An in vivo study on the diuretic activity of Holarrhena antidysenterica

Abstract

Holarrhena antidysenterica is used as diuretic in traditional medicine. The aim of this study was to evaluate the crude extract of H. antidysentrica seeds (Ha.Cr) and its fractions, n-hexane (Ha.Hx), n-butanol (Ha.Bu) and aqueous (Ha.Aq), for their diuretic effect in Wistar rats and to investigate whether the activity is concentrated in any of the fractions. Wistar rats kept on fasting for 24 h with water ad labium, divided into normal, positive control and treated groups were orally given normal saline (20 ml/kg), hydrochlorothiazide (HCT; 10 mg/kg) and different doses of the plant material, respectively. Immediately after dosing, the rats were housed in the metabolic cages. The urine was collected at 2 h interval for 6 h and volume, pH and electrolytes levels were measured. Ha.Cr caused dose-dependent (30 and 100 mg/kg) increase in urine output, indicating the diuretic effect. In addition, Ha.Cr increased urine contents of Na+ and K+, suggesting that the diuretic effect is mediated through increased electrolyte excretion. Similarly, the reference drug, HCT (10 mg/kg), increased urine volume and Na+ and K+excretion. None of the resultant fractions exhibited diuretic effect comparable to that of the parent crude extract. Ha.Hx was devoid of diuretic effect, Ha.Bu exhibited a mild diuretic effect at 30 mg/kg, whereas, Ha.Aq caused a significant increase in urine output only at 100 mg/kg, indicating that the diuretic activity is distributed among fractions but in an order of increasing polarity of the solvent. The enhanced diuretic effect in the crude extract as compared to any individual fraction is suggestive of the existence of additive and/or synergistic effect in the crude extract. This study shows the presence of diuretic activity in the H. antidysentrica possibly mediated through its saluretic effect, which rationalizes its medicinal use as diuretic. Key words: Holarrhena antidysenterica, diuretic, rats, Na+, K+.