Bio-Prospecting for Phytochemical Repellents/Adulticides of Anopheles Gambiae

Abstract

Mosquitoes are vectors of vast economic and medical importance. They transmit life threatening human and animal diseases such as malaria, viral encephalitis, dengue fever, filariasis, and dog heart worms. Currently, malaria causes more than 500 million cases of acute illness and > 1 million deaths annually, with 90% of the deaths occurring in Africa. This disease is responsible for 25% of the deaths in children. It leads to miscarriage, low birth weight, and deaths among pregnant women. The malaria parasites and vectors have developed resistance to the available commercial antimalarial drugs and insecticides as well as insect repellents respectively. There is no successful malaria vaccine that has been developed. Plant derived new mosquito repellents and mosquitocides, may contribute to the control and the spread of malaria among other mosquito- transmitted diseases. Our research has covered 33 plants within the families: Labiatae, Compositae, Verbeneceae, Euphorbaceae, and Rutaceae. The selection of the plants was based on the ethno-botanical and chemo-taxonomic information, as well as random sampling of plants with aromatic leaves. Out of all the plants screened, 10 showed mosquito repellent activity, while 6 exhibited both insecticidal and mosquito repellent properties. Six compounds with good mosquito repellency and two with mosquitocidal activity have been discovered. Formulation of these compounds into topical repellents have shown good protective efficacy.