Phytopharmacological evaluation of aerial parts of Woodfordia fruticosa (L.) Kurz in Cough Variant Asthma

Background: Cough variant asthma (CVA) is characterized by prolonged non productive cough which responds to bronchodilator therapy. None of herbal drug is reported to possess pharmacological activity against CVA. Objective: To investigate the pharmacological potential of ethanolic extract of Woodfordia fruticosa (L.) Kurz (EEWF) against CVA as well as to develop an efficient screening model for CVA. Material and Method: Anti-tussive effect of EEWF was evaluated against nebulized aqueous solution of 0.1 g/ml of citric acid to determine the cough response. EEWF potential was finally accessed against aerosolic mixture of 0.3 g/ml of citric acid mixed with 0.1% histamine and 2% acetylcholine chloride to evaluate the convulsive latency, percentage protection and cough frequency against CVA. Results: EEWF at aerosolic dose of 6% w/v exhibit decrease in of the average coughs frequency (4.83 ± 0.30) which is quite significant effect as compared to standard drug codeine. EEWF against aerosol induced CVA was found to exhibit a significant bronchoprotection of 41.75% and decreases number of coughs (7.16 ± 0.47) at 200 mg/kg as compared to control (14.16 ± 0.60). Conclusion: EEWF at 200 mg/kg dose exhibited bronchoprotective and anti-tussive effects against aerosol induced CVA.