ABSTRACT
BACKGROUND: Croton macrostachyus (Euphorbiaceae) extract is a folk medicine traditionally used for treating a number of disorders, including edematous conditions. The present study aimed to evaluate the diuretic effects of aqueous and 80% methanol leaf extracts of Croton macrostachyus in saline-loaded rats. METHODS: Rats of either sex were randomly assigned into eight groups of eight animals per group. The animals were treated with vehicle (distilled water), standard (furosemide 10 mg/kg), and three doses (100, 200, and 400 mg/kg) of aqueous and 80% methanol leaf extracts after loading of normal saline (15 mL/kg). Then, urine volume, electrolyte concentration, and pH were measured as parameters of evaluation. Concentrations of urinary Na+ K+, and Cl- were determined and Na+:K+ and Cl-:Na+ + K+ ratios calculated to reveal possible mechanisms. RESULTS: The aqueous extract at 200 mg/kg had produced significant diuresis by hour 3, while the same dose of 80% methanol extract had produced substantial diuresis by the end of hour 4. Both extracts at 400 mg/kg produced significant diuresis from hour 2 to hour 5. In terms of effect on electrolysis, 400 mg/kg aqueous extract produced significant natriuresis, and a kaliuresis effect was observed for both extracts at higher doses and 200 mg/kg aqueous extract. CONCLUSION: The findings collectively indicated that both aqueous and 80% methanol extract showed significant diuretic activity, thereby justifying the plant's traditional use as a diuretic agent.