Table 2.
Colonic eicosanoid concentrations (in ng/mg protein) at baseline and after 12 weeks of target ω-3 fatty acid dosing
Eicosanoid | Major enzymesa | Baseline | After 12 weeks of target dose | Pb |
---|---|---|---|---|
PGE2 | Cyclooxygenases 1 and 2, prostaglandin E synthase | 6.55 (5.78) | 3.59 (3.29) | <0.001c |
Prostaglandin E3 | COX-2, prostaglandin E synthase | 0.25 (0.21) | 0.69 (0.64) | <0.001c |
5-S-Hydroxyicosatetraenoic acid | 5-Lipoxygenase | 1.82 (1.30) | 1.90 (1.96) | 0.90 |
5-R-Hydroxyicosatetraenoic acid | 5-R-Lipoxygenase | 2.24 (1.24) | 2.90 (1.93) | 0.02 |
12-S-Hydroxyicosatetraenoic acid | 12-Lipoxygenase | 3.95 (3.36) | 2.20 (2.43) | <0.001c |
12-R-Hydroxyicosatetraenoic acid | 12 (R)-Lipoxygenase or cytochrome P450 | 4.12 (4.23) | 2.70 (2.63) | 0.001c |
15-S-Hydroxyicosatetraenoic acid | 15-Lipoxygenase | 892 (616) | 993 (649) | 0.05 |
15-R-Hydroxyicosatetraenoic acid | Cytochrome P450 or acetylated COX-2 | 18.0 (12.9) | 15.8 (11.0) | 0.28 |
14,15-S-dihydroxyeicosatrienoic acid | Cytochrome P450 and epoxide hydrolase | 1.04 (0.90) | 1.17 (1.05) | 0.008 |
14,15-R-dihydroxyeicosatrienoic acid | Cytochrome P450 and epoxide hydrolase | 0.99 (0.79) | 1.13 (0.93) | 0.06 |
13-S-Hydroxyoctadecadienoic acid | 15-Lipoxygenase | 12.10 (10.3) | 10.91 (9.0) | 0.18 |
13-R-Hydroxyoctadecadienoic acid | Lipoxygenases, or cytochrome P450 | 20.63 (11.0) | 20.96 (15.2) | 0.88 |
Data shown are mean and SD for 47 participants at each time point except for PGE2, where n = 46 was used due to one outlier that was an obese participant with a large increase in PGE2.
All of the eicosanoids shown are formed from arachidonic acid except for PGE3, which is formed from eicosapentaenoic acid, and 13-hydroxyoctadecadienoic acids, which are formed from linoleic acid. Nonenzymatic oxidation of AA is also possible and is not stereospecific.
P values are for comparing baseline and posttarget dose measures and are based on Wilcoxon signed rank test owing to nonnormality of some of the eicosanoids. There were 47 participants eligible for analysis. There was one outlier in the overweight–obese group who had a 3-fold increase in PGE2 and was omitted from the analysis of PGE2 concentrations, resulting in n = 46 (see Results).
Values with P < 0.005 were considered significant to adjust for multiple comparisons.