Isolation and Characterization of Anti-inflammatory Compound from Ocimum gratissimum Leaves Extract

Abstract

The study was undertaken to identify the possible bioactive compound responsible for the anti- agent in Nigerian traditional medicine. Thin layer chromatographic profile of the extract was determined using appropriate solvent system. The compound isolated had a percentage yield of 33.3% and corresponding Rf value of 0.78 with characteristic aromatic, reddish-brown, oily appearance. Paper and Sudan III tests gave positive test for oil. Subsequent isolation and characterization of the purified compound using column
chromatography, alpha-D determination and spectroscopic techniques (UV, IR, NMR and MS) led to the discovery of the proposed compound: methyl-octadeca-9, 12-dienoate also known as methyl linoleate. An increase in the rats hind paw diameters induced by sub-planter injection of a phlogistic agent (formalin 0.1 mL/kg of 2.5 %) was used as a measure of acute inflammation. Ethyl acetate extract was found to have a significant (P <0.01) inhibitory effect on the formalin-induced oedema in rats at the doses of 50, 100, and 200mg/kg body weight (orally) tested in rats when compared to the normal saline (negative control). The extract
also competed significantly (p<0.05) and favourably with standard drug, prednisolone (positive control) at 10 mg/kg body weight. The results confirmed that ethyl acetate extract contains bioactive compound which maybe responsible for the anti-inflammatory activity of the plant’s leaves and is probably the reasons for the widespread use of the plant as anti-inflammatory agent locally and in Nigerian traditional medicine