PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Weizmann Institute scientists discover: Antioxidants cause fertility problems in females

2011-01-19
(Press-News.org) Antioxidants are sold over the counter everywhere. They're added to food, drink and face cream. But according to Prof. Nava Dekel of the Biological Regulation Department, we still don't have a complete understanding of how they act in our bodies. New research by Dekel and her team, recently published in the Proceedings of the National Academy of Sciences USA (PNAS), has revealed a possible unexpected side effect of antioxidants: They might cause fertility problems in females.

Common antioxidants include vitamins C and E. These work by eliminating molecules called reactive oxygen species that are produced naturally in the body. Stress can cause these chemically active molecules to be overproduced; in large amounts they damage cells indiscriminately. By neutralizing these potentially harmful substances, antioxidants may, theoretically, improve health and slow down the aging process.

But when Dekel and her research team including her former and present Ph.D. students Dr. Ketty Shkolnik and Ari Tadmor applied antioxidants to the ovaries of female mice, the results were surprising: ovulation levels dropped precipitously. That is, very few eggs were released from the ovarian follicles to reach the site of fertilization, compared to those in untreated ovaries.

To understand what lies behind these initial findings, the team asked whether it is possible that the process of ovulation might rely on the very 'harmful' substances destroyed by antioxidants – reactive oxygen species.

Further testing in mice showed that this is, indeed, the case. In one experiment, for instance, Dekel and her team treated some ovarian follicles with luteinizing hormone, the physiological trigger for ovulation, and others with hydrogen peroxide, a reactive oxygen species. The results showed hydrogen peroxide fully mimicked the effect of the ovulation-inducing hormone. This implies that reactive oxygen species that are produced in response to luteinizing hormone serve, in turn, as mediators for this physiological stimulus leading to ovulation.

Among other things, these results help fill in a picture that has begun to emerge in recent years of fertility and conception, in which it appears that these processes share a number of common mechanisms with inflammation. It makes sense, says Dekel, that substances which prevent inflammation in other parts of the body might also get in the way of normal ovulation, and so more caution should be taken when administering such substances.

Much of Dekel's research has focused on fertility -- her previous results are already helping some women become pregnant. Ironically, the new study has implications for those seeking the opposite effect. Dekel: 'On the one hand, these findings could prove useful to women who are having trouble getting pregnant. On the other, further studies might show that certain antioxidants might be effective means of birth control that could be safer than today's hormone-based prevention.'

Dekel and her team are now planning further studies to investigate the exact mechanics of this step in ovulation and to examine its effect on mice when administered in either food or drink. In addition, they plan to collect data on the possible link between females being administered antioxidant supplements and the difficulty to conceive.

INFORMATION:

Prof. Nava Dekel's research is supported by the M.D. Moross Institute for Cancer Research; the Jeanne and Joseph Nissim Foundation for Life Sciences Research; the Yeda-Sela Center for Basic Research; the Willner Family Center for Vascular Biology – Head; the Dwek Family Biomedical Research Fund; the Phyllis and Joseph Gurwin Fund for Scientific Advancement; and the J & R Foundation. Prof. Dekel is the incumbent of the Philip M. Klutznick Professorial Chair of Developmental Biology

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,700 scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.

Weizmann Institute news releases are posted on the World Wide Web at http://wis-wander.weizmann.ac.il, and are also available at http://www.eurekalert.org.

END



ELSE PRESS RELEASES FROM THIS DATE:

Scientists identify avoidable breast cancer risk factors

2011-01-19
Many risk factors for breast cancer are well studied and documented. Thus, scientists are sure by now that early first menstrual period, late onset of menopause and a family history of breast cancer are associated with an increased breast cancer risk. However, neither an individual woman nor medicine can influence whether family members develop breast cancer or at what age menopause starts - these are risk factors on which we have no influence. Scientists of the German Cancer Research Center in the team of Associate Professor (PD) Dr. Karen Steindorf and Professor Dr. ...

2 new species of 'leaping' beetles discovered in New Caledonia

2 new species of leaping beetles discovered in New Caledonia
2011-01-19
Only five species of these so-called 'flea' beetles, out of a global total of 60, had been found to date in New Caledonia, in the western Pacific. A three-year study has now enabled Spanish researchers to discover two new herbivorous beetles – Arsipoda geographica and Arsipoda rostrata. These new beetles hold a secret – they feed on plants that the scientists have still not found on the archipelago. "The study, financed by the National Geographic, went some way beyond merely classifying species, and investigated the ecology of these herbivorous insects with a prodigious ...

New research examines how HIV infections occur on the molecular level

2011-01-19
The UK's National Physical Laboratory (NPL) with the University of Edinburgh and IBM's TJ Watson Research Center have published new research about the structure of an HIV-1 protein that could help to develop new drugs to stop the virus infecting healthy cells. The research provides a new insight into how the changes in structure of a small part of an HIV protein (a membrane proximal peptide) may alter the infection of the virus into healthy cells. The team was able to observe key changes in this part of the protein implicated in the early stages of the infection by using ...

Revealed: 48-hour 'scramble' to discredit MMR concerns

2011-01-19
A series of denials and a failure to formally investigate allegations of misconduct in Andrew Wakefield's MMR research meant the public was misled about the credibility of the paper for six years. Dr Fiona Godlee, BMJ Editor in Chief, says the UK has consistently failed to take research misconduct seriously. She calls on the UK government to establish mandatory oversight of clinical research integrity within the NHS, as happens for publicly funded research in the USA. "This case reveals major flaws in pre and post-publication peer review," she says. "Allegations of ...

