Photoprotective effects of sunscreens in cosmetics on sunburn and Langerhans cell photodamage.

It has become common practice to add sunscreening agents of variable potency to cosmetics to protect against the adverse effects of ultraviolet (UV) radiation exposure. The purpose of this study was to determine whether cosmetic preparations containing sunscreening agents protected against the adverse effects of acute UV radiation exposure and, if so, to identify the components responsible for the photoprotective effects. Pretreatment of skin with one such cosmetic product provided complete protection against UV-induced erythema, sunburn cell formation and Langerhans cell damage in volunteers, skin types II and III, whose skin was exposed to a 1.5 minimal erythema dose daily for 4 consecutive days. When individual components of the cosmetic preparation were analyzed for their photoprotective activities, it was found that both the cinnamate and benzophenone sunscreen combination and an extract of baker's yeast present in the preparation had photoprotective properties. These studies indicate that incorporation of photoprotective agents into cosmetic preparations provides a beneficial function and should therefore be encouraged.     

Cutaneous photoprotection from ultraviolet injury by green tea polyphenols

BACKGROUND: In animal models, extracts from green tea have been shown to be remarkably effective at reducing the severity of adverse human health effects of overexposure to ultraviolet (UV) radiation. Although sunscreens and other photoprotective measures have traditionally been used for this purpose, there is a need for additional measures and natural products are increasingly being explored for that purpose. OBJECTIVE: Our purpose was to evaluate the effect of polyphenols from green tea on parameters associated with acute UV injury. METHODS: Areas of skin of normal volunteers were treated with an extract of green tea or one of its constituents. Thirty minutes later, the treated sites were exposed to a 2 minimal erythema dose solar simulated radiation. UV-treated skin was examined clinically for UV-induced erythema, histologically for the presence of sunburn cells or Langerhans cell distributions, or biochemically for UV-induced DNA damage. RESULTS: Application of green tea extracts resulted in a dose-dependent inhibition of the erythema response evoked by UV radiation. The (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) polyphenolic fractions were most efficient at inhibiting erythema, whereas (-)-epigallocatechin (EGC) and (-)-epicatechin (EC) had little effect. On histologic examination, skin treated with green tea extracts reduced the number of sunburn cells and protected epidermal Langerhans cells from UV damage. Green tea extracts also reduced the DNA damage that formed after UV radiation. CONCLUSION: Polyphenolic extracts of green tea are effective chemopreventive agents for many of the adverse effects of sunlight on human health and may thus serve as natural alternatives for photoprotection.     

Topical indomethacin protects from UVB and UVA irradiation

Conclusions Indomethacin is known to decrease the UVB (290–310 nm) induced erythema when applied topically in regular intervals after irradiation [2,5,6], probably via inhibition of prostaglandin synthesis. The absorption spectrum of an IM solution (Fig. 1) suggests that this drug may also exert a high filter capacity in the UVB and UVA range, when applied as a topical suncreen before exposure to UV light. The present study demonstrates that a 2.5% solution of IM indeed protects from UVB induced erythema, and these results are in accordance with those of Lim et al., recently published in abstracted form (1983). The present study demonstrates that topically aplied IM exerts a photoprotective effect also at the cellular level since it prevents UV induced keratinocyte cell death (formation of sunburn cells).Topical application of 2.5% IM decreases the induction of PUVA erythema and inhibits the development of immediate pigment darkening, which demonstrates a potent photoprotective effect also in the UVA range.The photoprotective mechanism of IM when applied prior to irradiation seems to be a filter effect (as to be expected from the absorption spectrum) rather than a biochemical action such as inhibition of prostaglandin synthesis, although the latter explanation cannot be excluded completely from the present results. Preliminary data, however, indicate that sunburn cells do occur in skin irradiated with erythemogenic doses of UVB light and treated with topical IM after exposure, which prevents erythema formation. Before IM can be widely used, it is necessary to evaluate optimal concentration and vehicles and in particular percutaneous absorption and possible systemic toxicity. The UVB screening potency of topical IM seems to be similar to other sunscreens (e.g. para-aminobenzoic acid/PABA), but IM offers a much higher protection against UVA light. This may be important in the treatment of certain photodermatoses and also in the prevention of elastotic skin damage by sunlight.     

