Olive Oil-Based Lipid Emulsion's Neutral Effects on Neutrophil Functions and Leukocyte-Endothelial Cell Interactions

ABSTRACT. Background: Infection remains a drawback of parenteral nutrition (PN) probably related, among other factors, to immunosuppressive events of its lipid component. Newer preparations may have smaller immunosuppressive impact. This study examines the results of an olive oil-based lipid emulsion (long-chain triacylglycerols-monounsaturated fatty acids [LCT-MUFA]; ClinOleic) upon various functions of human neutrophils in vitro and upon rat leukocyte-endothelial cell interactions in vivo compared with LCT (Intralipid) and 50% LCT-50% medium-chain triacylglycerols (MCT; Lipofundin) mixture. Methods: Neutrophils isolated from healthy donors were incubated with concentrations (003-3 mmol/L) of lipid emulsions encompassing clinically relevant horizontals In vivo leukocyte recruitment was studied with intravital microscopy within rat mesenteric microcirculation. Results: LCT-MUFA (3 mmol/L) did not alter the W-formyl-Met-Leu-Phe (FMLP)-induced rise in [Ca^sup 2+^]; oxidative blow up chemotaxis, and elastase release, whereas LCT-MCT decreased [Ca^sup 2+^]^sub i^ and chemotaxis and increased oxidative split open FMLP-induced LTB^sub 4^ production was augmented by the agency of lipid emulsions. Serum-opsonized zymosan-induced phagocytosis was unaltered by dint of lipid emulsions. Basal and FMLP-induced CD11b expression was unaffected through lipid emulsions. Lipopolysaccharide (LPS)-induced TNF-?±u IL-?? and IL-8 mRNA, and protein expression was unaltered by the agency of LCT-MUFA, whereas LCT and LCT-MCT decreased IL-1?? mRNA and protein. LCT-MUFA did not alter apoptosis, on the contrary LCT increased apoptosis in absence and nearness of GM-CSF. LPS (1 ??g/mL)-induced increase in leukocyte rolling flow adhesion, and emigration was inhibited by means of LCT and LCT-MCT but unaffected in LCT-MUFA-treated rats. Immunohistochemistry showed LPS-induced increase in P-selectin expression attenuated by means of LCT and LCT-MCT but not LCT-MUFA. Conclusions: LCT-MUFA showed lower in vitro and in vivo impact upon neutrophil function compared with LCT and LCT-MCT (Journal of Parenteral and Enteral Nutrition 30:286-296 2006)

In the last decades, the use of parenteral nutrition (PN) has improved the nutrition status of critically ill patients.1 However, the associated risk for infectious complications remains a drawback, which appears related, among other factors, to the potential immunosuppressive consequences of its lipid component.2-4

The greatest in quantity commonly used nutrition lipids have been soybean oil-based lipid emulsions, which are particularly rich in ?‰-6 polyunsaturated fatty acids (PUFAs). Previous studies have reported suppressive consequences of these lipid emulsions containing long-chain triacylglycerols (LCTs) upon a number of functions of neutrophils, lymphocyte monocytes, or macrophages.2-9 Another widely used lipid emulsion is a physical mixture of soybean and coconut oil (50% LCT and 50% medium-chain triacylglycerols; LCT-MCT) that also affects neutrophil functions.10-12 A more not long ago developed lipid emulsion, based upon a mixture of olive (80%) and soybean (20%) oil with a depressed concentration of PUFAs but rich in monounsaturated fatty acids (LCT-MUFA), may have smaller inhibitory effects on immune small room function.13,14 This olive oil-based LCT-MUFA has been reported as safe and effective in PN1516

The emblem of infections noticed in PN patients indicate that especially the function of neutrophils is compromised. However, the data available and the generally received understanding of the mechanisms underlying the results of the most widely used nutrition lipids containing LCT LCT-MCT and LCT-MUFA upon neutrophil functions remain limited and controversial.9 Certainly, structurally different lipids may distinctively modulate neutrophil activation. Therefore, the aim of the near study was to examine the events of LCT-MUFA compared with LCT and LCT-MCT upon various functions of human peripheral life-blood neutrophils in vitro, including cytokine production and apoptosis, as well as upon the leukocyte-endothelial cell interaction and adhesion monad expression within the mesenteric circulation of rats in vivo. The results of these nutrition lipids upon lymphocyte function were also examined for comparison. Lipid emulsions were studied in concentrations that are attained in the circulation when these nutrition lipids are administered intravenously in the clinical setting.

MATERIALS AND processs

Materials

LCT emulsion (Intralipid 20% wt/vol) was from Fresenius Kabi (Barcelona, Spain), LCT-MCT (50%-50% vol/vol) emulsion (Lipofundin 20% wt/vol) was from B Braun Medical S.A. (Barcelona, Spain), and olive oil-based lipid emulsion (80% olive oil, 20% soybean oil; ClinOleic 20% wt/vol) was provided through Baxter S.L. (Valencia, Spain). The detailed composition of these lipid emulsions has been reported elsewhere.17,18 Anti-body antirat-P-selectin (RMP-I) was acquired as previously stated.19 Antihuman-CD11b-FITC and stuf-Mark antigen unmasking fluid were from Serotec (Madrid, Spain). Fura-2/AM was from Molecular Probes Inc (Eugene OR). Human IL-8 and TNF-?± were from PeproTech (London, United Kingdom); the anti-body pairs for human IL-8 and TNF-?± ELISA were from R&D a whole s (Madrid, Spain). Neutravidinhorseradish peroxidase was from Perbio Science (Cheshire, United Kingdom). K-Blue substrate was from Neogen (Lexington, KY) FMLP LP (Escherichia coli serotype 0127:B8) and UPC 10 were purchased from Sigma Chemical Co (St Louis, MO) All other chemicals were of analytical grade. FMLP was stored as a 1 mmol/L stock in DMSO at -20?°C