Byrsonima crassifolia extract and fraction prevent UVB-induced oxidative stress in keratinocytes culture and increase antioxidant activity on skin

Abstract

Solar ultraviolet radiation exposure, particularly UVB rays (280–320nm), can lead to skin lesions, photocarcinogenesis and acceleration of skin photoaging since UVB radiation may reach both the epidermal and dermal layers of the skin. Treatments that can ameliorate UVB-induced skin damage include natural extracts, which can act as skin photochemoprotective agents. Byrsonima crassifolia is widely used in the folk medicine. Previously studies have shown high antioxidant activity of BC leaves extracts. In this study we described the first photochemoprotective potential of Byrsonima crassifolia extract (BCP) and fraction (BCF) against UVB-induced damage in keratinocytes and the ability of topical formulations with BCP or BCF to increase the antioxidant activity in pig ear skin. The results of characterization of BCP and BCF indicate that the phenolic content was increased two-fold after an enrichment process for obtaining BCF. Despite differences in the phenolic content, both BCP and BCF exhibited similar IC50 values for lipid peroxidation and the DPPH method during the antioxidant activity study. However, for the chemiluminescence assay using the xanthine/luminol/XOD, BCF exhibited higher antioxidant activity than BCP. The different phenolic content in BCP and BCF did not influence their photochemoprotective activity in HaCaT cells, and both samples exhibited similar levels of protection. After treatment with BCP and BCF (1.2–5μg/mL) and UVB irradiation exposure, the effect of lipid peroxidation in vitro was maintained in cell culture, and both IL-6 and TNF-α secretion and NF-κB activation were suppressed. After the development of the different formulations, BCP and BCF increased the antioxidant activity on skin and the formulation containing BCF showed higher skin retention, especially for (+) catechin, which was able to pass through the stratum corneum. Based on these findings, BCF could be topically applied to prevent/treat the damage induced by UVB radiation in the skin.