ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Siddha medicine literature claims that the Amaranthus spinosus Linn. (family: Amaranthaceae) whole plant possesses diuretic property. AIM OF THE STUDY: To evaluate the diuretic potential of Amaranthus spinosus aqueous extract (ASAE) in rats. MATERIAL AND METHODS: Different concentrations of ASAE (200, 500, 1000, 1500mg/kg), thiazide (10mg/kg) and vehicle were orally administered to rats (n=6 animals per group) and their urine output was collected after 24h. Volume, pH, Na(+), K(+) and Cl(-) concentrations of urine were estimated. RESULTS: ASAE produced increase in Na(+), K(+), Cl(-) excretion, caused alkalinization of urine, showed strong saluretic activity and carbonic anhydrase inhibition activity. These effects were observed predominantly at 500mg/kg dose and there was no dose-response relationship. CONCLUSION: Our study strongly suggests that the Amaranthus spinosus is acting as a thiazide like diuretic with carbonic anhydrase inhibitory activity which restates the claim as diuretic herb in Siddha medicine.