Looking into anti-oxidants that target mitochondria, the team from Newcastle University found that the most potent was Tiron which provided 100% protection of the skin cell against UVA sun damage and the release of damaging enzymes causing stress-induced damage.
“To discover that Tiron offers complete protection against UVA damage is exciting and promising, however, it is early days as Tiron is not a naturally occurring compound and has not yet been tested for toxicity in humans although there have been a few studies on rats,” says author, Mark Birch-Machin, Professor of Molecular Dermatology.
Co-author at Newcastle University Dr Anne Oyewole adds: “This finding on Tiron provides us with a platform to study an antioxidant - preferably a naturally occurring compound with a similar structure which could then be safely added to food or cosmetics.”
Lab tests
The laboratory tests carried out compared the protection offered against either UVA radiation or free radical stress by several antioxidants, some of which are found in foods or cosmetics.
While UVB radiation easily causes sunburn, UVA radiation penetrates deeper, damaging our DNA by generating free radicals which degrades the collagen that gives skin its elastic quality.
The scientists found that the most potent anti-oxidants were those that targeted the batteries of the skin cells, and compared these mitochondrial-targeted anti-oxidants to other non-specific antioxidants such as resveratrol, found in red wine, and curcumin found in curries, that target the entire cell.
Skin cells treated with a panel of antioxidants were exposed to a physiological dose of UVAradiation. The DNA within the skin cells was then copied using a polymerase chain reaction machine, in order to assess the amount of DNA damage present.
Tiron on top
Using this method, Tiron which has the chemical composition 4,5-Dihydroxy-1,3-benzenedisulfonic acid disodium salt monohydrate was revealed to provide 100% protection against mitochondrial DNA damage.
Resveratrol was found to protect against 22% of both the UVA radiation and stress-induced damage, whilst curcumin offered 16% protection against oxidative stress and 8% against UVA.
The team intends to take the work forward by further understanding the mechanism of how Tiron works, developing a compound similar to Tiron and testing for toxicity in humans. They say it will be several years before it is ready for use as a skin product or supplement.
The research was funded by BBSRC and Unilever, and published in The FASEB Journal.
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Comparing the effects of mitochondrial targeted and localized antioxidants with cellular antioxidants in human skin cells exposed to UVA and hydrogen peroxide. Anne O. Oyewole, Marie-Claire Wilmot, Mark Fowler, and Mark A. Birch-Machin. The FASEB Journal. doi: 10.1096/fj.13-237008