To explore lead compounds for biological insecticides, nine fatty acids (FAs)' insecticidal activities against Helicoverpa zea (Lepidoptera, Noctuidae) and their cytotoxicity on H. zea neuronal cells (AW1 cells) were evaluated. The results showed that FAs at 1000 mg/L had a mortality rate of 10.0–83.33% and an inhibitory rate on AW1 cells with IC50 values of 74.6–287.37 μM. Particularly, lauric acid exhibited the most excellent bioactivity both in vivo and in vitro among nine FAs. Further, its mode of action was investigated on the AW1 cells, and the results showed that lauric acid induced apoptosis on the AW1 cells, involving a decrease of mitochondrial membrane potential (ΔΨm) and an increase of caspase-9/3 activity and reactive oxygen species (ROS) levels. Furthermore, by detecting the expression of apoptosis protein, we found that the levels of Bcl-2 fell whereas the levels of cytochrome c and Bax rose remarkably. These results showed that FAs such as lauric acid could be potential lead compounds with a novel mode of action and highly insecticidal activity against H. zea.
Ye Zifan,Fu Lei,Li Shuangyu,Chen Ziying,Ouyang Jianhong,Shang Xinci,Liu Yanli,Gao Lianghui,Wang Yipeng
Non-direct antimicrobial cationic peptides (NDACPs) are components of the animal innate immune system. But their functions and association with antimicrobial peptides (AMPs) are incompletely understood. Here, we reveal a synergistic interaction between the AMP AW1 and the NDACP AW2, which are co-expressed in the frog Amolops wuyiensis . AW2 enhances the antibacterial activity of AW1 both in vitro and in vivo, while mitigating the development of bacterial resistance and eradicating biofilms. AW1 and AW2 synergistically damage bacterial membranes, facilitating cellular uptake and interaction of AW2 with the intracellular target bacterial genomic DNA. Simultaneously, they trigger the generation of ROS in bacteria, contributing to cell death upon reaching a threshold level. Moreover, we demonstrate that this synergistic antibacterial effect between AMPs and NDACPs is prevalent across diverse animal species. These findings unveil a robust and previously unknown correlation between AMPs and NDACPs as a widespread antibacterial immune defense strategy in animals.
危险品化学品经营许可证（带存储）