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 luteinizi
|Contact: Yivsam Azgad|
Weizmann Institute of Science