| Title | Subchronic toxicity study on soy isoflavones in rats. | | Author(s) | Zhang WZ, Cui WM, Zhang X, Wang W, Jia XD, Zhang XP, Li N | | Institution | Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100021, China. | | Source | Biomed Environ Sci 2009 Jun; 22(3):259-64. | | MeSH | Animals
Dose-Response Relationship, Drug
Drug Administration Schedule
Follicle Stimulating Hormone
Isoflavones
Male
Rats
Rats, Sprague-Dawley
Soybeans
Thyroxine
Triiodothyronine
| | Abstract | OBJECTIVE: To investigate the subchronic toxicity of soy isoflavones (SIF) in male rats.
METHOD: Fifty Sprague-Dawley rats were randomly divided into 5 groups, 10 rats per group. SIF were given to rats in different groups by gavage at dose of 0, 0.2, 0.5, 1.5, and 4.5 g/kg bw, respectively for 13 weeks. Clinical manifestations, body weight, and food consumption were observed weekly. At the end of the study, urinalysis, hematology, clinical chemistry, total testosterone, and follicle-stimulating hormone were tested, and histopathological examinations were performed.
RESULTS: No mortality, ophthalmic abnormalities or treatment-related clinical signs were identified during the study. As compared with the control group, significantly lower body weights and food consumption were observed in 1.5 and 4.5 g/kg bw groups. In clinical chemistry tests, triglyceride was significantly decreased and high-density lipoprotein cholesterol was significantly increased in all SIF-treated groups. Total testosterone levels were significantly lower in 0.50, 1.50, and 4.5 g/kg bw dose groups than in the control group. Microscopic examination showed that the mammary glands exhibited hyperplasia and excreted latex in rats of the 4.5 g/kg bw group. No changes attributable to treatment of SIF in other parameters were found.
CONCLUSION: SIF at high dosages caused significant endocrine disruption in male rats. The no observed adverse effect level (NOAEL) of SIF to male rats in this study is considered to be 0.20 g/kg bw. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, Non-U.S. Gov't
| | PubMed ID | 19725470 |
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