Abstract
Eight medicinal plant extracts (Bidens pilosa Linn, Eysenhardtia polystachya Sarg, Lepidium virginicum L., Litsea glaucescens H.B.K., Mirabilis jalapa Linn., Satureja macrostema Brieq., Sophora secundiflora Lag, and Tagetes micrantha Cav.) were tested for their effect on jejunum muscular contractility. All showed inhibitory activity and extracts of M. jalapa and S. macrostema exhibited highest activity with inhibitory concentrations (IC50) of 18 and 73 µg/mL, respectively. Thus, we could corroborate some common traditional uses afforded to these plants. Flowers (petals, calices, and buds) of M. jalapa were the most active part of the plant. We obtained a semipurified sample of the flowers that was more or less five times more active than the crude extract. Furthermore, β-sitosterol, a compound reported as constitutive of M. jalapa, showed no effect on jejunum contractility.