Harmine induced apoptosis in Spodoptera frugiperda Sf9 cells by activating the endogenous apoptotic pathways and inhibiting DNA topoisomerase I activity.
Harmine, a useful botanical compound, has demonstrated insecticidal activity against some pests. However, harmines mechanism of action has not been thoroughly elucidated to date. To preliminarily explore harmines insecticidal mechanisms, the cytotoxicity of harmine against Spodoptera frugiperda Sf9 cells was comprehensively investigated. Our results indicated that harmine induced apoptosis in Sf9 cells, as evidenced by cellular and nuclear morphological changes, DNA laddering and increases in caspase-3-like activities. In addition, activation of the mitochondrial apoptotic pathway by harmine was confirmed by the generation of ROS, opening of mitochondrial permeability transition pores (MPTPs), increase in cytosolic Ca