Extraction, Compositional Analysis and Trypanocidal Activities of Essential Oils of Four Aromatic Plants Obtained From North-Eastern Nigeria

Abstract

The advantage of having in abundance aromatic plants in the North-eastern part of Nigeria was again utilized with the sole aim of harnessing their composition into useful discovery in the aromatic chemistry. To achieve this aim, the stem bark of Bosweillia dalziellii, the leaves of Ocimum americanus, Hyptis spicigera and Hyptis suaveolens were subjected to steam distillation for possible extraction of essential oils. The oils obtained were then analyzed using Gas Chromatography Mass Spectroscopy (GC-MS) technique. The results showed that 55 components were identified in the essential oil of Bosweillia dalzielii with α-pinene (18.515 %), isophthaldehyde (10.695 %) and β-pinene (5.641 %) as the major components of the essential oil. The essential oil of Ocimum americanus has a total 45 components in which terpinene-4-ol (14.507), copaene (7.438 %) and terpinene (6.178 %) are the predominant components. On the other hand α-pinene (30.536 %), β-pinene (15.840 %) and eucalyptol are the lead components in the essential oil of Hyptis spicigera out of 30 components identified. The GC-MS result for the essential oil of Hyptis suaveolens revealed that out of the 31 components identified carryophyllene (20.643 %), sabinene (16.711 %) and terpinolene (8.490 %) are the lead components. The various essential oils were tested for trypanacidal activities using trypanasoma congoles and the result obtained shows that essential oil of Hyptis spicigera inhibited the motility of the parasites in 60 and 30 minutes after the start of experiment, at concentrations of 25 and 50 µL/ml respectively. However complete inhibition of the motility of the parasites was noticed 90 minutes after the start of the experiment at same concentrations above when essential oils of Ocimum americanus and Hyptis suaveolens where introduced into the test tubes containing blood infested with trypanasoma congoles. The essential oil of Bosweillia dalzielii exhibited least trypanacidal activity having inhibition on the motility of the parasites at 120 minutes of the start of the experiment.