Anti-inflammatory and anti-fibrotic profile of fish oil emulsions used in parenteral nutrition-associated liver disease

Investigation of the Effect of Omega-3 Fatty Acids on Antioxidant System and Serum Aluminum, Zinc, and Iron Levels in Acute Aluminum Toxicity

Aluminum (Al), one of the three most prevalent metals in the Earth's crust, adversely impacts all metabolic systems of living organisms due to its extensive utilization by humans. It is known that omega-3 fatty acids (ω-3FA) protect the organism against diseases and have positive effects on the immune system. The aim of the study was to investigate the effect of ω-3FA on 8-OH-2-deoxyguanosine (8-OHdG), glutathione (GSH) levels and adenosine deaminase (ADA), paraoxonase (PON), and catalase (CAT) activities in rats with acute aluminum toxicity. The study also aimed to investigate the antioxidant system, as well as Al, zinc (Zn), and iron (Fe) levels. Forty Sprague-Dawley rats (n = 40) were used in the study and the rats were divided into four equal groups (n = 10). In group I, 0.5 mL of 0.9% saline solution (NaCI) was injected intraperitoneally. Group II was injected with 34 mg/kg aluminum chloride (AlCI3) intraperitoneally. Group III received 400 mg/kg ω-3FA for 7 days and group IV received both AlCI3 and 400 mg/kg ω-3FA for 7 days. At the end of the study, blood samples were obtained by cardiac puncture. The findings showed that Al exposure increased serum 8-OHdG and total oxidant status (TOS) levels, as well as ADA activity, which are markers associated with oxidative damage. Conversely, PON and CAT activities, GSH, and total antioxidant status (TAS) levels decreased compared to the control group. Furthermore, Zn and Fe levels decreased as Al levels increased. In conclusion, Al has the capacity to induce oxidative damage and lipid peroxidation, while ω-3 fatty acids may mitigate this damage through a regulatory mechanism. Moreover, ω-3-FA could be used as a therapeutic agent that reduces Al toxicity.

High carbohydrate is preferable to high lipid parenteral nutrition in healthy dogs undergoing prolonged sedation

Parenteral nutrition (PN) is commonly used in intensive care units (ICUs) and is associated with earlier hospital outcome. However, there is scarcity of information about the metabolic effects of PN caloric distribution for dogs. Considering the high tolerance of dogs to lipids and, also, that hospitalized animals usually present insulin resistance, PN formulation with high fat instead high glucose can provide metabolic benefits in this specie. This study evaluated two PN protocols, based on high lipid or high carbohydrate in 12 healthy dogs under sedation/ventilation during 24 h. For baseline data, blood samples were collected 24 h before the study beginning. After fasting, the dogs were anesthetized and put under mechanical ventilation without energy support for 12 h to obtain: daily energy expenditure (DEE), respiratory quotient (RQ), oxygen consumption (VO2), carbon dioxide production (VCO2), lactate, glucose, cholesterol, and triglycerides concentrations. After, the dogs were allocated into two groups: lipid-based energy group (LEG) and carbohydrate-based energy group (CEG). Both groups received the PN infusions at a rate of 3 mL/kg/h for 12 h. Blood tests were performed 12, 24, and 48 h after infusion's completion. VO2 increased after PN in LEG, increasing energy expenditure compared to CEG. RQ remained close to 1 in CEG, indicating carbohydrate preferential consumption. Triglycerides increased in both groups after propofol infusion, remaining higher in LEG until the end of the evaluation. Glycaemia increased in CEG compared to baseline. In conclusion, both PN protocols can be used in healthy animals undergoing prolonged sedation protocols. However, high lipid PN had higher VO2 and DEE, and resulted in higher triglycerides concentrations and lower glycaemia indexes than carbohydrate, making high carbohydrate PN preferable to high lipid PN. Therefore, for use in critically ill patients, the data obtained in this study should be extrapolated, taking into consideration the specificity of each case.

