Effects of different insecticidal components on induction of apoptosis in Spodoptera frugiperda cultured cell line Sf9.
The induction of apoptosis of eight typical insecticidal components, including azadirachtin, in Spodoptera frugiperda cultured cell lines Sf9 were determined in this paper to investigated the specificity of apoptosis induction by insecticides through the research model of inverted phase contrast microscope assay and DNA agarose gel electrophoresis. The results were showed that the typical morphological characteristics of apoptosis appeared, including a lot of apoptotic bodies, treated in 72 h with azadirachtin at a mass concentration of 0.15-1.50 µg/mL and 36 h with comptothecin at 0.35-3.50 µg/mL. The necrosis would become a dominant role after the treatment prolonged or the concentration increased. The typical DNA Ladder was got by agarose gel electrophoresis, which showed that azadirachtin and comptochetin possessed distinct apoptosis induction and the induction peak time was 24-48 h or 12 h after treatment with at a mass concentration of 1.5 µg/mL of azadirachtin or 0.35-3.50 µg/mL of comptochetin, respectively. However, the same changes could not appeared in Sf9 cells within 72 h treated at a mass concentration of 0.1-10.0 µg/mL of matrine, hexaflumuron, chlorpyriphos, methomyl or cypermethrin, and 0.048-4.800 µg/mL of 20-hydroxyecdysone, respectively. It was suggested that the apoptosis induction by insecticide would be specific and the induction effectiveness depend on the kind of test chemicals, cell line, treated dose and time.