海发菜提取物脱镁叶绿素酸盐A对六种癌细胞的光毒性

目的 探讨脱镁叶绿素酸盐A（PPBa）的体外光动力抗肿瘤活性及化学特性。方法 将乳腺癌细胞（MCF-7）、肺癌细胞（A549）、宫颈癌细胞（HeLa）和3种肝癌细胞（HepG2、hep3B、sk-Hep1）接种于96孔板中，MTT法观察PPBa的光毒性和暗毒性大小，光照强度和药物浓度对PPBa光毒性的影响，Hoechst染色在共聚焦显微镜观察PPBa的摄取，活性氧检测试剂盒通过流式检测和共聚焦显微镜下观察单线态氧的产生，根据PPBa自身的发光特性通过酶标仪测吸光度观察PPBa的光漂性。结果 PPBa对6种癌细胞都有极强的光毒性和极低的暗毒性，PPBa的主要摄取部位是细胞质，单线态氧的产生与给药浓度具有强依赖性，光漂性极低。结论 脱镁叶绿素酸盐A对乳腺癌细胞（MCF-7）的光毒性最强，各种性质优良，具有理想的光敏剂特性。

Phototoxicity of Pheophorbide A Extracted from Gracilaria Lemaneiformis on Six Kinds of Cancer Cells

Objective To investigate the photodynamic antitumor activity and chemical characteristics of pheophorbide A (PPBa) in vitro. Methods Breast cancer cells (MCF-7), lung cancer cells (A549), cervical cancer cells (HeLa), and three kinds of hepatoma cells (HepG2, hep3B and sk-Hep1) were planted in 96-well plates. The effects of light and dark toxicity, light intensity, and drug concentration on the phototoxicity of PPBa were investigated by MTT, and the uptake of PPBa was observed by Hoechst staining under a confocal microscope. The production of singlet oxygen was observed by flow cytometry and confocal microscopy with the reactive oxygen species detection kit. The photobleaching of PPBa was investigated by measuring the absorbance by a microplate reader according to the luminescence characteristics of PPBa. Results PPBa showed strong phototoxicity and low dark toxicity to six kinds of cancer cells, and IC50 values to cancer cells were as follows: MCF-7: 1.033 μmol/L, A549: 1.911 μmol/L, HeLa: 2.319 μmol/L, HepG2: 2.015 μmol/L, Hep3B: 2.089 μmol/L, sk-Hep1: 2.467 μmol/L. The main uptake site of PPBa was the cytoplasm. The production of singlet oxygen was strongly dependent on the administration concentration, and photobleaching was very low. Conclusion For the six kinds of cancer cells, PPBa has the highest phototoxicity to breast cancer cells (MCF-7), with excellent properties and ideal photosensitizer characteristics.