Antidiuretic Activity of the Methanol Extract of Aporusa lindleyana Wight (Euphorbiacea) Baillon in Rats

Abstract

Purpose: To determine the diuretic activity of Aporusa lindleyana in rats following its claimed use in Sri Lankan traditional medicine.Methods: Three doses (500, 1000 and 1500 mg/kg) of the methanol extract (ME) of Aporusa lindleyana (Leaf and bark in 5:1 ratio) were orally administered to female, adult Sprague Dawley rats. Furosemide, vasopressin (antidiuretic hormone) and distilled water were used as diuretic reference, antidiuretic reference and control, respectively. Urine output was recorded up to 6 h at hourly intervals. To investigate the mode of action, pH, specific gravity, conductivity, total dissolve solids, Na+, K+, Ca2+, Mg2+, leucocytes, nitrite, urobilinogen, protein, blood, ketones, bilirubin and glucose were tested in the urine of 500 mg/kg treated and control rats. Six hours later, serum electrolyte levels (Na+, K+, Ca2+ and Mg2+) were evaluated. Glomerular filtration rate (GFR) was also determined in terms of creatinine clearance. Overt toxicity, hepatotoxicity, nephrotoxicity and a phytochemical studies were conducted.Results: Significant (p < 0.05) reduction of urine output (by 45 %) and aldosterone secretion index (Na+/K+) were observed while sodium (by 38 %) and potassium (by 114 %) levels were increased significantly (p < 0.05). GFR was not changed significantly (p > 0.05). Further, the methanol extract (leaf/bark in 5:1 ratio) was non-toxic in terms of overt signs of toxicity, serum alanine transaminase (ALT) and aspartate aminotransferase (AST), urea and creatinine levels. Phytochemical evaluation revealed the presence of alkaloids, unsaturated sterols, unsaturated terpenes, unsaturated lactones, lucocyanins, tannins and polyphenols and cyanogenic glycosides.Conclusion: The methanol extract of Aporusa lindleyana has moderate and safe oral antidiuretic activity.Keywords: Aporusa lindleyana, Antidiuretic, Diuretic, Toxicity, Phytochemicals, Sri Lankan traditional medicine