Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 36: 2383 - 2388. Published December 7, 2010.
Comparative effectiveness of ethnobotanical mosquito repellents used in Ibadan, Nigeria
Egunyomi A, Gbadamosi I.T. and Osiname K.O
Department of Botany & Microbiology, University of Ibadan, Nigeria.
*Corresponding author email: gita4me2004@yahoo.com
ABSTRACT
Objective: Owing to the adverse effects of synthetic insecticides, there has been increasing need to search for natural and environment friendly insecticides of plant origin as agents of control of vector of malaria parasite. This study aimed to investigate the repellent activity of ten ethnobotanicals against Anopheles stephensi.
Methodology and results: Ten mosquito repellent plants popularly used by the indigenous people of Ibadan, Nigeria were tested for their relative effectiveness against the malarial fever mosquito Anopheles stephensi. The methanol and hexane extracts were investigated for phytochemical compounds with repellent activities against A. stephensi using guinea pigs (Cavia porcellus) and according to standard procedures. Repellency was determined every 10 minutes for a period of 1h. The extracts of C. citratus and L. camara showed very high repellency while the methanol extract of H. suaeveolens were inactive against the mosquitoes. The test plants contained phenols and steroids.
Conclusion and application of results: The active extracts are promising ethnobotanical repellents at 2mg/ml against A. stephensi and could be sources of new natural repellent compounds. The ethnobotanical knowledge of therapeutic potential or bioactivity of plants should form the basis of scientific research to confirm the claim of the indigenous people and increase the number of candidates of plant drugs. The isolation and identification of the active compounds responsible for the observed repellent activity from Azadirachta indica, Cymbopogon citratus, Ocimum gratissimum, Ageratum conyzoides., Annona squamosa, Hyptis suaveolens, Tridax procumbens, Citrus sinensis, Lantana camara. and Solanum nigrum could be necessary. Further research on their potentialities as antimicrobials and insecticides against other insects (disease vectors) should also be investigated. The toxicity test of the plants will confirm their safety in administration. Crude drugs such as ointments and oils could be prepared from the active ethnobotanicals for topical application as mosquito repellents.
Key words: Mosquito repellents, ethnobotanicals, Anopheles stephensi, guinea pigs, phytochemical analysis
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