sun damage repair

Sun damage repair in skin care

As any living being, humans also need sun to exist. Sun light, besides being responsible for creating a proper living environment on Earth is also responsible for several metabolic processes in the human body (for example Vitamin D is metabolized during sun exposure). However, due to considerable changes in the human society, a more comfortable life style which involves less and less outdoor activitiesm and due to environmental development such as ozone depletion and pollution, sun exposure can become a danger if protection measures aren’t taken.

Skin, the barrier between the human body and the environment, is the most susceptible tissue to be damaged by sun.  Prolonged and unprotected sun exposure has several damaging effects from cutaneous manifestations such as erythema and inflammation on the epidermis to more profound ones such DNA damage and reactive oxygen species in the profound layers – dermis and hypodermis. Ultraviolet radiation (UVR), a component of the electromagnetic light spectrum shorter than the visible spectrum rays and longer than x-rays, is the main responsible for sun damage. UVR components are mostly absorbed by the ozone layer except UVB – partially absorbed and UVA – not at all absorbed.  UVR is considered to be the most harmful and damaging natural radiation to living beings. Its effects on skin, depending of the time of the exposure can be superficial or profound. The longer the exposure, the greater and sometimes irreversible the damage. UVR is responsible or an aggravating factor for several skin conditions such as dryness, scaling, hypopigmentation, hyperpigmentation, photoaging, initiation and proliferation of non-malignant and malignant skin tumours.

Both UVA and UVB are categorized as carcinogenetic radiations, even though their mechanisms are different. While UVB is a tumor initiator mainly trough DNA mutation, UVA is a tumor accelerator by affecting the mitochondrial metabolism and exaggerating the reactive oxygen species (ROS) levels.

The process of DNA (DNA – dezoxiribonucleic acid) damage is mainly caused by UVB radiation which directly harms the proteins from the double helix structure implicitly affecting the stored genetic information within skin cells, causing photoproducts. If not repaired properly, these specific lesions can lead to the development of skin cancer. Considering that DNA encodes the genetic information which is basically the cell instruction book for the form, structure, function and behaviour when it is threatened or destructed several mechanisms come into play. The damaged double helix protein structure is either repaired and if the operation fails to succeed cell death is scheduled. Sometimes under UVR exposure the DNA remains defective or incorrectly fixed. Such a mutation can proliferate and migrate thus being a serious threat for initiation and progress of skin cancer.

The process of oxidation is fundamental in living beings being responsible for the mitochondrial energy production. Reactive oxygen species (ROS) is an aggressive category of reactive ionized oxidants that is naturally produced as a by-product of oxidation in very low levels that are needed in certain metabolic reaction. Unfortunately the fine balance between demand and supply is affected by UVR exposure especially UVA. This an unwanted effect leads to increased free radicals and reactive oxygen species levels. Increased ROS levels are toxic to the cell that encloses them. [1][2][3]

Natural ingredients are only beginning to regain their rightful place in medicine including the dermatology and cosmetology fields after being ignored for years in the favor of pharmaceuticals. Some natural active ingredients have been used in medicine since the beginning of mankind and topical application of various mixtures for protection or healing purposes have been documented.
When it comes to sun damage protection and repair, numerous in vitro and in vivo studies proved that natural antioxidants used topically alone or in combination with chemical or physical sunscreen not only protect the skin against UVR related damage but even more, it repairs the damage, preventing it from proliferation.

Regular application of skin care products containing antioxidants proved to be beneficial in efficiently preparing the skin against exogenous oxidative stressors occurring during daily life and, sunscreening agents may also benefit from combination with antioxidants resulting in increased safety and efficacy of such photoprotective products [4].

The addition of botanical broad-spectrum sunscreen further decreases UV-induced damage compared with sunscreen alone. These agents have been shown to enhance protection against UV-induced epidermal effects. Non-sunscreen materials such as botanical extracts, antioxidants, and DNA repair enzymes can contribute value when applied topically to human skin in vivo [5].
In almost all cases, natural actives fight and repair UVR related damage on multiple levels: either directly – by free radicals and ROS scavenging or indirectly – by restoring enzymatic levels that allows the cell to self-repair.

Allantoin is the final product of the nitrogen metabolism in mammals but also naturally available in several plants. Topically applied it showed considerable reduction of sun-induced redness and erythema [6].

Alpha Bisabolol is an essential oil extracted from chamomile – a traditional medicinal plant – now available from sustainable and eco-friendly sources. Renowned especially for both its anti-inflammatory and tissue regeneration booster properties alpha bisabolol proved to be topically effective in repairing epidermal sun damage [7].

Alpha Lipoic Acid (RS-ALA) is a natural occurring animal cofactor that peaks into young adults but decreases with aging. It is best known for its antioxidant properties and traditionally used in OTC oral supplements. RS-ALA as an ROS scavenger is superior even to Vitamin C and E and showed relevant results in sun damage repair at epidermal and dermal levels [8].