Crosstalk within peripheral blood mononuclear cells mediates anti-inflammatory effects of n-3 PUFA-rich lipid emulsions in parenteral nutrition

BACKGROUND AND AIMS

Parenteral nutrition (PN) rich in n-6 and n-3 long-chain fatty acids is used in clinical practice for nourishing patients who are unable to receive adequate nutrition through their digestive systems. In this study, we compare the effect on inflammation of the commonly used lipid emulsions Omegaven (n-3-rich) and Intralipid (n-6-rich) in human peripheral blood mononuclear cells (PBMCs).

METHODS

PBMCs were treated with different doses of n-3-rich Omegaven and n-6-rich Intralipid and the immune cells were characterized by flow cytometry.

RESULTS

We show that incubation of PBMCs with n-3-rich Omegaven leads to an increase in expression of CD1d and CD86 in CD14+monocytes. At the same time, an increased number of NKT cells expressing cytotoxic T cell antigen 4 is observed, suggesting immunological synapse formation. Both CD14+monocytes and NKT cells showed an increase in IL-10 production and a reduction in the pro-inflammatory cytokines IFN-γ, TNF-α, and IL-4, which led to an increase in the number of FOXP3+T regulatory cells. In addition, we show that n-3-rich Omegaven reduces the expression of TNFα, IFNγ and IL-4 in CD4+T and CD8+T cells independent of the presented interaction between CD14+monocytes and NKT cells. The described mechanism of n-3 rich lipid emulsions was confirmed in PBMCs from patients with inflammatory bowel disease but not in colorectal cancer patients which seem to lack the interaction between CD14+monocytes and NKT cells.

CONCLUSIONS

These results show a mechanism for the beneficial effect of the n-3-rich Omegaven in patients with inflammatory conditions but questions its use in patients with cancer. Hence, our results may assist in choosing the best lipid emulsion for patients who require PN.

Down regulation of NDUFS1 is involved in the progression of parenteral-nutrition-associated liver disease by increasing Oxidative stress

Parenteral nutrition (PN)-associated liver disease (PNALD) is a common and life-threatening complication of patients receiving PN. However, its definitive pathology remains unclear. Ubiquinone oxidoreductase core subunit S1 (NDUFS1), which is the largest core subunit of mitochondrial complex I, could alter the mitochondrial reactive oxygen species (ROS) formation. The purpose of this study was to investigate the role of NDUFS1 in the pathogenesis of PNALD and its underlying mechanism. We performed hepatic proteomics analysis of PNALD patients, and established a PNALD rat model to verify the role of oxidative stress, NDUFS1, pyrin inflammasome, and IL-1β in the progression of PNALD. Proteomics analysis revealed the NDUFS1 expression was decreased in PNALD patients, and the differentially espressed proteins were involved in mitochondrial respiratory chain complex Ⅰ. Treatment with MitoQ or overexpression of NDUFS1 can alleviate the progression of PNALD by reducing oxidative stress. The expression of pyrin, caspase-1, and IL-1β was increased in PN rats. Pharmacological antagonism of pyrin by colchicine can alleviate liver injury and hepatic steatosis. NDUFS1 prevents PNALD pathogenesis by regulating oxidative stress. Pyrin inflammasome and IL-1β may participate in the process of PNALD development by suppressing the transcription of MTTP and impairing the secretion of VLDL. Oxidative stress reduction may be employed as a strategy in the prevention and treatment of PNALD.

Effect of Polymeric Nanoparticles with Entrapped Fish Oil or Mupirocin on Skin Wound Healing Using a Porcine Model

