The initiation of atherosclerosis involves up-regulation of molecules such as E-selectin, VCAM-1, and ICAM-1. The progression of atherosclerosis is linked to proliferation and migration of vascular smooth muscle cell via MMP-2 and MMP-9 activities. However, the etiology of atherosclerosis concerning plasticizers is unknown. We evaluated beta-thujaplicin in preventing the development of atherosclerosis in a model induced by pro-inflammatory cytokines. Moreover, we established a new atherosclerosis model in vascular smooth muscle cells (VSMC) exposed to a common contact plasticizer, di(2-ethylhexyl)phthalate (DEHP). SEVC4-10 endothelial cells were treated with 50% RAW conditioned medium and A7r5 VSMC was treated with the plasticizer, with/without beta-thujaplicin (4 or 12 mu M). Production of E-selectin, ICAM-1, and VCAM-1 in SEVC4-10 cells as well as MMP-2/MMP-9 (both expression and activity) in VSMC were monitored. Results showed that the conditioned medium induced E-selectin and ICAM were significantly prevented by beta-thujaplicin. However, inhibition on the production of VCAM by beta-thujaplicin was only seen in a concentration of 12 mu M. Both concentrations of beta-thujaplicin also significantly prevented DEHP-induced MMP-2 and MMP-9 expression and activities. Evidence uncovers that beta-thujaplicin has additional factors in amelioration of atherosclerosis and corroborates that beta-thujaplicin is a strong candidate in preventing the initiation and progression of atherosclerosis.
