Anti-inflammatory and analgesic activities of methanolic extract of Elaeis guineensis Jacq. leaves (Arecaceae) and its fractions

Elaeis guineensis Jacq. is an arborescent monocotyledon of the Arecaceae family. It is a plant originated from tropical rainforest of West Africa. For centuries, it has been a source of food and a natural remedy against several pathologies. The aim of the present research was to evaluate anti-inflammatory and analgesic activities of methanolic extract E. guineensis Jacq. (Arecaceae) leaves and phytochemical groups. Extraction with methanol and various liquid-liquid fractionations were carried out. These extract and fractions were administered orally at different doses. The experiments were performed on models of carrageenan-induced inflammatory edema in rat and acetic acid-induced pain in mouse. The extraction protocols gave a methanolic extract and different fractions, methanolic tannins free, alkaloid, terpenoid, and flavonoid. The methanolic extract administered at doses of 1, 3 and 10 mg/kg significantly prevents inflammatory edema. The percentages of increase in edema 5 h after induction are 38.31±3.55, 37.48±4.98, 40.82±4.14 versus 92.72±6.05 in the control group. The same profiles are observed with the methanolic fractions tannins free, flavonoid and terpene. However, the latter show dose-dependent activities between 1 and 3 mg/kg. The methanol fraction tannins free at 3 mg/kg is better in preventing inflammatory edema. Oral tannin-free methanolic fraction significantly prevents acetic acid-induced pain in mice. Elaeis guineensis leaves possess anti-inflammatory and analgesic properties on models of carrageenan-induced inflammatory edema in rat and acetic acid-induced pain in mouse. The anti-inflammatory and analgesic activities could be linked to the combined action of alkaloids, flavonoids and terpenes, on the different targets of the inflammatory reaction. Key words: Elaeis guinensis Jacq., anti-inflammatory, analgesic, methanolic extract, alcaloïds, flavonoïds, terpenes