[Enhancement of di-n-butyl phthalate on the estrogenic activities of esters of p-hydroxybenzoic acid].
OBJECTIVE
To studied the estrogenicity of single propylparaben (PP), butylparaben (BP), di-n-butyl phthalate (DBP), and their joint treatment.


METHODS
Estrogenicity was studied using the uterotrophic assay of immature female Wistar rats. Animals were subcutaneously (sc) treated for three consecutive days with single PP, BP, DBP and their joint treatment. Estrogenic activity effects were identified through the ratio of uterus/body weight.


RESULTS
Estrogenic activities of PP and BP was detected, the lowest observed effect level (LOEL) of PP and BP were 400mg/kg and 200mg/ kg, respectively, estrogenic activity of DBP was not detected at the doses of 400mg/kg and 100mg/kg. In the equal effect dosage joint treatment of PP and BP, uterus proliferation effects were observed at the doses of 1 and 1/2 LOEL, but the effect was not observed at the doses of 1/4 LOEL. In the joint treatment with DBP increased uterus proliferation effects of PP or BP were observed at matches of 100mg/kg PP(1/4LOEL) + 400mg/kg DBP, 200mg/kg PP(1/2LOEL) + 400mg/kg DBP and 100mg/kg BP(1/2LOEL) + 400mg/kg DBP.


CONCLUSIONS
It was suggested that the DBP could have potential enhancing action to estrogenic activities of PP or BP, and the estrogenic activity of PP enhancement by DBP could be stronger than that of BP.
Chang
Bing
B
Institute of Occupational Health and Poisoning Control, China CDC, Beijing 100050, China. bjchangbing@sohu.com
Ge
Junhui
J
Liang
Yuxiang
Y
D000818:Animals; D000831:Animals, Newborn; D003993:Dibutyl Phthalate / Q000633:toxicity*; D004357:Drug Synergism; D052244:Endocrine Disruptors / Q000633:toxicity*; D005260:Female; D010226:Parabens / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects
D052244:Endocrine Disruptors; D010226:Parabens; D003993:Dibutyl Phthalate; C038091:butylparaben; C038193:4-hydroxybenzoic acid; C006068:propylparaben