Phytochemical Screening and Evaluation of the Diuretic Activity of Aqueous Methanol Extract from Aerial Parts of Mentha viridis Linn (Labiatae) in Albino Rats

Purpose: To evaluate the diuretic effect of the aqueous methanol extract of Mentha viridis Linn (Labiatae) in Albino rats. Methods: The aqueous-methanol extract of Mentha viridis was administered to experimental rats at doses of 30, 50 and 100 mg/kg, (i.p.) Furosemide 10 mg/kg (i.p.) and normal saline were used as reference drug and control, respectively. Diuretic effect was examined immediately after injecting the drugs and on an hourly basis by measuring the urine volume of the rats, sodium and potassium content and pH of the urine, comparing with that of the control. Preliminary phytochemical analysis of the extract was carried out to determine major constituents. Results: The extract induced diuretic effects and induced electrolytes excretion in a dosedependent manner in comparison with control. The extract (100 and 50 mg/kg) significantly (p < 0.01) increased the volume of urine in comparison to control group. Excretion of potassium and sodium also significantly (p< 0.05) increased following extract administration. However, there was no significant change in the pH of urine samples of the extract-treated group compared with control. The diuretic effect of extract was comparable to that of the reference drug (furosemide). Phytochemical analysis revealed the presence of alkaloids, flavonoids, tannins and saponins. Conclusion: The results indicate that the aqueous-methanol extract of Mentha viridis produced a diuretic effect that was comparable with that of the reference diuretic, furosemide, thus lending support for the traditional use of Mentha viridis as a diuretic agent.