Evaluation of the anti-asthmatic and antitussive effects of concurrently administered extracts of Bryophyllum pinnatum and Andrographis paniculata in rodents

Abstract

We evaluated the anti-asthmatic and antitussive effects of concurrently administered doses of aqueous Bryophyllum pinnatum (BP) and methanol Andrographis paniculata (AP) extracts in rodents. Doses of 200 and 400 mg/kg of BP were variously administered concurrently with 4 or 8 mg/kg of AP. In the anti-asthmatic evaluation, ovalbuminsensitized guinea pigs were given oral doses of both extracts for seven days and then exposed to 0.2% histamine aerosol in a glass chamber. Latency to preconvulsive dyspnea (PCD), tracheal fluid volume and viscosity were measured. In guinea pigs given acute doses of the extract, bouts of cough were counted after exposure to 7.5% citric acid aerosol. Phenol red expectoration was estimated in mice after 7 days of treatment with the extracts. Doses of BP administered alone significant increased latency to PCD (P < 0.05); and reduced the number of cough bouts (P < 0.0001). The concurrent administration of 400 mg/kg BP with the doses of AP significantly increased latency to PCD compared to 400 mg/kg BP alone. Doses of AP significantly altered the antitussive effect of BP but significantly reversed the reduction of phenol red release by 400 mg/kg BP. We conclude that while concurrent administration of 400 mg/kg BP with doses of AP may be beneficial in asthma, this is not the case in cough. This has implication on the label indications following possible co formulation of the extracts.

Keywords: Concurrent extract administration, Asthma, cough, expectoration