, Volume 50, Issue 2, pp 121–129 | Cite as

EPA and DHA Exposure Alters the Inflammatory Response but not the Surface Expression of Toll-like Receptor 4 in Macrophages

  • Kaori L. Honda
  • Stefania Lamon-Fava
  • Nirupa R. Matthan
  • Dayong Wu
  • Alice H. LichtensteinEmail author
Original Article


Dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their respective enrichment in cell membranes have been negatively associated with atherosclerotic lesion development. This effect may be mediated, in part, by dampened inflammatory response of macrophages triggered by toll-like receptor 4 (TLR4) activation. This study investigated the influence of membrane fatty acid profile on TLR4-mediated inflammation in RAW 264.7 macrophages. Cells pretreated with myristic acid (MA), EPA, DHA or vehicle control for 24 h were stimulated with ultra-pure LPS, a specific TLR4 agonist, for 6 or 24 h, corresponding to early and late stages of TNFα and IL-6 protein induction. Treatment significantly increased cell membrane MA, EPA, and DHA by 4.5-, 20.6-, and 8.9-fold, respectively. MA significantly increased IL-6 secretion 6 h post-exposure to the fatty acid, but did not change TNFα secretion in response to any other treatment condition. EPA and DHA significantly reduced TNFα secretion by 36 and 41 %, respectively, in cells stimulated for 24 h but not 6 h. In contrast, EPA and DHA significantly reduced IL-6 secretion at both 6 h (67 and 72 %, respectively) and 24 h (69 and 72 %, respectively). MA or DHA treatment had no significant effect compared to vehicle on factors influencing cellular LPS recognition, including LPS-cell association, and cell surface expression of TLR4, TLR4-MD2 complex, and CD14. These data suggest that membrane fatty acid profiles influence the TLR4-mediated inflammatory response in macrophages, via mechanisms that occur downstream of TLR4 receptor activation.


Eicosapentaenoic acid Docosahexaenoic acid Macrophages Toll-like receptor 4 Tumor necrosis factor alpha Interleukin 6 



Arachidonic acid (20:4n-6)


Analysis of variance




Bovine serum albumin


Cluster of differentiation 14


Docosahexaenoic acid (22:6n-3)


Dulbecco’s Modified Eagle’s Medium


Docosapentaenoic acid (22:5n-3)


Enzyme-linked immunosorbent assay


Eicosapentaenoic acid (20:5n-3)


Fetal bovine serum


Fluorescein isothiocyanate-conjugated lipopolysaccharide


G-Protein coupled receptor


Isotype control


Interleukin 6




Myristic acid (14:0)


Mitogen activated protein kinase


Myeloid differentiation 2


Mean fluorescence intensity


Myeloid differentiation primary response gene 88


Nuclear factor kappa B


Phosphate buffered saline




Toll-like receptor 2


Toll-like receptor 4


Tumor necrosis factor alpha



This work was supported by the NIH Grant: NHLBI-T32-HL069772 (NLS) and the USDA Agreement No. 58-1950-0-0014.

Conflict of interest

Any opinions, findings, conclusion, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the US Department of Agriculture.


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Copyright information

© AOCS 2014

Authors and Affiliations

  • Kaori L. Honda
    • 1
  • Stefania Lamon-Fava
    • 1
  • Nirupa R. Matthan
    • 1
  • Dayong Wu
    • 1
  • Alice H. Lichtenstein
    • 1
    Email author
  1. 1.Cardiovascular Nutrition LaboratoryJean Mayer USDA Human Nutrition Research Center on Aging at Tufts UniversityBostonUSA

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