title: Endocrine-disrupting effects of styrene oligomers that migrated from polystyrene containers into food.
abstract: The endocrine-disrupting effects of styrene dimers (SD: NSD-01, -08 and -09) and styrene trimers (ST: NST -01, -03 and -12), which migrated from polystyrene (PS) containers into instant food, were investigated together with styrene monomer (SM) using in vitro and in vivo assays. In the estrogen (ER) and androgen receptor (AR) binding assay, SM, SD and ST showed no binding activity at concentration of 10(-10)-10(-5) mol/l. In order to evaluate the estrogenic activity in vivo, the uterotrophic assay was conducted. When prepubertal and ovariectomized adult rats were dosed with SM, SD and ST for 3 days by subcutaneous injection, these compounds did not induce significant increase in uterine weight. Additionally, to evaluate anti-androgen activity in vivo, the Hershberger assay for anti-androgenic activity in the presence of testosterone treatment was conducted. When castrated, testosterone-treated immature male rats were dosed SM, SD and ST for 7 days by oral gavage, these compounds did not induce a decrease in the seminal vesicle, ventral prostate and levator ani plus bulbocavernosus muscle weights. To evaluate the effects on hormones other than sex hormones, the thyroid hormone receptor (TR) binding assay and rat serum prolactin (PRL) was conducted. In the TR binding assay, SM, SD and ST showed no binding activity at a concentration of 10(-5) mol/l. When ovariectomized rats were dosed with SM, SD and ST for 3 days by sc injection, the results showed there was no change in rat serum PRL. From the above these results, we concluded that SM, SD and ST exhibit no apparent estrogenic, androgenic, anti-androgenic and thyroid activity.
authors.affiliation: Central Research Institute, Nissin Food Products Co., Ltd, 2247, Noji-Cho, Shiga 525-0055, Kusatsu, Japan. k-date@mbl.nissinfoods.co.jp
authors.forename: K
authors.initials: K
authors.lastname: Date
authors.forename: K
authors.initials: K
authors.lastname: Ohno
authors.forename: Y
authors.initials: Y
authors.lastname: Azuma
authors.forename: S
authors.initials: S
authors.lastname: Hirano
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Sakurai
authors.forename: Y
authors.initials: Y
authors.lastname: Nobuhara
authors.forename: T
authors.initials: T
authors.lastname: Yamada
mesh_terms: D000818:Animals; D019281:Dimerization; D004702:Endocrine Glands / Q000187:drug effects*; D005260:Female; D005506:Food Contamination; D018857:Food Packaging; D005837:Genitalia, Male / Q000033:anatomy & histology; D008297:Male; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D011137:Polystyrenes; D011388:Prolactin / Q000097:blood; D051381:Rats; D011916:Rats, Inbred F344; D011944:Receptors, Androgen / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000378:metabolism; D013343:Styrenes / Q000378:metabolism / Q000633:toxicity*; D014599:Uterus / Q000033:anatomy & histology
chemical_list: D011137:Polystyrenes; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011988:Receptors, Thyroid Hormone; D013343:Styrenes; D011388:Prolactin