A natural broad-spectrum sunscreen formulated from the dried extract of Brazilian Lippia sericea as a single UV filter

Abstract

Despite the challenges in producing plant-derived photoprotective products, novel natural, broad-spectrum sunscreens have gained momentum in the cosmetic industry in the past few years. Traditionally, most of these products have been derived from plants producing polyphenolic and flavonoid compounds. In this study, we focused on plants belonging to the genus Lippia. The study aimed to develop a natural broad-spectrum sunscreen from a Lippia species that could be used as a single UV filter in formulation. Initially, UV transmission of sunscreens (10%, w/w) derived from four different Lippia species was determined to estimate their UVB protection factor (SPF). Next, the extract from species showing the best result was subjected to in vivo SPF and in vitro UVA radiation protection factor (UVAPF) determination using diffuse transmittance spectroscopy. The natural sunscreens obtained in vitro SPF values ranging from 1.7 to 7.6. The higher SPF was obtained with L. sericea species; the in vivo SPF of this sunscreen was 7.5 and its UVAPF was 2.97 when used as a single UV filter in a lotion. The photoprotective activity of this sunscreen was found to be related to the total polyphenolic content of the plant and not to its flavonoid content or antioxidant capacity. Thus, the results of this study suggested that the natural sunscreen from L. sericea has the potential to be used commercially.