651 UVB-induced p53 is reduced by a mixture of natural extracts G Caiazzo 1 , A Balato 2 , E Scala 1 , A Raimondo 1 and G Monfrecola 1 1 Department of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy and 2 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy The aim of this study was to evaluate, in vitro, the protective effects of taurine, omega3/6 and a mixture of tocotrienols, tocomonoenol and tocopherol (DVL 95), in UVB-irradiated kera- tinocytes. For this purpose, immortalized human keratinocytes were pre-incubated for 2h with the above mentioned substances, singularly or in combination, and irradiated with UVB 60 mJ/cm 2 . Both, UVB dose and substance concentrations, have been selected after multiple cell viability experiments. Their possible protective effect was explored analyzing p-53 levels at 24h after UVB irradiation. Our results showed that the tested substances displayed sig- nificant cytoprotective properties. In particular, these compounds when used synergistically resulted more effective in reducing UVB-induced p-53 protein expression. Probably, their effects would be enhanced when used in combination. Since the regulation of p-53 pathway is considered an essential part of treatment in multiple inflammatory diseases, this mixture natural extracts may be an interesting option to improve or prevent UV-induced or aggravated clinical conditions. 652 Protection strategies to inhibit blue light irradiation effects in-vitro and in skin ex-vivo R Campiche, C Mendrok-Edinger, K Gadsinski, A Janssen, R Schu ¨tz, T Rudolph, J Klock and J Vollhardt Personal Care, DSM Nutritional Products, Kaiseraugst, Switzerland The negative impacts of visible light, particularly high energy visible light (HEV) or blue light (wavelength 380-500nM), to skin are still not fully understood. A few studies have shown an increase of blue light-induced oxidative stress and hyperpigmentation in-vitro suggesting a contribution to photo-aging. Only two UV-filters were found to partially block wavelength >400nm, hence additional means of protection are needed. We investigated blue light- induced cutaneous damages and screened for compounds to suppress these damages. Vita- mins B3, B6 and E as well as Q10 could prevent beta-carotene from blue light-dependent degradation in-vitro on PMMA plates. To investigate the potential of these compounds to suppress blue light induced damages in skin, we developed an ex-vivo model of blue light irradiation. Using fluencies of up to 100J/cm 2 we could show a dose-dependent increase of reactive oxygen species (by immunofluorescent labeling), and we established protein carbonylation (by Oxyblot analysis) as a novel marker of blue light induced skin damage. We found that distinct compounds like e.g vitamin B3, lutein or Q10 as well as an extract of the green fresh water microalgae Scenedesmus rubescens could suppress blue light induced damage significantly (p<0.05). In summary, we provide evidence that blue light induces cutaneous damage via protein carbonylation, that can be suppressed by specific vitamins, Q10 and carotenoids, or algae extracts. 653 New lipophilic pro-vitamin C, tetra-isopalmitoyl ascorbic acid (VC-IP), suppresses senile lentigo through controlling of melanocytes-keratinocytes interaction M Yokota and S Yahagi NIKKOL GROUP Cosmos Technical Center co., ltd., Tokyo, Japan Senile lentigo are hyperpigmented macules of skin that occur in irregular shapes, appearing most commonly in the sun-exposed areas of the skin such as on the face and back of the hands, and are a common component of photoaged skin. Vitamin C is well known to play an important role in maintaining skin physiology, especially as a skin whitening and blighting agent. We previously demonstrated that a new stable lipophilic pro-vitamin C derivative, tetra-isopalmitoyl ascorbic acid (VC-IP), showed significant suppressive effect for UVB- induced skin pigmentation by conversion into vitamin C in skin tissue. In addition, we re- ported that VC-IP showed multiple physiological activities represented by scavenging of ROS and reduction of inflammatory cytokines, IL-1a and PGE2, in keratinocytes. In this study, we evaluated that effectiveness of VC-IP on senile lentigo by conducting clinical test approved by the institutional ethical committee. VC-IP significantly improved brightness of aging spot and skin tone to evenness by mechanical measurements. Moreover, self-assessment study demonstrated that subjects were satisfied with the following parameters; appearance of aged spot, skin brightness, fading of dullness or yellowing and zero adverse reaction. Furthermore, we newly identified that VC-IP strongly suppressed the melanin delivery by inhibition of dendrite elongation stimulated by endothelin-1 in melanocytes-keratinocytes co-culture system. There are still many discussions on how senile lentigo represents in skin, however, these results suggested possibility that VC-IP is effective for improving hyperpigmented spot based on controlling of melanocytes-keratinocytes interaction. 