Diuretic Action of Paeonol

Abstract

Effects of paeonol, a major component of the root bark of Paeonia suffruticosa, on urinary excretion of water (UV), sodium (U_NaV), potassium (U_KV), chloride (U_clV) and osmolality (U_osmV) were investigated in bicarbonate saline loaded rats. Paeonol at the doses of 62.5 to 250 mg/kg p.o. produced dose-dependent increases in UV, U_NaV and U_ClV (P < 0.05 or 0.01 vs. control). U_KV was unchanged at the lower doses and decreased at the highest dose. U_osmV was also increased by paeonol (P < 0.05 or 0.01). The lowest effective dose of paeonol in diuretic action was 62.5 mg/kg which is somewhat lower than those reported to produce an antiinflammatory action or a reduction of gastric secretion (125 to 500 mg/kg). The highest dose of paeonol produced the same degree of increase in UV as hydrochlorothiazide (HTZ) (10 mg/kg), while the increases in electrolytes excretion by HTZ were significantly greater than by paeonol. These data demonstrate that paeonol has a diuretic action, and suggest that its sites of action in the kidney are different from those of HTZ.