Abstract

ANTI-INFLAMMATORY EFFECT AND ACUTE TOXICITY OF AQUEOUS EXTRACT OF THE STEM BARK OF PIPTADENIASTRUM AFRICANUM (FABACEAE)

Juliette Koubé*, Valentin Désiré Guiama, Steve Carnot Asseng Atangana, François Eya'ane Meva and Gisèle Marie Etame-Loé

ABSTRACT

Piptadeniastrum africanum (Fabaceae) is extensively used in tropical pharmacopoeia. However, there is shortage of scientific information regarding its safety and activity in management inflammatory syndrome related diseases. The present study aimed to evaluate acute toxicity, and to test in vitro and in vivo anti-inflammatory activity of P. africanum stem bark. In order to achieve this objective, the aqueous extract of P. africanum stem bark served as substrate for analyses, in particular phytochemical screening, and assessment of acute oral toxicity and the test of in vitro and in vivo anti-inflammatory effect. Twelve female rats were used for acute oral toxicity study at the following limit doses at the doses 300, 2000 and 5000mg/kg. The evaluation of the anti-inflammatory activity was demonstrated firstly by an in-vitro test according to the denaturation of hen egg albumin at concentrations of 50, 100, 200, 400 and 800 μg/ml, and secondly by an in-vivo test according to the carrageenan-induced swelling of the paw in female rats, at concentrations of 50, 100, 200 and 400 mg/kg. The results showed that the extract contains polyphenols, Gallic tannins, cathechin tannins, coumarins and saponins. The LD50 of the extract was above 5000mg/kg, hence it is devoid of acute oral toxicity. The inhibition of protein denaturation increased significantly with doses of extract, similarly to standard drug (diclofénac). The diameter of carrageenan-induced paw oedema in rats inversed with time regardless of the concentrations of the extract, suggesting that it may possess a strong acute anti-inflammatory activity in rat. Therefore, P. africanum stem bark appears as a promising source of natural anti-inflammatory drug.

Keywords: Piptadeniastrum africanum, aqueous extract, acute toxicity, protein denaturation, oedema, anti-inflammatory activity.