Chronic diuretic effect of the water extract of Spergularia purpurea in normal rats

The purpose of this study was to examine the chronic diuretic effect of the water extract of the whole plant of Spergularia purpurea (SP) at different doses (100, 200 and 400 mg/kg) in normal rats. Daily oral administration of the water extract was tested for 4 weeks. Urinary water and electrolytes excretion were determined weekly. Oral administration of the water extract at different doses produced a significant and dose-dependent diuresis and increase in electrolytes excretion. The highest dose (400 mg/kg) of the water extract of SP enhanced urine output from 7.15 +/- 0.42 ml/24 h at the start to 23.01 +/- 0.75 ml/24 h after 4 weeks (p < 0.001). It also produced significant increase in urinary excretion of Na+ (P < 0.01), K+ (P < 0.01) and Cl- (P < 0.01). Chronic treatment with SP decreased significantly urine osmolality (P < 0.01 vs. control), while a slight increase in glomerular filtration rate was also observed (P < 0.05) for both doses of water extract (100 and 400 mg/kg). It is concluded that the water extract of whole plant of SP has a significant diuretic effect in rats. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.