ETHYL ACETATE FRACTION OF TETRACERA ALNIFOLIA (WILD) STEM EXTRACT POSSESSES ANTINOCICEPTIVE AND ANTI-INFLAMMATORY ACTIVITIES
Obonga WO*, Agbo, MO, Nnadi CO, Okechukwu, EI
Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka 410001, Enugu State, Nigeria
Afr. J Pharm Res Dev; Volume 10(2): 107-114 ; 2018
ABSTRACT
The study evaluated the antinociceptive and anti-inflammatory properties of Tetracera alnifolia used to treat pains associated with rheumatoid disorders in Southern Nigeria. The anti-inflammatory activity of the alcoholic leaves and stem extracts/fractions of T. alnifolia was evaluated using the fresh egg albumin-induced paw edema and xylene-induced ear edema tests in albino rats and mice respectively. The acetic acid-evoked writhing model was used to evaluate the antinociceptive action in albino mice. The extract (150–600 mg/kg, p.o.) produced significant (p < 0.05) dose-dependent inhibition of rats paw and mice ear edema elicited by fresh egg albumin and xylene respectively. The extracts (200 – 600 mg/kg) also significantly (p < 0.05, 0.01) decreased the nociceptive reaction writhes induced by acetic acid in dose-dependent manner. In respect of analgesic and anti-inflammatory activities of the solvent fractions, the ethyl acetate (EtOAc) fractions were the most potent; the stem fraction (100 mg/kg) eliciting 55.6 % inhibition of paw edema in rats and 72.9 % nociceptive reaction in mice. The EtOAc fraction (100 mg/kg) of the leaves produced 71.8 % inhibition of the writhing movement in mice comparable with the effects of diclofenac. Phytochemical screening of both extracts revealed similar composition; however, saponins and alkaloids were detected only in the stem extract. The extract did not produce any death or visible signs of delayed toxicity when administered orally up to 5000 mg/kg. The results obtained in this study suggest that T. alnifolia possesses antinociceptive and anti-inflammatory activities possibly mediated via mechanisms involving inhibition of release and/or actions of pro-inflammatory substances, thus further supporting the use of the plant as analgesic and as an adjuvant in rheumatoid disorders.
Email of correspondence:wilfred.obonga@unn.edu.ng;
KEYWORDS: Dilleniaceae, Analgesic, Anti-inflammatory, Egg albumin, Xylene, Acetic acid