title: Bioassay-guided investigation of two Monarda essential oils as repellents of yellow fever mosquito Aedes aegypti.
abstract: As part of an ongoing research program to identify active mosquito repellents, Monarda bradburiana Beck and Monarda fistulosa L. essential oils showed good repellent activity with minimum effective dosages (MED) of 0.055 ± 0.036 and 0.078 ± 0.027 mg/cm(2), respectively, compared to reference standard N,N-diethyl-3-methylbenzamide (DEET) (0.039 ± 0.014 mg/cm(2)). 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/cm(2). Active repellent compounds were also tested for larvicidal activity against 1-day-old Aedes 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.
authors.affiliation: National Center for Natural Products Research and ‡Department of Pharmacognosy, School of Pharmacy, The University of Mississippi , University, Mississippi 38677, United States.
authors.forename: Nurhayat
authors.initials: N
authors.lastname: Tabanca
authors.forename: Ulrich R
authors.initials: UR
authors.lastname: Bernier
authors.forename: Abbas
authors.initials: A
authors.lastname: Ali
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.forename: Betul
authors.initials: B
authors.lastname: Demirci
authors.forename: Eugene K
authors.initials: EK
authors.lastname: Blythe
authors.forename: Shabana I
authors.initials: SI
authors.lastname: Khan
authors.forename: K Husnu Can
authors.initials: KH
authors.lastname: Baser
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
mesh_terms: D000330:Aedes; D000818:Animals; D000081007:Cymenes; D004305:Dose-Response Relationship, Drug; D005054:Eugenol / Q000008:administration & dosage*; D007302:Insect Repellents / Q000008:administration & dosage*; D007306:Insecticides / Q000008:administration & dosage; D007814:Larva; D031338:Monarda / Q000737:chemistry*; D039821:Monoterpenes / Q000008:administration & dosage; D009822:Oils, Volatile / Q000008:administration & dosage*; D013943:Thymol / Q000008:administration & dosage
chemical_list: D000081007:Cymenes; D007302:Insect Repellents; D007306:Insecticides; D039821:Monoterpenes; D009822:Oils, Volatile; D013943:Thymol; D005054:Eugenol; C073316:carvacrol