Therapeutic role of eicosapentaenoic and arachidonic acid in benzo(a) pyrene-induced toxicity in HUVEC endothelial cells.

Endothelial cells are characterized by intense metabolic activity and control of homeostasis. Exposure to benzo(a)pyrene (BaP) plays an important role in the etiology of atherosclerosis. The study aimed to determine the effect of arachidonic (ARA), and eicosapentaenoic acid (EPA) on pro-inflammatory gene and protein levels in human umbilical vein endothelial cells (HUVEC) exposed to BaP. Cyclooxygenase-2 (COX-2), aryl hydrocarbon receptor (AHR), and glutathione S transferase Mu1 (GSTM1) proteins expression were analyzed by Western blot. Prostaglandin synthase 2 (PTGS2), AHR, GSTM1, phospholipase A2 (PLA2G4A), cytochrome P450 CYP1A1, intercellular adhesion molecule-1 (ICAM-1), endothelial nitric-oxide synthase (NOS3), and vascular adhesion molecule-1 gene expression (VCAM-1) was analyzed in Real time-qPCR. Phospholipase A2 activity was measured using the ELISA technique, and CYP1A1 activity was analyzed in luminescence assay. The highest amount of COX-2, the most increased activity of CYP1A1 and cPLA2, and overexpression of GSTM1, CYP1A1, ICAM-1, and VCAM-1 gene was observed in HUVEC cells treated with BaP. After co-treatment with BaP and ARA or EPA, an increase of GSTM1 level was observed. Incubation of endothelial cells with ARA or EPA and BaP resulted in lower CYP1A1 and cPLA2 activities and lower expression of VCAM-1 and ICAM-1 genes. Significant overexpression of AHR, GSTM1, CYP1A1, PTGS2, PLA2G4A, and NOS3 genes was noted in cells treated with EPA and BaP. Our data suggest a beneficial effect of EPA and ARA on endothelial function. Thus, it justifies further research on the participation of fatty acids in the regulation of physiological and pathological processes in endothelial cells.

Effect of Eicosapentaenoic Acid Supplementation on Murine Preadipocytes 3T3-L1 Cells Activated with Lipopolysaccharide and/or Tumor Necrosis Factor-α.

The beneficial effect of n-3 fatty acids can be related to anti-inflammatory properties. The aim of the study was to analyzed the effect of eicosapentaenoic acid (EPA) on 3T3-L1 cells (murine embryonic fibroblasts‒preadipocytes) activated with inflammatory factors (IF). Cells were incubated with 50 µmol of EPA for 48 h, and then activated with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α). The level of cycloxygenase-2 (Prostaglandin-Endoperoxide Synthase 2, PTGS2, COX-2), cytosolic prostaglandin synthase E2 (cPGES), fatty acid binding protein 4 (FABP4), toll-like receptor 4 (TLR4), glucose receptor type 4 (GLUT-4), and cannabinoid receptor 2 (CB2) was determined using Western blot analysis. The phospholipase A2 (Pla2g4a), and prostaglandin-Endoperoxide Synthase 2 (Ptgs2) gene expression was analyzed by real-time qPCR. After EPA and IF activation, a significant decrease in the COX-2, cPGES, and TRL4 protein levels was observed. Incubation of cells with EPA and IF resulted in a decrease in Ptgs2 and an increase in the Pla2g4a gene. A significant increase in the CB2 protein was observed in adipocytes co-treated with EPA and IF. The results indicated an anti-inflammatory properties of EPA. Interestingly, the activation of the GLUT4 receptor by EPA suggests an unique role of this FA in the regulation of the adipocyte metabolism and prevention of insulin resistance.