Nanotech medicine

2011-01-19
According to the World Health Organisation (WHO), an estimated 322,000 deaths globally per year are linked to severe injuries from fire and in many of these cases death could have been avoided with surgical intervention. In this type of intervention, when major burn patients have insufficient skin left to graft on the most damaged part of their body, new skin has literally to be grown from the patient's own skin cells. However, the long delay in growing the skin can expose the burns patient to increased risk of infection and dehydration; so to help those cells to multiply, ...

Travel websites should inform people about malaria, say doctors

2011-01-19
Travel websites, especially those that offer 'last minute' deals, should inform people about the risks of malaria and the need to take preventative medication before travelling, say experts in infectious diseases today. Their warning, in a letter to this week's BMJ, follows three recent cases of malaria in UK citizens returning from 'winter sun' holidays to the Gambia, where malaria is highly endemic. They all used the same travel website. Two had made a late booking and all failed to take preventative drugs (chemoprophylaxis). Within two weeks of returning to the UK, ...

Answers to black hole evolution beyond the horizon?

2011-01-19
One of the most important predictions of Einstein's theory of General Relativity is the existence of black holes. The dynamics of these systems are not yet fully understood, but researchers from Queen Mary, University of London have now provided a rigorous way of determining the evolutionary stage of a black hole by analysing the region outside where matter cannot escape, the event horizon. Dr Thomas Bäckdahl and Dr Juan A. Valiente Kroon at Queen Mary's School of Mathematical Sciences have developed a method based on properties of the Kerr solution, a time-independent ...

Adult ADHD significantly increases risk of common form of dementia

2011-01-19
Adults who suffer from attention-deficit and hyperactivity disorder (ADHD) are more than three times as likely to develop a common form of degenerative dementia than those without, according to research in the January issue of the European Journal of Neurology. Researchers from Argentina confirmed the link during a study of 360 patients with degenerative dementia and 149 healthy controls, matched by age, sex and education. The dementia patients comprised 109 people with dementia with Lewy bodies (DLB) and 251 with Alzheimer's. "Our study showed that 48 per cent of ...

Are sharks color blind?

2011-01-19
Sharks are unable to distinguish colors, even though their close relatives rays and chimaeras have some color vision, according to new research by Dr. Nathan Scott Hart and colleagues from the University of Western Australia and the University of Queensland in Australia. Their study shows that although the eyes of sharks function over a wide range of light levels, they only have a single long-wavelength-sensitive cone* type in the retina and therefore are potentially totally color blind. Hart and team's findings are published online in Springer's journal Naturwissenschaften ...

Biological Psychiatry special issue: Postmortem research

2011-01-19
Philadelphia, PA, 18 January 2011 - Biological Psychiatry is proud to announce this week's publication of a special issue focusing on postmortem studies of psychosis. This special issue showcases the use of human brains postmortem to study psychiatric disorders, focusing on schizophrenia. The review articles highlight the benefits, achievements, problems, and perhaps most importantly, the future of postmortem research. Postmortem research, which allows scientists to study the brain directly via its tissue, is difficult and expensive. Hence, it is a relatively rare avenue ...

LAST 30 PRESS RELEASES:

Women’s brain regions may lose ability to synchronize after sexual assault

Quitting smoking, even late in life, linked to slower cognitive decline

Critical raw materials are a vital new currency; Europe’s e-waste is the vault

Anesthesiologist-led care helps hip-fracture patients get to surgery faster, with fewer complications

Two-dose recombinant shingles vaccine is effective even accounting for prior receipt of live shingles vaccine

Excessive daytime sleepiness may raise risk of cognitive problems after surgery

Flipping the switch on sperm motility offers new hope for male infertility

Twisting sound: Scientists discover a new way to control mechanical vibrations in metamaterial

Drip by drip: The hidden blueprint for stalagmite growth

mRNA therapy restores sperm production and fertility in mice

New way to weaken cancer cells could supercharge prostate cancer treatment

How sound—but not touch—shapes rhythm in the brain

Exploring the therapeutic potential of hypothermia

Research alert: Bioengineering breathes new life into failed cancer treatment

AI, health, and health care today and tomorrow – the JAMA Summit Report on artificial intelligence

Large genetic study links cannabis use to psychiatric, cognitive and physical health

Social media use trajectories and cognitive performance in adolescents

Music for the brain: Study tests the effect of slow-tempo relaxing music to address delirium in critically ill older adults 

AI models predict sepsis in children, allow preemptive care

Liraglutide vs semaglutide vs dulaglutide in veterans with type 2 diabetes

Antenatal corticosteroids and infectious diseases throughout childhood

New lab-grown human embryo model produces blood cells

Life after near death: Research reveals how to improve support for near-death experiencers

Illinois Chat is launched for campus community

FAU receives $3M federal grant to prevent substance use in at-risk youth

New report shows action to improve gender equity linked to career gains and better business performance

Kiwis could help manage chronic constipation

Breast, lung, and bladder cancer phase 3 trials led by Dana-Farber presented at ESMO Congress 2025

New open-source software allows for efficient 3D printing with multiple materials

Decoding the secrets of ‘chemo brain’

[Press-News.org] Weizmann Institute scientists discover: Antioxidants cause fertility problems in females