Table of Contents
ISRN Oncology
Volume 2011, Article ID 896826, 9 pages
http://dx.doi.org/10.5402/2011/896826
Research Article

Prepubertal Daidzein Exposure Enhances Mammary Gland Differentiation and Regulates the Expression of Estrogen Receptor-Alpha and Apoptotic Proteins

1School of Life Sciences, Jawaharlal Nehru University, New Mehrauli Road, New Delhi-110067, India
2School of Life Sciences, Devi Ahilya University, Khandwa Road Complex, Indore-452 017, MP, India

Received 4 April 2011; Accepted 10 May 2011

Academic Editor: A.-B. Jacobsen

Copyright © 2011 Prachi Mishra et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Mechanism of chemoprevention by daidzein (500 μg/g bwt) was examined by injecting it subcutaneously at 16th, 18th, and 20th day postpartum, followed by counting of terminal end buds (TEBs), terminal ducts (TDs), and lobules and immunohistochemistry of ER-α, Bcl2, Bax, and caspase-3. DNA fragmentation was also analysed to measure the apoptosis level. Estradiol benzoate (EB) (500 ng/g bwt) and dimethyl sulphoxide (DMSO) were used as reference and vehicle, respectively. Observations show a significant enhancement of mammary gland differentiation at postnatal day 21 (PND21) as well as PND50. There was a significant decrease of ER-α expression at PND21 and increase in its expression at PND50, in daidzein-treated animals. The ratio of expression of Bcl-2 to Bax proteins increased at PND50 the same whereas, it decreased at PND50 due to daidzein. An increased expression of caspase-3 and DNA fragmentation was also seen due to daidzein at PND50. The mammary gland of EB-treated animals showed response a somewhat similar to that of daidzein-treated animals.