基于Nrf2/TLR4信号通路的低聚木糖皮肤防护功效原料开发、功效及机制研究OA

To investigate the regulatory effect and molecular mechanism of xylooligosaccharides(XOS)on skin barrier immune function,we systematically evaluated two HaCaT cell models:ultraviolet B(UVB)-induced injury and Staphylococcus aureus culture supernatant(SA-CS)-induced inflammation.In the UVB injury model,HaCaT cells were irradiated with 30 mJ/cm2 UVB and then treated with low,medium and high doses of XOS(50,100,200 μg/mL)and an Nrf2 inhibitor(ML385)for 24 h.In the SA-CS inflammation model,cells were treated with 20%SA-CS for 24 h,with low,medium and high doses of XOS and a TLR4 agonist(LPS)added simultaneously.Each group consisted of six replicate wells.Cell viability,apoptosis rate(TUNEL assay),mRNA levels of apoptosis-related genes(Bax,Bcl-2),transepithelial electrical resistance(TEER)value,mRNA levels of barrier-related proteins(FLG,Claudin-1/4),oxidative stress indicators(ROS,MDA,SOD),proteins of the Nrf2/Keap1 pathway,inflammatory factors(IL-1β,IL-8,TNF-α,etc.)and protein levels of the TLR4/NF-κB pathway were measured.The results show that UVB irradiation significantly decreases cell viability and TEER value,downregulates mRNA expression of barrier-related proteins,promotes cell apoptosis,induces oxidative stress and inhibits Nrf2 nuclear translocation in HaCaT cells.XOS reverses these injuries in a dose-dependent manner,an effect that can be blocked by ML385.SA-CS treatment significantly reduces cell viability and TEER value,downregulates mRNA expression of barrier-related proteins,promotes cell apoptosis,and increases the levels of inflammatory factors and protein expression of TLR4 and p-NF-κB p65.XOS also ameliorates these injuries in a dose-dependent manner,while LPS reverses this effect.In summary,XOS antagonizes UVB-induced oxidative damage in skin cells by activating the Nrf2 pathway,and alleviates SA-CS-mediated inflammatory damage by inhibiting the TLR4/NF-κB pathway,thereby protecting skin barrier function.This study provides experimental evidence and theoretical support for the development of cosmetic raw materials with skin barrier protection,antioxidant and anti-inflammatory effects.