Repellency of Cinnamomum cassia bark compounds and cream containing cassia oil to Aedes aegypti (Diptera: Culicidae) under laboratory and indoor conditions.
Patch and skin bioassays were used in laboratory and indoor tests to evaluate the repellency of (E)-cinnamaldehyde, identified in Cinnamomum cassia Blume bark and essential oil, and a cream containing 5% (w/w) cassia oil against Aedes aegypti (L.) females. Results were compared with those of a known C. cassia compound cinnamyl alcohol, N,N-diethyl-m-toluamide (DEET) and two commercial repellents: MeiMei cream containing citronella and geranium oils and Repellan S aerosol containing 19% DEET. In patch bioassay tests with A. aegypti females, (E)-cinnamaldehyde at 0.153 mg cm(-2) and DEET at 0.051 mg cm(-2) provided 93 and 89% protection at 40 min after exposure. In skin bioassay tests, (E)-cinnamaldehyde at 0.051 mg cm(-2) and DEET at 0.025 mg cm(-2) provided 87 and 95% protection at 30 min after application. (E)-Cinnamaldehyde was significantly more effective than cinnamyl alcohol in both bioassays. In indoor tests with four human volunteers, 5% cassia oil cream provided 94, 83 and 61% protection against A. aegypti females exposed for 30, 50 and 70 min after application respectively. Cassia oil cream was a slightly less effective repellent than MeiMei cream. Repellan S aerosol provided 91% repellency at 120 min after application. Products containing cassia oil merit further study as potential repellents for the protection of humans and domestic animals from blood-feeding vectors and the diseases they transmit.
Chang
Kyu-Sik
KS
National Institute of Health, Korea Center for Disease Control and Prevention, Seoul, Republic of Korea.
Tak
Jun-Hyung
JH
Kim
Soon-Il
SI
Lee
Won-Ja
WJ
Ahn
Young-Joon
YJ
D000279:Administration, Cutaneous; D000330:Aedes; D000818:Animals; D032904:Cinnamomum aromaticum / Q000737:chemistry*; D003671:DEET; D005260:Female; D031315:Geranium; D006801:Humans; D007302:Insect Repellents / Q000008:administration & dosage / Q000302:isolation & purification*; D024301:Plant Bark / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry
D007302:Insect Repellents; D010938:Plant Oils; D003671:DEET; C076730:citronella oil