Diuretic activity and acute oral toxicity of Palicourea coriacea (Cham.) K Schum

Palicourea coriacea (Cham.) K Schum, is an endemic plant used in the Midwestern Region of Brazil, popularly known as "douradinha do campo" and "congonha do campo". This plant has been used in traditional medicine for several ailments, especially to treat kidney diseases. Since no formal studies on the biological activities and medicinal properties of the ethanolic extract of Palicourea coriacea (PCEE) have been carried out previously, the present study represents the first research into the efficacy of this plant as a diuretic agent employing laboratory rats as test animals.

For diuretic activity evaluation we assayed three doses of PCEE (20, 40 and 80mg/kg) and measurement of the urinary volume and electrolytes (Na(+), K(+)) concentration were taken. The acute oral toxicity of PCEE was investigated according to OECD Guideline 423.

The oral administration of a single dose of PCEE significantly increased the urinary volume in 24h. Additionally, the treatment with PCEE increased, in a dose-dependent manner, the excretion of both, Na(+) and K(+). No sign of toxicity was observed in the animals.

The present study confirmed the ethnopharmacological use of Palicourea coriacea as a diuretic agent in the experimental condition tested here. Additionally, this work supports the importance of the preservation of local knowledge as well as the conservation of Brazilian biodiversity.