Pharmacological basis for the gut stimulatory activity of Raphanus sativus leaves

The crude extract of Raphanus sativus leaves (Rl.Cr) showed a dose-dependent (0.03-5.0 mg/ml) spasmogenicity in guinea-pig ileum and colon. The effect was insensitive to atropine pre-treatment but was completely abolished by pyrilamine indicating involvement of histaminergic (H(1)) receptors. The contractile effect at high doses (3.0-5.0mg/ml) was followed by relaxation. Rl.Cr also enhanced the transit of charcoal meal in mice at 30-100 mg/kg. The petroleum spirit, chloroform and aqueous fractions all showed histaminergic activity in ileum; aqueous fraction being more potent. The study shows the presence of a histaminergic component(s) along with a weak spasmolytic factor thus providing sound mechanistic basis for the traditional use of the plant in constipation.