The herbal polysaccharides have been the subject of many studies for a very long time, especially because of their physical properties, chemical and physical modification and application. Adhatoda vasica has also been traditionally included in preparations for the relief of cough, asthma and bronchitis recommended by Ayurvedic physicians for the management of various types of respiratory disorders. In this study, we have focused on activities of pectic arabinogalactans isolated from Adhatoda vasica on experimentally induced cough reflex and the changes of specific airway resistance in vivo conditions. The substance from leaves of Adhatoda vasica was marked as P-601 and the substance from stem bark of this shrub as P-602. The aim of presented study was to compare the antitussive activity of isolated arabinogalactans with cough suppressive activity of codeine ("positive" control) and effect acquired after application of water for injection ("negative" control). Conscious male Trik guinea pigs (200-350g) were exposed to citric acid aerosol. Peroral administration of these substances in a dose of 50 mg.kg-1 body weight decreased the number of citric acid induced cough efforts in guinea pigs more effectively than codeine. They did not induce any significant changes in the values of specific airway resistance and did not provoke any observable adverse effects. Our test results confirmed that polysaccharides isolated from Adhatoda vasica in vivo conditions have expressive antitussive effect compared with the oldest and the most effective cough suppressive agent - the codeine. The positive thing is the studied substances, despite strong supressive activity, did not induced any adverse side effects.
