289 Oral administration of table grapes has a photoprotective effect on the sunburn response and on cyclobutane pyrimidine dimers in humans in vivo

Abstract

288 Dietary green tea catechins protect dermal elasic fibers from UV-induced remodeling N Charoenchon, LE Rhodes, A Nicolaou, G Williamson, MD Farrar and RE Watson 1 The University of Manchester, Manchester, United Kingdom and 2 The University of Leeds, Leeds, United Kingdom Cutaneous photoaging is associated with dermal elastic fiber remodeling; daily photoprotection is therefore essential to prevent ultraviolet (UV)-induced skin damage. Green tea (C sinensis), rich in polyphenol catechins (GTC), have been reported to have significant skin benefits in vitro and in vivo. We have performed a double-blind randomised controlled trial to assess whether systemic GTC supplementation can protect dermal elastic fibers from acute UV exposure. Healthy white Caucasians (n1⁄450; 18-65 years) were randomized (1:1) to 12 weeks daily oral supplement (1080mg GTC with 100mg viatmin C) or placebo (maltodextrin). Biopsies were taken from skin exposed to 3xMED of solar simulated radiation (SSR) and unexposed skin at baseline and post-supplementation; compliance was confirmed by urinary GTC metabolite analysis. Dermal elastic fibers were identified via histology and immunohistochemistry, their distribution assessed in the papillary dermis (from the dermal-epidermal junction to a depth of 100mm) by image analysis. Differences between UV-exposed and unexposed skin were analysed by paired t-test. A total of 44 subjects completed the study, being compliant with supplementation and providing all skin samples. At baseline, SSR induced a significant overall loss of elastic fiber components (P1⁄4 0.001), and specifically fibulins-2 and -5. Post-supplementation, UV-mediated loss of fibulin-5 remained significant in the placebo group with mean (SD) % fiber area 19.4 (3.8) and 17.7 (4.1) in unexposed and UV-exposed skin resectively (P1⁄40.01), whilst in the active group fibulin-5 was protected with % fiber area 18.1 (4.0) and 17.1 (2.7) in unexposed and UV-exposed skin respectively (P1⁄4 0.30). Hence, acute SSR exposure results in elastic fiber remodeling similar to that observed in chronically photoaged skin. Furthermore, in a randomized control trial, dietary GTC protected fibulin-5 microfibrils in the papillary dermis from UV-mediated degradation. 289 Oral administration of table grapes has a photoprotective effect on the sunburn response and on cyclobutane pyrimidine dimers in humans in vivo AS Oak, R Shafi, S Katiyar, AT Slominski, W Cantrell, C Wang, RK Srivastava, C Li, M Athar and C Elmets Dermatology, University of Alabama at Birmingham, Birmingham, AL Table grapes contain proanthocyanidins and resveratrol which have been shown to have photoprotective properties in animal models. The purpose of this study was to determine whether oral administration of grapes had a similar effect in humans. Eleven healthy human volunteers (Fitzpatrick skin phototypes I-III, aged 19-46 and without any significant comorbidities) were recruited for the study (uncontrolled longitudinal study). The minimal erythema dose (MED) on the inner aspect of the forearm was determined using a broadband UVB light source. Skin biopsies were also performed at baseline from a sun protected area on the hip and from the 1 MED treated site on the forearm. Volunteers were then instructed to take 25 grams of grape powder three times per day for 2 weeks. At the end of the treatment period, the MED was again performed. In addition, skin biopsies were repeated at the end of two weeks in 9 of the 11 subjects after taking the grape powder. The biopsies were processed and stained for cyclobutane pyrimidine dimers (CPDs). The mean MED SEM increased in subjects from 205 30 J/m to 346 59 J/m, after taking the grape powder, which was statistically significant (paired t-test, p1⁄40.05). Oral administration of grape powder also inhibited CPD formation. There was a 32% decline in CPDs in pretreatment vs. post-grape treatment biopsies from the MED skin site (pretreatment: 32.6 5.2%, posttreatment: 23.1 4.1%, p1⁄40.005). Oral administration of grape powder did not have a significant effect on the number of CPDs in the unirradiated skin sites (pretreatment: 2.7 .9%, posttreatment: 3.8 .9%, p1⁄4.15). These studies demonstrate that oral administration of grapes has a photoprotective effect on the MED and in attenuating CPDs in human skin, and validate the findings from preclinical studies.