中文摘要：

【目的】研究从苦瓜Momordica charantia叶乙醇提取物中分离出的苦瓜素Ⅰ和新化合物苦瓜苷B对亚洲玉米螟Ostrinina furnacalis幼虫血细胞（Ofh）的毒力作用,并探讨其作用机理。【方法】用CCK-8法比较了苦瓜素Ⅰ、苦瓜素Ⅱ、苦瓜苷B和印楝素A对Ofh细胞的增殖抑制作用;用倒置相差显微镜和荧光倒置显微镜观察了苦瓜素Ⅰ及苦瓜苷B对Ofh细胞形态结构的影响,并用台盼蓝染色法和流式细胞术研究了其对Ofh细胞的致坏死作用。【结果】苦瓜素Ⅰ、苦瓜素Ⅱ和苦瓜苷B对Ofh细胞有明显的增殖抑制作用,36 h后的IC50值分别为7.566,24.340及8.514μg/m L,苦瓜素Ⅰ及苦瓜苷B对Ofh细胞的增殖抑制作用明显强于苦瓜素Ⅱ及对照药物印楝素A。苦瓜素Ⅰ和苦瓜苷B处理后的Ofh细胞表现为体积膨大、表面变得粗糙并有明显的空泡现象,严重破坏了Ofh细胞的形态结构。进一步的研究结果表明,8μg/m L的苦瓜素Ⅰ及苦瓜苷B处理Ofh细胞12~48 h,细胞死亡率均高于对照组,呈一定的时间依赖关系,说明苦瓜素Ⅰ对Ofh细胞的急性毒力高于苦瓜苷B。Ofh细胞经AO/EB染色后,用荧光显微观察发现,苦瓜素Ⅰ和苦瓜苷B处理组细胞膜破裂,细胞核受损严重,细胞呈不均匀桔黄色-橙红色荧光,呈典型的坏死特征。流式细胞仪检测结果表明,苦瓜素Ⅰ和苦瓜苷B对Ofh细胞具有明显的致坏死作用。8μg/m L苦瓜素Ⅰ和苦瓜苷B处理Ofh细胞36 h后,总坏死率分别为74.92%±2.02%和49.77%±1.69%。【结论】苦瓜素Ⅰ和新化合物苦瓜苷B对Ofh细胞均具有有效的增殖抑制和致坏死作用,这可能是苦瓜素类化合物对亚洲玉米螟的拒食作用及抑制其生长发育和生殖力的主要机制之一。

英文摘要：

【Aim】To ascertain the toxic effect of momordicin I and a new compound（ charantin B） from ethanol extracts of Momordica charantia leaves on larval Ostrinina furnacalis hemocytes（ Ofh）,and to illuminate its action mechanism as well. 【Methods】The inhibition effects of momordicin I,momordicin II,charantin B and azadirachtin A on Ofh cells were compared by using CCK-8 assay. The effects of momordicin I and charantin B on Ofh cell morphology structure were observed by using inverted phase contrast microscopy and fluorescence microscopy,and the induced necrosis effects on Ofh cells were studied by using trypan blue staining and flow cytometry（ FCM） technologies. 【Results】Momordicin I,momordicin II and charantin B had apparent inhibition effects on Ofh cell proliferation,with the IC50 values of 7. 566,24. 340 and 8. 514 μg / m L,respectively,at 36 h after treatment. The cytotoxicity of momordicin I and charantin B were significantly higher than that of momordicin II and azadirachtin A.Using inverted phase contrast microscopy,we found that after exposure to momordicin I and charantin B,Ofh cell shapes changed to circular and swelling increased, and the cellular membrane bubbled,suggesting that both momordicin I and charantin B could destruct cell morphology structure. Further research indicated that the mortality rates of cells in the groups treated with 8 μg / m L momordicin I and charantin B were significantly higher than that of the control group at 12- 48 h after treatment,and in a time-dependent manner,indicating that the cytotoxicity of momordicin I is significantly higher than that of charantin B. Fluorescence microscopy observation revealed that nuclear morphology was irregular,the cell membrane dissolved and the nucleus appeared to be severely damaged after AO / EB staining,and cells exhibited a non-uniform orange-yellow fluorescence after treatment with 8 μg / m L momordicin I and charantin B,showing a typical characteristic of necrosis. Flow cytometry analysis showed that Ofh cells tr