Andrograpanin-induced growth disruption and histopathological effects on the larval midgut of Aedes aegypti (Linnaeus) and Culex quinquefasciatus (Say) (Diptera: Culicidae)
摘要
Andrograpanin, a bioactive compound derived from Andrographis paniculata, exhibits growth-disrupting and histopathological effects on the larvae of Aedes aegypti and Culex quinquefasciatus, two major vectors of mosquito-borne diseases. Larvae were exposed to sublethal concentrations (0.5, 1.0, 1.5, and 2.0 ppm) of andrograpanin for 24 h, and their developmental changes were assessed through morphological and histopathological analyses. Significant developmental delays were observed in both species, with prolonged larval and pupal periods and disruptions in normal metamorphosis. In Ae. aegypti, the larval period increased from 5.8 days (control) to 8.2 days at 0.5 ppm, and the pupal stage extended from 2.0 to 2.5 days. The most severe effects were observed at 2.0 ppm, where adult emergence was completely inhibited. Similarly, Cx. quinquefasciatus exhibited an extended larval period from 6.0 days (control) to 7.6 days and a prolonged pupal stage from 2.0 to 2.6 days. Morphological abnormalities, including dark and pale pigmentation, elongated abdomens, and distorted body structures, were prominent at higher concentrations. Histopathological analysis revealed epithelial cell damage and inflammatory responses in the midgut of treated larvae. Statistical analysis confirmed highly significant effects of andrograpanin on mosquito development (p < 0.0001). These findings suggest that andrograpanin, even at low sublethal concentrations, has larvicidal potential that could be explored for mosquito control, particularly in vector-borne disease management.