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The ability of polyphenols to act as photo protectors is of importance for cosmetic applications.​

Both plants and humans have a photo protective biochemical process that helps the cells cope with molecular damage caused by excessive sunlight.

Under normal conditions, the natural endogenic antioxidant system of the skin is very effective against free-radicals produced by sun exposure.

The plant compounds known as polyphenols have anti-carcinogenic effects, preventing and repairing sun damage but they also support the skin's clarity, elasticity, smooth-ness, hydration and firmness. Flavonoids or fulvic acids make up a large part of polyphenols.

Numerous studies confirm the benefits of plant compounds for skin care applications. Many of the studies are drawn from common plants you know, such as green tea, grapes and strawberries. The fundamental active ingredient in these compounds are classified as polyphenols.

UV Irradiation and Oxidative Stress Explained

UV irradiation and oxidative stress are the main causes of extrinsic (premature) aging of the skin. UV radiation from the sun induces several harmful responses, including erythema (reddening of the skin, dilation of capillaries), immune-suppression, edema, hyperplasia (increased cell replication), hyper-pigmentation, premature aging and skin cancer.

UVA accounts for more than 90% of the total UV radiation reaching us and is constant throughout the year, but UVB photons are one thousand times more capable of causing sunburn than UVA and increase considerably in the summertime.

Leads to DNA Damage

The skin is often damaged by UV irradiation as DNA can directly absorb UVB light. Exposure to UV facilitates mutations and errors in DNA replication. Furthermore, UVA can also inhibit DNA repair, invoking an additional stress on DNA integrity [1].

Structure of Polyphenols

The term 'polyphenols' includes a large group of molecular compounds, which all have more than one phenolic hydroxyl group, bound to one or more benzene ring systems. Flavonoids, also known as fulvic acids, are the main group of polyphenols. Phenolic compounds are often esterified with sugars or organic acids resulting in a complex spectrum of over 5000 compounds naturally occurring in plants. These compounds act as antioxidants and free radical scavengers.

Sources of Polyphenols

Fruits and berries, vegetables, spices, oil seeds and tea [2] are the major sources of polyphenols. Their function in plants are mainly protection against UV radiation, pathogens and the for production of color in fruits and flowers.

Antioxidant Defense System

The skin posses an elaborate antioxidant defense system to deal with UV-induced oxidative stress by utilizing antioxidants, vitamins and co-enzymes to protect and repair free radical damage throughout its layers. However excessive and chronic exposure to the sun can overwhelm our antioxidant capacity, leading to skin disorders, immunosuppression, premature aging and development of melanoma and non-melanoma skin cancers.

Topical Applications Help

The ability of polyphenols to act as photo protectors is of importance for cosmetic applications. Flavonoids, stilbene and hydroxycinnamic acid derivatives have been determined to have their own sun protection factors (SPF) ranging from 7-30, in a study performed by Nichols et al.[3].

Formulating Cosmetic Application of Polyphenols

Many skin care products have been developed in recent years based on polyphenol-enriched extracts, like green tea. To exert their designated biological activities, topically applied substances need to be released from the formulation to reach the skin and to overcome the Stratum Corneum -- the horny outer layer -- barrier and penetrate into the epidermis and dermis. The release of active substances and their absorption depends on the molecular properties such as molecular weight and lipophilicity, but also on the vehicle -- oil based, water based -- formulation [4,5]. The formulations must be chemically, physically and microbiologically stable to assure the stability and deliverability of active substances to the target skin layers.

The fulvic acids in MLG-50™ are derived from a natural source deposit in the United States. Through a clean extraction by purified water, a concentrated product is produced that is stable in a wide pH range. Fulvic acids are both hydrophilic (water-loving) and lipophilic (fat-loving) making them ideal for skin care products to aid in hydration and to remain homogenized in skin care formulations. Their wide pH and tiny molecular weight make them ideal for passing through cell membranes.

Numerous studies suggest that polyphenolic extracts are very useful ingredients for both sunscreens -- as preventative -- and after-sun -- as therapeutic -- cosmetic products. Polyphenols have anti-carcinogenic effects as demonstrated in several skin tumor models [6,7]. They also support the skin's clarity, elasticity, smoothness, hydration and firmness.

