Investigation of antitussive and toxicological activity of Ballota limbata in mice.

BACKGROUND

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.

METHODS

Whole air-dried plants were partitioned with various solvents and the butanol fraction was subjected to antitussive evaluation using a sulfur dioxide (SO(2))-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 SO(2) gas in mice in a dose-dependent manner. The extract exhibited maximum protection against SO(2)-induced cough after 60 min of administration. B. limbata offered maximum cough suppressive effects, that is, number of coughs during 60 min was 11.66 ± 1.2 (mean ± SEM), after s.c. administration of 800 mg/kg, as compared with codeine 10 mg/kg, s.c., dextromethorphan 10 mg/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. LD(50) value of B. limbata was greater than 5000 mg/kg. No sign of neural impairment was observed at antitussive doses and the extract has been well-tolerated at higher doses.

CONCLUSIONS

This study demonstrates that the extract of B. limbata has shown strong cough suppressive effect in mice without yielding any notable toxicity.