Relevance of vitamins C and E in cutaneous photoprotection

Ultraviolet (UV) radiation-induced oxidative stress may result in acute and chronic photodamage. Based on the endogenous antioxidant system, the administration of antioxidants for scavenging reactive oxygen species might be a promising strategy in the prevention of UV-induced skin reactions. The relevance of the most common antioxidants, vitamins E and C, is reviewed focusing on topical and systemic photoprotective effects in animals and humans. Topically applied vitamin C induced significant photoprotective effects at concentrations of at least 10% in animals and humans, whereas a photoprotective effect has not been demonstrated by oral administration even at high doses in humans. Topical vitamin E reduced erythema, sunburn cells, chronic UV-B-induced skin damage, and photocarcinogenesis in the majority of the published studies, whereas only high doses of oral vitamin E may affect the response to UV-B in humans. Combination of vitamins C and E, partly with other photoprotective compounds, did increase the photoprotective effects dramatically compared to monotherapies. This synergistic interplay of several antioxidants should be taken into consideration in future research on cutaneous photoprotection.     

Protective effect of oral selenium plus copper associated with vitamin complex on sunburn cell formation in human skin

An organic form of selenium (plus copper) and a vitamin complex (with tocopherol and retinol) were examined for their ability to prevent sunburn cell formation in human skin exposed to ultraviolet radiation from a xenon solar simulator. After three weeks of supplementation with selenium, especially in association with vitamins, there was a relative protection (versus placebo) against ultraviolet-induced cell damage in the suberythemal range but not in the supraerythemal area. Antioxidant properties of the compounds can explain such cellular photoprotective effect. Supplementation was ineffective in preventing light-induced erythema.     

Supplementation with oral probiotic bacteria protects human cutaneous immune homeostasis after UV exposure-double blind, randomized, placebo controlled clinical trial

There is now strong evidence that probiotic bacteria can regulate inflammatory immune responses. Here, we analyzed whether oral supplementation with the probiotic bacterial strain Lactobacillus johnsonii (La1) could interfere with skin immune status following UV exposure. A randomized, double-blind, placebo controlled clinical trial was conducted with 54 healthy volunteers receiving either La1 or placebo, during six weeks prior to solar-simulated UV irradiation. Blister roofs and skin biopsies were recovered 1, 4 and 10 days after UV exposure from un-irradiated and irradiated skin and used for immunohistochemical analysis and mixed epidermal cell lymphocyte reaction (MECLR), respectively. La1 supplementation did not prevent the UV-induced phenotypic maturation of Langerhans cells (LCs) or the decrease in MECLR in irradiated skin samples, one day post-irradiation. On day 4, MECLR was still decreased in the placebo group, with a parallel reduction in the CD1a LC marker in irradiated epidermis. In contrast, the allostimulatory capacity of epidermal cells was totally recovered in the La1 group correlating with the normalization of CD1a expression within the epidermis. For the first time, the results provide evidence that ingested probiotic bacteria accelerate the recovery of skin immune homeostasis after UV-induced immunosuppression.     

Protective effects of a topical antioxidant mixture containing vitamin C,ferulic acid,and phloretin against ultraviolet‐induced photodamage in human skin

Background Ultraviolet (UV) irradiation of the skin leads to acute inflammatory reactions, such as erythema, sunburn, and chronic reactions, including premature skin aging and skin cancer. Aim In this study, the effects of a topical antioxidant mixture consisting of vitamin C, ferulic acid, and phloretin on attenuating the harmful effects of UV irradiation on normal healthy volunteers were studied using biomarkers of skin damage. Subjects/methods Ten subjects (age, 18–60 years; Fitzpatrick skin types II and III) were randomized and treated with antioxidant product or vehicle control on the lower back for four consecutive days. On day 3, the minimal erythema dose (MED) was determined for each subject at a different site on the back. On day 4, the two test sites received solar‐simulated UV irradiation 1–5× MED at 1× MED intervals. On day 5, digital images were taken, and 4‐mm punch biopsies were collected from the two 5× MED test sites and a control site from each subject for morphology and immunohistochemical studies. Results UV irradiation significantly increased the erythema of human skin in a linear manner from 1× to 5× MED. As early as 24 h after exposure to 5× MEDs of UV irradiation, there were significant increases in sunburn cell formation, thymine dimer formation, matrix metalloproteinase‐9 expression, and p53 protein expression. All these changes were attenuated by the antioxidant composition. UV irradiation also suppressed the amount of CD1a‐expressing Langerhans cells, indicating immunosuppressive effects of a single 5× MED dose of UV irradiation. Pretreatment of skin with the antioxidant composition blocked this effect. Conclusion This study confirms the protective role of a unique mixture of antioxidants containing vitamin C, ferulic acid, and phloretin on human skin from the harmful effects of UV irradiation. Phloretin, in addition to being a potent antioxidant, may stabilize and increase the skin availability of topically applied vitamin C and ferulic acid. We propose that antioxidant mixture will complement and synergize with sunscreens in providing photoprotection for human skin.     

