Antihistaminic evaluation of formulated polyherbal cough syrup

Accepted 7 July, 2010 Allergic rhinitis is one of the most common allergic disorders throughout the world. The conventional therapies are effective in alleviating symptoms but the efficacy is limited and not persistent. Many of the indigenous herbal preparations used by the tribes are little known to the public due to lack of scientific evaluation. The aqueous ethanol extracts of various traditional herbs like Adhatoda vasica, Acorus calamus, Glyzyrrhiza glabra, Ocimum sanctum, Tylophora asthmatica, Piper longum and Solanum xanthocarpum was evaluated for its antihistaminic activity by the inhibition of histamine induced contractions on the guinea pig ileum. The results showed that the formulated cough syrup inhibited histamine induced contractions of guinea pig ileum at 2.5 to 25 µg/ml concentrations in a dose dependent manner (p < 0.01, p < 0.05) and also significantly (p < 0.05) inhibited degranulation of mast cells. All the results were well comparable with the standard benadryl cough syrup (diphenhydramine).