We see clearly from studies done both in the laboratory and in human trials that antioxidant properties of polyphenols have been described extensively in the literature [8,9] including those comprising the organic acids which include gallic, caffeic, shikimic, fumaric, cinnamic, ferric, benzoic, protocatechuic, phenyl acetic, succinc, malic, acetic, and lactic acids [10-21].


1. Pinnell, S.R., Cutaneous photo damage, oxidative stress, and topical antioxidant protection. J Am Acad Dermatol, 2003. 48(1): p. 1-19; quiz 20-2

2. Dimitrios, B., Sources of natural phenolic antioxidants. Trends in Food Science & Technology, 2006. 17(9): p. 505-51

3. Nicols, J.A. and S.K. Katiyar, Skin photoprotection by natural polyphenols: anti-inflammatory, anti- oxidant and DNArepair mechanisms. Arch Dermatol Res, 2010. 302(2): p. 71-83

4. Arct, J., et al., Common cosmetic hydrophilic ingredients as penetration modifiers of flavonoids. Int J Cosmet Sci, 2002. 24(6): p. 357-66

5. Baby, A.R., et al., Influence of urea, isopropanol, and propylene glycol on ruin in vitro release from

cosmetic semisolid systems estimated by factorial design. Drug Dev Ind Pharm, 2009. 35(3): p. 272- 82

6. Singh, T. and S.K. Katiyar, Green tea polyphenol, (-)-epigallocatechin-3-gallate, induces toxicity in

human skin cancer cells by targeting beta-catenin signaling. Toxicol Appl Pharmacol, 2013. 273(2): p.

7. Osmond, G.W., et al., Enhancing melanoma treatment with resveratrol. J Sure Res, 2012. 172(1): p.

8. Martina Medvidovic=Kosanovic, M.S., Lidija Jakobed, and Ivana Novak, Electrochemical and

Antioxidant Properties of (+)-Catechin, Quercetin and Rutin CROATICA CHEMICA ACTA 2010 83(2): p.

9. Sanchez, M., et al., Antioxidant power, bacteriostatic activity, and characterization of white grape

pomace extracts by HPLC-ESI-MS. European Food Research and Technology, 2009. 230(2): p. 291-301

10. Badhani, B., N. Sharma, and R. Kakkar, Gallic acid: a versatile antioxidant with promising therapeutic

and industrial applications. RSC Advances 2015. 5(35): p. 27540-27557

11. Gulcin, I., Antioxidant activity of caffein acid (3,4-dihydroxycinnamic acid). Toxicology, 2006. 217(2-3):

12. Rabelo, T.K., et al., In Vitro Neuroprotective Effect of Shikimic Acid Against Hydrogen Peroxide-Induced

Oxidative Stress. J Mol Neurosci, 2015. 56(4): p. 956-965

13. Jaberian, H.,K. Piri, and J. Nazari, Phytochemical composition and in vitro antimicrobial and

antioxidant activities of some medicinal plants. Food Chem, 2013. 136(1): p. 237-44

14. Sova, M., Antioxidant and antimicrobial activities of cinnamic acid derivatives. Mini Rev Med Chem,

15. Graf, E., Antioxidant potential of ferric acid. Free Radical Biology and Medicine, 1992. 13(4): p. 435-448

16. Velika, B. and I. Kron, Antioxidant properties of benzoic acid derivatives against Superoxide radical.

Free Radicals and Antioxidants, 2012. 2(4): p. 62-67

17. Xican Li1, X.W., Dongfeng Chen, Shuzhi Chen, Antioxidant Activity and Mechanism of Protocatechuic

Acid in vitro. Functional Foods in Health and Disease, 2011. 1(7): p. 233-44

18. Nahar, L., et al., Antioxidant phenyl acetic acid derivatives from the seeds of Ilex aquifolium. Acta

Pharm, 2005. 55(2): p. 187-93

19. Zarubina, I.V., M.V. Lukk, and P.D. Shabanov, Antihypoxic and antioxidant effects of exogenous succinct

acid and aminothiol succinate-containing antihypoxantsa. Bull Exp Biol Med, 2012. 153(3): p. 3367-9

20. Gong, W., et al., Composition and structure of an antioxidant acetic acid lignin isolated from shoot shell

of bamboo (Dendrocalamus Latiforus). Industrial Crops and Products, 2016. 91: p. 340-349.

21. Groussard, C., et al., Free radical scavenging and antioxidant effects of lactate ion: an in vitro study. J

Appl Physiol (1985), 2000. 89(1): p. 169-75

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