The study is a breakthrough in determining how these compounds can cause reproductive health problems, as well as in providing a key building block for how to treat these problems.
The study is the first to show that the actual physical organization of a region of the brain that is important for female reproduction can be significantly altered by exposure to phytoestrogens – or plant-produced chemicals that mimic hormones – during development.
Specifically, the study finds that the compounds alter the sex-specific organization of the hypothalamus – a brain region that is essential to the regulation of puberty and ovulation. The study also shows that the phytoestrogens could cause long-term effects on the female reproductive system.
While the study examined the impact of these compounds on laboratory rats, neurotoxicologist Dr. Heather Patisaul – who co-authored the study – says the affected “circuitry” of the brain is similar in both rats and humans. Patisaul is an assistant professor in NC State’s Department of Zoology. Her co-author is Heather Bateman, a doctoral student in the department.
Patisaul says this finding is extremely important because, while the changes in brain structure cannot be reversed, “if you understand what is broken, you may be able to treat it.” Patisaul says she is in the process of evaluating the effects of these compounds on the ovaries themselves.
Patisaul says that this study is also “a step towards ascertaining the effects of phytoestrogens on developing fetuses and newborns.” Patisaul adds that these phytoestrogenic compounds cross the placental barrier in humans and that, while many people are concerned about the effects of man-made compounds on human health, it is important to note that some naturally occurring substances can have similar effects.
In the study, which will be published in an upcoming issue of Neurotoxicology, the researchers exposed newborn rats to physiologically relevant doses of the phytoestrogens genistein and equol, and then looked at reproductive health markers in the rats throughout their adulthood. The neonatal stage of development in rats is comparable to the latter stages of pregnancy for humans, Patisaul says. Genistein is a phytoestrogen that is found in various plants, including soybeans and soy-based foods. Equol is a hormone-like compound that is formed when bacteria found in the digestive system metabolize another phytoestrogen. However, only approximately a third of humans have the necessary bacteria to produce equol.
The study shows that both genistein and equol result in the early disruption of the rats’ estrus cycle – which would be corollary to early onset of menopause in a human. The study also showed that genistein caused the early onset of puberty. The disruption of the estrus cycle could stem from problems with the brain or the ovaries, so the researchers decided to determine if the compounds had any effect on brain development or function.
Patisaul explains that the brains of both female rats and female humans have a region that regulates ovulation. “That part of the brain,” Patisaul says, “is organized by hormones during development – which is the neonatal stage for rats and during gestation for humans.” Patisaul says the new study shows that the female brain is “critically sensitive” to genistein and equol during this crucial stage of development – and that this may indicate that the brain is also especially sensitive during this period to all phytoestrogens and possibly other man-made chemicals, such as bisphenol-A.
Matt Shipman | Newswise Science News
Some brain tumors may respond to immunotherapy, new study suggests
11.12.2018 | Columbia University Irving Medical Center
Climate change and air pollution damaging health and causing millions of premature deaths
30.11.2018 | International Institute for Applied Systems Analysis (IIASA)
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
17.12.2018 | Physics and Astronomy
17.12.2018 | Architecture and Construction
17.12.2018 | Life Sciences