Diuretic activity of ethanol extract of Mirabilis jalapa (Linn.) leaf in normal male Wistar rats

Background: Ethanol extract of Mirabilis jalapa leaf (EEMJL) has been used in the folk medicine of Nigeria as diuretics without any scientific evidence. Aim: Ethanol extract of Mirabilis jalapa leaf at 200, 400 and 600 mg/kg body weight was investigated for diuretic activity in male Wistar rats. Setting: Fresh leaf of M. jalapa was collected from a farmland at the Alanamu area in Ilorin, Kwara State, Nigeria, authenticated and processed for the study. Methods: Thirty male rats (231.50 g ± 13.51 g) were assigned into five groups (A–E) of six rats each. Rats in group A (control) received 1.0 mL of physiological saline (the vehicle). Animals in groups B (positive control), C, D and E received 1.0 mL equivalent to 100 mg/kg body weight of furosemide, 200, 400 and 600 mg/kg body weight of EEMJL, respectively. All administrations were done by oral gavage. The animals were monitored for indicators of diuresis for 5 h using standard methods. Results: Ethanol extract of Mirabilis jalapa leaf dose-dependently increased ( p < 0.05) urine volume, urine concentrations of Na+, K+ and Cl − and decreased ( p < 0.05) the body weight of the animals. Ethanol extract of Mirabilis jalapa leaf increased the urine pH, saliuretic activity, saliuretic index, Na+ index, K+ index, Cl − index, diuretic action (diuretic index), kaliuretic index, Lipschitz value and percentage saline load excreted, whereas the latency of urination, natriuretic index, carbonic anhydrase inhibitory activity and carbonic anhydrase inhibition index were decreased. The EEMJL treatment-related changes in these parameters were essentially similar to those of the furosemide-treated animals. Conclusion: This study has thus validated diuretic activity of M. jalapa leaf with the 600 mg/kg body weight of EEMJL being the most effective.