Potential natriuretic effect of jungia polita in rats

Abstract

Jungia polita Griseb. (Asteraceae-Multisieae) is popularly known as “zarzaparrilla” or “viña”. This shrub species is used in argentine folk medicine as diuretic, anti-sclerotic, hypotensive, and also for skin affections; antihyperlipidemic, bradicardic and depurative. Infusion (10%) of the aerial parts was prepared, separated by filtration and the aqueous extract was concentrated and lyophilized to preserve it. Orally administration of Jungia polita up to 2g/kg produced no mortality and visible signs of delayed toxicity 14 days post-treatment. This study was designed to determine the natriuretic activity of Jungia polita lyophilized extract (JPLE). The test was performed as described by Lipschitz et al. The experiments were approved by the local Committee CICUA (Protocol F-405/22). Wistar rats (150-180 g) were employed. The animals, randomly assigned into groups (n=6-8), were deprived of food for 18 hours prior to starting the experiments and had free access to water. The test groups were administered with different doses of JPLE (250 or 500 mg/kg, orally). Reference group received Furosemide (10 mg/kg, intra-peritoneal). Control group received only the vehicle (50 ml/kg, orally). Immediately after administration, rats were paired and placed in metabolism cages. At the end of the experiments, the animals were euthanized by inhalation of carbon dioxide. Urinary volumetric excretion (UVE), urine chemical parameters, urine Na+ and urine K+ were measured in 3-hour diuresis. All values were expressed as the mean ± SEM. Graph Pad Prism was used for the statistical analysis and p values less than 0.05 were considered statistically significant. Student’s t-test was performed to evaluate the differences between the control and the experimental samples. Lot treated with JPLE showed natriuretic activity between 250 mg/kg doses (urine Na+ (mEq/L): 17.13±5.52 vs. control: 9.01± 2.65; p<0.05) and 500 mg/kg doses (urine Na+ (mEq/L): 14.91±4.67 vs. control: 9.01±2.65; p<0.05). The urinary K+ showed significant differences for the lot treated with 500 mg/kg JPLE [urine K+ (mEq/L): 66.79±9.25 vs. control: 50.30±10.23; p<0.05]. Non-significant differences were observed with 250 mg/kg JPLE [urine K+ (mEq/L): 51.09±24.45 vs. control: 50.30± 10.23; p>0.05]. The lot treated with JPLE (500 mg/kg) showed diuretic activity between 45 min (UVE: 20.06±8.04 vs. control: 4.84± 1.69; p<0.01) and 180 min (UVE: 82.95±8.92 vs. control: 52.74±6.03; p<0.001). Urine samples presented normal chemical parameters in all the cases: urinary density and pH were similar to controls. The data reported in this work indicate that the infusion of J. polita showed diuretic activity (0.59), compared to furosemide, a loop diuretic potent. Further investigations are necessary prior to their recommendation for use as natriuretic.