Abstract

The pharmacological effects of volatile oil fraction, butanol and the residual water extracts of Mentha longifolia (L. Huds, family Lamiaceae) on intestinal smooth muscle were studied in vitro. Volatile oil fraction (40- 100 ug/ml) exhibited an inhibitory effect on the acctyl choline-induced contraction of the rabbit ileum. This action was transient and reversible after washing the tissue. In addition, volatile oil fraction (40-100 ug/ml) inhibited the histamine-induced contraction of the ileum in guinea pig. Butanolic extract (100 ug/ml) exhibited weaker inhibitory effect on both acetylcholine- and histamine-induced contractions on‘ rabbit and guinea pig ileums. Residual water extract (40-200 ug/ml) showed no effect. However, further investigations are still recommended