654 Milk thistle and olive extract: Mediterranean cytoprotection R Di Caprio 1 , G Monfrecola 1 , A Balato 2 , G Caiazzo 1 , F Gasparri 3 and S Lembo 4 1 Deparment of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy, 2 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy, 3 Department of Pharmacy (DIFARMA), University of Salerno, Salerno, Italy and 4 Department of Medicine, Surgery and Dentistry, Scuola Medica Salernitana, University of Salerno, Salerno, Italy The aim of this study was to evaluate, in vitro, the protective effect of milk thistle and olive purified extracts on cultured keratinocytes, after solar simulator radiation (SSR). For this purpose, immortalized human keratinocytes were pre-incubated for 2h with different con- centrations of milk thistle (5, 10, 30 and 50 mg/mL) and olive (5, 50, 100 and 150 mg/mL) purified extracts, and irradiated with increasing doses of SSR (5, 10 and 20 J/cm 2 ). SSR- induced cytotoxicity was measured through cellular vitality analysis using the Trypan blue method and the micronucleus assay-CBMN- test. Substances’ cytotoxicity was analyzed through Trypan blue and MTT assay. Direct DNA damage was assessed by measuring cyclobutane pyrimidine dimers (CPDs) and p53 expression, oxidative stress was evaluated through the consumption of cellular antioxidants (GSH and NADPH) and the production of peroxidated lipid membranes (TBARs). The study substances resulted well tolerated with significant cytoprotective and anti-oxidant properties, being milk thistle dry extract more effective in limiting the direct DNA damage (p< 0.05), and olive extract particularly able to reduce lipid membrane peroxidation and to increase cellular antioxidants (p< 0.05). In conclusion, both study substances can be defined as safe compounds, showing differential cytoprotective and anti-oxidant activities and might represent interesting options for non- melanoma skin cancers chemoprevention. 655 Solar urticaria: Basophil activation test with UV-irradiated serum G Pietsch, B Eberlein and M Al-Sisi Department of Dermatology and Allergy Biederstein, Technische Universita¨t Mu ¨nchen, Mu ¨nchen, Germany It is supposed, that an inactive photoallergen in the skin or serum of patients with solar ur- ticaria (SU) exists. This photoallergen is activated by light, resulting in an immediate type hypersensitivity reaction with urticarial symptoms after sun exposure. We wanted to inves- tigate the existence of this reactive photoallergen in the pathogenesis of solar urticaria, based on measuring the basophil activation with UV-irradiated serum of SU-patients and controls. Basophil activation tests (Flow CASTÒ) were performed to measure the allergen-specific response with UVA (50, 100 J/cm 2 ) and UVB (100, 200 mJ/cm 2 ) irradiated serum. Blood and serum were gained from three men (18, 21, and 21 years) with solar urticaria, proven by phototesting. Blood and irradiated serum from individuals without SU were used as controls. There was no significant CD63 activation of patients’ or controls’ basophils with the irradiated SU-patients’ or controls’ serum. Despite positive results in a former case report (CD203c expression was up-regulated more than 10% in relation to the negative control after irradi- ation with UVA 40 J/cm 2 ) we were not able to activate basophils of our SU-patients with irradiated serum. We draw the conclusion that a photoallergen could not be detected in our patients by the method used. It is supposed, that there are two types of solar urticaria. In type I there is a pathologic photoallergen in the patients’ serum assumed and in type II a precursor of the photoallergen in the patients’ skin. In our collective it is most likely, that the photoallergen is present in patients’ skin, but not in serum. This explains the different outcome of studies with similar tests. Another cause could be, that CD63 activation is not as sensitive as CD203c activation of basophils. It is also known that the photoallergen can differ in size and shape, which would explain the individual reaction and outcome. So more detailed information on fundamental pathophysiology of solar urticaria is needed to understand and characterise this complex disease completely. 656 WITHDRAWN ABSTRACTS | Photobiology and Pigmentation S304 Journal of Investigative Dermatology (2017), Volume 137