Phosphatidylcholine from krill increases plasma choline and its metabolites in dogs

Higher omega-3 index after dietary inclusion of omega-3 phospholipids versus omega-3 triglycerides in Alaskan Huskies

Background and Aim

Numerous studies have found benefits of omega-3 polyunsaturated fatty acids (PUFAs), namely, for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in dogs. The objective of the present study was to assess the efficacy of dietary inclusion of equal amounts of omega-3 FAs in phospholipid (PL) from krill meal to triglyceride structure from fish oil to increase the omega-3 FA profile in red blood cells (RBCs) in dogs.

Materials and Methods

Ten adult Alaskan Huskies of both genders were supplemented with daily 1.7 g EPA and DHA from krill meal for 6 weeks, while another ten dogs received 1.7 g EPA and DHA from fish oil. FA and omega-3 index measurements of the two groups were taken after 0, 3, and 6 weeks for comparison.

Results

It was mainly the EPA levels that increased in the krill meal group (from 1.84% to 4.42%) compared to the fish oil group (from 1.90% to 2.46%) (p<0.001), which drove the group differences in the omega-3 index. This resulted in the krill meal group having a mean omega-3 index increase from 3.9 at baseline to 6.3%, which was significantly greater than the increase from 3.9% to 4.7% observed in the fish oil group (p<0.001). Concomitantly, omega-6 PUFAs, such as arachidonic acid and linoleic acid, were reduced in RBC membranes and the omega-6 to omega-3 ratio was significantly more reduced in the krill meal compared to the fish oil group.

Conclusion

The results showed that krill meal supplementation was associated with a reduction of omega-6 PUFAs, which compensated for the increased omega-3 index, suggesting that PLs are efficient delivery molecules of omega-3 PUFAs.

Enzymatically Produced Trimethylamine N-Oxide: Conserving It or Eliminating It

Trimethylamine N-Oxide (TMAO) is the product of the monooxygenation reaction catalyzed by a drug-metabolizing enzyme, human flavin-containing monooxygenase 3 (hFMO3), and its animal orthologues. For several years, researchers have looked at TMAO and hFMO3 as two distinct molecules playing specific but separate roles, the former to defend saltwater animals from osmotic or hydrostatic stress and the latter to process xenobiotics in men. The presence of high levels of plasmatic TMAO in elasmobranchs and other animals was demonstrated a long time ago, whereas the actual physiological role of hFMO3 is still unknown because the enzyme has been mainly characterized for its ability to oxidize drugs. Recently TMAO was found to be related to several human health conditions such as atherosclerosis, cardiovascular, and renal diseases. This correlation poses a striking question of how other vertebrates (and invertebrates) can survive in the presence of very high TMAO concentrations (micromolar in humans, millimolar in marine mammals and several hundred millimolar in elasmobranchs). Therefore, it is important to address how TMAO, its precursors, and FMO catalytic activity are interconnected.