Corynoline Exhibits Anti-inflammatory Effects in Lipopolysaccharide (LPS)-Stimulated Human Umbilical Vein Endothelial Cells through Activating Nrf2

Corynoline, a bioactive compound isolated from Corydalis bungeana Turcz., has been known to have anti-inflammatory activity. However, its effects on the inflammation of the cardiovascular system have not been reported yet. The aim of this study was to investigate the anti-inflammatory effects of corynoline on lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs). The results showed that LPS significantly increased the expression of VCAM-1 and ICAM-1. The production of cytokines TNF- and IL-8 was also up-regulated by LPS. However, these increases were concentration-dependently suppressed by the treatment of corynoline. To investigate the anti-inflammatory mechanism of corynoline, we checked the activation of NF-B and the expression of Nrf2. The results showed that LPS-induced NF-B activation was suppressed by corynoline. The expression of Nrf2 and HO-1 was up-regulated by the treatment of corynoline. Knockdown of Nrf2 could reverse the anti-inflammatory effects of corynoline. In conclusion, the results indicated that corynoline exhibited anti-inflammatory activity by activating Nrf2.