Photoprotective activity and increase of SPF in sunscreen formulation using lyophilized red propolis extracts from Alagoas

The excessive sun exposure, coupled with lack of sun protection represents one of the biggest risks to the occurrence of skin cancer and photoaging. Recent strategies for photoprotection have included the incorporation of natural antioxidant and anti-inflammatory compounds, into sunscreens, and the oral administration of natural antioxidant extracts. In this work, we use Brazilian red propolis extract because its antioxidant and anti-inflammatory activities. The aim of this work was to evaluate the sun protection factor and antioxidant activity of different hydroalcoholic extracts of red propolis (70% and 75%) prepared from lyophilized red propolis at room and high temperatures. The sun protection factor in vitro was determined by a spectrophotometric method developed by Mansur. The hydroalcoholic extracts of red propolis incorporated with Filter UVA-UVB 5% Gel Permulem TR-1 presented absorption in the UVB region. Also, the in vitro capacity of the hydroalcoholic extracts of red propolis to increase photoprotective activity of Filter UVA-UVB 5% Gel was evaluated. The hydroalcoholic extracts of red propolis incorporated presented higher values of sun protection factor and showed synergism in the photoprotective activity of Filter UVA-UVB 5% Gel Permulem TR-1. The antioxidant activity and sun protection factor are correlated with total phenolics content of the extracts and the hydroalcoholic extract of red propolis 75% at room temperature was choosen. The formulation developed with Filter UVA-UVB 5% Gel Permulem TR-1 with this hydroalcoholic extract of red propolis showed safe to be applied on the skin according HET-CAM test. Suggests indication of hydroalcoholic extract of red propolis (75% - room temperature) associated to photoprotective formulations for use in photoprotective products. (C) 2019 Sociedade Brasileira de Farmacognosia. Published by Elsevier Editora Ltda.