A 13-week subchronic toxicity study of dietary administered saponin-rich and isoflavones-containing soybean extract in F344 rats.
A subchronic toxicity study of soybean extract was performed in F344 rats with dietary administration at concentrations of 0%, 1.25%, 2.5% and 5% for 13 weeks. No mortality or abnormal clinical signs in any group were observed. Body weight gains were decreased with a tendency for reduction of feed intake in the 1.25% and above female and 5% male groups. In males, absolute and relative liver weights were increased in the 1.25% and above groups. In females relative kidney weights were increased in the 1.25% and above groups. Other significant changes such as decreased RBC and hematocrit and increased urea nitrogen were detected in the 2.5% and/or 5% groups. On histopathological observation, atrophy of the ventral prostate was observed in all animals in the 5% male group. Mucification and atrophy of the vaginal epithelium and increased atretic follicles in ovaries were noted in 2.5% and 5% female rats. Based on the above findings the lowest-observed-adverse-effect level for male and female rats was estimated to be 1.25% (707.2 and 751.8 mg/kg b.w./day, respectively).
Cho
Y-M
YM
Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-Ku, Tokyo 158-8501, Japan. ymcho@nihs.go.jp
Imai
T
T
Ito
Y
Y
Takami
S
S
Hasumura
M
M
Yamazaki
T
T
Hirose
M
M
Nishikawa
A
A
D000818:Animals; D001772:Blood Cell Count; D001835:Body Weight / Q000187:drug effects; D004032:Diet; D004435:Eating / Q000187:drug effects; D005260:Female; D005518:Food Preferences; D006128:Growth / Q000187:drug effects; D007529:Isoflavones / Q000633:toxicity*; D008297:Male; D019055:No-Observed-Adverse-Effect Level; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000473:pathology; D010936:Plant Extracts / Q000633:toxicity; D011467:Prostate / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D012503:Saponins / Q000633:toxicity*; D013025:Glycine max / Q000633:toxicity*
D007529:Isoflavones; D010936:Plant Extracts; D012503:Saponins