Figure 4. GC31 inhibited lipopolysaccharide-induced inhibitor of nuclear factor kappa B alpha degradation and nuclear factor kappa B nuclear translocation in human umbilical vein endothelial cells (HUVECs). A: Cells were preincubated with GC31 or VP30 for 30 min and then with 1 μg/mL lipopolysaccharide for 1 h. Nuclear extracts were analyzed with western blot analysis using antibody against phosphorylated nuclear factor kappa B (NF-κB) p65. Lamin A/C was used as the internal control. B: Human umbilical vein endothelial cells (HUVECs) were pretreated with GC31 (0.1–10 μM) or VP30 (10 μM) for 30 min, then stimulated with LPS (1 μg/ml) for 30 min, and the expression of inhibitor of nuclear factor kappa B alpha (IκBα) and phosphorylated IκBα (p-IκBα) in the protein extracts was determined with western blot. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as the loading control. The band density was determined by Image J software and the results represent means±SD of three independent experiments. *p<0.05, **p<0.01 versus the LPS group.