Antitussive, expectorant activity of Marsilea minuta L., an Indian vegetable

Marsilea minuta L., an aquatic or sub-aquatic fern used as a vegetable, has wide applications in traditional/folk medicine in India and Bangladesh. In our study, we evaluated the antitussive, expectorant activity of M. minuta crude extracts. The antitussive activity of M. minuta methanol, ethyl acetate, and petroleum ether extracts was evaluated using ammonia and sulfur dioxide induced mice coughing. The expectorant activity was evaluated by the volume of phenol red in mice's tracheas. Extracts significantly increased mice's cough latent period and inhibited the frequency of cough induced by ammonia and sulfur dioxide, and improved tracheal phenol red output in expectorant evaluation. Methanol extract produced the highest activity in all tested models. Methanol extract at 500 mg/kg showed 59.5% and 55.8% inhibition in the number of coughing induced by ammonium liquor and SO(2), respectively, while it showed 89.3% increase in phenol red secretion at the same dose, which showed superior activity compared to other extracts. The present study provided evidence for M. minuta to be used as an antitussive and expectorant in Indian folk medicine.