Anti-inflammatory effects of a Chinese herbal medicine in atherosclerosis via estrogen receptor β mediating nitric oxide production and NF-κB suppression in endothelial cells

Bu-Shen-Ning-Xin Decoction (BSNXD) administration has alleviated the early pathologic damage of atherosclerosis by inhibiting the adhesion molecule expression and upregulating the estrogen receptor (ER) β expression in endothelial cells, and increasing the serum nitric oxide (NO) level without any effect on serum lipid status, endometrium and fat deposition in liver in ovariectomized rabbits. The BSNXD-derived serum increases ER β expression in the human umbilical vein endothelial cells (HUVECs), and decreases malondialdehyde (MDA) production, and upregulates eNOS expression then increases NO synthesis through ERβ-dependent pathway. NO not only suppresses the LPS-induced NF-κB transcription in HUVECs, but also decreases apoptosis of endothelial cells. The BSNXD-derived serum decreases monocyte chemoattractant protein-1 production, and suppresses cell adhesion molecules (ICAM-1, VCAM-1 and E-selectin) expression in HUVECs injured by oxidized low-density lipoproteins (ox-LDL), and these effects can be abolished by ERβ antagonist (R,RTHC) and NO synthase inhibitor (L-NAME). The BSNXD-derived serum-treated HUVECs supernatant reduces CCR2, LFA-1 and VLA-4 expression in monocytes cell line U937 cells, which in turn inhibits adherence of U937 to injured endothelial cells. NO synthesis increases, and MDA production decreases through ERβ-mediated pathway that suppresses apoptosis and NF-κB activity in endothelial cells that downregulates adhesion molecules expression on endothelial cells via ERβ/NO/NF-κB pathway, and in turn leukocyte adhesion, which suggests BSNXD potential value in prophylaxis atherosclerosis.