蒲葵子抗肿瘤活性部位筛选及抗血管生成作用

目的：筛选蒲葵子抗肿瘤作用的活性部位,探讨蒲葵子抗血管生成的作用机制。方法：采用MTT法检测蒲葵子醇提物各分离部位对肿瘤细胞株增殖的影响,ELISA法检测对肿瘤细胞分泌血管内皮生长因子（VEGF）水平的影响。以活性部位作用于VEGF诱导的人脐静脉内皮细胞株（HUVEC）,RT-PCR和Western Blotting方法分析内皮细胞Flk-1 mRNA和蛋白的表达变化。结果：蒲葵子醇提物乙酸乙酯部位可选择性抑制结肠癌细胞株HT-29和膀胱癌细胞株T24肿瘤细胞的生长,其抑制率可分别达74.66%和86.52%,并可显著降低各肿瘤细胞株分泌VEGF水平。石油醚部位对HT-29和T24生长也有一定的抑制作用,其最高抑制率分别为43.80%和38.67%,并可降低各肿瘤细胞分泌VEGF水平,但作用强度均不及乙酸乙酯部位。水和正丁醇部位未表现抗肿瘤活性。对VEGF诱导内皮细胞表达FlK mRNA和蛋白,乙酸乙酯部位表现出明显的抑制作用。结论：蒲葵子醇提物乙酸乙酯分离部位有较好的抗肿瘤作用,是抗肿瘤作用的主要活性部位,其作用机制可能与降低肿瘤细胞分泌VEGF,抑制VEGF诱导内皮细胞表达Flk-1 mRNA和蛋白有关。

Screening of Anti-tumor Parts from the Seeds of Livistona chinensis and Its Anti-angiogenesis Effect

OBJECTIVE: To screen the anti-tumor active parts from the seeds of Livistona chinensis R. Br. and its mechanism of anti-angiogenesis effect. METHODS: MTT assay and ELISA were used to detect the proliferation and the secretion of vascular endothelial growth factor (VEGF) of chronic myelogenous leukemia K562, ovarian neoplasm SKOV3, colon carcinoma HT-29 and bladder cancer T24 cell lines respectively. The expression of fetal liver kinase (Flk-1) protein and mRNA in endothelial cells induced by VEGF was analyzed by Western blotting and RT-PCR. RESULTS: The ethyl acetate part of alcohol extract from seeds of Livistona chinensis R. Br. could selectively inhibit the proliferation of HT-29 and T24 cell lines in a dose-dependent manner, the maximum inhibitory rate were 74.66% and 86.52%, and could significantly inhibit the secretion of VEGF protein of the four tumor cell lines. The petroleum ether part had similar inhibitory effect as well as the ethyl acetate part, but its potency was inferior to the ethyl acetate part, the maximum inhibitory rate were 43.80% and 38.67%, the water-soluble and n-butanol parts had no effect on different tumor cell lines. The ethyl acetate part could reduce significantly the expression of Flk-1 protein and mRNA of HUVEC induced by VEGF. CONCLUSION: The ethyl acetate part, which is considered as active part of alcohol extract from seeds of Livistona chinensis R. Br., has fine anti-tumor activity, and its mechanism might be associated with reducing VEGF protein secretion and inhibiting the expression of Flk-1 mRNA and protein.