Lack of influence of omega-3 fatty acid-enriched lipids on apoptosis and secondary necrosis of cultured human lymphocytes.
OBJECTIVE
The anti-inflammatory properties of parenteral nutrition might be improved by enrichment with omega-3 polyunsaturated fatty acids (PUFAs), which are responsible for the enhanced release of metabolites derived from eicosapentaenoic acid. Under physiologic conditions, lymphocyte populations are regulated by cellular mechanisms such as apoptosis. In contrast to cell death by necrosis, apoptosis does not induce an inflammatory response that might injure the host.


METHODS
Apoptosis and necrosis of cultured human blood lymphocytes were investigated in vitro after incubation for 48 and 72 h with three lipid emulsions containing 50% medium-chain triacylglycerols. The lipid emulsions differed in the percentage of long-chain triacylglycerols, which were replaced in part by different amounts of omega-3 PUFA (8%, 20%, or 40%). Rates of apoptosis and necrosis of lymphocyte subpopulations were analyzed with a sensitive annexin V flow cytometric assay.


RESULTS
After 48 and 72 h of incubation, time- and dose-dependent increases of apoptosis and necrosis, respectively, were found in all lymphocyte subsets regardless of the percentage of omega-3 PUFAs.


CONCLUSIONS
Our results suggested that enrichment with omega-3 PUFAs in the tested lipid emulsions does not alter apoptosis and secondary necrosis of lymphocyte populations. Thus PUFAs may exert their functional effects through other mechanisms.
Scheinichen
Dirk
D
Department of Anaesthesiology, Hannover Medical School, Hannover, Germany. scheinichen.dirk@mh-hannover.de
Jankowski
Michaela
M
Ruschulte
Heiner
H
Jüttner
Björn
B
Kleine
Hans Dieter
HD
Meyer zu Vilsendorf
Andreas
A
Piepenbrock
Siegfried
S
Heine
Jörn
J
D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D018836:Inflammation Mediators / Q000494:pharmacology; D007700:Kinetics; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D009336:Necrosis
D015525:Fatty Acids, Omega-3; D018836:Inflammation Mediators