Immunomodulatory activity of a gut microbial metabolite of dietary linoleic acid, 10-hydroxy-cis-12-octadecenoic acid, associated with improved antioxidant/detoxifying defences

•A gut microbial metabolite of linoleic acid (HYA) elicits anti-inflammatory effects in vitro.•HYA down-regulates the Lipopolysaccharide-induced maturation of bone marrow dendritic cells (DCs).•HYA treatment associated with an anti-inflammatory profile in murine enterocyte and in mature DCs.•HYA up-regulates cytoprotections in murine enterocyte and in mature DCs.•HYA is considered a functional component in foods and pharmaceutical products. Various hydroxy-, oxo-, and conjugated fatty acids are generated by gut microbes throughout the metabolism of dietary PUFAs. Specifically, 10-Hydroxy-cis-12-(HYA), 10-oxo-cis12-(KetoA) and 10-oxo-cis9,trans11-octadecenoic acid (KetoC) are intermediates free fatty acids (iFFA) produced during the isomerization of dietary linoleic acid to cis9,trans11 (c9,t11) isomer of conjugated linoleic acid (CLA). Herein, immunomodulatory and antioxidant activity of selected iFFA was studied in resting (iDCs), LPS-matured DCs (mDCs) and in murine enterocyte cells (MODE-K). Phenotypic maturation of iDCs was not influenced by iFFA, but the release of pro-inflammatory molecules from mDCs was reduced following HYA pre-treatment. HYA ability to improve antioxidant/detoxifying defenses associated with decreased expression of maturation markers in mDCs and in MODE-K cells. The pro-oxidant activity, via NADPH oxidase activation, was responsible for the pro-inflammatory effect of 10-hydroxy-octadecanoic acid. Presented data suggest that the immunomodulatory ability of HYA is determined, at least in part, by its ability to improve antioxidant/detoxifying defenses.