Regulation of bone metabolism by omega-3 fatty acids

Abstract

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are omega-3 polyunsaturated fatty acids abundant in fish oil. DHA and EPA have been reported to have antithrombotic effects, prevent cardiovascular diseases, and reduce serum triglycerides and total cholesterol levels; however, their effect on bone metabolism remains unclear. We investigated the effects of DHA and EPA on inflammatory bone resorption. We found that DHA and EPA inhibited osteoclast differentiation in a coculture system of mouse osteoblasts and bone marrow cells. Additionally, in primary mouse osteoblasts, DHA and EPA suppressed the production of the inflammatory mediator prostaglandin E2 (PGE2) and the gene expression of receptor activator of nuclear factor kappa-B ligand (RANKL). In Raw264.7 cells, DHA and EPA inhibited RANKL-induced osteoclast differentiation and suppressed the mRNA expression of osteoclast differentiation marker genes, such as cathepsin K and Clc-7.