Combined protection against UVB-induced photoaging by oleuropein, hydroxytyrosol, and verbascoside through modulation of inflammation, oxidative stress, and collagen homeostasis.

Abstract

Ultraviolet B (UVB) exposure induces skin photoaging through triggering oxidative stress, inflammation, apoptosis, and collagen degradation. Oleuropein (OLE), Hydroxytyrosol (HT), and Verbascoside (Verb) are polyphenols derived from olive leaves, exhibiting potent antioxidant and anti-inflammatory properties. In the present study, we investigated the protective effects of OLE, HT, and Verb combination (O/H/V) against UVB-induced photoaging using in vitro models. The results showed that O/H/V treatment reduced the expression of senescence and apoptosis-related markers, while concurrently downregulated inflammatory factors and matrix metalloproteinases via suppression of MAPK and NF-κB pathways in UVB-irradiated HDF cells. In UVB-irradiated HaCaT cells, O/H/V treatment attenuated collagen degradation and pro-inflammatory factors expression via upregulation of Nrf2 levels. Furthermore, in a HaCaT-HDFs co-culture system, treatment of UVB-irradiated HaCaT cells with the O/H/V combination led to a significant reduction in pro-inflammatory factors and collagen degradation-related genes in HDFs. Together, these findings indicate that the O/H/V combination exerts protection against UVB-induced photoaging through multiple mechanisms, including inhibition of MAPK/NF-κB pathway and enhancement of Nrf2 expression.