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Author Topic: Antioxidant Tiron / Total protection against some types of sun damage  (Read 1677 times)


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Fresh faced: Looking younger for longer

Newcastle University researchers have identified an antioxidant Tiron, which offers total protection against some types of sun damage and may ultimately help our skin stay looking younger for longer.

Publishing in The FASEB Journal, the authors describe how in laboratory tests, they 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 Newcastle team found that the most potent anti-oxidants were those that targeted the batteries of the skin cells, known as the mitochondria. They 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.  They found that the most potent mitochondrial targeted anti-oxidant was Tiron which provided 100%, protection of the skin cell against UVA sun damage and the release of damaging enzymes causing stress-induced damage.

Author, Mark Birch-Machin, Professor of Molecular Dermatology at Newcastle University said: “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.”

Of the work which was funded by BBSRC and Unilever, co-author at Newcastle University Dr Anne Oyewole said: “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.”
DNA damage

Our skin ages due to the constant exposure to sunlight as ultraviolet radiation from the sun penetrates cells and increases the number of damaging free radicals, especially the reactive oxygen species.  Too many reactive oxygen species can be harmful because they can damage the DNA within our cells.

Over time, this can lead to the accumulation of mutations which speed up ageing and destroy the skin’s supportive fibres, collagen and elastin, causing wrinkles.  Recent studies strongly suggest the damage caused by reactive oxygen species may also initiate and exacerbate the development of skin cancers.

Antioxidants in our diets from green tea, resveratrol which is found in red wine, turmeric which is used in curries and lycopene found in tomatoes, as well as some components in cosmetic creams, are known to neutralise this damage within the cells. They can slow down the damage and the rate of ageing and potentially lower the rate of other sun-induced skin lesions.

The method developed offers the first test which enables the comparison of different antioxidants for their potency in a skin cell based system.

Skin cells treated with a panel of antioxidants were exposed to a physiological dose of ultraviolet A radiation – that is, the same dose that our skin would normally be exposed to on a warm summer’s day. 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.

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, the antioxidant found in red wine, was found to protect against 22% of both the ultraviolet A radiation and stress-induced damage. NAC, a frequently used laboratory-based anti-oxidant, offered 20% protection against oxidative stress and 8% against UVA and curcumin offered 16% protection against oxidative stress and 8% against UVA.

In comparison Tiron offered 100% protection against UVA radiation and 100% protection against oxidative stress.

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.

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

published on: 10th January 2014
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Key Facts:

    Newcastle University is a Russell Group University
    We rank in the top 20 of UK universities in The Sunday Times 2013 University Guide
    Amongst our peers Newcastle is:
        5th in the UK for graduates into jobs (HESA 2011-12)
        10th in the UK for student satisfaction
        Ranked 8th in the UK for Medical research power
        In the UK’s top 12 for research power in Science and Engineering
    95% of our students are in a job or further training within six months of graduating
    We have a world-class reputation for research excellence and are spearheading three major societal challenges that have a significant impact on global society. These themes are: Ageing and Health, Sustainability, and Social Renewal
    Newcastle University is the first UK university to establish a fully owned international branch campus for medicine at its NUMed Campus in Malaysia which opened in 2011
    Our International students put Newcastle University in world's top 12 (ISB 2011)

FASEB J. 2014 Jan;28(1):485-94. doi: 10.1096/fj.13-237008. Epub 2013 Oct 10.
Comparing the effects of mitochondrial targeted and localized antioxidants with cellular antioxidants in human skin cells exposed to UVA and hydrogen peroxide.
Oyewole AO, Wilmot MC, Fowler M, Birch-Machin MA.
Author information

Skin cancer and aging are linked to increased cellular reactive oxygen species (ROS), particularly following exposure to ultraviolet A (UVA) in sunlight. As mitochondria are the main source of cellular ROS, this study compared the protective effects of mitochondria-targeted and -localized antioxidants (MitoQ and tiron, respectively) with cellular antioxidants against oxidative stress-induced [UVA and hydrogen peroxide (H2O2)] mitochondrial DNA (mtDNA) damage in human dermal fibroblasts. With the use of a long quantitative PCR assay, tiron (EC50 10 mM) was found to confer complete (100%) protection (P<0.001) against both UVA- and H2O2-induced mtDNA damage, whereas MitoQ (EC50 750 nM) provided less protection (17 and 32%, respectively; P<0.05). This particular protective effect of tiron was greater than a range of cellular antioxidants investigated. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway provides cellular protection against oxidative stress. An ELISA assay for the Nrf2 target gene heme oxygenase-1 (HO-1) and studies using Nrf2 small interfering RNA both indicated that tiron's mode of action was Nrf2 independent. The comet assay showed that tiron's protective effect against H2O2-induced nuclear DNA damage was greater than the cellular antioxidants and MitoQ (P<0.001). This study provides a platform to investigate molecules with similar structure to tiron as potent and clinically relevant antioxidants.-Oyewole, A. O., Wilmot, M.-C., Fowler, M., Birch-Machin, M. A. Comparing the effects of mitochondrial targeted and localized antioxidants with cellular antioxidants in human skin cells exposed to UVA and hydrogen peroxide.

DNA damage, Nrf2, ROS, mitochondria, reactive oxygen species, ultraviolet radiation

    [PubMed - in process]
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