Suppressive effect of pectic polysaccharides from Cucurbita pepo L. var. Styriaca on citric acid-induced cough reflex in guinea pigs.

Several water-soluble pectic polysaccharides were isolated from the pumpkin fruit biomass and characterized by composition, structural features and molecular properties. The pectic polysaccharides were tested for antitussive activity by studying the effects of citric acid-induced cough reflex in guinea pigs and reactivity of the airway smooth muscle in vivo conditions in comparison to the narcotic drug codeine. Oral administration of all pectic polysaccharides from pumpkin inhibited the number of coughs induced by citric acid in guinea pigs, but to various extents. The results indicated that the antitussive activity of the pectic polysaccharides is affected by their molecular and structural properties, whereby a synergistic action between the polysaccharide and non-carbohydrate components on the biological response has been suggested as well. The cough depressive efficacy of most of the tested polysaccharides was comparable and even higher than that of codeine. Moreover, the application of these polysaccharides provoked any side effects what is their advantage towards the conventional opioid-derived antitussive agents.

The pharmacological activity of wheat bran polysaccharides.

(Glucurono)arabinoxylans were extracted from the wheat bran with acetate buffer in the first step (WBH1) and with dilute alkali in the second step (WBH2). In both samples xylose and arabinose dominated, accompanied with smaller amounts of galactose, glucose, mannose and uronic acids mainly in WBH1. WBH1 was free of protein and with low content of phenolic compounds. Fraction WBH2 contained relatively low levels of proteins and about 4.5% of the total phenolic. When tested for antitussive activity, the (glucurono)arabinoxylans exhibited comparable cough-suppressing effect with centrally acting codeine. The observed effects of bronchoconstriction are limiting practical application of WBH2.