RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Gomphrena celosioides (Amaranthaceae) is a native medicinal plant found in Mato Grosso do Sul State that is used for treating urinary tract and kidney stones. This study aimed to evaluate the diuretic effects of ethanolic extract from G. celosioides (EEGC) on acute and extended diuresis to provide a pharmacological basis for its use in traditional medicine. AIM OF THE STUDY: To evaluate the diuretic and natriuretic activity of EEGC and its mechanism of action in an animal model. MATERIALS AND METHODS: EEGC (30, 100 and 300mg/kg) was orally administered in male Wistar rats, and urinary excretion was measured at intervals of up to 8h after administration. To evaluate participation of the nitric oxide (NO), prostaglandin and bradykinin pathways in its effect, respective inhibitors were also administered together with effectives doses of EEGC and compared with control groups. A 7-day model with daily administration and urine measurement was also carried out. RESULTS: Oral administration of doses of 100 and 300 significantly increased urine output after 8h compared to the control group. It was observed this effect is dependent on the NO, prostaglandin and bradykinin pathways because their inhibitors reduced the diuretic effects of EEGC. Moreover, after 7 days of treatment, the effect was sustained and a decrease in serum aldosterone was observed in the extract group. CONCLUSION: According to the results, G. celosioides extract showed diuretic and natriuretic effects associated with more than one mechanism of action. Considering that all diuretic drugs are currently available for the treatment of volume and electrolyte disturbances, especially hypertensive status, the present results may have clinical relevance and open new possibilities for the development of new natural diuretics from G. celosioides.