Excito-repellency and biological safety of β-caryophyllene oxide against Aedes albopictus and Anopheles dirus (Diptera: Culicidae)

• Published in: Acta tropica 2020-10, Vol.210, p.105556, Article 105556
• Main Authors: Nararak, Jirod, Giorgio, Carole Di, Sukkanon, Chutipong, Mahiou-Leddet, Valerie, Ollivier, Evelyne, Manguin, Sylvie, Chareonviriyaphap, Theeraphap
• Format: Article
• Language: English
• Subjects: 3T3-L1 Cells; Aedes; Animals; Anopheles; CHO Cells; Cricetinae; Cricetulus; Excito-repellency test system; Genotoxic; Insect Repellents - pharmacology; Life Sciences; Male; Mice; Mosquito Control - methods; Mosquitoes; Phototoxic; Polycyclic Sesquiterpenes - adverse effects; Polycyclic Sesquiterpenes - pharmacology; Rats; Rats, Sprague-Dawley; β-Caryophyllene oxide
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2020.105556

•β-caryophyllene oxide had stronger repellent and irritant effect than DEET•Ae. albopictus was more sensitive to β-caryophyllene oxide than An. dirus while, knockdown responses (37%) were observed in An. dirus exposed to 1% β-caryophyllene oxide in the contact trial.•β-caryophyllene oxide did not show any phototoxic activity.•None of the tested β-caryophyllene oxide induced a significant increase of micronucleated cells with or without metabolic activation.•β-Caryophyllene oxide could be considered as a safe repellent, effective against mosquitoes. The activity of β-caryophyllene oxide as either a contact or noncontact repellent was evaluated against two laboratory strains (Aedes albopictus and Anopheles dirus) using an excito-repellency test system. N, N-Diethyl-3-methylbenzamide (DEET) was used as a standard reference baseline for comparative purposes. β-Caryophyllene oxide and DEET were tested at concentrations of 0.1, 0.25, 0.5 and 1.0% (v/v). In addition, the phototoxic and genotoxic effects of β-caryophyllene oxide were investigated on Balb/c 3T3 mouse fibroblasts (3T3-L1) and Chinese hamster ovary cell line (CHO-K1). The results demonstrated that the higher concentrations of test compounds (0.5 and 1.0%) produced greater behavioral responses. Aedes albopictus was more sensitive to β-caryophyllene oxide than An. dirus. Moderate avoidance response rates (25-56% escape) of Ae. albopictus at 0.5% and 1.0% β-caryophyllene oxide were observed in contact and noncontact trials compared with low response rates from An. dirus (26-31% escape). DEET at ≤1% displayed lower irritancy and repellency (1-38%) than β-caryophyllene oxide when tested against the two mosquito species. Knockdown responses (37%) were only observed in An. dirus exposed to 1% β-caryophyllene oxide in the contact trial. β-Caryophyllene oxide did not show any phototoxic potential (PIF= 0.38) nor was there any significant genotoxic response as indicated by no increase in micro-nucleated cells with or without metabolic activation. β-Caryophyllene oxide could be considered as a safe repellent, effective against mosquitoes. [Display omitted]