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Early Effects of Blueberry and Concord Grape Intake on Rat Mammary Gland Development Suggest Potential Protective Mechanisms for Mammary Tumorigenesis
Author(s) -
Wu Xianli,
Till S. Renee,
Badger Thomas M,
Prior Ronald L,
Simmen Rosalia CM
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a366-d
Subject(s) - mammary gland , endocrinology , biology , medicine , mammary tumor , lactation , offspring , pten , carcinogenesis , epithelium , andrology , cancer , apoptosis , pregnancy , breast cancer , biochemistry , genetics , pi3k/akt/mtor pathway
Blueberries (BB) and Concord grapes (CG) are rich in anthocyanins and other polyphenols, which may be linked to reduced incidence of chemically‐induced mammary carcinogenesis in animal models. We evaluated the early effects of dietary exposure to BB and CG on mammary glands of female rat offspring. Dams at gestation day 4 were assigned to AIN‐93G (control) or test (AIN‐93G + BB or CG freeze‐dried powders; 2.5, 5, and 10% w/w) diets. Female pups were sacrificed at postnatal day 21, and their mammary glands isolated and analyzed for morphology and expression of the tumor suppressor PTEN. Carmine‐stained whole mounts showed that the mammary ‘epithelial trees’ of BB and CG rats were more highly branched than those of control rats. The architectural differences between BB or CG and control mammary glands were dose‐dependent, with 5% BB and 2.5% CG showing the greatest morphological effects. Immunoreactive PTEN, whose increased expression was previously correlated with mammary tumor protection, was highest in ductal epithelium of 5% BB rats (P<0.026), but did not differ in 2.5% CG rats relative to controls. However, vaginal opening (a measure of sexual maturity) occurred one day earlier in 2.5% CG rats (P<0.04) than in rats of other diet groups. Findings suggest that early exposure to CG and BB may advance mammary gland development to lower mammary tumor risk, albeit through distinct mechanisms. USDA‐CRIS‐6251‐5100002‐06S.