不同浓度中药柴胡提取物对人肝癌细胞内Ca2+和p53表达的影响

目的：测定不同浓度中药柴胡（Bupleurun Chinese DC，BCDC）提取物对BEL-7402细胞内游离钙离子浓度（Ca^2＋]i）和p53表达的影响，以探索柴胡逆转BEL-7402细胞多药耐药的机制。方法：用Fura-2／AM作为细胞内钙离子的荧光指示剂，用双波长荧光分光光度计测定不同浓度柴胡提取物作用下BEL-7402细胞内Ca^2＋]i及其剂量-效应关系；用免疫组化法检测不同条件下BEL-7402细胞的p53表达。结果：柴胡可使人肝癌细胞BEL-7402细胞内游离钙离子浓度下降（P〈0．001），但不具有剂量-效应关系；BEL-7402细胞呈p53天然突变。结论：柴胡可使人肝癌细胞BEL-7402细胞内游离钙离子浓度下降，为一种钙离子通道阻滞剂（calcium channel blocker，CCB），提示钙离子通道阻滞作用为柴胡逆转BEL-7402细胞多药耐药的机制之一；BEL-7402细胞呈p53天然突变也可直接或间接影响肿瘤多药耐药性的表达。

Effects of the Extracts from BCDC on Intracelluar Calcium and p53 of Human Hepatoma Cells

Objective: To measure the effects of the extracts from BCDC on intracellular free calcium and the expression of p53of human hepatoma BEL-7402 cells,in order to explore the mechanism of BCDC reversing the multidrug resistance of BEL-7402 cells of human hepatoma.Methods: Double wavelength spectrofluorometer with Fura-2/AM as the fluorescence indicator for intracellular free calcium ions(Ca~(2+)]i) was used to measure the changes of Ca~(2+)]i in BEL-7402 cells of human hepatoma affected by BCDC and the expression of p53 was examined by immunochemical assay.Results: BCDC can reduce intracellular free calcium of human hepatoma BEL-7402 cells(P<0.001).Immunochemical assay showed that BCDC had no effect on p53 gene expression.Conclusion: BCDC is one of calcium channel blocker and is able to reduce intracellular free calcium of human hepatoma BEL-7402 cells,which indicats that the effect of calcium channel blocker may be one of the mechanism of BCDC reversing the mutidrug resistance of BEL-7402 cells of human hepatoma.And the p53 mutation of BEL-7402 cells can affect the expression of MDR1.