Eicosapentaenoic acid suppressed the proliferation of vascular smooth muscle cells through modulation of various steps of growth signals.

Among fatty acids, only n-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) inhibited the proliferation of vascular smooth muscle cells. DHA was less effective than EPA. To clarify the anti-proliferative effect of n-3 polyunsaturated fatty acid, we have explored the effect of EPA on the signal transduction pathway of platelet derived growth factor (PDGF). EPA inhibited PDGF binding on its receptor and activation of protein kinase C. EPA also suppressed c-fos mRNA expression, one of immediate early genes, through partly inhibiting c-fos transcription. These data revealed that EPA could inhibit vascular smooth muscle cell proliferation through modulating various steps of the signal transduction by PDGF.