Inhibitory effects of phenolic compounds on development of naturally occurring preneoplastic hepatocytic foci in long-term feeding studies using male F344 rats
✍ Scribed by A. Hagiwara; Y. Kokubo; Y. Takesada; H. Tanaka; S. Tamano; M. Hirose; T. Shirai; N. Ito
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 682 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0270-3211
No coin nor oath required. For personal study only.
✦ Synopsis
Five phenolic compounds, namely caffeic acid, sesamol, hydroquinone, catechol, and 4-methoxyphenol, were fed to groups of 30 male F344 rats at dietary levels of 2, 2, 0.8, 0.8, and 2%, respectively, for 2 years. Retardation of body weight and elevated relative liver weights were noted for all groups. Formalin-fixed and paraffinembedded liver tissues from rats killed terminally were cut and stained for glutathione S-transferase placental form (GST-P) and tumor growth factor CI (TGFa) immunohistochemically. Numbers and areas of GST-P-positive (GST-P') foci per unit area of liver section were measured, and the respective treatedkontrol proportional values were calculated to be 58 and 57% for caffeic acid, 58 and 54% for sesamol, 71 and 71% for hydroquinone, 58 and 133% for catechol, and 49 and 39% for 4methoxyphenol. These data were comparable with results obtained with mediumterm liver bioassays (It0 test). However, no intergroup differences were detected with regard to quantitative findings for TGFa' foci, which were relatively rare. Longterm inhibitory effects of phenolic compounds on liver carcinogenesis, predicted from the It0 test, were thus confirmed in the present feeding studies using quantitative analysis of immunohistochemically demonstrable GST-P' foci as end point marker lesions.