In vitro Tocolytic Activity of Sarcostemma

The effect of a chloroform soluble fraction (F-A) of the acetone extract of twigs of Sarcostemma brevistigma Wight on contractions induced by oxytocin and KCl, in the isolated rat uterine smooth muscles, has been evaluated. At concentrations of 32.8 μg/ml, the F-A significantly inhibited (P<0.001) the contractions induced by 60 mM KCl in Ca, containing physiological salt solution to the extent of 88.7 ± 2.2%. The F-A, at concentrations of 26.3 μg/ ml, completely inhibited the rhythmic contractions induced by oxytocin in Ca, containing physiological salt solution. However, it failed to inhibit the contractions induced by oxytocin in Ca free PSS. These results suggest that fraction F-A exhibits uterine relaxant activity, by interfering with the extracellular Ca.