Real Importance of Oxidants and Antioxidants - New Measurement Techniques Developed

New methods provide insights into the body's own oxidants
The state of oxidation in the organism is closely related to nutrition, physical activity, infections, cancer and possibly even aging, according to the latest release from the German Cancer Research Center (DKFZ) in Heidelberg. Scientists at the DKFZ have developed two new biological measuring systems with which disease-relevant changes in the oxidation state of the cells can be better analyzed.

The importance of the antioxidants and antioxidants for human health according to the researchers according to "many errors and myths." So the oxidants are traditionally more likely to have a harmful effect, while antioxidants are considered beneficial to health. "But researchers have known for many years that body-own oxidants as essential messengers help to maintain the functions of the organism," reports the DKFZ. The type and amount as well as the spatial and temporal concentration of the oxidants decide here according to the experts about the effect. "That's why we're interested in which cells and tissues in the context of the entire organism in which situation and for how long which oxidants produce," says cell biologist Tobias Dick from the DKFZ.

Cancer cells cause most of a significant change in the oxidation state in the organism. (Image: vitanovski / fotolia.com)

Oxidation state so far difficult to measure
The exact detection of the oxidation state is of particular interest to physicians in view of the connection with various diseases. According to the DKFZ, the development of luminous biosensors, which Tobias Dick and his team had already achieved a few years ago, was "an important step in exploring the body's own oxidants." The biosensors' blueprints were thus incorporated into the genetic material of experimental animals and the transmitted light signals from the sensors indicated the presence of very specific oxidants - "in real time and on the single cell exactly", reports the DKFZ. However, the medical benefit has been low so far, as the light signals can penetrate the tissue only at a short distance. So far, the application of such sensors, according to the researchers so far focused on small or transparent organisms. For example, the sensors are particularly well suited for fruit flies or zebrafish. By contrast, the sensors were less well suited for use in mice, which are an important model organism in medical research.

Distribution of oxidants visualized
The research team led by Tobias Dick, however, has now managed to overcome the difficulties in capturing the biosensor by permanently preserving its condition in tissue removed. For this purpose, the scientists use a special combination of cold and chemical treatment. "The spatial distribution of the oxidants could be visualized on a fixed tissue section just as it corresponds to the distribution in the living organism," reports the DKFZ. The results of the researchers were published in the journal "Science Signaling". The authors describe in the article as examples the distribution of oxidants in a growing tumor, the reaction of the liver to an inflammation and the reaction of muscle fibers to hunger. "With the new method, the researchers now want to study the influence of diseases and drugs on the distribution of oxidants throughout the body," said the DKFZ.

Real time measurement of the oxidant level
In a second study, Tobias Dick's scientists focused on improving the sensitivity of biosensors in order to visualize "the smallest metabolic fluctuations in the production of oxidants, such as those occurring during dietary changes or during physical activity". For this they developed for the first time a biosensor based on the so-called peroxiredoxins, which are known as proteins with the highest sensitivity to hydrogen peroxide. The new sensors are designed to be highly sensitive to the slightest increase or decrease in the oxidant level, the scientists report. In a test of the sensors in yeast cells, according to the DKFZ, "even the movement of oxidants between individual structures within the cell could be monitored." The second study was published in the journal "Nature Chemical Biology". The next goal is now to bring together the two new developments, for example, to explore how a minimal change in the production of oxidants related to the development of metabolic diseases. (Fp)