Antitussive activity of polysaccharides isolated from the Malian medicinal plants

Abstract

From the leaves of popular Malian medicinal plants Trichilia emetica (TE) and Opilia celtidifolia (OC), and fruits of Crossopteryx febrifuga (CF) water and water–ethanol soluble polysaccharide materials were isolated. The results of chemical analysis of the crude polysaccharides showed the dominance of the arabinogalactan (∼54%) and the rhamnogalacturonan (∼30%) in T. emetica leaves, the arabinogalactan (∼60%), the rhamnogalacturonan (∼14%) and the glucuronoxylan (∼14%) in O. celtidifolia leaves, and pectic type of polysaccharides (∼75%) with a lower content of the arabinogalactan (∼17%) in C. febrifuga fruits . The plant polysaccharides showed various biological effects on the citric acid-induced cough reflex and reactivity of airways smooth muscle in vivo conditions. T. emetica and O. celtidifolia polysaccharides possessed significant cough-suppressive effect on chemically induced cough. Furthermore, values of specific airways resistance pointed on bronchodilatory property of polysaccharides isolated from O. celtidifolia. However, the crude extract from C. febrifuga in the same dose as T. emetica and O. celtidifolia did not influence the experimentally induced cough as well as reactivity of airways smooth muscle despite of the fact that the water–ethanol extract is recommended for cough therapy in Mali in the form of syrup.