O.6 Does the presence of fish oil (FO) in emulsion particles affect the elimination of MCT/LCT emulsion?

Elimination and Tolerance of a New Parenteral Lipid Emulsion (SMOF) – A Double-Blind Cross-Over Study in Healthy Male Volunteers

AIMS

The objective of this phase I study was to investigate plasma elimination and tolerance of a new lipid emulsion based on soybean oil, medium chain triglycerides (MCT), olive oil and fish oil (SMOF).

METHODS

In a double-blind, randomized, cross-over study, 12 healthy male subjects received SMOF 20% and a standard soybean oil emulsion (Lipovenoes 20%, both Fresenius Kabi). Lipid emulsions were infused at a rate of 0.125 g fat/kg body weight/h over 6 h. Before, during and up to 24 h after infusion, lipid metabolism parameters and numerous clinical, chemical and hematological parameters, vital signs and local tolerance were determined.

RESULTS

Infusion of SMOF induced a less marked increase of serum triglyceride concentration. At the end of infusion, mean serum triglyceride concentration was significantly lower with SMOF (p < 0.05). Triglyceride half-life was significantly shorter for SMOF than for Lipovenoes (p < 0.001). Infusion of SMOF was apparently associated with higher glycerol concentration (NS). Routine laboratory parameters, vital signs and local tolerance showed no evidence of infusion-related abnormalities.

CONCLUSION

SMOF was eliminated significantly faster than the standard lipid emulsion. This is of potential benefit in patients with limited triglyceride elimination capacity. The safety evaluation revealed a good systemic and local tolerance of SMOF.

Omega-3 triglycerides modify blood clearance and tissue targeting pathways of lipid emulsions

Omega-3-rich (n-3) triglycerides (TG) are increasingly recognized as having modulating roles in many physiological and pathological conditions. We questioned whether the catabolism of lipid emulsions would be changed after enrichment with fish oil (n-3) TG as compared to enrichment with omega-6-rich soy oil (n-6) TG. Phospholipid-stabilized emulsions of n-3 TG and n-6 TG were labeled with [(3)H]cholesteryl oleoyl ether and administered by bolus injection to wild-type (WT) mice, mice lacking the low-density lipoprotein receptor (LDL-R) (LDL-R -/-), and apolipoprotein E (apoE) knockout mice (apoE -/-). The effects of exogenous apoE, heparin, Triton WR 1339, and lactoferrin on catabolism of emulsions were also assayed. n-3 TG emulsions were cleared faster from blood and had different extrahepatic tissue targeting compared to n-6 TG emulsions. In apoE -/- and LDL-R -/- mice, blood clearance of n-6 TG emulsions slowed with decreased liver uptake, but no changes were observed in n-3 TG emulsion clearance and tissue uptake compared to WT mice. In WT mice, addition of exogenous apoE to the emulsion increased liver uptake of n-6 TG emulsions but had no impact on n-3 TG emulsions. Pre-injection of heparin increased and Triton WR 1339 and lactoferrin decreased blood clearance of n-6 TG emulsions with little or no effect on n-3 TG emulsions. Liver uptake of n-6 TG emulsions increased after heparin injection and decreased after Triton WR 1339 injection, but uptake of n-3 TG emulsions was not changed. These data show that the catabolism of n-3 TG emulsions and the catabolism of n-6 TG emulsions occur via very different mechanisms. Removal of chylomicron-sized n-6 TG emulsions is modulated by lipoprotein lipase (LPL), apoE, LDL-R, and lactoferrin-sensitive pathways. In contrast, clearance of chylomicron-sized n-3 TG emulsions relies on LPL to a very minor extent and is independent of apoE, LDL-R, and lactoferrin-sensitive pathways.