Acta Vet. Brno 2010, 79: 51-59
Influence of Polysaccharides from Aloe vera (Aloe barbadensis Miller, Liliaceae) on Mechanically Induced Cough in Cats
Different plants have been reported to be a source of polysaccharides that possess a great variety of biological activities, including cough suppression. The experiments were aimed on the influence of two polysaccharides isolated from the gel (A, HF1-Z) and one from the epidermis (SL-1) of Aloe vera leaves, characterized by chemical composition and structural properties, on the cough reflex. The method of mechanically induced cough was used in conscious cats. A nylon fibre directed individually into the mucous area of the laryngopharyngeal and tracheobronchial airways via endotracheal cannula elicited the cough reflex. Statistical evaluation registered cough reflex indicators (number of cough efforts - NE, cough frequency - NE min–1 intensity of cough attacks during expiration and inspiration - IA+ and IA-, intensity of maximal inspiratory and expiratory cough efforts - IME- and IME+) showed that gel polysaccharide HF1-Z possessed higher cough-suppressing activity than dropropizine, a nonnarcotic peripheral cough suppressant. Their antitussive activity was accompanied mainly with a decrease of NE, IA+ and IA- from both laryngopharyngeal and tracheobronchial mucous areas of the airways. Results of the presented study also showed minimal influence of polysaccharide HF1-Z on expectoration predictor, IME- and IME+. New pharmacodynamic property of polysaccharides isolated from Aloe vera was shown during experiments, which could be a base of their possible therapeutic use in this indication in future.