Anti-Inflammatory Effect of Buddleja officinalis on Vascular Inflammation in Human Umbilical Vein Endothelial Cells

Vascular inflammation process has been suggested to be an important risk factor in the initiation and development of atherosclerosis. In this study, we investigated whether and by what mechanisms an aqueous extract of Buddleja officinalis (ABO) inhibited the expressions of cellular adhesion molecules, which are relevant to inflammation and atherosclerosis. Pretreatment of human umbilical vein endothelial cells (HUVEC) with ABO (1-10 mu g/ml) for 18 hours dose-dependently inhibited TNF-alpha-induced adhesion U937 monocytic cells, as well as mRNA and protein expressions of vascular cell adhesion molecule-1 (VCAM-1), and intercellular cell adhesion molecule-1 (ICAM-1). Pretreatment with ABO also blocked TNF-alpha-induced ROS formation. Nuclear factor-kappa B (NF-kappa B) is required in the transcription of these adhesion molecule genes. Western blot analysis revealed that ABO inhibits the translocation of the p65 subunit of NF-kappa B to the nucleus. ABO inhibited the TNF-alpha-induced degradation of I kappa B-alpha, an inhibitor of NF-kappa B, by inhibiting the phosphorylation of I kappa B-alpha in HUVEC. Taken together, ABO could reduce cytokine-induced endothelial adhesiveness throughout down-regulating intracellular ROS production, NF-kappa B, and adhesion molecule expression in HUVEC, suggesting that the natural herb Buddleja officinalis may have potential implications in atherosclerosis.