The Beneficial Effect of Melatonin on Gentamicin-induced Liver Injury in Rats.

Background: Gentamicin is a potent, broad-spectrum aminoglycoside antibiotic used in the treatment of many infections. Gentamicin can induce hepatotoxicity through oxidative stress and apoptosis. Since melatonin has antioxidant properties, its protective effects on liver tissue damage were evaluated in this study. Objective: The aim of this study was to conduct our investigation to assess the hepatoprotective effects of melatonin in rats treated with gentamicin. Methods: Forty eight adult male Wistar rats were used. The animals were randomly distributed into six groups of equal size. During the period of 11 days, three control groups of rats were daily injected i.p. with the vehicle or with melatonin at a dose of 5 or 10 mg/kg. The gentamicin group was injected with gentamicin at a dose of 80 mg/kg during 8 days and vehicle for 11 days. The other two experimental groups were administered gentamicin (80 mg/kg during) 8 days and melatonin (doses of 5 and 10 mg/kg) 3 days before and 8 days concomitantly with melatonin. Obtained liver sections were analyzed using qualitative, semi-quantitative, and stereological analysis. Results: Gentamicin expressed hepatotoxic effects inducing congestion of lobular blood vessels, hydropic degeneration of periportal hepatocytes and mononuclear infiltration in the portal tract. Treatment with gentamicin resulted in an increase in the Vv of blood vessels, a decrease in the Vv of hepatocytes, and a decrease in the glycogen content in all three lobular zones. Melatonin administration reduced the liver alterations induced by gentamicin; the higher dose had a more potent protective effect. Conclusion: Melatonin has a beneficial effect on gentamicin-induced liver damage and the effect is dose-dependent.