Location: Mosquito and Fly Research Unit
Title: Bioassay-guided investigation of two monarda essential oils as repellents of yellow fever mosquito Aedes aegypti Authors
|Tabanca, Nurhayat -|
|Ali, Abbas -|
|Wang, Mei -|
|Demirci, Betul -|
|Blythe, Eugene -|
|Khan, Shabana -|
|Husnu Can Baser, K -|
|Khan, Ikhlas -|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 6, 2013
Publication Date: August 26, 2013
Citation: Tabanca, N., Bernier, U.R., Ali, A., Wang, M., Demirci, B., Blythe, E.K., Khan, S.I., Husnu Can Baser, K., Khan, I.A. 2013. Bioassay-guided investigation of two monarda essential oils as repellents of yellow fever mosquito Aedes aegypti. Journal of Agricultural and Food Chemistry. 61:8573-8580. Interpretive Summary: Scientists from the Turkey, Saudi Arabia and the University of Mississippi and the Center for Medical, Agricultural, and Veterinary Entomology, USDA-ARS, in Gainesville, FL, report that essential oils from plants Monarda bradburania and Monarda fistulosa, had the ability to repel mosquitoes nearly as good as the commercial repellent DEET (N,N-diethyl-3-benzamide). The oils were separated into fractions and tested for their ability to repel mosquitoes. From this separation process, four compounds were identified as being the best repellents in the oils. The best repellents were carvacrol, thymol, eugenol, and carvacrol methyl ether. The compounds were also evaluated against mosquito larvae and thymol was the best of these compounds. The results of this research will be useful to other researchers performing research to discover new mosquito repellents as well as be of potential use to commercial companies developing new mosquito repellent products.
Technical Abstract: As part of an ongoing research program to identify active mosquito repellents, Monarda bradburiana Beck and M. fistulosa L. essential oils showed potent repellents with minimum effective dosages (MED) of 0.055 ± 0.036 and 0.078 ± 0.027 mg/cm2, respectively, compared to reference standard N,N-diethyl-3-methylbenzamide, DEET (0.039 ± 0.014 mg/cm2). Systematic bioassay-guided fractionation of essential oils of both Monarda species was performed to identify the active repellent compounds and isolated pure compounds were individually tested for repellency. Of the isolated compounds, carvacrol, thymol, eugenol, and carvacrol methyl ether were found to be the repellent compounds with MEDs in the range of 0.013-0.063 mg/cm2. Active repellent compounds were also tested for larvicidal activity against 1-day-old Ae. aegypti larvae. Thymol was the best larvicide among the tested individual compounds (LD50 of 13.9 ppm). None of the individual compounds showed cytotoxicity against mammalian cells; however, the essential oils were toxic to all cell lines.