Abstract:

The present study investigated the protective effect of methanol leaf extract of Annona muricata (soursop) against bromate-induced kidney and liver damage in male albino Wistar rats. After acclimatization to laboratory conditions for 7 days, 36 rats were randomly and equally assigned to 6 groups. Five groups received bromate ion at a dose of 60 mg/kg body weight (bwt) via gavage. Bromate-exposed rats in the negative control (group II) were untreated, while 3 groups of bromate-exposed rats (III, IV, and V) were co-administered graded doses of Annona muricata extract (200, 300, and 500 mg/kg bwt, respectively). Rats in the normal control (group I) received saline only, while rats in group VI were given the standard liver-protective drug silymarin at a dose of 100 mg/kg bwt. All treatments were given via orogastric tube, and all groups were permitted ad libitum access to standard rat chow and water. At the end of 21 days, the rats were sacrificed under chloroform anesthesia, and blood samples were collected through cardiothoracic puncture, after which the liver and kidneys were excised. Sections for histology were preserved in formol saline, while the remaining sections were kept deep-frozen before analysis. Serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total and direct bilirubin (Tbil and Dbil), lactate dehydrogenase (LDH), creatinine, blood urea nitrogen (BUN) and electrolytes, were determined using standard biochemical procedures. Glutathione peroxidase and catalase were assayed in liver and kidney tissue homogenates. Histopathological examinations were also carried out on the liver and kidney.
The results obtained showed that bromate ion induced toxicity in the experimental animals, as indicated by significant (p < 0.05) elevations in serum levels of ALT, AST, Tbil and Dbil., LDH, creatinine, and BUN, especially in the negative control group (II) which received only bromate ion. Moreover, bromate induced significant decreases in tissue GPx activities. However, these changes were reversed by the leaf extract of Annona muricata to levels largely comparable with those of the standard drug silymarin, although there were no significant changes in serum electrolyte levels. These results indicate that the methanol extract of Annona muricata exerted a protective effect against bromate-induced kidney and liver lesions in albino rats, most likely through its antioxidant potential.