title: Chronic oral toxicity of a synthetic antioxidant, 2,2'-methylenebis(4-ethyl- 6-tert-butylphenol), in rats.
abstract: Groups of 30 Wistar rats of each sex were treated with 2,2'-methylenebis(4-ethyl-6-tert-butylphenol) (MBEBP) in the diet at levels of 0, 0.03, 0.1 and 0.3% for up to 18 months. In both sexes, survival rates of treated groups were similar to those of the controls. Body weight gain was depressed (0.3% group in males, 0.1 and 0.3% groups in females). Slight anaemia (0.3% groups in both sexes) and increase of blood urea nitrogen (0.3% groups in both sexes) were observed. Histopathologically, vacuolization of the parathyroid gland cells (0.3% group in males and all treated groups in females) and degenerative changes of the kidney (0.1 and 0.3% groups in males) were observed. No neoplastic responses following MBEBP administration were noted. From these results, the no-observed-adverse-effect level (NOAEL) for MBEBP toxicity was estimated as 12 mg kg-1 body wt. day-1 in male rats. In female rats, the lowest-observed-adverse-effect level (LOAEL) was estimated as 15 mg kg-1 body wt. day-1.
authors.affiliation: Division of Toxicology, National Institute of Health Sciences, Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takagi
authors.forename: K
authors.initials: K
authors.lastname: Takada
authors.forename: K
authors.initials: K
authors.lastname: Sai
authors.forename: J
authors.initials: J
authors.lastname: Momma
authors.forename: Y
authors.initials: Y
authors.lastname: Aida
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Naitoh
authors.forename: M
authors.initials: M
authors.lastname: Tobe
authors.forename: R
authors.initials: R
authors.lastname: Hasegawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kurokawa
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000633:toxicity*; D001774:Blood Chemical Analysis; D001835:Body Weight / Q000187:drug effects; D002084:Butylated Hydroxytoluene / Q000031:analogs & derivatives* / Q000633:toxicity; D004032:Diet; D004435:Eating / Q000187:drug effects; D005260:Female; D006128:Growth / Q000187:drug effects; D007668:Kidney / Q000473:pathology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010280:Parathyroid Glands / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D002084:Butylated Hydroxytoluene; C030577:2,2'-methylenebis(ethyl-6-tert-butylphenol)