Anti-inflammatory and anti-aging effects of hydroxytyrosol on human dermal fibroblasts (HDFs)

Background Hydroxytyrosol is discovered in a form of elenolic acid ester oleuropein in olive leaf and oil. The anti-carcinogenic, antioxidant, and anti-inflammatory effects of hydroxytyrosol have been reported in the food, medical, pharmaceutical, and life science fields. But it has not been studied on skin biology field. This study is demonstrated using UVA-induced cellular aging model of human dermal fibroblast. Methods The cell survival rate was measured using the principle of water-soluble tetrazolium salt-1 assay, which is a measurement method for cell survival rate. The quantitative real-time PCR (qRT-PCR) was used to quantitatively analyze the gene expression changes in human dermal fibroblasts (HDFs) by hydroxytyrosol. Senescence-associated β-galactosidase (SA-β-gal) assay was implemented to dye β-galactosidases (used as a cell aging biomarker) to measure HDF cell aging by UVA. Results Hydroxytyrosol decreased the SA-β-galactosidase activity in a dose-dependent manner in UVA-exposed HDFs. Also, the elevated expression of MMP-1 and MMP-3 by UVA were decreased by hydroxytyrosol in a dose-dependent manner. To examine the anti-inflammatory effect of hydroxytyrosol in UV exposed HDFs, the expression of inflammatory interleukins IL-1β, IL-6, and IL-8 were analyzed. Quantitative RT-PCR showed that hydroxytyrosol decreased the expression of IL-1β, IL-6, and IL-8 gene. Conclusion Through this research, we demonstrate that hydroxytyrosol has effects on anti-inflammatory and anti-aging in HDFs damaged by UVA. We suggest that hydroxytyrosol is fully worthy of using as a cosmetic material effective to anti-inflammatory and to delay cellular senescence on HDFs.