Preventive effect of Curcuma zedoaria extract on UVB-induced skin inflammation and photoaging

We sought to investigate whether Curcuma zedoaria extract (CZE) has preventive effects against UVB-induced skin inflammation and photoaging. CZE was identified as a promising anti-inflammatory and photoaging candidate based on a matrix metalloproteinase (MMP)-1 promoter assay and the suppressive effects of CZE on UVB-induced cyclooxygenases (COX)-2 and MMP-13 expression were confirmed in immortalized skin human keratinocytes. CZE suppressed UVB-induced phosphorylation of c-Jun N-terminal kinases, mitogen-activated protein kinase kinases 3/6/p38, B-Raf/ERK kinase (MEK)1/2/extracellular signal-regulated kinases (ERK)1/2, and Akt as well as phosphorylation of epidermal growth factor receptor (EGFR) and Src. Using a chronic skin inflammation and photoaging model, we observed that CZE significantly suppressed repetitive UVB-induced wrinkle formation and COX-2 and MMP-13 expression in vivo. Among the compounds investigated, curcumin was found to exhibit the strongest inhibitory effect on UVB-induced MMP-1 promoter activity. These results demonstrate that CZE has a potent preventive activity for UVB-induced skin inflammation and photoaging, which occurs via the suppression of EGFR, Src, MAPKKs/MAPKs, and Akt phosphorylation. Practical applications. This study is a study to develop materials that can prevent skin inflammation and photoaging by UVB exposure. Therefore, it can be applied to functional cosmetics or functional foods after standardization and clinical studies on this material.