| Summary: | Objective To investigate the inhibitory effect of phillyrin (PHI) on lipopolysaccharide (LPS)-induced hepatic stellate cell (HSC) activation and explore the possible mechanisms. Methods Cultured rat hepatic stellate cells (HSC-T6) were divided into blank control group, LPS (1 μg/mL) group, LPS (1 μg/mL) + PHI (1 μg/mL) group, and LPS (1 μg/mL) + PHI (10 μg/mL) group. We assessed the changes in the proliferation and migration of the cells (HSC-T6) after the treatments using MTT assay and Transwell migration assay, respectively. The intracellular reactive oxygen species (ROS) level in the cells was determined with flow cytometry, and the concentrations of proinflammatory cytokines in the supernatant were tested using enzyme-linked immunosorbant assay (ELISA). The expression levels of α-SMA and phosphorylated nuclear factor-κB (NF-κB) p65 in the cells were analyzed with Western blotting. Results PHI from the concentration of 1 to 100 μmol/L did not significantly affect the proliferation of HSC-T6 cells. LPS stimaulation significantly promoted the proliferation and migration of the cells, and such effects were obviously suppressed by PHI treatment at both 1 (16.13% and 17.14%) and 10 μmol/L(48.99% and 58.86%). PHI at 10 μmol/L significantly reduced the expression of α-SMA (27.33%) in HSC-T6 cells exposed to LPS; at both 1 and 10 μmol/L, PHI strongly suppressed LPS-induced elevation of intracellular ROS level(30.03% and 51.26%), lowered the levels of proinflammatory cytokines TNF-α(23.16% and 39.51%), IL-6(36.57% and 43.75%) and IL-1β(58.99% and 73.01%) and decreased the expression of phosphorylated NF-κB p65(13.90% and 24.96%) in LPS-stimulated cells. The decreased expression level of phosphorylated NF-κB p65 protein in HSC-T6 cells was positively correlated with intracellular ROS level, concentrations of TNF-α and IL-1β, and the expression level of HSC activation marker α-SMA protein. Conclusion PHI can inhibit HSC activation induced by LPS possibly by down-regulating inflammatory responses mediated by NF-κB signaling pathway.
|
|---|
