Research On The Interaction Between Typical Chlorinated Phosphorus Flame Retardants And Protein And Their Cytotoxicity

Chlorinated phosphorus flame retardants has been a new kind of environmental pollutants with wide attention because of its wide distribution in the environment.The research on its ecotoxicity has become a hot issue at present.This study combined analytical chemistry with cell biology and chose tris?1,3-dichloroisopropyl?phosphate?TDCPP?,tris?2-chloropropyl?phosphate?TCPP?,and tris?2-chloroethyl?phosphate?TCEP?as typical representatives of chlorinated phosphorus flame retardants to analyze the interaction with human serum albumin?HSA?and their oxidative damage to SMMC-7721 human hepatocarcinoma cells.The main work and conclusions are as follows:1.Capillary electrophoresis?CE?has been used to establish the analytical method of binding reactions between typical chloro-phosphorusflame retardants and human serum albumin?HSA?.The binding mechanisms of TDCPP,TCPP,TCEP and HSA were studied by simulating and constructing interaction system of ligand?retardants?-receptor?HSA?,and then the similarities and differences of the binding mechanism between different typical chlorinated phosphorus flame retardants and different concentrations was compared.The results showed that the combined reactions of TDCPP,TCPP and TCEP with HSA were reacted to form TDCPP-HSA,TCPP-HSA and TCEP-HSA compounds.The mean apparent competition binding constants(K_TDCPP–_HSA=6.3111×10⁴ L·mol^-1,K_TCPP–_HSA=1.2598×10³ L·mol^-1,K_TCEP–_HSA=2.5706×10³ L·mol^-1)which was based on the changes of the effective mobility and determined through theoretical equation.The binding parameters indicated that the binding reactions of TDCPP-HAS was slow equilibrium reaction while TCPP-HSA and TCEP-HAS were quick equilibrium reaction.The research results have illustrated the physiological effects of serum protein transporting TDCPP,TCPP and TCEP and provided a theoretical reference for in-depth studying of the combined reaction of chloro-phosphorusflame retardants with biological macromolecules.2.We used TDCPP,TCPP and TCEP as typical representatives of chlorinated phosphorus flame retardants to analyze their cytotoxicity to SMMC-7721 human hepatocarcinoma cells.All three chemicals reduced cell viability over a period of 72 h.The exposure increased extracellular levels of lactate dehydrogenase and decreased intracellular levels of superoxide dismutase and catalase in a concentration-dependent manner.Expression of the SOD-1 and CAT genes was down-regulated.The results showed that TDCPP,TCPP,and TCEP could exert oxidative damage to SMMC-7721 cells.The oxidative damage may one of the cytotoxic mechanisms for organism.The ecological toxicity of chlorinated phosphorus flame retardants should be investigated in detail.