Lipid peroxidation of isolated chylomicrons and oxidative status in plasma after intake of highly purified eicosapentaenoic or docosahexaenoic acids

Fourteen healthy male volunteers were given two separate high-saturated-fat meals with and without the addition of 4 g highly purified ethyl esters of either eicosapentaenoic acid (EPA) (95% pure, n = 7) or docosahexaenoic acid (DHA) (90% pure, n = 7) supplied as I-g capsules each containing 3.4 mg vitamin E. The chylomicrons were isolated 6 h after the meals, at peak concentrations of n-3 fatty acids (FA). Addition of n-3 FA with the meal caused a 10.4-fold increase in the concentration of n-3 FA in chylomicrons compared to the saturated fat meal without addition of n-3 FA. After the saturated-fat meal, the concentration of thiobarbituric acid-reactive substances (TBARS) was 327.6 +/- 34.6 nmol/mmol triacylglycerol (TAC), which increased to 1015.8 +/- 212.0 nmol/mmol TAG (P < 0.0001, n = 14) after EPA and DHA were added to the meal. There was no significant correlation between the concentrations of TEARS and vitamin E in the chylomicrons collected 6 h after the test meal. The present findings demonstrate an immediate increase in chylomicron peroxidation ex vivo provided by intake of highly purified n-3 FA. The capsular content of vitamin E was absorbed into chylomicrons, but the amount of vitamin E was apparently not sufficient to protect chylomicrons against lipid peroxidation ex vivo. Daily intake of 4 g n-3 FA either as EPA or DHA for 5 wk did not change the plasma concentration of TEARS. Although not significantly different between groups, DHA supplementation decreased total glutathione in plasma (P < 0.05) and EPA supplementation increased plasma concentration of vitamin E (P < 0.05). The other lipid-soluble and polar antioxidants in plasma remained un changed during 5 wk of intervention with highly purified n-3 FA.