Background: Ultraviolet (UV) rays are the major environmental factor that damage skin physiology causing deleterious effects such as oxidation, photoaging and pigmentation. There has been considerable interest in using botanicals to prevent skin damages caused by UV irradiation.
Aim: In this study, three plant extracts were tested either individually or combined together (mixture) as well as their corresponding main active compound: pomegranate/punicalagin, osmanthus/verbascoside and olive/hydroxytyrosol. We evaluated the properties of whitening and anti-photoaging of the nutritional mixture using 2D human culture model and a 3D full-thickness pigmented skin model exposed to UVB and UVA.
Methods: For exploring skin pigmentation, oxidation and aging, we performed cell viability, tyrosinase activity and melanin content assays as well as histology analysis (Warthin–Starry staining), immunodetection (PMEL, MDA, collagen type I and elastin) and carbonylated proteins analysis by electrophoresis separation.
Results: Results showed that the pomegranate extract and the active molecule punicalagin could reduce the tyrosinase activity and melanin content in melanocytes (P < 0.05), which suggested that punicalagin contributed to the whitening properties of the plant extracts mixture. The mixture, pomegranate extract and punicalagin inhibited the melanin production and pre-melanosomal protein (PMEL) expression in the 3D skin pigmented model (P < 0.001). Furthermore, the mixture treatment repaired the expressions of collagen I and elastin decrease by UV exposure (P < 0.01). The mixture also significantly decreased lipid peroxidation (P < 0.001) and carbonylated proteins (P < 0.05) in the skin model compared to the UV-exposed condition.
Conclusion: To conclude, the mixture composed of pomegranate, osmanthus and olive extracts protects human skin from UV rays deleterious effects and exhibits antioxidative, anti-aging and skin whitening properties. The mixture might be good candidates for further development as natural antioxidants and skin care products.
Keywords: ultraviolet radiation, plants extracts, antioxidation, punicalagin, pigmentation