The skin, by far the largest organ, serves as a barrier between the individual organism and the environment. And it is constantly exposed to a pro-oxidative environment that in many cases overwhelms it.
It means that our skin, this highly active protective layer is constantly exposed to oxidative stress, which is caused by internal and external factors. These factors, especially the sun’s rays, generate harmful radicals, mostly reactive oxygen species (ROS). Each layer of skin – from the outside in: stratum corneum, epidermis, dermis and hypodermis – has its own protective system against the attack of free radicals and is composed differently depending on the function of this layer.
What is Oxidative Stress?
Oxidation is the scientific term for the loss of an electron from an atom or molecule, while oxidative stress is the burden placed on organisms by the production of free radicals plus whatever other pressures the environment brings to bear. Oxidative stress arises from an excess of ROS in our system, for example as a result of UV exposure or ozone pollution, indoor pollution that we need to reduce to support our skin. So to recap, when experiencing oxidative stress, more free radicals and oxidants (ROS) are formed in the skin than the antioxidative protective systems can intercept. The excess ROS change the redox balance of the skin cells. This activates redox-sensitive signalling pathways that trigger a change in gene expression (1).
What are Free Radicals?
Free radicals are atoms or molecules that are missing an electron and therefore unstable as they search for an electron to steal from the other atoms and molecules around it. (When two free radicals share their unpaired electrons, a free radical is created.) When a free radical successfully steals another electron from a neighbouring molecule, that molecule becomes a free radical itself, setting off a chain reaction of cellular disruption in which cells can grow and reproduce abnormally. Chaos on its way!
Imagine, you are at the fun fair and going for a ride on the bumper cars. This is essentially what free radicals do in our systems. The prevalence of free radicals in our skin causes damage which can lead to a variety of skin issues, like accelerated ageing, acne and rosacea.
We get free radicals in our skin from things like sun exposure, pollution, emotional stress, physical stress and poor diet. Antioxidants are our body’s natural defence against them. They neutralise free radical damage by offering up one of their own electrons. Thereby helping to prevent and repair cell and tissue breakdown that can result in further damage and disease—everything from wrinkles to hyper-pigmentation.
How can Oxidative Stress be triggered?
The UV-C component is largely filtered out by our ozone layer. However, in regions where the ozone layer is weakened or missing („ozone hole“), it can result in extreme UV exposure.
The next one, are the short-wave UV-B radiation. UV-B triggers the sunburn but does not penetrate deeply into the skin. As the short-wave UV-B radiation is largely absorbed in the epidermis and mainly changes DNA and proteins in epidermal keratinocytes and Langerhans cells (3). To a lesser extent, UV-B radiation also stimulates the formation of radicals by hydrolysis. Lipids, proteins and nucleic acids are damaged by different UV wavelengths in different layers.
UV-A is much more dangerous because it penetrates deeply into the skin and reaches the subepidermal layers. This means that it can react not only with the epidermal cells, but also with the fibroblasts of the dermis and trigger the formation of radicals there. This is where the reactive oxygen species and other radicals are formed. The oxidative protective mechanism of the skin, vitamin E, vitamin C, glutathione and uric acid, can be overcome if a large amount of ROS is formed. Such a disorder can then damage lipids, proteins and DNA, ultimately something that is then called oxidative stress.
Oxidative stress through pollution
Another oxidative stressor is smog. This collective name for air pollution can consist of soot particles, sulfur dioxide, pollen and indoor pollution such as dust, VOCs that can trigger various processes on the skin that overwhelm the natural skin defence.
Oxidative stress through the skin flora
The natural skin flora is a finely balanced system of different microbes. Up to 103 germs / cm2 can be found on healthy skin. When pathogenic germs like Streptococcus and Staphylococcus take over, they produce high amounts of ROS. Candida albicans also continuously forms hydrogen peroxide. This alone is a high stress for the skin. For the reasons set out above, a modern skin care product should always have a high antioxidant effect in the skin, inhibit or stop inflammatory processes in the skin and include an intelligent antimicrobial effect on the skin.
What helps against oxidative stress?
The amount of low molecular weight antioxidants in the skin has been observed to decrease after radiation (1). It is therefore generally believed that oral or topical application of antioxidants can minimize radiation damage to the skin. While the protective effect of topical application is often proven, there is usually only initial evidence of the skin-protective effect.
Vitamin C (ascorbic acid)
A study in healthy patients showed that vitamin C combined with oral intake of vitamin E can reduce UVA / UVB-induced damage (4). After topical application, ascorbic acid acts as an effective radical scavenger and thus reduces oxidative stress. In addition, it can increase collagen production and is therefore considered by some authors to be an anti-skin ageing agent because the skin looks more youthful due to more collagen (5).
