Geraniin is a diuretic by inhibiting the Na+:K+:2Cl- cotransporter, NKCC2.

This study was designed to determinate whether geraniin possesses diuretic activity and to elucidate the mechanism of action. Geraniin was extracted and purified from Geranium seemannii Peyr. Male Wistar rats were divided into four groups: 1) Control, 2) 75 mg/kg of geraniin, 3) 20 mg/Kg of furosemide, and 4) 10 mg/Kg of hydrochlorothiazide. Each treatment was administered by gavage every 24 h for 7 days. The urinary excretion of electrolytes and the fractional excretion of sodium (FENa) were determined. To uncover the molecular target of geraniin, Xenopus laevis oocytes were microinjected with cRNAs encoding the Na-Cl cotransporter (NCC) and the Na-K-2Cl cotransporter NKCC2 to functionally express these cotransporters. Geraniin significantly increased diuresis, natriuresis and calciuresis to a similar extent as was observed in the furosemide-treated rats. Consistent with the furosemide-like effect, in Xenopus oocytes, geraniin significantly reduced the activity of NKCC2, with no effect on NCC activity. In contrast with furosemide, the effect of geraniin on NKCC2 was irreversible, apparently due to its inhibitory effect on the heat shock protein 90. Our observations suggest that geraniin could have a potential role in the treatment of hypertension or edematous states. PMID: 29046296 [PubMed - as supplied by publisher]
Source: American Journal of Physiology. Renal Physiology - Category: Physiology Authors: Tags: Am J Physiol Renal Physiol Source Type: research