Ascorbic Acid (AA,Vitamin C)  with its more stable derivatives Ethyl Ascorbic Acid, Sodium Ascorbyl Phospate, Ascorbyl Glucoside (AA-2G,resulting from the reaction of Vit C and Glucose) and Ascorbyl Tetraisopalmitate (a derivate from Vitamin C and Isopalmitic Acid) is perhaps the most well known natural antioxidant. It counteracts the UVR exposure related damage by scavenging reactive oxygen species (ROS) including oxidized alpha-tocopherol thus implicitly restoring the Vitamin E levels in the skin. Vitamin C stops the sun damage proliferation and even reverses its effects speeding the epidermis recovery [9][10][11].
 
Baobab Oil, preferably from an organic source, is a natural extract from the baobab tree, rich in fatty acids. Studies have proved to help in repairing sunburn and photo-aging, chronic skin damage due to excessive sun exposure [12].

Boswellic Acid, extracted from the Boswellia Serata tree is an effective active ingredient in preventing long term UVR damage such as photoaging. Clinical studies showed considerable improved appearance of fine lines and skin roughness associated with photoaging and increased skin thickness [13].

L-Carnitine is a natural occurring substance in the animal tissue, including skin, vital for the glucose and fat metabolisms. At the dermal and epidermal levels is known to prevent DNA damage and boost repair by restoring the glycation processes balance. It is usually mixed with Vitamin C and/or E in topical treatments [14].

Centella Asiatica an extract obtained from the tropical plant Gotu Kola is traditionally and extensively used in Indian medicine. This botanical active showed relevant results both in sun damage protection and repair when used topically by complex mechanisms of reducing glycation processes and implicitly slowing the oxidative damage [15].

CoEnzyme Q10 is one of the most popular skin care active ingredients. A natural occurring enzyme it is involved in the energy metabolism of animal cells. Due to its antioxidant properties efficiency in sun damage repair was tested with relevant results. Topically applied CoQ10 mixtures proved to boost the repair mechanism 2 to 3 times the normal rate [16].

D- panthenol the stable alcohol form of pantothenic acid (vitamin B5) is involved in the process of reducing UV induced erythema.  The efficacy of the active was assessed by colorimetry via the reduction of redness and by measuring the change in microcirculation by laser Doppler [17]. 

Ferulic Acid, preferably from a natural source, is an organic acid found in several plants, especially cereals as rice bran. It proved to be effective in UV damage repair, especially in mixtures with Vitamin C and E. The combination prevents DNA damage and is excellent in ROS scavenging. Even standalone, topical applied ferulic acid is superior to each of the two vitamins when it comes to UVR induced damage repair [18].

Fucoidan, a dietary fiber extracted mainly from the brown seaweed, showed efficiency in repairing aggravated atopic dermatitis, a skin pathology where sun exposure is a potent allergen [19].
Gamma-oryzanol is a natural active ingredient obtained from rice bran, basically a bundle of sterols build on a ferulic acid structure. Due to its antioxidant properties it has the ability to prevent and repair sun damage and reverse photoaging by scavenging ROS and inhibiting sun-related DNA damage [20]

Ginkgo Biloba is a natural active extracted from the unique tree species with the same name, renowned for its potency and versatility. In vitro and in vivo studies showed that the ginkgo biloba components, especially the flavonoids repairs both cutaneous and derma sun damage by scavenging UV generated free radicals and additionally increasing the levels of ROS scavenging enzymes. [21]

Glucosamine is a natural precursor of the hyaluronic acid that proved to be a great resource for topical skin care. N-acetyl glucosamine increases activity of antioxidant enzymes reducing the amount of harmful free radicals and ROS produced after UV exposure, repairing and reversing photoaging effects and sun dmage [22].
 
Grape seed oil with a high fatty acid content, Grape seed proanthocyanidins - molecules with very strong antioxidant proprieties, and Rosveratrol – an  antioxidant active extracted from grapes and other botanical resources  are also used in both preventing and repairing sun damage. While the oil mainly repairs cutaneous manifestations of photoaging [23] the proanthocyanidins scavange ROS, reducing the oxidative agents to normal levels [24].

Green tea extract (90%ECCG) is a powerful, polyphenol rich antioxidant. Used in topical mixtures the green tea extract repairs the cutaneous effects of sun exposure such as erythema and scaling. It is also active in repairing DNA damage and preventing cell death following UV exposure by restoring the balance in the oxidation metabolism [25].

Gynostemma pentaphyllum extract is extracted from Jiaogulan - a plant from original from Asia and used for centuries in the Chinese traditional medicine. Its strong antioxidant makes a perfect candidate for sun damage repair topical treatment with relevant results in the ability to neutralize free radicals and stope the aggressive UV induced oxidation process [26].