Effect of topical melatonin on ultraviolet radiation-induced suppression of Mantoux reactions in humans

BACKGROUND: Melatonin, the central neurohormone in circadian rhythm pathways, is recognized to have a variety of immune-enhancing effects. It has previously been shown to reduce ultraviolet (UV) radiation-induced erythema in mice and in humans, but there are as yet no published studies on the effects of melatonin on UV-induced immunosuppression in humans. METHODS: We investigated the effects of topical melatonin on solar-simulated (ss) UV-induced suppression of Mantoux reactions in 16 healthy, Mantoux-positive volunteers. Melatonin (5%) and its vehicle were applied in a double-blinded manner to separate areas on the lower back, immediately after each of three consecutive daily ssUV exposures. Various sites on the back received either no irradiation or one of three-graded ssUV doses. Mantoux testing was performed at each site 24 h after the final irradiation, and assessed 72 h later using a reflectance erythema meter. In a separate group of 19 volunteers, the effect of melatonin on minimal erythema dose was assessed both visually and with an erythema meter. RESULTS: We found dose-responsive UV-induced suppression of the Mantoux response in the presence of both vehicle and melatonin; melatonin did not prevent UV-induced immunosuppression in this model. Melatonin was also found to have no effect on the minimal erythema dose. CONCLUSIONS: Melatonin conferred no protection against immune suppression or sunburn when applied topically to human skin immediately after irradiation.     

Green tea extract reduces induction of p53 and apoptosis in UVB-irradiated human skin independent of transcriptional controls

Ultraviolet (UV) irradiation plays a pivotal role in human skin carcinongenesis. Preclinically, systemically and topically applied green tea extract (GTE) has shown reduction of UV-induced (i) erythema, (ii) DNA damage, (iii) formation of radical oxygen species and (iv) downregulation of numerous factors related to apoptosis, inflammation, differentiation and carcinogenesis. In humans, topical GTE has so far only been tested in limited studies, with usually very high GTE concentrations and over short periods of time. Both chemical stability of GTE and staining properties of highly concentrated green tea polyphenols limit the usability of highly concentrated green tea extracts in cosmetic products. The present study tested the utility of stabilized low-dose GTE as photochemopreventive agents under everyday conditions. We irradiated with up to 100 mJ/cm(2) of UVB light skin patches which were pretreated with either OM24-containing lotion or a placebo lotion. Biopsies were taken from both irradiated and un-irradiated skin for both immunohistochemistry and DNA microarray analysis. We found that while OM24 treatment did not significantly affect UV-induced erythema and thymidine dimer formation, OM24 treatment significantly reduced UV-induced p53 expression in keratinocytes. We also found that OM24 treatment significantly reduced the number of apoptotic keratinocytes (sunburn cells and TUNEL-positive cells). Carefully controlled DNA microarray analyses showed that OM24 treatment does not induce off-target changes in gene expression, reducing the likelihood of unwanted side-effects. Topical GTE (OM24) reduces UVB-mediated epithelial damage already at low, cosmetically usable concentrations, without tachyphylaxis over 5 weeks, suggesting GTE as suitable everyday photochemopreventive agents.     

Effect of topical application of antioxidants and free radical scavengers on protection of hairless mouse skin exposed to chronic doses of ultraviolet B

