Evaluation of repellent activities of the essential oil of Ocimum basilicum against Anopheles mosquito and formulation of mosquito repellent cream

This study was conducted to evaluate the repellent activities of the essential oils of Ocimum basilicum against Anopheles mosquito and to formulate cream repellent for mosquitoes from essential oil of O. basilicum L . Ocimum basilicum L. (Lamiaceae) commonly known as sweet basil, has been used as a traditional medicinal plant for the treatment of headaches, coughs, diarrhoea, constipation, warts, worms, and kidney malfunctions.The essential oil of the plant of O. basilicum was obtained by hydro-distillation and analyzed by gas chromatography coupled to mass spectrometry (GC-MS).The physical properties of essential oil were also identified. Fifty-one compounds were characterized and identified by GC–MS, comprising 99.7% of the total oil. Major compounds were linalool (18.88%), cinnamic acid (18.31%), and eucalyptol (8.46%). In this work, the oil was assessed for topical repellence effects against malarial vector Anopheles mosquito in cages. The essential oil was tested at three different concentrations 2, 4 and 6% of the oil. From the results obtained, the essential oil of Ocimum basilicum exhibited relatively high repellency effect (> 250 minutes at 6% concentration). The oil was successively formulated as a cream. The formulated cream was prepared using the concentration of 6% of the essential oil. The cream was tested for repellency effect and showed same effect as the essential oil of Ocimum basilicum at the concentration of 6%. The results achieved suggest that essential oils of Ocimum basilicum have activities repellency against female Anopheles and could be used in the form of natural repellent cream.