Figure 5. GC31 reduced lipopolysaccharide-induced activation of mitogen-activated protein kinase pathways in human umbilical vein endothelial cells. Human umbilical vein endothelial cells (HUVECs) were pretreated with or without indicated concentrations of GC31 for 30 min, followed by induction with 1 μg/mL lipopolysaccharide (LPS) for 30 min. The levels of phospho-p38 (A) and phosphoextracellular signal-regulated kinase-1/2 (p-ERK1/2) (B) were determined with western blot analysis. The relative levels were calculated as the ratio of the phosphorylated target protein to the total protein expression. Data were expressed as means±SD of three independent experiments. *p<0.05, **p<0.01 versus the LPS group.