Methanolic extract of Garcinia kola elicits diuretic activity with alteration in circulating electrolyte concentration in male Wistar rats

Abstract

Objective: Garcinia kola is a kolaviron-containing nut native to tropical African and cultivated extensively in the new world tropics. Several studies have reported its effects on body weight and reduction in body fat without undesirable side effects as well as on gastric secretion. This study was designed to investigate the diuretic activity of methanolic extract of Garcinia kola (MEGCO) in male Wistar rats.  Design and Method: Adult male Wistar rats were randomly allotted into control (distilled water, po), Furosemide (po), MEGCOA (200 mg/ kg), MEGCOB (400 mg/ kg), MEGCOC (600 mg/ kg), groups with 5 rats/group. The extract was prepared as previously described and the treatment lasted for 4 weeks. Urine electrolytes, serum electrolytes, serum uric acid, urea and creatinine as well as liver ALT and AST were assayed using standard colorimetric method. Urine volume and diuretic indices were also monitored. Results: Treatment of all rats with different doses of Garcinia kola did not significantly alter body weight but increased kidney weight (400 mg and 600 mg/kg doses) and increased urine volume, urine Na+, K⁺ and Cl^- concentration,  did not alter serum Na⁺, but  600 mg/kg of MEGCO increased serum K⁺ and Cl- concentration. In addition, 600 mg/k of MEGCO increased hepatic ALT but not AST activity, increased serum creatinine, urea and uric acid concentration when compared with control and furosemide-treated groups. Conclusion: The present study demonstrates that methanolic extract of Garcinia Kola, particularly 600 mg/kg dose causes diuresis, natriuresis and kaliuresis, but put the animals at risk of renal toxicity and electrolyte imbalance.