PHYTOCHEMICAL ANALYSIS AND REPELLENT ACTIVITIES OF METHANOL EXTRACT OF MENTHA PIPERITA AGAINST ADULT MOSQUITOES ANOPHELES GAMBIAE.

This study evaluates the repellent activity and protective effect of the methanol leaves extract of M.piperita against Anopheles gambiae. M. piperita is a medicinal plant with many therapeutic uses in different parts of the world. The microscopic screening, phytochemical analysis and repellency activities of M.piperita were studied. The fresh leaves of M. piperita were collected and air dried for 7 days. The dried leaves were pulverized to facilitate extraction. The microscopic screening of powdered leaf of M.piperita shows the presence of Calcium oxalate, Xylem vessels, Epidermal cells, Palisade cells and Elongated fiber. The phytochemical analysis revealed the presence of secondary metabolite that could be responsible for its successful therapeutic effect. The test shows the presence of of Terpenes, Glycosides, Steroids,and absent of Alkaloids and Tannins. The mosquitoes were exposed to different concentrations of the leaves extract using modified arm-in-edge test technique as described by Schreek et al (1989) and WHO (1996). The repellent effect of the leaves extract is proportional to it`s concentration. Upon the exposure of 50 mosquitoes on M. piperita extract, the number of mosquitoes landing on the arm of volunteers reduces as the concentration of the extract increases. At 2% extract of the leaf, 30% repellency was obtained. At 4% extract of the leaf, 42% repellency was obtained. At 6% extract, 56% repellency was obtained. At 8% extract, 66% repellency was obtained. At 10% leaf extract,76% repellency was obtained. From the result, it can be concluded that repellency activity of M. piperita leaves extract against Anopheles gambiae is dose dependent.