Cutaneous antioxidants

In untreated human stratum corneum there is a concentration gradient of vitamin E with the lowest levels at the surface and the highest levels in the deepest layer.50-55 This a-tocopherol gradient in the epidermis was confirmed in another study, where the stratum corneum of atopic patients had a twofold higher concentration of a-tocopherol together with a significantly lower lipid peroxide concentration than in healthy volunteers. This less pronounced oxidative stress in stratum corneum of atopic dermatitis patients may result from an increase in cutaneous antioxidant defences due to the chronic inflammation.56... 

Vessey DA. The cutaneous antioxidant system. Clin Dermatol 1993 8 81-103. 

Such studies in excised skin showed that skin antioxidant systems are compromised by a single dose of UV light, and that UVB irradiation probably initiates free radical production, depleting cutaneous antioxidants. But no free radical-induced damage was directly detected, and antioxidant supplementation was not attempted. 

The free radical hypothesis of UV-light-induced cutaneous pathology is supported by these studies - antioxidant levels decrease on irradiation, as would be expected with a free radical load, lipid peroxidation increases tremendously, and supplementation with a-tocopherol prevents this damage. Future studies are necessary to clarify the relationships between cutaneous antioxidants during... 

Fuchs, J., Huflejt, M.E., Rothfuss, L.M., Wilson, D.S., Carcoamo, G., and Packer, L. (1989) Acute effects of near ultraviolet and visible light on the cutaneous antioxidant defense system, Photochem. Photobiol. 50, 739-744. 

Hoppe U, BergemannJ, DiembeckW, EnnenJ, Gohla S, Harris I, et al. Coenzyme QIO, a cutaneous antioxidant and energizer. Biofactors 1999 9 371-80. 

Shukla A, Rasik A, Patnaik M (1997) Depletion of reduced glutathione, ascorbic acid, vitamin E and antioxidant defense enzymes in healing cutaneous wounds. Free Radic Res 26(2) 93-101... 

Skin constitutes the interface between the human body and the environment. It represents a major target of oxidative stress since it is exposed to external oxidant aggressions like UV radiation, ozone, chemicals or pollution. Continuous exposure to such damaging effects and/or deficiency of the antioxidant protection systems result in skin premature aging and contribute to the development of cutaneous diseases and cancers [23]. Electrochemical studies dealing with the effect... 

The analyses of cutaneous removals have been performed using HPLC. The results confirmed the presence of antioxidant species on epidermis surface, i.e. ascorbic and uric acids and glutathione (Table 8.3). 

Blister fluid obtained from patients with cutaneous thermal injury had TAC 24% lower than that of blood serum. This may reflect oxidative stress and consumption of antioxidants in the blister site (H8). However, TAC of blood serum of severely burned patients was increased in 42% of the patients (mean value of TAC was elevated by 11% in the whole group of burned patients) (F2). 

H8. Haycock, J. W., Ralston, D. R., Morris, B., Freedlander, E., and MacNeil, S., Oxidative damage to protein and alterations to antioxidant levels in human cutaneous thermal injury. Bums 23, 533-540 (1997). 

Pinnell, S.R., Cutaneous photodamage, oxidative stress, and topical antioxidant protection, J. Am. 

Thiele, J.J. et al., The antioxidant network of the stratum corneum, in Oxidants and Antioxidants in Cutaneous Biology. Current Problems in Dermatology, vol. 29, Thiele, J. and Eisner, P., Eds., Karger, Basel, 2001, p. 26. 

In the second experiment, mice were irradiated with the highest dose from the dose-response experiment. Concentrations of lipid hydroperoxides and lipophilic antioxidants were measured simultaneously on single skin samples from irradiated and non-irradiated sides of each mouse. The lipid hydroperoxide assay directly measured lipid peroxidation and thus was superior to the TBARS assay, which is indirect. Lipid-peroxyl radicals have been linked to chemically induced cutaneous carcinogenesis [31] as well as to UV-light-induced cutaneous carcinogenesis [32],... 

Fig. 8. Response of cutaneous lipophilic antioxidants to increasing doses of simulated sunlight (combined UVA and UVB). The lowest dose (0.25 J/cm2) is the equivalent of about 0.1 MED the highest dose (25 J/cm2) is the equivalent of about 10MED.

Fig. 9. Concentrations of cutaneous lipophilic antioxidants after a single large dose (25J/cm2) of simulated sunlight. Total quinol/one = ubiquinol + ubiquinone, n = 6. Inset (A) concentration of lipid hydroperoxides in the same skin samples, irradiated and non-irradiated (none detectable in non-irradiated samples). Statistically different from unirradiated controls double asterisks, p < 0.01 ...

The cutaneous vitamin E concentrations of mice were augmented by feeding them diets containing either 30 IU/kg diet a-tocopherol (n = 8) or lOOOOIU/kg diet a-tocopherol (n = 12). At intervals in the feeding regimen, mice from each group were irradiated with UV light, skin was sampled, and its content of lipophilic antioxidants and lipid hydroperoxides was analyzed as described for Experiment 1. 

F. Dreher and H. Maibach in J. Thiele and P. Eisner, Eds., Oxidants and Antioxidants in Cutaneous Biology. Karger, Basel, Switzerland, 2001, pp. 157-164. 

An example of a cutaneous preparation in which an antioxidant - butylhydroxytoluene - is added to prevent oxidation of the active substance is a tretinoin cutaneous solution (Table 12.11). During preparation tretinoin has to be protected from light and no metal utensils should be used. 

Ruffien-Ciszak, A., et al., 2008. Electrochemical microsensors for cutaneous surface analysis application to the determination of pH and the antioxidant properties of stratum corneum. ITBM-RBM 29, 162-170. 

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