Moringa stenopetala (Baker f.) Cufod. is a medicinal plant that has been used for the treatment of different ailments such as hypertension and diabetes in Ethiopia. This study aims to assess the diuretic activity of the aqueous crude extract and hot tea infusion of M. stenopetala leaves in saline-loaded rats. Male Wistar rats were divided into ten groups (n = 5). The control group received distilled water (5 mL/kg), whereas the reference group received Furosemide (10 mg/kg). Groups III-X orally received different doses of aqueous crude extract (62.5, 125, 250, and 500 mg/kg) and hot tea infusion (1, 2, 4, and 6 teaspoons [Tsp]) based on community use. Urine volume was recorded every hour until the end of the 5th hour, and total urine volume of each animal was calculated. The diuretic activity and diuretic action were determined based on the urine output. Additionally, concentration of urinary sodium, chloride, and potassium ions was determined. The urinary Na+/K+ ratio and carbonyl anhydrase activity (Cl-/(Na+/K+)) were also assessed. The findings verified that the aqueous crude extract as well as the hot tea infusion of the leaves of M. stenopetala possesses significant (P < 0.01) diuretic, natriuretic, and kaliuretic effects. The aqueous crude extract (125 mg/kg) and hot tea infusion (2 Tsp) displayed the highest diuretic activity (101% and 96%, respectively) comparable to the reference drug, Furosemide (10 mg/kg). They also displayed a good natriuretic activity. The aqueous crude extract and hot tea infusion revealed a significant Na+ urinary excretion (P < 0.001) and Na+/K+ ratio (P < 0.05) at all test doses. There was also a significant (P < 0.01) Cl- urinary excretion at all test doses of aqueous crude extract except 62.5 mg/kg and all test doses of hot tea infusion except higher doses (4 and 6 Tsp). Thus, the aqueous crude extract as well as the hot tea infusion of the leaves of M. stenopetala causes a plausible increase in the urine volume and concentration of urinary electrolytes in rats.
Keywords: Moringa stenopetala; diuretic activity; dose simulation; electrolyte excretion; rats; urine volume.