Effects of single and repeated in vitro exposure of three forms of parabens,methyl-,butyl-And propylparabens on the proliferation and estradiol secretion in MCF-7 and MCF-10A cells

Background: here,we analyzed the dose-(0.2,2,20,200 nm or 2 μm) and time-(48,96,144 and 196 h) dependent activity of a single or repeated exposure of methyl-,butyl-and propylparaben on the proliferation of mcf-7 human breast cancer cells and mcf-10a human breast epithelial cells. additionally,the effect on estradiol secretion,gene and protein expression of aromatase (cyp19a1) was investigated. methods: cell proliferation was determined by alamarblue assay,and estradiol secretion by elisa kits. gene and protein expression of cyp19a1 was measurement using real time pcr and western blot,respectively. results: stimulatory effect of a single exposure of all doses of tested parabens and time dependent effect of repeated exposure to methylparaben,propylparaben and butylparaben,the same as that of 17b-estradiol,on proliferation of mcf-7 cells was observed. only at low doses methyl-and butylparabens increased mcf-10a cells proliferation after single exposure,but no effect of repeated exposure was noted. exposure at low doses of all of the parabens significantly increased 17b-estradiol (e2) secretion in mcf-7 cells but had the opposite effect on mcf-10a cells. it was correlated with gene and protein expression of cyp19a1 in mcf-7 and mcf-10 cells. conclusions: in summary,present study indicates a different mechanism of proliferative action of parabens in investigated cell lines. in mcf-7 breast cancer cell line it is probably due to stimulatory action on estradiol secretion and aromatase activity. in mcf-10aby an unknown mechanism,independent on stimulatory action on estradiol section,which requires further investigation. copyright © 2013 by institute of pharmacology.