Vitamin E for protection against oxidative stress

Vitamin E protects T cells from oxidative stress

09/04/2015

Oxidative stress, which can be triggered for example by increased UV radiation or other environmental influences, leads to impairment of the immune system, which in turn is associated with an increased susceptibility to various diseases, according to the Communication from ETH Zurich. However, vitamin E can counteract the threat of damage to the immune system, the ETH continues.

The scientists at the Swiss Federal Institute of Technology (ETH) have taken a closer look at the effects of oxidative stress on the immune system and found that the division of the so-called T cells is disturbed by oxidative stress, which increases susceptibility to and increases infectious diseases Chronic illnesses bring with it. The supply of vitamin E, however, can alleviate this stress on the immune cells and protect them from damage, reports ETH Zurich.

UV radiation as a cause of oxidative stress
As an example of the causes of oxidative stress, the scientists mention, among other things, skiing in high mountains in bright sunshine and dazzling white snow. Not infrequently formed under this condition after the day of skiing of herpes viruses produced cold sores, according to the statement of the ETH. Because the increased UV radiation can cause free radicals in the body, which leads to oxidative stress, which weaken the immune system, and thus favor the proliferation of herpes viruses. „In addition to UV radiation, other environmental influences also lead to high oxidative stress in the body, such as air pollution, smoking or alcohol consumption, and not least infections“, The scientists report on Professor Manfred Kopf from the Institute for Molecular Health Sciences of ETH Zurich. Similarly, oxidative stress is involved in many diseases, if not the cause of their development.

Explanation for the effects of oxidative stress
Given the negative health effects of oxidative stress, various ways to reduce it are discussed, with the emphasis on the use of vitamin supplements to combat free (oxygen) radicals. Scientists at the Institute of Molecular Health Sciences at ETH Zurich have now investigated the effects of the administration of vitamin E on oxidative stress and immune defense. Based on these questions, they came across a phenomenon, „that explains the effects of oxidative stress on immune cells“, so the message of the ETH.

Propagation of T cells after infection
The scientists explain that when a foreign body such as a virus or other pathogen enters the body, certain immune cells, the so-called T cells, react with strong and rapid multiplication. One of its subclasses, the CD8 + T cells, would, for example, kill the virus-infested body cells and thereby eliminate the virus. Other T cells, the CD4 + T cells, are responsible for the coordination of the immune response against all types of pathogens. Until this as „generals“ immune system cells „It can take one week because there are too few of them at the beginning of an infection that can specifically recognize a particular pathogen“, This is the message from ETH Zurich. Only after „enemy contact“ would be the few „scout“ begin to divide, making a copy (clone) every eight to twelve hours. After a few days, there would be hundreds of thousands of special T cells „only this superiority can successfully fight the infection“, Report Professor Kopf and colleagues.

Missing tools to ward off the infections
However, according to the scientists, the process of cell division does not work if the T cells are damaged by severe oxidative stress. Because the enzyme (Gpx4), which is responsible for the repair of oxidative damage to the cell membrane, lacking as a repair enzyme in the immune cells, causing the dividing T cells die. The immune system can not eliminate the pathogens and the infection becomes chronic, reports the doctoral candidate and first author May Matsushita, in the journal „Journal of Experimental Medicine“ (JEM) (http://jem.rupress.org/content/212/4/555.abstract) from the study results.

Vitamin E protects the immune cells from genetic defects
In their experiments on mice, „where the Gpx4 gene can be inactivated cell-specifically or at any time“, To their own surprise, the researchers found that administering a high dose of vitamin E through the feed saved the animals' immune cells from cell death. The special mice were developed by researchers from the Helmholtz Zentrum München. The ETH scientists changed the genome of the rodents so, „that the Gpx4 gene was inactive only in T cells or in certain phagocytes of the immune system.“ Normally, this would have required cell death during division. But with simultaneous intake of high vitamin E doses, no corresponding adverse effects were noted. If the amount of vitamin E in the mouse food was 500 milligrams per kilogram of feed (about ten times higher than in the standardized normal diet), the „Amount of antioxidant 'to protect the cell membrane of T cells from damage, so that they could multiply and successfully fend off the virus infection“, reports ETH Zurich.

Evidence for the benefits of food supplements
According to the researchers, the study results are certainly to be evaluated as an argument for the previously controversial vitamin supplementation. Although the benefit of vitamin tablets remains according to Professor Kopf „a controversial topic“, there is little strong scientific evidence for the benefits of vitamin supplements. However, the more interesting is the current study, which proves the benefits of vitamin E. „Our work shows that even a genetic defect of a major component of the antioxidant machinery of a cell can be compensated by administering a high dose of vitamin E.“, reports head and adds: „This is new and surprising.“ Also, the decoding of the effect of oxidative stress on the T cells should be considered scientifically valuable and significant. In the investigations had become clear, „that immune cells die the same way in oxidative stress as certain types of cancer cells undergo treatment with a cytostatic drug.“ This programmed cell death is called „Ferroptose“ and was first described in 2012 in a scientific publication. „We are the first to show that immune cells as well as cancer cells suffer the same death due to oxidative stress“, so head professor.

Targeted prescription of antioxidants for oxidative stress?
The importance of the current study results for human health is in the view of the ETH professor so far unclear, because people who are normally healthy and eat a balanced diet usually do not need vitamin supplementation. However, it can be quite useful to think of supplementing with vitamin E or other fat-soluble antioxidants with high levels of oxidative stress, such as those that arise in everyday life from infections or UV light. In addition, there is massive oxidative stress in patients with certain neurodegenerative diseases or diabetes, with antioxidants providing good support for treatment, according to the ETH Zurich Communication. On the basis of the current study results, however, no statement can be made about the required dosage, since the investigations were carried out only on the basis of a mouse model and no differentiated analysis of the required dosages was carried out. (Fp)