血啉甲醚对斜纹夜蛾SL细胞的氧化损伤

通过研究血啉甲醚（hematoporphyrin monomethyl ether, HMME）对斜纹夜蛾Spodoptera litura (SL)细胞的增殖抑制率IC₅₀、处理后细胞内丙二醛（malondialdehyde, MDA）的生成量、细胞内还原型谷胱甘肽（glutathione, GSH）水平和细胞器超微结构的变化，明确血啉甲醚对SL细胞的氧化损伤，并探讨将血啉甲醚及其衍生物拓展应用到农业害虫防治领域的可行性。用MTT法测定血啉甲醚光照处理下对SL细胞24 h和48 h的IC₅₀值分别为8.35 μg/mL和7.66 μg/mL。硫代巴比妥酸（TBA）法测定表明，血啉甲醚光活化后能导致胞内MDA含量明显升高，且MDA的生成量与其浓度呈正相关；当血啉甲醚浓度为50.000 μg/mL，光照处理48 h时，细胞内MDA生成量达到173.08±3.51 nmol/L。5,5′-二硫代双 (2-硝基)苯甲酸（DTNB）法对处理后细胞内GSH水平测定结果表明，光活化后的血啉甲醚处理SL细胞能导致细胞内还原型GSH相对含量随血啉甲醚浓度升高而显著降低；当血啉甲醚浓度为50.000 μg/mL，处理48 h时，光照处理组细胞内GSH相对含量较之同浓度黑暗处理下降了39.59%。扫描电镜观察显示，6.250 μg/mL的HMME处理细胞并光照后，细胞膜表面出现了明显的孔洞，有的细胞出现了花样皱褶和内陷。这些结果表明在血啉甲醚的试验剂量下，SL细胞受到了氧化损伤。

Oxidative damage to Spodoptera litura SL cells by hematoporphyrin monomethyl ether

The oxidative damage to Spodoptera litura (SL) cells by hematoporphyrin monomethyl ether (HMME), the second generation photosensitizer for PDT, was investigated. IC₅₀ value, the output of MDA and the content of GSH, and the alteration of cell organelles were assayed or observed to explore the feasibility of applying HMME and its derivatives to control agricultural pest insects. IC₅₀ values obtained with MTT at 24 h and 48 h post HMME treatment with irradiation were 8.35 μg/mL and 7.66 μg/mL, respectively. The results obtained with TBA method showed that photoactivated HMME could induce MDA increasing in dose dependent manner. When the treatment concentration of HMME was 50.000 μg/mL, the output of MDA at 48 h post treatment was 173.08±3.51 nmol/L. The GSH level, however, exhibited a contrary tendency. When the treatment concentration of HMME was 50.000μg/mL, the GSH content decreased by 39.59% compared with the same concentration treatment without irradiation. The SEM photographs showed that distinct pores in SL cells treated with 6.250 μg/mL HMME and irradiation, and sunken and plicate membrane appeared in the treated SL cells. All the evidence indicated that HMME had induced oxidative damage to SL cells.