all rats were sacrificed and livers were dissected out for histological study.

Results: Cisplatin increased liver enzymes (ALT, AST). Cisplatin induced histopathological changes such as vaculation of hepatocytes, sinusoidal dilatation, congestion of central and portal veins, and inflammatory cell infiltration. Cisplatin significantly decreases PAS reaction in hepatocytes and increases collagen fiber deposition. Melatonin administration significantly ameliorated these changes.

Conclusion: melatonin with its antioxidant and anti-inflammatory properties can be recommended as a promising medication in treatment of cisplatin induced hepatotoxicity in cancer patients.