Spasmolytic and spasmogenic activities of crude extract and subsequent fractions of Paeonia emodi.

The crude extract and subsequent fractions from the aerial parts of P. emodi were studied for their effects on the isolated rabbit jejunum. The crude extract displayed significant spasmolytic activity in a dose-dependent manner and inhibited the spontaneous motility of the rabbit jejunum by 76% at 5 mg/mL concentration. The ethyl acetate and chloroform fractions exhibited excellent spasmolytic activities and were more potent than the native crude extract. The n-butanol fraction showed a very low inhibitory activity in this bioassay. The water soluble fraction, unlike crude extract, displayed an overall spasmogenic activity. The crude extracts also effectively reduced the acetylcholine induced contractions in the isolated rabbit jejunum.