Anti-tussive, muco-suppressant and expectorant properties, and the safety profile of a hydro-ethanolic extract of Scoparia dulcis.

Background: Scoparia dulcis is used in Ghanaian folkloric medicine for the management of asthma and its related complications. This study was therefore aimed at evaluating the anti-tussive, muco-suppressant and expectorant properties of hydroethanolic extract of S. dulcis (SDE), and to ascertain its safety for use in asthma and obstructive pulmonary disease management. Methods: The number of coughs induced in guinea pigs using citric acid and the concentration of phenol red secreted in tracheae of mice were measured. Preliminary phytochemical analysis was conducted on the extract using standard procedures. Safety for use of the extract was assessed by conducting an acute and delayed toxicity test. Results: The extract showed a dose-independent inhibition (p ≤ 0.001) of cough elicited by 7.5% citric acid, and a dose-dependent increase (p ≤ 0.05) in the amount of phenol red output in mice tracheae similar to that of ammonium chloride. For the muco-suppressant activity, SDE dose-dependently reduced (p ≤ 0.001) the concentration of ammonium chloride-induced phenol red secretions from mice tracheae. Phytochemical screening showed the presence of tannins, alkaloids, glycosides, saponins, steroids, and phenolic compounds. No acute and/or delayed toxic symptoms were observed after an oral administration of up to 5 g/kg of S. dulcis extract. Conclusion: The results showed that S. dulcis extract has anti-tussive, muco-suppressant and, expectorant and/or mucolytic properties; making it a possible remedy for asthma, and obstructive pulmonary disease.