No abstract

Aqueous root extract of Salacia lehmbachii (ARESL) has been implicated in preterm usage by herbalists in South Eastern Nigeria. Consequently, the extract, thought used in other ailment like malaria fever, is prohibited in normal pregnancy situation. The present study was aimed at investigating effects of ARESL on activities of uterine muscle strips isolated from non-gravid, oestrogen-primed Wistar rats. Uterine muscle strips were prepared and mounted in an organ bath with aerated De-Jalon's solution maintained at 36 ± 1 C. Dose-response relationships for oxytocin (OT) and acetylcholine (ACh) constituting uterotonic (contractile) agents were studied isometrically in the presence and absence of fixed concentrations of ARESL (0 25 × 10 −2 and 0 5 × 10 −2 mg/ml). Similarly, salbutamol (SBL) and verapamil (VER) controls were investigated in the presence of uterotonic agents and the effects compared with those of the extract. Effects of extract on amplitude and frequency and on maximum achievable response (E max and concentration which inhibited 50% of maximum response (IC 50 were also assessed. Data was computed by one-way analysis of variance followed by Tukey test as post hoc. ARESL at a concentration of 0 5×10 −2 mg/ml significantly (P < 0 01) reduced E max of OT from 1 22±0 20 to 0 30±0 02 g and that of ACh from 1 45 ± 0 43 to 0 28 ± 0 11. Frequency of contractions was equally reduced. Hence, ARESL is a nonspecific uterine smooth muscle contractile antagonist with very high affinity for receptors with no efficacy. This, undoubtedly, explains why folkloric medicine uses the extract in situations of threatened abortion.