Leonurine attenuates lipopolysaccharide-induced inflammatory responses in human endothelial cells: involvement of reactive oxygen species and NF-κB pathways.

Leonurine, an active alkaloid of Traditional Chinese Medicine Herba leonuri, displayed cardioprotective effects by anti-oxidative and anti-apoptotic activities in vitro and in vivo. Herein, we explored the effects and possible mechanisms of leonurine on lipopolysaccharide (LPS)-induced inflammatory responses in human umbilical vein endothelial cells (HUVEC). We found that leonurine pretreatment concentration-dependently attenuated LPS-induced mRNA expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and monocyte chemoattractant protein-1. Meanwhile, LPS-mediated expression/release of ICAM-1, VCAM-1, and cyclooxygenase-2, and tumor necrosis factor-α was also reduced by leonurine. In addition, we confirmed that leonurine suppressed degradation of IκBα and phosphorylation of nuclear factor-κB (NF-κB) p65 as well as production of intracellular reactive oxygen species in a concentration dependent manner. Furthermore, the cytoprotective enzyme heme oxygenase-1 could be upregulated in leonurine-treated HUVEC. Our present results indicated leonurine exerted beneficial effects in inflammatory conditions partly through inhibition of reactive oxygen species and NF-κB signaling pathways.