Strong antinociceptive effect of Incarvillateine, a novel monoterpene alkaloid from Incarvillea sinensis

Incarvillea sinensis is a wild plant distributed in northern China. The dri ed whole plant has been traditionally used to treat rheumatism and relieve pain as an ancient Chinese crude drug. To investigate its antinociceptive a ctivity, we evaluated several fractions derived from the methanolic extract of Incarvillea sinensis in the formalin-induced pain model in mice. Incarv illateine, a novel monoterpene alkaloid, has been found to show significant antinociceptive activity. Here we report the antinociceptive activity of i ncarvillateine and compare its activity with that of morphine. Additionally , we suggest that its action may be related to influence on the central opi oid pathways.