CHEMICAL COMPOSITION AND ANTI-INFLAMMATORY ACTIVITY OF ESSENTIAL OILS FROM THE LEAVES OF OCIMUM BASILICUM L. AND OCIMUM GRATISSIMUM L. (LAMIACEAE)

Ocimum basilicum L. and Ocimum gratissimum L. (Lamiaceae) are widely distributed aromatic herbs used in ethnomedicinal management of a range of inflammatory disorders. In the present work we evaluated the topical anti-inflammatory effects of the volatile constituents extracted from the fresh leaves of these plant species. Fresh leaves of the plants were subjected to hydro distillation to obtain the volatile oils OBV and OGV from O. basilicum and O. gratissimum respectively.  The fresh leaves were also extracted with n-hexane to obtain OBHE and OGHE respectively. OBV, OGV, OBHE and OGHE were screened for anti-inflammatory effect using xylene-induced ear edema as a model of inflammation. Their chemical constituents were also analysed using GC/MS apparatus. At 50 µg/ear OBV, OGV, OBHE and OGHE exhibited significant (P<0.05) topical anti-inflammatory effect with edema inhibitions of 50.0, 63.3, 62.7 and 80 % respectively. The effects were comparable (P<0.05) with that of 100 µg/ear hydrocortisone (% edema inhibition of 54.8). 11 of the compounds from OGV are monoterpenes while 4 are sesquiterpenes. 8 of the compounds identified in OGHE are oxygenated monoterpene derivatives, 5 are sesquiterpenes, and the others are long chain carboxylic acid, eugenol and phthalate derivatives. OGV and OGHE contain linalool, 1-terpinen-4-ol, alpha-caryophylene and trans longipinocarveol in common. Compounds identified in OBV include 2 monoterpenes, 7 oxygenated monoterpene derivatives, 2 sesquiterppenes, a long chain monocarboxylic acid and a triterpene, alpha-amyrin. OBV and OBHE contain eugenol acetate in common. Some of these identified volatile constituents may be contributing to the observed anti-inflammatory effects.