Effects of <10-㎛ Particulate Matter on Cultured Human Sebocytes and Outer Root Sheath Cells and Usefulness of Siegesbeckia Herba Extract

Background Particulate matter (PM) is one of the air pollutants that can damage human skin; the recent increase in the amount of PM may be detrimental to skin health. Objective We aimed to investigate the effects of PM on cultured human sebocytes and outer root sheath (ORS) cells and the effects of Siegesbeckia Herba extract (SHE) on PM-treated cultured cells. Methods Sebocytes and ORS cells were cultured. The cultured cells were treated with various concentrations of PM of <10 ㎛ in size (PM10) (10 ㎍/ml, 25 ㎍/ml, 50 ㎍/ml, and 100 ㎍/ml) for 24 h. Real-time polymerase chain reaction, measurement of reactive oxygen species (ROS), small interfering (si) RNA transfection, Oil Red O and Nile red staining, and immunofluorescence staining were performed to analyze the presence of inflammatory cytokines, matrix metalloproteinases (MMPs), aryl hydrocarbon receptor (AhR), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), ROS, and lipid production. In addition, PM10 (100 ㎍/ml)-treated cultured cells were treated with 10 mg/ml of SHE. Results PM10 upregulates the expression of inflammatory cytokines, MMPs, AhR, NF-κB, and ROS in cultured human sebocytes and ORS cells. The production of ROS was dramatically reduced in AhR siRNA-transfected cells. In addition, PM10 upregulates sebum production in cultured sebocytes. SHE inhibited the upregulation of inflammatory cytokines, MMPs, AhR, NF-κB, ROS, and sebum production in cultured human sebocytes and/or ORS cells by PM10. Conclusion Effects of PM10 on cultured human sebocytes and ORS cells can be regulated by SH.