Hesperidin methyl chalcone is a stable version of hesperidin – an active usually extracted from citrus plants and a natural occurring flavonoid. Its action when topically applied reduces sun damage effects and also prevents damage proliferation trough DNA mutation, inhibiting the evolution of potential UV induced skin tumors [27]. Lemon peel bioferment is another active high in hesperidin.

Idebenone a bioengineered active identical with Coenzime Q10 can succesfuly replace its role in topical treatments, having the advantage of considerable higher availability. It is directly involved in the mitochondrial oxidation processes and helps maintain the balance and implicitly preventing premature cell aging and apoptosis [28]

Lactic Acid is another natural active extensively used in dermatology, including in sun damage prevention and repair. It proved to be extremely effective in multiple clinical in vivo studies in reducing the appearance of photoaging by both stimulating the production of extracellular matrix components – especially hyaluronic acid and by boosting the synthesis of lipids and ceramides – vital in repairing the skin barrier [29].

Niacinamide (Vitamin B3), a multipurpose cosmetical active agent is well known to have antioxidant effects by scavenging free radicals. This help repairing the DNA damaged by unprotected UVR exposure b is also an adjuvant in speeding the restoration of the skin surface  [30]

Pine bark extract contains active molecules called proanthocyanidins renowned for their very strong antioxidant properties effective in counter-acting ROS aggressiveness and reducing erythema caused by sun exposure. Topically applied, the extract reduces UVR related redness and inflammation and helps regulate the capillary growth and implicitly faster healing of the damage [31].
Pomegranate (40% ellagic acid) and highly rich in fatty acid Pomegranate seeds oil – are both efficient botanical actives used in topical skin protection against sun damage. Studies have shown that ellagic acid reduces UV-induced cell death, inflammatory processes, and even freezes cells in an non-dividing stage, giving them more time to repair their DNA. The seeds extract also proved to be effective in reducing fibroblasts apoptosis and decreasing ROS levels after UVR exposure [32].

Quercetin is a natural botanical flavonoid found especially in onion and related family. It is a very effective free radicals scavenger acting on two levels – directly or by binding iron – a vital metal in the ROS metabolism. It quickly restores and sometimes increases the anti-ROS enzyme levels, slowing, stopping and even reversing the effects of UVR skin damage [33]

Rosehip oil a natural source of Vitamin A showed wrinkle reducing in photoaged skin, elasticity restoration in scared skin and burned skin. Its effects are consistent in reducing photoaging appearance and attenuating erythema [34]

Safflower seed oil,extracted from Carthamus Tinctorius is popular for being high in fatty acids especially in  linoleic acid a multipurpose topic ingredient. It has multiple utilizations, one of them being the reduction of hyperpigmentation and other sun-related epidermal damage in UVR exposure [35].

Salicylic Acid (Beta Hydroxy Acid), a botanical active extracted from the seeds white willow bark is another effective protector against sun damage. Topically applied salicylic acid before prolonged sun exposure proved to reduce redness and inflammation in clinical trials [36].

Sylimarin, an extract from the seeds of Milk thistle has potent antioxidant activity has potential as an antiphotodamage and anticarcinogenic agent demonstrated in several clinical trials. The extract of is suitable for inclusion in topical skin care products and sunscreen as active ingredient being efficient in both UVR damage protection and repair [37].

Soy isoflavones are natural phytoestrogens with promising results in inhibiting UV-stimulated tyrosine kinases responsible for initiation of inflammation. Besides reducing it also protects the integrity of the dermal matrix and helping the skin recovery [38].

Squalane olive oil is a versatile active with numerous cosmetic uses. Its most important function is as an antioxidant and due to the fact that squalane is also found in the normal occurring skin sebum the protection against UVR damage is very natural and well tolerated [39].

Vitamin E, preferably natural, in its most stable and efficient forms tocopherols and tocotrienols is a popular ingredient in UVR protection topical mixtures. Both its forms proved to be efficient in preventing and repairing UVR related DNA damage, ROS scavenging and restoring oxidation processes to normal levels [40].

Wheat germ oil is known to be rich in vitamins A, D and E. The vitamin E in its component is proved to inhibit collagen degradation preventing and repairing photoaging effects [41].

Yeast beta glucan is a natural polymer occurring especially in fungi and algae. Its structure is optimized for skin penetration. In sun damage repair relevant results were observed especially in the reduction of UVB induced skin damage [42].

The success of a sun damage repair topical mixture is also determined by the vehicle/carrier used to deliver the active. In DIY it’s highly recommended to use multi-lamellar base creams with liquid crystal systems. Besides efficiently deliver the active ingredients it also moisturizes and help restores the skin barrier.
 

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