ABSTRACT

The biochemical and histological effects of Annona muricta leaf ethanol and water extracts in melamine-induced nephrotoxicity were evaluated in male albino rats aged 8- 10 weeks. Fifty six (56) albino rats were randomly selected into Groups A to G (n=8). Group A (vehicle control) received 7ml/kg b.w of 10% tween 80, Groups B to G were administered lOOOmg/kg b.w of melamine for 10 days. After 10 days, Group C was administered lOOmg/kg b.w standard reference drug allopurinol. Groups D and E were treated with 300 and 500mg/kg b.w of ethanol extracts respectively, while Group F and G were treated with 300 and 500mg/kg b.w ofwater extracts. Four animals in Groups C to G were sacrificed on day 15 and the remaining four were sacrified on day 22. The analysis of phytochemical constituents, acute toxicity test, serum non protein nitrogenous substances, serum electrolytes, and renal biopsy were done using standard procedures. Phytochemical analysis of the ethanol extract gave higher yield of flavonoids (120mg/g), alkaloids (90mg/g), tannin (1.36mg/g), reducing sugar (0.0248mg/g), and oxalate (0.77mg/g) while that of water extract yielded more of Saponin (7.90mg/g), Cyanogenic glycoside (1.73mg/g), and phytate (1.34mg/g). The oral acute toxicity test gave zero mortality at up to 5000mg/kg b.w for both ethanol and water extracts. Treatment with 300mg/kg b.w ethanol extracts caused a significant (P<0.05) decrease in serum creatinine, urea, calcium and magnesium while treatment with water extracts at 300mg/kg b.w resulted in significant (P<0.05) decrease in serum creatinine and urea when compared to nephrotoxic group that received melamine only. Both ethanol and water extracts at 500mg/kg b.w only resulted in significant (P<0.05) decrease in creatinine when compared to nephrotoxic group that received melamine only. The histology ofthe kidneys of albino rats administered lOOOmg/kgbw melamine only without treatment resulted in persistent dilation ofrenal tubule typical of occluded crystal deposition. Administration of 500mg/kg b.w of ethanol and water extracts to melamine-induced nephrotoxic rats resulted in persistent dilation of renal tubule coupled with many collapsed vessels of the glomeruli while treatment with 300mg/kg b.w of ethanol and water extracts were characterized by moderate tubular dilation, increased secretions in the tubules and few collapsed vessels of the glomeruli. The findings from this study suggest that renal impairment caused by melamine could be ameliorated at low dose of leaf extract of Annona muricata. Hence the leaf could be effective in the management ofrenal impairment.