Preliminary isolated organ studies using an aqueous extract of Clivia miniata leaves

An infusion of Clivia miniata leaves is a traditional medicine taken by Black South African women to induce or augment labour. A boiling water extract of C. miniata leaves was studied for its pharmacological effects on rat uterus and ileum. The extract caused concentration-dependent contractions in both the uterus and ileum, but at a fraction of the intrinsic activity of acetylcholine. When the organs were pretreated with the extract before the cumulative addition of either oxytocin or acetylcholine, the extract augmented the initial response of the organs to the reference drugs. The frequency of contractions in the spontaneously contracting uterus was increased by the presence of the extract. C. miniata extract, however, inhibited the maximal response of the ileum to acetylcholine in a non-competitive way. It did not affect the maximal response of the uterus to either oxytocin or acetylcholine.