Carcinogenicity study of gamma-oryzanol in F344 rats.
The carcinogenic potential of gamma-oryzanol, a drug mainly used for the treatment of hyperlipidaemia, was studied in F344 rats. Groups of 50 males and 50 females were fed a diet containing 0 (control), 200, 600 or 2000 mg gamma-oryzanol/kg body weight/day for 2 yr. Although females in the highest dose group (2000 mg/kg body weight) showed a slight decrease in body weight at 104 wk, there were no treatment-related changes in general condition, food consumption, mortality, organ weight or haematology. Histopathological examination showed various tumours in all groups, including the control group. In the control and 2000-mg/kg groups, high tumour incidences were observed in the testes, pituitary and thyroid of males, and in the pituitary, uterus and mammary gland of females; however, there was no significant increase in the incidence of any tumours between the control and the 2000-mg/kg groups. The findings indicate that under the experimental conditions described gamma-oryzanol was not carcinogenic in F344 rats.
Tamagawa
M
M
Department of Toxicology, Otsuka Pharmaceutical Co. Ltd, Tokushima, Japan.
Shimizu
Y
Y
Takahashi
T
T
Otaka
T
T
Kimura
S
S
Kadowaki
H
H
Uda
F
F
Miwa
T
T
D000284:Administration, Oral; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D000960:Hypolipidemic Agents / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced*; D009929:Organ Size / Q000187:drug effects; D010666:Phenylpropionates / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344
D002273:Carcinogens; D000960:Hypolipidemic Agents; D010666:Phenylpropionates; C013172:gamma-oryzanol