不同终点检测5种双酚A类化合物对MCF-7的细胞毒性

双酚A(BPA)及其类似物作为聚碳酸酯的主要合成原料,一直是环境污染的重要问题.其雌激素效应是当今科学研究的重点,而毒性效应研究甚少.为评估环境中BPA类物质的毒性效应,实验采用四唑盐(MTS)比色法检测5种双酚A类化合物对人雌激素受体缺失乳腺癌细胞MCF-7(ER-)增殖活性的影响,2,4-二硝基苯肼法检测细胞乳酸脱氢酶(LDH)露出率,单细胞凝胶电泳(SCGE)检测DNA损伤.用非线性最小二乘法对MTS实验结果拟合剂量-效应曲线,表明所有的剂量-效应曲线(DRC)均能用Weibull或者Logit函数有效表征.以模型估算的半数效应浓度负对数值(pEC50)评估5种化合物的毒性大小依次为:BPB>BPC>TDP>BPE>BPA.LDH检测以及SCGE检测受试化合物对MCF-7(ER-)的损伤作用表明,在效应浓度EC20下,细胞核DNA轻微损伤,细胞增殖受轻微抑制;在效应浓度EC40下,细胞核DNA损伤严重,细胞增殖受到显著抑制,从而导致细胞膜通透性显著改变,使LDH大量露出.

Detecting the Cytotoxicities of Five Bisphenol A Analogues to the MCF-7 Human Breast Carcinoma Cell Line Through Different Endpoints

As the main synthetic raw materials of polycarbonate, bisphenol A (BPA) and its analogues have been important issues in environmental pollution. The current studies focus mainly on BPA's estrogen effects and little on their cytotoxic effects. To assess the cytotoxicities of the five BPA analogues, we employed the MTS assay to determine the inhibition toxicity to MCF-7 (ER-), 2,4-dinitrophenylhydrazine assay to determine the release rate of lactate dehydrogenase (LDH) escaping into cell culture medium, and single cell gel electrophoresis assay (SCGE) to detect DNA damage. The dose-response curves (DRC) between the observed inhibition toxicities and concentrations of the BPA compounds in MTS assay were fitted by using the nonlinear least squares (NLS) and the results showed that all the dose-response relationships were effectively described by the Weibull or Logit function. The toxicities expressed by -lgpEC₅₀ were BPB>BPC>TDP>BPE>BPA. LDH assay and SCGE assay showed that when the concentrations of BPA analogues were EC₂₀, the MCF-7 cell proliferation was slightly inhibited due to its little damaged DNA, and at EC₄₀the cell proliferations were significantly inhibited due to the seriously damaged DNA, leading to the damage of cell membrane and release of LDH.