甘青虎耳草乙酸乙酯提取物对小鼠肝癌细胞及原位移植瘤的抑制作用

Inhibitory effect of EtOAc extract from Saxifraga taugutica on hepatocellular carcinoma cells and orthotopic-transplanted tumors in mice

目的探讨甘青虎耳草乙酸乙酯提取物(Et OAc extract from Saxifraga taugutica,EST)对小鼠肝癌细胞及原位移植瘤的抑制作用。方法体外实验用不同浓度EST处理H22细胞48 h后,AO/EB双荧光染色,激光共聚焦显微镜观察细胞形态变化;用核酸电泳和流式细胞术检测H22细胞的凋亡情况。建立小鼠肝癌原位移植瘤模型进行体内实验,对比EST低、中、高剂量组对荷瘤小鼠抑瘤率、T淋巴细胞增殖能力以及肝病理变化的影响。结果 EST处理后H22细胞出现凋亡形态学变化,且与浓度正相关;核酸电泳呈凋亡特征性梯状带;流式细胞分析,500μg/m L处理组凋亡率达31%;体内试验显示,EST低、中、高剂量的抑瘤率分别为33.0%、46.7%、64.3%;显著提高小鼠的胸腺指数、T淋巴细胞增殖能力(P <0.05);组织学观察证明EST各剂量组癌细胞有不同程度的生长抑制,形态固缩、向周围组织浸润减少。结论 EST可增强小鼠免疫功能和诱导肿瘤细胞凋亡,具明显的抗肿瘤作用,与剂量正相关。

Objective To explore the effect of Et OAc extract from Saxifraga taugutica( EST) on carcinoma cells and orthotopic-transplanted tumors. Methods Murine cancer cells( H22 cells) were incubated with different concentrations of EST for 48 h in vitro. Morphological changes were examined by laser confocal microscopy after AO/EB double staining. Apoptosis of carcinoma cells was determined by DNA electrophoresis. and flow cytometry. Orthotopictransplanted tumors in mice were established in vivo. The tumor inhibition rate,thymus index,spleen index,and liver pathology were compared between low-dose,medium-dose,and high-dose groups. Results Apoptotic morphological changes of H22 cells were observed,with the level of apoptosis gradually increasing with increased EST concentration. DNA electrophoresis demonstrated a typical ladder pattern. Flow cytometry revealed that the apoptosis rate of H22 cells was 31%in the EST group with 500 μg/m L. In vivo experiments showed that the tumor inhibition rate was dose-dependent to some extent;the best tumor inhibition rate was 64. 3% in the high dose group,followed by tumor inhibition rates of 46. 7% in the medium dose group and 33% in the low dose group. Spleen and thymus indexes in the EST group was significantly higher than those in the model group( P< 0. 05). Histological observation showed that the proliferation and invasion of cancer cells was inhibited to different degrees,and karyopyknosis of cancer cells was identified in the EST group. Conclusion EST could enhance the immune function of mice,induce apoptosis of tumor cells,and significantly inhibit the proliferation of carcinoma cells in a dose-dependent manner.