, 2005, Kand’árová, 2006 and Trauer et al., 2006). Hayden et al. (2005) observed that avobenzone had the highest toxicity in culture human keratinocytes, however it did not penetrate the skin and thus the concentration of the UV-filter detected on viable epidermis after topical application was at least 5-fold lower than the toxic concentration on keratinocytes monolayer. Other authors observed that 1 h after application of a sunscreen formulation containing avobenzone (Parsol™ 1789), Doxorubicin manufacturer this UV-filter were located in the upper 30% of the horny layer and did not reach the living

cells (Lademann et al., 2009). Organic UV-filters are among the most common agent groups currently responsible for photo-allergic contact dermatitis. A multicenter photopatch test study conducted with 1031 patients in 30 European centers found that the UV-filters octocrylene, benzophenone-3 Pirfenidone and avobenzone most frequently elicited photo-allergic contact dermatitis and they also reported some cross-reactions between some UV-filters combinations (EMCPPTS, 2012). This way, although the extrapolation of the positive results obtained in the present study to the human situation may be performed only to a limited extent, they are valid to investigate

the phototoxic potential of new combinations of UV-filters and antioxidant substances like vitamin A. The results obtained in the present study showed that despite the four formulations studied did not present any acute phototoxicity potential due to their reduced penetration, the combination 2 containing octyl methoxycinnamate (OMC), avobenzone (AVB) and 4-methylbenzilidene camphor (MBC) presented an indication of phototoxicity that should be better investigated. On the other hand, some previous studies of our group performed in humans showed that some formulations containing vitamins could induce

allergic responses after a 2-week period of application, mainly when applied on the face (Gaspar et al., 2008). Thus, although no acute phototoxicity was detected in the H3D PT model, the formulations may have photoallergic or chronic phototoxicity buy Sunitinib and nowadays the development of additional models and endpoints is a challenge among researchers to avoid underpredictions and to increase the sensitivity of the these in vitro assays to replace animal use. The results obtained when avobenzone and vitamin A palmitate were submitted to 3T3 NRU Phototoxicity test showed that avobenzone presented a pronounced phototoxicity enhancement that was UVA dose dependent. However when vitamin A was analyzed, the obtained results showed that vitamin A presented a tendency to a weak phototoxic potential that was not confirmed in the UVA dose response study. When combinations 2 and 4 containing avobenzone were evaluated, there was an enhancement of MPE values, which were closer to borderline phototoxicity values.