Eicosapentaenoic acid and docosahexaenoic acid suppress the proliferation of vascular smooth muscle cells.

Eicosapentaenoic acid, which is one of the n-3 polyunsaturated fatty acids (PUFA), is reported to exert its antithrombotic and anti-atherogenic effect partly through the modulation of vascular cell functions. Vascular smooth muscle cell (VSMC) proliferation plays an important role in the pathogenesis of atherosclerosis. We reported the differential effect of various PUFA on VSMC proliferation. First we established a method for preparing PUFA rich cells in culture to mimic the in vivo situation using PUFA triacylglycerol emulsion. Using these fatty acid rich cells, we found that only EPA and docosahexaenoic acid, although less potent than EPA, inhibited the proliferation of VSMC among the fatty acids tested. This effect of EPA was reversed by the addition of anti-oxidants. It is suggested that production of the oxidized species at a low concentration from EPA inhibited the proliferation of VSMC. This anti-proliferative effect of EPA and DHA on VSMC could partly explain the anti-atherosclerotic effect of marine lipids.