2'-Fucosyllactose Attenuates Particulate Matter-Induced Inflammation via Inhibition of Hypoxia-Inducible Factor in Keratinocytes.

2'-Fucosyllactose (2FL) is the most abundant component of the oligosaccharide content in human milk. It has been reported that 2FL has the ability to protect against infectious disease caused by bacterial pathogens. In this study, we investigated the protective effects of 2FL on particulate matter (PM)₁₀-induced pro-inflammatory cytokines in HaCaT keratinocytes. 2FL reduced PM₁₀-induced excess expression of interleukin (IL)-6, IL-8, IL-1α and IL-1β in HaCaT keratinocytes. In addition, PM₁₀ also increased hypoxia-inducible factor (HIF)-1α protein levels; however, 2FL inhibited the accumulation of HIF-1α protein and the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/Akt stimulated by PM₁₀. Furthermore, 2FL improved PM₁₀-induced the decrease in epidermal thickness and integrity of the cornified layer in the reconstructed human epidermal skin model (RHE). In our results, 2FL inhibited PM₁₀-induced pro-inflammatory mediators by regulating the HIF-1α/PI3K/Akt pathway and protected the skin epidermis against PM₁₀ irritation. Taken together, these results suggest that 2FL can be used as a primary ingredient in cosmeceutical products to alleviate skin irritation and inflammation caused by urban air pollution.