Antidiarrhoeal and bronchodilatory potential of Valeriana wallichii

This study describes the antidiarrhoeal and bronchodilatory activities of Valeriana wallichii D.C. (Valerianaceae). The crude extract of V. wallichii (Vw.Cr) caused inhibition of castor oil-induced diarrhoea in mice at 300-600 mg kg ^-1. In guinea-pig trachea, Vw.Cr concentration dependently (0.03-3.0 mg mL ^-1) relaxed the low K ⁺ (25 mM)-induced contractions, with a mild effect on the contractions induced by high K ⁺ (80 mM). In the presence of glibenclamide, the relaxation of low K ⁺-induced contractions was prevented. Similarly, cromakalim caused glibenclamide-sensitive inhibition of low K ⁺, without any effect on high K ⁺. These results indicate that V. wallichii exhibits antidiarrhoeal and bronchodilatory activities, possibly through K ⁺ channel activation, and thus reveal its medicinal usefulness in hyperactive gut and airway disorders such as diarrhoea and asthma.