Abstract

Plant materials serve as valuable sources of new medicinal agents, with a considerable number of them being used medicinally. However, it is important to follow systematic research methodology to evaluate the pharmacological properties of these plant materials. The aim of this study was to evaluate the effects on some smooth muscle preparations of Adansonia digitata L (Bombacaceae) fruit pulp and Lawsonia inermis L (Lythraceae) leaves extracts. When tested on isolated rabbit jejunum and isolated rat uterus, the extract of A. digitata fruit pulp (5 mg/ml) induced contraction in both tissue preparations, which was further blocked by pre-addition of atropine and adrenaline, respectively. However, the addition of 5 mg/ml of L. inermis leaves extract to the same preparations slightly increased the muscle tone without clear contraction magnitude, and this effect was not affected by pre-addition of atropine but was antagonized by pre-addition of adrenaline. Additionally, it was observed that the combination of L. inermis leaves extract with acetylcholine resulted in an increased contractile response of the two isolated tissue preparations compared to the action of acetylcholine alone at the same doses for each preparation. The obtained results revealed that A. digitata fruit pulp extract elicited contractile responses on isolated rabbit jejunum and isolated rat uterus preparations, possibly through its action on muscarinic receptors since it was effectively blocked by pre-addition of atropine. In contrast, the stimulatory response elicited by the extract of L. inermis leaves was related to the direct action of the extract on the smooth muscle preparations and/or by potentiation of acetylcholine action in both isolated tissues.

Key words: Adansonia digitate, Baobab, Lawsonia inermis, Henna, Rabbit jejunum, rat uterus.