Protective activity of caffeic acid and sinapic acid against UVB-induced photoaging in human fibroblasts

In this study, the protective effects of caffeic acid (CA) and sinapic acid (SA) on photoaging in human skin fibroblasts induced by UVB irradiation (30 mJ/cm2) were examined. The results revealed that exposure to UVB irradiation reduced cell viability by approximately 33% compared with the non-UVB irradiated control. However, CA and SA blocked the UVB irradiation-induced cytotoxicity greater than the other phenolic acids. CA and SA also significantly inhibited the release of matrix metalloproteinase 1 (MMP-1) and reduced the expression of MMP-1 mRNA in UVB-irradiated Hs68 cells. Furthermore, CA and SA reduced UVB-induced production of reactive oxygen species (ROS) and collagen degradation in Hs68 cells. Finally, CA and SA effectively downregulated activation of the UVB-induced mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NFκB) signaling pathways. These results imply that hydroxylated cinnamate derivatives can be therapeutic agents against UVB-induced skin photoaging. Practical applications Hydroxylated cinnamate derivatives such as CA and SA have a high cytoprotective effect against UV irradiation-induced photoaging in human fibroblasts via the inactivation of the MAPKs/NFκB signaling pathway. The present study suggests that CA and SA may be useful in therapeutic and cosmetic applications for the treatment of skin photoaging.