Toxicity And Injury Research Of Eight Bisphenol A Analogues To The MCF-7 Human Breast Carcinoma Cell Line

Bisphenol A(BPA) is a widespread environmental endocrine disruptor (EDC). As additives of epoxy resins, polycarbonate plastics, flame retardants and other produts, bisphenol A analogues were widely used in the production of cups, bottles, food and beverage containers, medical equipments etc, and meanwhile, new uses have been developed. In the long-term use process, or under alkaline conditions and high temperature, bisphenol A was slowly released into the environment from related products, and accumulated in the environment easily, impacting on the surrounding organisms through water, air, soil and food contamination.The current research all focus on BPAs’estrogen effects, little on cytotoxic effects. So far, studys found that within a narrow concentration range, BPA affected MCF-7 cell proliferation was mainly dependent on its estrogenic action through interference intracellularenzyme activity and cellular metabolic activity, while slightly higher concentrations of BPA would damage cells and cause inapoptosis.So it is very important to research cytotoxicity of BPA analogues at the cellar level by mulitiple evaluate index. And also, the pollutants in the environment is not separate existence, the crowd is always in the production and life in a variety of pollutants under mixed exposure. Study the combined effects of pollutants more than the separate role of the pollutants close to the actual, more practical significance. In this study, the toxic effects of 8 kinds of BPA compounds exposed to MCF-7(ER-) cells were analyzed by microplate toxicity analysis, and preliminary foundated for further evaluation of the environmental toxic effects of BPA analogues with DNA damage and cell membrane damage. We used eight kinds of bisphenol Analogues in this study: (2,2-bis(4-hydroxyphenyl)propane (BPA),2,2-bis (4-hydroxyphenyl) butane (BPB), 4,4’-ethylidenebisphenol (BPE).2-bis (4-hydroxy-3-methylphenyl) propane (BPC). 5,5’-(1-Methylethylidene)bis[1,1’-(bisphenyl)-2-ol] (BPQ), bis (4-hydroxyphenyl) sulfide (TDP),4,4’-(hexafluoroisopropylidene)-diphenol (BPAF),4,4’-(1-phenylethylidene)-bisphenol (BPAP). The proliferation of 8 bisphenol A analogues and 12 mixtures constructed by the effect-equivalent concentration (EC50 or EC 10) method and uniform design consisted of all 8 bisphenol A analogues on MCF-7 (ER-) were detected by MTS assay. The concentration-response curve(CRC) between the observed inhibition toxicity test compounds were developed and concentration addition (CA) and independent action (IA) fuctions were used to study the interaction of mixtures.2,4-dinitrophenylhydrazine was used to detect lactate dehydrogenase (LDH) released to cell culture medium by 8 BPA analogues exposing to MCF-7(ER-). Comet assay was used detect DNA damage by 5 BPA analogues exposing to MCF-7(ER-).The results showed that all the concertration-response relationships were effectively described by the Weibull or Logit fuction. The toxic order among 8 bisphenols(expressed in-logEC50) was:BPQ>BPAF>BPAP>BPB>BPC<TDP> BPE> BPA. Mixture toxicities were evaluated and predicted with CA and IA, the results showed that the combination of various concentrations of eight kinds of BPA analogues can be predicted by CA fuction perfectly. Results of LDH assay and SCGE assay showed that in effect concentration of EC20, cell proliferation was inhibited slightly; In effect concentration of EC40, cell proliferations were inhibited and DNA was damaged significantly, cell membranes began to show obvious damage and LDH revealed evidently, large number of apoptotic cells began to appear.At the end, a cytotoxicity detection system about stable expression of Metridia luciferase of MCF-7 (ER-) was planed to build to measure luciferase activity in the indirect detection of toxic effects of environmental pollutants, making toxicity detection more simple.