Biology and Medicine

Abstract

Evaluation of Diuretic Activity of Methanol Crude Extract of Thymus serrulatus Leaves and its Solvent Fraction in Mice

Amelework Eshetu, Eyasu Makonnen, Asfaw Debella, Netsanet Fekadu and Bekesho Geleta

Background: Thymus serrulatus is an indigenous plant to Ethiopia and used widely in the treatment of many illnesses including renal diseases and hypertension. The present study was undertaken to investigate the diuretic activity of the 80% methanol crude extract and solvent fractions of T. serrulatus leaves in saline-loaded mice. Methods: Swiss albino mice of either sex were divided into six groups (five animals in each group). The control group received normal saline (25 ml/kg) in 2% Tween 80, the reference group received hydrochlorothiazide (10 mg/ kg). Group-III to Group-XIV received the test substances at dose levels of 125, 250, 500, and 1000 mg/kg orally. At the end of the 5th hour, urine was collected and the total volume of urine excreted by each animal was recorded. Concentration of urinary Na+, K+, and Na+/K+ ratio were also determined. The acute toxicity test was conducted for the most active fraction of the crude extract. Results: The findings demonstrated that the crude methanol extract of T. serrulatus leaves and its n-butanol fraction have significant (P<0.01) diuretic activity. The n-butanol fraction, at the dose of 1000 mg/kg, displayed a pronounced diuretic activity (104.0%) which was greater than the reference drug. It also showed a good natriuretic activity (1.34). However, the chloroform fraction was observed to lack significant diuretic activity and effect on electrolyte excretion except at the highest test dose. Conclusion: The present findings indicate that the crude methanol extract of the leaves of T. serrulatus as well as its n-butanol fraction has significant diuretic effect with increased concentration of urinary electrolytes in mice. Further studies, however, should be carried out to come up with possible mechanism/s of action and look for the active component responsible for the diuretic effect.