Paeonol from Paeonia suffruticosa prevents TNF-alpha-induced monocytic cell adhesion to rat aortic endothelial cells by suppression of VCAM-1 expression.

Paeonol (2'-hydroxy-4'-methoxyacetophenone), the main active compound of the radix of Paeonia suffruticosa, has been reported to have a beneficial effect in prevention and treatment of cardiovascular diseases. Vascular cell adhesion molecule-1 (VCAM-1), plays a crucial role in case of early inflammatory responses, including atherosclerosis. In this study, we investigated the effect of paeonol on TNF-alpha-induced VCAM-1 expression in rat aortic endothelial cells (RAECs). The VCAM-1 expression in paeonol treated RAECs was measured. Paeonol inhibited TNF-alpha-induced VCAM-1 expression in a concentration-dependent manner. TNF-alpha induced p38 and extracellular signal-regulated kinase 1/2 (ERK1/2) activities that contributed to VCAM-1expression was obviously attenuated after pre-treating RAECs with paeonol. The decrease of VCAM-1 expression by paeonol pretreatment led to a reduction of monocytes adhesion to RAECs. Taken together, our results demonstrated that paeonol inhibited VCAM-1 expression by the attenuation of p38 and ERK1/2 signal transduction pathways. We concluded that paeonol had the potential therapeutic development for use in anti-inflammatory and vascular disorders.