Background/aims: Within the past three decades, there has emerged a greater awareness of the molecular effects of solar rays especially ultraviolet radiation (UV-R), to the extent that the harmful effects of solar radiation are recognized not only by molecular biologists and physicians, but also by the general public (1). Various sunscreen molecules that effectively block the UVB component of the sun are available; however, a large part of Western populations elicits adverse reactions against chemical sunscreens (2). This study was designed to observe the protective effect of antioxidants against the damaging effects of chronic UVB exposure of skin in an attempt to introduce antioxidants and free radical scavengers as topical sun protective agents. Methods: Jackson hairless mice were exposed to suberythemal doses of UVB, three times a week, and topically treated with a cream containing the anti-oxidants vitamin E, butylated hydroxy-toluene, nordihydroguaradinic acid and vitamin C. Results: Treatment with vehicle alone along with UVB exposure resulted in an increase in epidermal thickness showing a 38%, 77% and 112% increase after 4 weeks, 8 weeks and 12 weeks, respectively. Chronic UVB exposed skin treated with the material containing free radical scavengers and antioxidants mix (AO mix) exhibited 39%, 73% and 124% thicker epidermis than the un-treated control after, respectively, 4 weeks, 8 weeks and 12 weeks of treatment. The vehicle did not appear to protect skin against UV irradiation, since there appeared to be more (16%) sunburn cells in vehicle treated skin than the untreated, UV exposed skin after 4 weeks of treatment. After 8 weeks and 12 weeks, there were 33% and 36% less sunburn cells in the vehicle treated skin than the untreated, UV exposed skin. The antioxidant mix was significantly effective (P=<0.001) in protecting against UVB irradiation, having 63%, 71 % and 79% fewer sunburn cells than the untreated, UV exposed skin after 4 weeks, 8 weeks and 12 weeks of treatment, respectively. Conclusion: Data from these studies suggest that low level chronic exposures to UV can lead to alteration of the skin, like epidermal thickening and appearance of sunburn cells. The data also indicates that a mix of common antioxidants and free radical scavengers are photoprotective against chronic skin damage in the hairless mouse skin model.     

Effect of beta-carotene supplementation on the human sunburn reaction

Abstract Beta-carotene, a quencher of excited species such as singlet oxygen and free radicals, has been reported to protect against cutaneous photodamage, including sunburn acutely and photocarcinogenesis chronically. The present double blind placebo-controlled study examines the ef-tect of beta-carotene supplementation on the human sunburn response and specifically on the induction of sunburn cells at the time of peak reaction intensity (24 h) after a single solar simulated light exposure 3 times the individually determined minimal erythema dose (MED). Administered orally either as a single 120 mg dose to dietarily restricted subjects or for 23 d as a daily 90 mg supplement to subjects on standard diets, beta-carotene increased plasma and skin levels of beta-carotene compared to both pretreatment levels and placebo-treated controls, but provided no clinically or histologically detectable protection against a 3 MED sunburn reaction. Thus, these data suggest that oral beta-carotene supplementation is unlikely to modify the severity of cutaneous photodamage in normal individuals to a clinically meaningful degree.     

Photoprotective effect of calcipotriol upon skin photoreaction to UVA and UVB

It has been shown that 1,25-dihydroxyvitamin D₃ has a photoprotective effect against UVB injury in mouse skin and cultured rat keratinocytes by induction of metallothionein (MT). Calcipotriol is a synthetic analogue of 1,25-dihydroxyvitamin D₃ with equipotent cell regulating properties, but with a lower risk of calcium-related side effects. The aim of the present study was to see whether calcipotriol has a photoprotective property both in vitro and in vivo. We examined the effect of calcipotriol on UV-induced damage of cultured human keratinocytes through a cell viability assay, and measurement of DNA synthesis by cultured keratinocytes, on UV-induced damage of mouse skin and on minimal erythema dose (MED). We found that calcipotriol was protective against UVB-induced reduction in DNA synthetic activity of cultured keratinocytes in relatively low doses (20 and 40 mJ/cm²) of UVB. With phototesting following application of calcipotriol, five subjects among 10 healthy volunteers and three among six psoriasis patients showed an increase in MED compared with the vehicle-treated site. These findings imply that calcipotriol may be photoprotective and that more extensive studies with various doses of UV irradiation and modes of calcipotriol delivery are required.     

Topical isoflavones provide effective photoprotection to skin

Background/purpose: Isoflavones, one main group of phytoestrogens, have antioxidative and photoprotective effects in cellular and mouse studies. The aim of this study is to obtain a more comprehensive understanding of the isoflavone‐mediated photoprotection with the pig skin model, a more human‐resembling model. Methods: The pig skin was treated with five well‐known isoflavone compounds (genistein, equol, daidzein, biochanin A, and formononetin) and one antioxidant combination solution of 15% vitamin C and 1% vitamin E and 0.5% ferulic acid (CEF) daily for 4 days. Skin was irradiated with solar‐simulated UV irradiation, 1 to 5 minimal erythema dose (MED) at 1‐MED intervals. Evaluation was carried out 24 h later by colorimeter‐measured erythema and sunburn cell numbers. Results: Topical application of 0.5% solutions of three individual phytoestrogens – genistein, daidzein, biochanin A – are better than similar solutions of equol or formononetin in protecting pig skin from solar‐simulated ultraviolet (SSUV)‐induced photodamage, as measured by sunburn cell formation and/or erythema. However, the protection was less than that provided by a topical combination antioxidant standard containing 15% L‐ascorbic acid, 1%α‐tocopherol, and 0.5% ferulic acid. Conclusion: Isoflavones provide effective photoprotection and are good candidate ingredients for protection against ultraviolet (UV) photodamage.     

