Aflatoxin induced renal toxicity in Albino rats and the ameliorative effect of green tea aqueous extract: Histological, Morphometric and Immuno-histochemical Study

Tea is the most common drink worldwide besides water. It is rich in antioxidant polyphenolic flavonoids. Further, it has anti-apoptotic, anti-inflammatory, and autoantigen-inhibitory properties. To evaluate the effects of oral administration of aqueous extract of green tea against experimental aflatoxicosis on the renal tissues of adult male albino rats. Twenty five adult male rats were included and they were divided equally into 5 groups: Group 1 (aflatoxin group): the rats received aflatoxins (2.5 mg/kg diet for 15 days), group 2 (aflatoxins and green tea aqueous extract group) for 15 days, group 3, the rats received aflatoxins for 15 days and aqueous extract of the green tea for 30 days, group 4 (green tea aqueous extract group) and group 5(control negative group). Detailed non-traditional histological and morphometrical analyses for renal tissues stained with Hematoxylin and Eosin, Masson's trichrome stain, Periodic Acid Schiff’s (PAS), Alizarin red S stains and immunohistochemical detection of Ki-67 were done. The main observed renal lesions in rats received aflatoxins were dilatation of the renal pelvis, increases in glomerular areas (GA), widening of Bowman's spaces and necrosis of the renal lining epithelium and proliferation of fibrous connective tissues. Morphometric analysis revealed the presence of significant difference between group I and the other experimental groups. Meanwhile, groups 2 and 3 revealed a significant improvement in the histological changes and decrease in most of parameters. The highest percentage of PAS positive reaction was significantly found in group 4. Quantitative analysis of positive reactions of Ki-67 revealed the highest positive immunohistochemical reactions were detected in group 1 which significantly different in groups 4 and 5. In conclusion, green tea has a protective effect against the adverse effects of aflatoxins on renal tissues evidenced by improvement of histopathological alterations and regulation of Ki-67 expressions.