The effects of steganotaenia araliacae extract on contractile function of isolated rat ileum.

A small tree, Steganotaenia araliacae is used as a medicine in local traditional settings in Zambia to initiate and augment parturition although very little is known and documented about its physiological and pharmacological effects. S. araliacae extract (SAEᶜ) has been observed to cause significant contractions of the uterine smooth muscle in rats but its effect on non-uterine smooth muscle is not known. The aim of this work was to establish the effects of S. aaraliacae
extract (SAEᶜ) on the contractility of isolated rat ileum smooth muscle. Effects of acetylcholine, a reference agonist and antagonists that include atropine (AT), indomethacin (IND), mepyramine (MPN), ondansetron (OND) and nifedipine (NF) in the presence and absence of SAEᶜ were also investigated. Our findings showed that SAEᶜ increased the contractile strength of isolated rat ileum in a dose-response manner but had no significant effects on the frequency of the
spontaneous contractions. Pre-treating the tissue with AT, IND, MPN or OND did not inhibit the contractile effects of SAEᶜ while pre-treating the tissue with NF significantly inhibited its contractile effects by 100% (p<0.05). These findings indicate that SAEᶜ causes contractions of isolated rat ileum by probable activation of calcium channels by either a direct or an indirect mechanism. Therefore, abdominal cramps could be induced if higher than normal pharmacological doses of SAEᶜ are taken during induction or facilitation of parturition. However, these undesirable intestinal contractions could possibly be controlled with nifedipine.