Ultraviolet B-induced DNA damage in human epidermis is modified by the antioxidants ascorbic acid and D-alpha-tocopherol

DNA damage caused by ultraviolet (UV) irradiation is considered the main etiologic factor contributing to the development of skin cancer. Systemic or topical application of antioxidants has been suggested as a protective measure against UV-induced skin damage. We investigated the effect of long-term oral administration of a combination of the antioxidants ascorbic acid (vitamin C) and D-alpha-tocopherol (vitamin E) in human volunteers on UVB-induced epidermal damage. The intake of vitamins C and E for a period of 3 mo significantly reduced the sunburn reaction to UVB irradiation. Detection of thymine dimers in the skin using a specific antibody revealed a significant increase of this type of DNA damage following UVB exposure. After 3 mo of antioxidant administration, significantly less thymine dimers were induced by the UVB challenge, suggesting that antioxidant treatment protected against DNA damage.     

Assessment of the skin photoprotective capacities of an organo-mineral broad-spectrum sunblock on two ex vivo skin models

UV irradiation can cause cutaneous damage that may be specific according to the wavelength of UV rays. For example, damage from UVB irradiation manifests itself in the form of sunburn cells and enhancement of the expression of p53, while damage from UVA exposure results in an increase in the expression of vimentin. These reactions to UV irradiation were used in this work to evaluate the photoprotective capacities of two sunblock preparations that were applied to the surface of the skin. One sunblock preparation is a UVB absorber containing zinc oxide (ZnO) and titanium oxide (TiO2) exclusively. The other sunblock preparation is a new organo-mineral sunblock containing Tinosorb M, OCM, ZnO and TiO2. Evaluation of the photoprotective capacities of both preparations on hairless rat skin and on in vitro reconstructed human epidermis revealed that they were effective in preventing UVB-induced damage. In contrast, only the organo-mineral sunblock was effective in the prevention of UVA-specific damage such as dermal alterations characterized by the expression of vimentin. Furthermore, our data support the fact that hairless rat skin and in vitro reconstructed human epidermis are a reliable basis for the evaluation of the photoprotective capacities of various sunscreens against UVB and UVA damage.     

The effects of heating and cooling on ultraviolet radiation-induced erythema and pigmentation in human skin

Background/Purpose: As most biochemical systems are affected by temperature, thermal changes before or after ultraviolet (UV) irradiation could influence skin vascular blood flow changes and inflammatory responses. In this study, our aim was to investigate the influence of thermal changes on UV-induced acute skin reactions, namely, erythema and pigmentation.
Methods: Our volunteers consisted of 10 males, with ages ranging from 22 to 24 years and with Fitzpatrick's skin type III or IV. Skin temperatures were changed with a 45°C heating pad or by ice pack application before or after UV irradiation (control, 1 minimal erythema dose (MED), 2 MED) and then changes in erythema and pigmentation were measured by a Minolta Spectrophotometer CM-2002.
Results: The present study demonstrates that both heating and cooling increase skin erythema and reduce pigmentation, and that the timing of heating and cooling influences the UV-induced skin reaction. Pre-heating and post-cooling groups showed more UV-induced erythema than the post-heating and pre-cooling groups, respectively.
Conclusion: Our results indicate that alteration of skin surface temperature could modulate UV-induced erythema and pigmentation responses.     

The relation between constitutional skin color and photosensitivity estimated from UV-induced erythema and pigmentation dose-response curves

In 54 healthy volunteers we assessed predictors of sensitivity to ultraviolet (UV) light, including Fitzpatrick's sun reactive skin types and constitutional skin color, and compared these with one another and with responses of the skin to UV irradiation, as determined experimentally by a minimal erythema dose (MED), a minimal melanogenic dose (MMD), and dose-response curves for UV-induced erythema and pigmentation. For these studies, a xenon arc solar simulator was used as the source of UV irradiation, and a chromameter interfaced with a computer for objective measurement of UV-induced erythema and pigmentation was employed. The skin type did not correspond well to the constitutional skin color, as measured by a chromameter prior to UV irradiation. Within each skin type, there were large ranges of MED and MMD values and great variability in the shapes of the dose-response curves. Constitutional skin color was also not a good predictor of the measured MED and MMD values but did appear to correlate with the steepness of the dose-response curves for erythema and for pigmentation. From these studies, we propose that objectively measured constitutional skin color is a better predictor of UV responses of the skin than skin type and that steepness of dose-response curves for erythema is a better measure of the response of the skin to UV irradiation than is a MED measurement.     

