Semi-Field Evaluation and Genotoxicity of Chlorophyllin Applied Against Aedes aegypti Larvae (Diptera, Culicidae)

Dengue fever is a mosquito-borne viral infection that recently appeared in Upper Egypt. Globally, more than 50 million new infections occur annually. It currently lacks effective treatment, necessitating vector control strategies targeting Aedes aegypti. This study investigates the potential of chlorophyllin as a control agent against dengue vectors. Chlorophyllin was characterized by FTIR analysis. The singlet oxygen quantum yield was determined by comparing the luminescence intensity at 1270 nm with that of phenalenone, yielding a value of 0.18. LC₅₀ and LC₉₀ values were calculated for chlorophyllin. Its larvicidal efficacy was assessed, revealing an LC₅₀ of 0.47 ppm in controlled laboratories and 93.3 ppm in semi-field conditions, demonstrating its superior potency against Aedes aegypti compared to pheophorbide and Bacillus sphaericus. Genotoxicity was analyzed through Random Amplified Polymorphic DNA (RAPD)-PCR, and histopathological changes were documented through microscopic examination. The genotoxicity results revealed high similarity in the DNA configurations of chlorophyllin-treated larvae and healthy individuals (similarity index of 0.8), whereas pheophorbide and Bacillus sphaericus exhibited substantial genetic deviations. Histopathological analysis demonstrated severe disruptions in chlorophyllin-treated larvae's gut epithelial cells and muscle tissues, including epithelial detachment and irregular cell shapes. These findings position chlorophyllin as a promising gut toxin larvicide for Aedes aegypti control, with a more favorable genetic safety profile than conventional chemicals.