Investigation of Phytochemical Constituents and Smooth Muscle Relaxation Activity of Various Herbal Plants in Myanmar

The leaves from Ageratum conyzoides L., Aegle marmelos Correa., Clerodendrum indicum (L.) Kuntze, and Mimosa pudica L. plants, reputed in folk medicine in Myanmar for their value as an anti asthmatic remedy, were selected for this study. These leaves were carried out to investigate the phytoconstituents and smooth muscle relaxation activity in both normal and histamine-induced guinea-pig. The compounds namely stigmasterol, myristic acid, palmitic acid, 9-hydroxy nonan-2-one and kaempferol from A. conyzoides; β-sitosterol and N-2-[4-(3´-methyl butoxy) phenyl] ethyl cinnamide from A. marmelos; palmitic acid, stigma-5,22,25-trienen-3-ol, hispidulin, pectolinarigenin and stigmasterol glucoside from C. indicum and 1-methylene-1H-indene and γ–sitosterol from M. pudica leaves could be isolated. In vitro screening on the alcoholic and aqueous extracts revealed the smooth muscle relaxation activity in the order of C.indicum > A. conyzoides > M. pudica > A. marmelos leaves. Maximum dose for all extracts except A. marmelos was found to be 2 mg L-1 bath concentration. Isolated compounds exhibited anti-asthmatic effect in the order of stigma-5, 22, 25-trienen-3-ol > hispidulin > pectolinarigenin> stigmasterol glucoside > N-2-[4-(3´-methyl butoxy) phenyl] ethyl cinnamide > stigmasterol> kaempferol. These results might supply the scientific evidence for smooth muscle relaxation activity of the leaves for the treatment of bronchial asthma in traditional herbal medicine.