Adalimumab,a fully human anti-TNF-alpha monoclonal antibody,treatment does not influence experimental UV response in the skin of rheumatoid arthritis patients

TNF-alpha is known to play an important role in UV-induced immunomodulation and photodamage. It plays a role in UVB-mediated induction of apoptosis and is a strong inducer of the c-Jun N-terminal kinase (JNK) pathway, which eventually leads to the loss of dermal collagen and elastin content. Recently chimeric anti-TNF-alpha has been introduced as a therapy for rheumatoid arthritis. The aim of the present study was to investigate the effect of anti-TNF-alpha treatment on UV-induced DNA damage, apoptosis, and induction of matrix metallo proteinases. Twelve patients with rheumatoid arthritis were included and irradiated with 2 MED broadband UVB before and after administration of 0.5 mg/kg anti-TNF-alpha monoclonal antibody. Twenty-four hours after irradiation biopsies were taken. Frozen and paraffin sections were stained for p53, c-Jun, phosphorylated c-Jun, sunburn cells and MMP-1. No significant changes were observed in the expression of p53 and sunburn cells and MMP-1 content after treatment with anti-TNF-alpha, whereas a slight but significant decrease in c-Jun and phosphorylated c-Jun expression was noted (P = 0.0250 and P = 0.0431, respectively). Our results showed no influence of anti-TNF-alpha on UV response at therapeutic doses in patients with rheumatoid arthritis.     

Relevance of oral supplementation with antioxidants for prevention and treatment of skin disorders

Reactive oxygen species can cause harmful effects in keratinocytes and fibroblasts if antioxidative defence mechanisms are exhausted. Therefore, it seems to be reasonable to prove if oral supplementation with various nutrient antioxidants is useful in prevention or treatment of skin disorders especially in those mediated by UV irradiation. Betacarotene, ascorbic acid and tocopherol have been tested alone or in combination for prevention of sunburn, photodermatoses and photocarcinogenesis with divergent results. Other candidates for oral antioxidative supplementation in humans are selenium and polyphenols. However, clinical data are limited or missing up to date.     

Immediate effects of UV radiation on the skin: modification by an antioxidant complex containing carotenoids

BACKGROUND/AIMS: The ultraviolet (UV) portion of sunlight is involved in the induction and development of skin cancers against which a limited photoprotection may be provided by reduced time of exposure, clothing, and sunscreen applications. The concept of an effective, safe, systemic photoprotection will circumvent many of the shortcomings. The UV-induced oxidative stress is a cause of DNA damage and a few publications have shown, in humans, minimal benefits, if any, of the oral intake of antioxidant complex, contrasting with the large literature showing beneficial effects in vitro or in animal models. METHODS: We investigated, in 25 healthy individuals, the capacity of an antioxidant complex (AOC) - vitamins (lycopene, beta-carotene, alpha-tocopherol), selenium - to reduce UV-induced damages. The AOC was administered orally, daily during 7 weeks. Before and after irradiations, before and after the intake of the product, six parameters were studied: skin color by chromametry, minimal erythemal dose and, on skin biopsies, sunburn cells (SBCs), p53 detected by immunohistochemistry, pigmentation index, and levels of lipoperoxides (thiobarbituric acid reaction). RESULTS: After the oral intake of AOC, we observed an elevation of the actinic erythema threshold (+20%, P=0.01) and a general reduction of the UV-induced erythemas, a reduction of the UV-induced p53 expression (P<0.05) and of SBCs (P<0.01), and a parallel reduction of the lipoperoxide levels (P<0.01). The pigmentation was increased (P<0.01). CONCLUSION: After the oral intake of an antioxidant complex, many parameters of the epidermal defense against UV-induced damages are significantly improved. The oral intake of AOC could provide a safe, daylong and efficient complement to photo-protective measures provided by topical and physical agents and may contribute to reduce the DNA damages leading to skin aging and skin cancers.