Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nutritional friend or foe? Vitamin E sends mixed messages

06.03.2006


One of the most powerful antioxidants is truly a double-edged sword, say researchers at Ohio State University who studied how two forms of vitamin E act once they are inside animal cells.



In the past couple of decades, a slough of studies has looked at the benefits of vitamin E and other antioxidants. While a considerable amount of this research touts the advantages of consuming antioxidants, some of the studies have found that in certain cases, antioxidants, including vitamin E, may actually increase the potential for developing heart disease, cancer and a host of other health problems.

This study provides clues as to why this could happen, say Jiyan Ma, an assistant professor of molecular and cellular biochemistry, and his colleague David Cornwell, an emeritus professor of molecular and cellular biochemistry, both at Ohio State.


The two men led a study that compared how the two most common forms of vitamin E –– one is found primarily in plants like corn and soybeans, while the other is found in olive oil, almonds, sunflower seeds and mustard greens – affect the health of animal cells. The main difference between the two forms is a slight variation in their chemical structures.

In laboratory experiments, the kind of vitamin E found in corn and soybean oil, gamma-tocopherol, ultimately destroyed animal cells. But the other form of vitamin E, alpha-tocopherol, did not. (Tocopherol is the scientific name for vitamin E.)

“In the United States we tend to eat a diet rich in corn and soybean oil, so we consume much greater amounts of gamma-tocopherol than alpha-tocopherol,” Cornwell said. “But most of the vitamin E coursing through out veins is alpha-tocopherol – the body selects for this version. We want to know why that is, and whether the selection of the alpha-tocopherol confers an evolutionary benefit in animal cells.”

Cornwell and Ma explain their findings in this week’s Early Edition of the Proceedings of the National Academy of Sciences. They conducted the study with several colleagues from the departments of molecular and cellular biochemistry and chemistry at Ohio State.

The researchers conducted laboratory experiments on cells taken from the brains of mice. They treated some of the cells with metabolic end products, called quinones, of alpha- and gamma-tocopherol.

When the body breaks down vitamin E, these end products are what enter and act on our cells. However, Ma said that our bodies get rid of most gamma-tocopherol before it ever has a chance to reach its quinone stage.

Still, some nutritional supplement companies make and sell gamma-tocopherol supplements, promoting this version of vitamin E as a good antioxidant source. In theory, taking a vitamin supplement – a concentrated form of the vitamin - increases the amount of that substance in the body.

Using laboratory techniques that allowed them to detect the activity of the quinones inside the cells, the researchers found that the gamma-tocopherol quinone formed a compound which destroyed that cell. It did so by preventing proper protein folding in the cells, which causes a cellular response that is involved in a variety of human diseases, including diabetes and Parkinson’s disease.

However, the alpha-tocopherol quinone did not kill cells, nor did it interfere with protein folding. The researchers repeated their experiments on kidney cells cultured from monkeys and on skin cells cultured from mice and found similar results.

“We think that gamma-tocopherol may have this kind of damaging effect on nearly every type of cell in the body,” Ma said.

While the study doesn’t get into the possible effects on health, the researchers raise the point that there is still a great deal that isn’t known about how antioxidants act in the body. In order to get to that point, scientists must study how antioxidants and cells interact on their most fundamental levels.

This work was funded through grants from the National Science Foundation Environmental Molecular Science Institute and the Large Interdisciplinary Grants Program in the Office of Research at Ohio State.

Jiyan Ma | EurekAlert!
Further information:
http://www.osu.edu

More articles from Health and Medicine:

nachricht Penn vet research identifies new target for taming Ebola
12.01.2017 | University of Pennsylvania

nachricht The strange double life of Dab2
10.01.2017 | University of Miami Miller School of Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>