Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Component in soy products causes reproductive problems in laboratory mice

12.01.2006


Genistein, a major component of soy, was found to disrupt the development of the ovaries in newborn female mice that were given the product. This study adds to a growing body of literature demonstrating the potentially adverse consequences of genistein on the reproductive system.


This illustration depicts normal egg cell development in mice as schown in the top: the bottom image shows the genistein-treated animals where the abnormal egg clustering occurs.



"Although we are not entirely certain about how these animal studies on genistein translate to the human population, there is some reason to be cautious," said Dr. David A. Schwartz, Director of the National Institute of Environmental Health Sciences (NIEHS). "More clinical studies are needed to determine how exposure during critical windows of development can impact human health."

Genistein is the primary naturally occurring estrogen in plants (called phytoestrogens) and can mimic the effects of estrogen in the body. Genistein can be found in foods containing soy such as soy-based infant formulas as well as over-the-counter dietary supplements.


The results of this study conducted by researchers at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, in collaboration with an investigator at Syracuse University, are published in the January issue of Biology of Reproduction.

The NIEHS researchers previously showed that mice given genistein immediately after birth had irregular menstrual cycles, problems with ovulation, and problems with fertility as they reached adulthood. The new study looks at the direct effects of genistein on the ovaries during early development.

"We knew genistein was linked to reproductive problems later in life, but we wanted to find out when the damage occurs," said Retha R. Newbold, MS, a developmental endocrinologist at NIEHS and an author on the study. "The study showed that genistein caused alterations to the ovaries during early development, which is partly responsible for the reproductive problems found in adult mice."

Female mice were injected with three different doses of genistein during their first five days of life. The genistein given to the mice was comparable to what human infants might receive in a soy-based formula, which is approximately 6-9 mg/kg per day. The researchers examined the effects on days 2 through 6.

The researchers found effects at all levels. Mice treated with the high dose (Gen 50 mg/kg) were infertile and mice treated with lower doses were subfertile, meaning they had fewer pups in each litter, and fewer pregnancies. Mice receiving the highest level of genistein, 50 mg/kg per day, had a high percentage of egg cells that remain in clusters, unable to separate and therefore develop abnormally. The researchers explain that oocytes that remain in clusters are less likely to become fertilized based on previous research. The largest difference between the genistein treated and normal mice was found at six days of age where 57 percent of the egg cells in the non-treated ovaries were single or unclustered; and only 36 percent in the genistein treated group were single

We think genistein inhibits the oocytes or egg cells from separating apart," said Wendy Jefferson, Ph.D. of NIEHS and lead researcher on the paper. "Since there are many egg cells in the same follicle instead of just one, the resources from the surrounding cells are spread too thin and they can’t get the support they need to become a mature functioning egg cell."

"You need at least one good healthy single oocyte that is ovulated and fertilized by a sperm to get a healthy baby. Genistein seems to have a way of making this task very difficult," said Newbold.

"I don’t think we can dismiss the possibility that these phytoestrogens are having an effect on the human population," said Dr. Jefferson. "They may not show their effects or be detected until later in life, but chances are they are having an effect."

Robin Mackar | EurekAlert!
Further information:
http://www.niehs.nih.gov
http://www.niehs.nih.gov/home.htm

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>