This vitamin is only produced in plants. It is a group of chromanol derivatives that are divided into tocopherols and tocotrienols. Vitamin E has radical scavenger properties and can protect unsaturated fatty acids from membranes from oxidation. The administration of vitamin E to cultures of human keratinocytes reduces the oxidative stress caused by radiation (6). Protection against skin cancer or sunburn has not been clearly demonstrated. Results in humans are contradictory. Some clinical studies found that a-tocopherol does not provide protection against sunburn or skin cancer (7), while a study by Wohlrab and co-workers in 2002 found a reduction in the risk of skin cancer in addition to the anti-inflammatory function (6). Some groups showed a reduced development of erythema (sunburn) with topical administration of vitamin E (6). Our star ingredient Cacay Oil is high in a range of different Vitamin Es.
Simultaneous administration of vitamins C and E potentiated the protective effect against sunburn in healthy volunteers (4). The combination makes sense because vitamin C is able to regenerate vitamin E. Vitamin E also has an anti-aging effect on the skin by stimulating collagen formation and reducing skin wrinkles. Protection against skin tumors was also shown with topical application (8).
The content of vitamin E in the skin layers decreases from the outside to the inside. In the lower layers of the stratum corneum, concentrations are sometimes ten times higher. To regenerate tocopherol in the upper layers, there is a special transport system from the epidermis, which also contains a lot of tocopherol, to the stratum corneum (1).
Under the influence of UV radiation, free radicals, mostly reactive oxygen species, arise that damage the skin in many ways. But also today’s environmental pollution from chemical oxidants in the air and harmful microorganisms on the skin are a major challenge for the skin. Modern cosmetics are supposed to support the skin’s natural defence function and help against oxidative stress.
Our skin is constantly exposed to oxidative stress, especially extensive sunbathing is pure stress for the skin. The body’s own repair, prevention and adaptation systems as well as various antioxidants counteract this damage. Nevertheless, their accumulation means that the antioxidant protective systems wear off in old age. Damage from solar radiation can drastically accelerate the ageing process of the skin.
Antioxidants and other active ingredients are said to protect against oxidative stress and premature skin ageing. It is also possible to reverse existing DNA damage. Thus it is important to start improving the skin’s antioxidant protection as early as possible. And different actives can intervene at different levels. Probably the most effective way to prevent oxidative light damage is certainly not the most enjoyable: avoiding direct sunlight.
Naya Team xx
- Thiele, J.J., Oxidative Targets in the stratum corneum. Skin Pharm. Appl Skin Physiol. 14 (2001) 87-91. Fischer, T. Wigger-Alberti, W., Elsner, P., Melatonin in der Dermatologie. Hautarzt.
- Weber, S.U., Han, N., Packer, L., Ozone: an emerging oxidative stressor to skin. Curr Probl Dermatol. 29 (2001) 52-61.
- Krutmann, J., New developments in Photoprotection of human skin. Skin Pharmacol Applied Skin Physiol 14 (2001) 401-407.
- Black, H.S., Lenger, W.A., Gerguis, J., Thornby, J.I., Relation of antioxidants and level of dietary lipid to epidermal lipid peroxidation and ultraviolet carcinogenesis. Cancer Res 45 (1985) 6254-6259.
- Dumas, M., Chaudagne, C., Bonte, F., Meybeck, A., Age-related response of human dermal fibroblasts to L-ascorbic acid: study of type I and III collagen synthesis. C R Acad Sci III 319 (1996)1127-32.
- Ryoo, Y.W., Suh, S.I., Mun, K.C., Kim, B.C., Lee, K.S., The effects of the melatonin on ultraviolet-B irradiated cultured dermal fibroblasts. J Dermatol Sci 27 (2001) 162-9.
- Savure, N., Maudet, M., Nicole, M., Pelissier, M.A., Albrecht, R., Briand, G., Combre, A., Modulation of ultraviolet light induced oxidative stress in mice skin related to dietary vitamin A and selenium intake. Int J Vitam Nutr Res 66 (1996) 306-315.
- Maalouf, S., El-Sabban, M., Darwiche, N., Gali-Muhtasib, H., Protective effect of vitamin E on ultraviolet B light-induced damage in keratinocytes. Mol Carcinog 34 (2002) 121-30.
OUR FREE RADICAL BUSTING PRODUCTS
 Oxidative Stress and Antioxidant Defence, Available on: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3488923/ What Are Free Radicals?, Available on: https://www.livescience.com/54901-free-radicals.html Free Radicals and Extrinsic Skin Ageing, Available on: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3299230/#B22 Chronic Inflammation and Its Potential Contribution to Age-Associated Diseases, Available on: https://academic.oup.com/biomedgerontology/article/69/Suppl_1/S4/587037/Chronic-Inflammation-Inflammaging-and-Its Free Radicals and Extrinsic Skin Ageing, Available on: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3299230/#B22
Oxidative stress, inflammation, and cancer: How are they linked? [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2990475/]
Clinical implications of lipid peroxidation in acne vulgaris: old wine in new bottles [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3012032/]