Effects of crocetin on VCAM-1 expression in human umbilical vein endothelial cells and monocyte-endothelial cell adhesion

Crocetin, a naturally occurring carotenoid, possesses antioxidant and antiatherosclerotic properties, of which the underlying mechanism remains unclear. In the present study, we examined the effects of crocetin (0.1, 1, 10 μmol·L^-1) on angiotensin II (Ang II, 0.1 μmol·L^-1) induced expression of vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) and monocyte-endothelial cell adhesion. The effects of crocetin on the activation of nuclear factor kappa B (NF-κB) and intracellular reactive oxygen species (ROS) were also observed. The results demonstrated that crocetin notably suppressed Ang II induced NF-κB activation (P < 0.01) and VCAM-1 expression (P < 0.05, P < 0.01) in HUVECs, accompanied by a markedly reduced monocyte-endothelial cell adhesion (P < 0.05, P < 0.01). In addition, preincubation with crocetin resulted in a significant enhancement of cellular antioxidant capacity (P < 0.05, P < 0.01), while Ang II induced intracellular ROS decreased markedly (P < 0.05, P < 0.01). These results indicated that crocetin was capable of suppressing Ang II induced VCAM-1 expression and monocyte-endothelial cell adhesion by suppression of NF-κB activation, which might be derived from the enhancement of antioxidant capacity and subsequent reduction of intracellular ROS.