Synergistic effects of oral milk ceramide-collagen peptides mixtures in preventing UV-induced inflammation and photoaging through TGF-β and NF-κB/MAPK signaling pathways in UV-exposed hairless mice

This study investigates the synergistic effects of oral milk ceramide-collagen peptides in inhibiting UV-induced inflammation and preventing photoaging. The optimal ratio of milk ceramide to collagen peptides was determined in HaCaT cells, and the effects of oral supplementation of milk ceramide-collagen peptides were evaluated in UV-exposed hairless mice. HaCaT cells did not exhibit cytotoxicity when treated with milk ceramide and collagen peptides at concentrations up to 200 μg/mL. UVB exposure decreased cell viability, but treatment with the milk ceramide-collagen peptides mixtures (1:1, 1:3) prevented further viability loss and improved collagen peptides synthesis markers, including MMPs and TIMPs. The combination also enhanced moisture-related factors (AQP3, FLG) and reduced inflammatory cytokines (IL-6, IL-1β) and COX expression. In hairless mice, oral supplementation of milk ceramide-collagen peptides mixture (1:1 ratio) improved skin hydration, reduced erythema, TEWL, skin thickness, and wrinkle formation in a dose-dependent manner. The treatment also suppressed the expression of MMPs and TIMPs, promoting collagen peptides synthesis. Furthermore, the mixtures regulated NF-κB and MAPK signaling pathways, reducing inflammation and photoaging. These results suggest that the 1:1 milk ceramide-collagen peptides mixture effectively prevents UV-induced skin damage and photoaging by enhancing collagen peptides production and improving skin barrier function.