Eicosapentaenoic acid reduces warfarin-induced arterial calcification in rats

Eicosapentaenoic acid (EPA), a major n-3 polyunsaturated fatty acid, is reported to have various protective effects for cardiovascular disease. However, few studies have focused on the influence of EPA on vascular calcification.

Arterial medial calcification (AMC) was induced by administering warfarin (3 mg/g food) and vitamin K1 (1.5 mg/g food) for 2 weeks in Sprague-Dawley rats (control group), and EPA (1 g/kg/day) was administered for 2 weeks simultaneously with warfarin and vitamin K1 (EPA group) or after initiation of AMC (late EPA group). EPA showed a marked reduction of medial calcification in the EPA group, and showed a similar effect in the late EPA group. Immunohistochemical and RT-PCR analyses showed that EPA lowered the expression of osteogenetic markers, such as osteopontin, alkaline phosphatase and core binding factor-α1 in the aorta. Significant migration of macrophages with expression of matrix-metalloproteinase (MMP)-2 or MMP-9 was observed in the aortic adventitia around calcification. EPA also reduced macrophage infiltration, MMP-9 expression as well as gene expression of monocyte chemotactic protein (MCP)-1.

These observations indicate that EPA attenuates arterial medial calcification through an effect associated with the suppression of MMP-9 activity and inhibition of macrophage infiltration as well as osteogenic protein expression in warfarin-induced rat models.