Abstract: 【Objective】It’s important of surveying the oxidative damage and its mechanism to insect cell of induced by photosensitizer to speed its application. 【Method】MTT was used to acquire the toxicity of α-terthienyl (α-T) to Spodoptera litura cell. The output of malondialdehyde and relative content of glutathione were determined by 2-thiobarbituric acid and 5,5’-dithio-bis(2-nitrobenzoic aicd) respectively. Transmission electron microscope was employed to observe the influence of α-T to the membrane and organelle of SL cell. 【Results】The LC50 value of α-T to SL cell was 0.21μg/mL, whereas the dose of rotenone was 12.25μg/mL . The output of MDA had the same changing tendency with the concentration of α-T, whereas the content of GSH had the negative correlation with the concentration of α-T. According to TEM, cell membrane and karyotheca swelled and couldn’t retain integrity. The intracellular substances leaked out. The mitochondria expanded, the nuclear appeared pycnosis, the chromatin condensed. The biological membrane and subcellular organelle were damaged severely. 【Conclusion】After oxidative damage occurring, the output of MDA increased notably, whereas the relative content of GSH decreased. This indicated that the antioxidant ability of cell weakened. The result of TEM implied that SL cell suffered from oxidative damage under the appointed dose.

Key words: α-terthienyl, Spodoptera litura cell, oxidative damage, malondialdehyde, glutathione