Investigation of antitussive and toxicological activity of Ballota limbata in mice

Abstract

Context: Ballota limbata Benth. (Lamiaceae) (syn, Otostegia limbata Hook.f.) is a species grown in the North West Frontier Province and the lower hills of West Punjab, Pakistan. Ballota species are renowned for their antispasmodic, antiulcer, diuretic, vermifuge, and especially sedative effects. However, little is known about the biological activity of B. limbata. Objective: Evaluation of antitussive activity and safety profile of dried B. limbata extract. Materials and methods: Whole air-dried plants were partitioned with various solvents and the butanol fraction was subjected to antitussive evaluation using a sulfur dioxide (SO2)-induced cough model in mice. Codeine and dextromethorphan were used as positive control. Safety profile of the testing material was established using standard toxicity tests. Results: B. limbata extract inhibited cough provoked by SO2 gas in mice in a dose-dependent manner. The extract exhibited maximum protection against SO2-induced cough after 60min of administration. B. limbata offered maximum cough suppressive effects, that is, number of coughs during 60min was 11.66±1.2 (mean ± SEM), after s.c. administration of 800mg/kg, as compared with codeine 10mg/kg, s.c., dextromethorphan 10mg/kg, s.c., and saline showing a frequency of cough of 11.75±1.18, 12.25±0.83, and 46.25±1.52, respectively. LD50 value of B. limbata was greater than 5000mg/kg. No sign of neural impairment was observed at antitussive doses and the extract has been well-tolerated at higher doses. Discussion and conclusion: This study demonstrates that the extract of B. limbata has shown strong cough suppressive effect in mice without yielding any notable toxicity. © 2011 Informa Healthcare USA, Inc.