Antioxidative effects of melatonin in protection against renal tubular damage caused by fumonisin [histological, histochemical and electronmicroscopical studies]

ABSTRACT

Melatonin is the chief secretory product of the pineal gland and has a very potent antioxidant activity. This study was designed to evaluate the effects of the mycotoxin fumonisin on renal tubular damage and protective role of melatonin to reduce this effect. A total of 48 female albino rats weighing [100-140 g] were used in this study. The animals were divided into six groups, each group contained 8 rats. The first group served as control. The animals of the second group were fed ration contaminated with fumonisin [100 mg/kg diet]. The third group of rats were fed ration contaminated with fumonisin [200 mg/ kg diet]. The fourth group was given daily interperitoneal injection of 10 mg/ kg melatonin and fed ration contaminated with fumonism [100 mg/ Kg diet]. The fifth group was given daily interperitoneal injection of 10 mg/kg melatonin and fed ration contaminated with fumonisin [200 mg/kg diet]. The sixth group was given melatonin only at a dose level of 10 mg /kg. The rats were treated for one month Histological effects in kidney were demonstrated in the form of vacuolar degeneration in tubular epithelial cells with degenerated and pyknotic nuclei in animals fed ration contaminated with fumonisin [100 mg/kg diet], markedly degenerated tubules and glomerular degeneration were noticed in group of rats treated with fumonisin [200 mg/kg diet]. Histochemical results showed marked diminution of protein content, mucopolysaccharides and increase in alkaline phosphatase activity. Quantitative DNA image analysis [Leica image] showed that the kidney contained 12.15% aneuploid cells in the group of rats fed fumonisine at dose level of 200 mg/kg diet. No pathological, histochemical or ultrastructural changes could be noticed in rats treated with melatonin only. Ultrastructural changes were observed in animals fed ration contaminated with fumonisin in the form of shrinkage and degeneration of nuclei. The mitochondria were condensed, fragmented and variable in size and shape. The endoplasmic reticulum was fragmented. The treatment of rats with melatonin along with fumonisin resulted in an improvement in histolgical picture as well as histochemical parameters and ultrastructural changes