Supplementation-induced changes in polyunsaturated fatty acid membrane and plasma composition do not modify mononuclear cell procoagulant activity

n-3 PUFA supplementation, monocyte PCA expression and interleukin-6 production

n-3 polyunsaturated fatty acids (PUFA) can affect several monocyte functions and the biochemistry of blood cells, thus possibly influencing the initiation of thrombosis, inflammatory disease and atherosclerosis. In this study, we have investigated the effect of dietary supplementation with n-3 PUFA ethyl esters on procoagulant activity (PCA) and interleukin-6 (IL-6) production by human mononuclear cells. Nine healthy volunteers received 4 g/d of n-3 PUFA ethyl esters (4 x 1 g capsules with at least 85% eicosapentaenoic + docosahexaenoic acid ethyl esters) for 18 weeks. Before and at the end of the treatment, mononuclear cells were obtained from peripheral citrated blood by Ficoll-Hypaque density gradient centrifugation. Cellular suspensions (10(7) cells/ml) were incubated at 37 degrees C for 4 h in the absence and presence of lipopolysaccharide (10 micrograms/ml); PCA was determined by one-stage clotting assay and IL-6 concentrations were assayed in supernatants by specific ELISA. After 18-week treatment, both unstimulated and stimulated monocyte PCA were significantly reduced by 66% and 63%, respectively (P < 0.01). Similarly, a significant inhibitory effect by n-3 PUFA treatment on basal and LPS-stimulated IL-6 monocyte production was observed (50% and 46%, respectively, P < 0.05). These data indicate that 18-week n-3 PUFA supplementation may influence monocyte activities, which play a specific role in atherosclerosis and its thrombotic complications.

Effect of long-term, moderate-dose supplementation with omega-3 fatty acids on monocyte procoagulant activity and release of interleukin-6 in patients with coronary artery disease

The influence of a moderate dietary supplementation with omega-3 polyunsaturated fatty acids (omega-3 PUFAs) (3.4 g eicosapentaenoic and docosahexaenoic acids per day) for six months on lipopolysaccharide (LPS) stimulated monocyte procoagulant activity (PCA) was studied in two series of experiments, evaluating the plasma and cellular phases, respectively. In the first series, standard cryopreserved monocyte cultures were examined in heparin plasma of atherosclerotic patients (n = 24, 12 given omega-3 PUFAs, 12 controls). In the second series, monocytes from patients (n = 32, 16 given omega-3 PUFAs, 16 controls) were investigated in a standard plasma milieu. Plasma and monocytes were obtained from the test subjects before as well as after six months of omega-3 PUFA supplementation. Monocyte PCA, measured by the formation of fibrinopeptide A, was not significantly different when comparing plasma and monocytes from the subjects supplemented with omega-3 PUFAs with plasma and monocytes, respectively, from the control subjects. In the second series of experiments we also determined the LPS induced release of interleukin-6 (IL-6), which was not significantly different in the two groups. However, a strong correlation between the stimulated monocyte IL-6 release and PCA was demonstrated (r = 0.70, p = 0.00001), probably reflecting an individual inflammatory response pattern.

n-3 fatty acid ethyl ester administration to healthy subjects and to hypertriglyceridemic patients reduces tissue factor activity in adherent monocytes

n-3 Fatty acids are known to influence several functions of monocytes, including adhesion, cytokine synthesis, and superoxide generation. Monocytes express tissue factor, a membrane-bound glycoprotein, that acts as a catalyst in the coagulation cascade. In this study we evaluated the effects of administration of n-3 fatty acid ethyl esters to healthy volunteers and to hypertriglyceridemic patients on tissue factor activity (TF activity) in adherent monocytes. n-3 Fatty acids containing 75% eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (ratio of EPA to DHA, 1.34) were administered (3 g/d) to normal volunteers for 18 weeks. In addition, the effects of this treatment were evaluated in 30 hypertriglyceridemic patients for 24 weeks by using a double-blind, placebo-controlled study. TF activity in adherent monocytes was evaluated with a one-stage clotting assay. Plasma and monocyte fatty acid compositions were determined by gas-liquid chromatography. In healthy volunteers, n-3 fatty acids significantly reduced TF activity in adherent monocytes either in the unstimulated condition or after exposure to endotoxin. The inhibitory effect was observed after 12 weeks of treatment and was more pronounced after 18 weeks (> 70%, P < .001 versus baseline). Concomitantly, levels of EPA and DHA increased in plasma and monocyte lipids. Interestingly, after stopping treatment, monocyte TF activity remained inhibited for at least 14 weeks. Treatment with n-3 fatty acids for 24 weeks also resulted in a significant reduction of TF activity in adherent monocytes from hypertriglyceridemic patients (-31% and -40% in unstimulated and endotoxin-stimulated cells; P < .05 versus baseline).(ABSTRACT TRUNCATED AT 250 WORDS)