Genotoxicity of Chlorophyllin Compared with Other Pesticides Used to Control Culex pipiens Larvae (Diptera: Culicidae)

Abstract

Mosquitoes are prime examples of vectors for various diseases such as malaria, the West Nile virus, elephantiasis, dengue fever, and yellow fever. The repeated use of chemical pesticides has created numerous obstacles and environmental risks including mosquito resistance to insecticides. This work aimed at assessing the larvicidal effect of chlorophyllin (a water-soluble substance obtained after removing the phytol tail from chlorophyll) and coumarin as photosensitizers, compared to the microbial insecticide Bacillus thuringiensis israelensis (Bti) and permethrin, a chemical insecticide, against the third larval instar of Culex pipiens larvae monitoring its mode of action and its genotoxic effect. Photosensitizers exposed to sunlight generate reactive oxygen species (ROS), with singlet oxygen (1O2) capable of killing parasitic organisms primarily in aquatic systems. Our experiments demonstrated a high potential activity of Na-Cu chlorophyllin against mosquito larvae after at least 8 hours of incubation in the dark. The LC50 values were 0.22x10-3, 0.96x10-2, 13.7x10-2, and 4.59x10-1 mg/ l after 24 hours of exposure to chlorophyllin, Bti, permethrin, and coumarin, respectively. The molecular changes after treatment with chlorophyllin were tracked using RAPD-PCR with six arbitrary DNA primers. Results confirmed no significant changes or genetic damage after treatment with chlorophyll derivatives