Hypotensive and spasmolytic activities of crude extract of Cyperus scariosus

Intravenous administration of hydro-methanolic extract of Cyperus scarious (3-10 mg/kg) produced hypotensive and bradycardiac effects. These effects remained unaltered in atropinized animals indicating that cardiovascular effects of the plant extract are not mediated through activation of muscarinic receptors. In the in vitro studies, it suppressed the spontaneous contractions of guinea-pig paired atria, rat uterus and rabbit jejunum in a concentration-dependent (0.1-1 mg/ml) manner. It also inhibited histamine or acetylcholine-induced contractions of guinea-pig ileum indicating non-specific spasmolytic action. In rabbit aorta, it inhibited norepinephrine (10 μM) as well as K⁺ (80 mM)-induced contractions at similar concentrations (0.1-1mg/ml). These data indicate that Cyperus scariosus contains Ca²⁺ channel blocker-like constituent(s) which may explain hypotensive effect observed in vivo and the general spasmolytic activity of plant may explain its folkloric use in diarrhoea.