Anticholinergic action of Swertia japonica and an active constituent.

The anticholinergic action of Swertia japonica, used in Japan as a bitter stomachic, was examined using in vivo experiments in rats in order to substantiate the presence or absence of antispasmodic properties. The methanol extract of Swertia japonica was found to be an effective anticholinergic given orally. Fractionation and purification of the methanol extract through column chromatography revealed that swertiamarin, found in the methanol extract in amounts of about 30%, was an active constituent with an anticholinergic action.