Antitussive and expectorant activities of Potentilla anserina.

Context The root of Potentilla anserina L. (Rosaceae) is an herbal medicine that has been used as an antitussive and expectorant drug for thousands of years in Chinese folk medicine.

OBJECTIVE

This study estimated the antitussive and expectorant effects of P. anserina extract to validate its traditional use. Materials and methods The antitussive and expectorant activities of the ethanol extract, aqueous extract, and polysaccharides from P. anserina were evaluated using classical animal models. Results The results showed that in three antitussive tests, the aqueous extract and polysaccharides at high and low doses significantly inhibited the frequency of cough induced by ammonia and sulfur dioxide in mice and by citric acid in guinea pigs, and increased the latent period of cough in guinea pigs. Similarly, the aqueous extract and polysaccharides also showed significant expectorant activity compared with the control in phenol red secretion experiments. Polysaccharides at dose of 600 mg/kg enhanced tracheal phenol red output by 121.1%, the ammonium chloride (positive control) at dose of 1000 mg/kg by 117.4%. However, the ethanol extract at a high dose (600 mg/kg) has antitussive activity only in the sulfur dioxide induced coughing test. Moreover, the polysaccharides at the same dose showed better bioactivity than the aqueous extract in all tests. Discussion and conclusion The results of the present study provide evidence that P. anserina can be used as an antitussive and expectorant herbal medicine and that polysaccharides may be the main active ingredients of P. anserina responsible for its bioactivities.