The utilization of poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) with entrapped fish oil (FO) loaded in collagen-based scaffolds for cutaneous wound healing using a porcine model is unique for the present study. Full-depth cutaneous excisions (5 × 5 cm) on the pig dorsa were treated with pure collagen scaffold (control, C), empty PLGA NPs (NP), FO, mupirocin (MUP), PLGA NPs with entrapped FO (NP/FO) and PLGA NPs with entrapped MUP (NP/MUP). The following markers were evaluated on days 0, 3, 7, 14 and 21 post-excision: collagen, hydroxyproline (HP), angiogenesis and expressions of the COX2, EGF, COL1A1, COL1A3, TGFB1, VEGFA, CCL5 and CCR5 genes. The hypothesis that NP/FO treatment is superior to FO alone and that it is comparable to NP/MUP was tested. NP/FO treatment increased HP in comparison with both FO alone and NP/MUP (day 14) but decreased (p < 0.05) angiogenesis in comparison with FO alone (day 3). NP/FO increased (p < 0.05) the expression of the CCR5 gene (day 3) and tended (p > 0.05) to increase the expressions of the EGF (day 7, day 14), TGFB1 (day 21) and CCL5 (day 7, day 21) genes as compared with NP/MUP. NP/FO can be suggested as a suitable alternative to NP/MUP in cutaneous wound treatment.

Exploring the long-term risk factors associated with intestinal failure-associated liver disease in pediatric and adult patients: The role of lipid injectable emulsions in the development of liver disease

BACKGROUND

Despite parenteral nutrition (PN) being life sustaining, one of the risk factors associated with its long-term use is intestinal failure-associated liver disease (IFALD), which increases the risk for morbidity and mortality. This review examines some of the risk factors associated with IFALD.

METHODS

A literature review using the databases PubMed, EMBASE, and CINAHL between 2010 and 2020 was performed using search terms, including long-term total PN and liver failure, serum plant sterols and liver failure, and complications and PN. Articles in English using both human and animal participants were included.

RESULTS

The pathophysiology associated with PN and liver disease is multifactorial and influenced by the remaining small-bowel length, presence of the ileal cecal valve, lack of enteral stimulation, type of lipid injectable emulsion (ILE), plant sterol content, and excessive calories. The type of ILE plays a major role because of the phytosterol (PS) content, affecting the microbiome composition and inhibiting key gut signals. The PS content is highest in soy oil (SO)-based ILE, which increases inflammation and impairs biliary flow.

CONCLUSION

Serum PS correlates with liver biomarker abnormalities and is highest in SO-based ILE use compared with mixed-oil emulsions. Selection of a low-PS content ILE is recommended to reduce the risk of biliary cholestasis. Stimulation of the gut, if possible, is recommended to maintain gut integrity and reduce bacterial overgrowth. Fish oil (FO) shows promise in IFALD reversal however, large randomized controlled trials are needed to further establish support for the use of FO in adults.

Parenteral Nutrition and Oxidant Load in Neonates

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

Intravenous Lipid Emulsions in the Prevention and Treatment of Liver Disease in Intestinal Failure

The development of intestinal failure-associated liver disease (IFALD) in pediatric and adult patients on parenteral nutrition is usually multifactorial in nature due to nutritional and non-nutritional causes. The role of lipid therapy as a contributing cause is well-established with the pathophysiological pathways now better understood. The review focuses on risk factors for IFALD development, biological effects of lipids, lipid emulsions and the mechanisms of lipid toxicity observed in laboratory animals followed by a synopsis of clinical studies in pediatric and adult patients. The introduction of fish oil-based lipid emulsions that provide partial or complete lipid replacement therapy has resulted in resolution of IFALD that had been associated with soybean oil-based therapy. Based on case reports and cohort studies in pediatric and adult patients who were at risk or developed overt liver disease, we now have more evidence that an early switch to partial or complete fish oil-based lipid therapy should be implemented in order to successfully halt and reverse IFALD.

Fish Oil Emulsion Reduces Liver Injury and Liver Transplantation in Children with Intestinal Failure-Associated Liver Disease: A Multicenter Integrated Study

OBJECTIVE

To compare the aspartate aminotransferase to platelet ratio index, liver transplantation, and mortality rates between children with intestinal failure-associated liver disease who received fish oil lipid emulsion (FOLE) or soybean oil intravenous lipid emulsion (SOLE).

STUDY DESIGN

In this multicenter integrated analysis, FOLE recipients (1 g/kg/d) (n = 189) were compared with historical controls administered SOLE (≤3 g/kg/d) (n = 73).

RESULTS

Compared with SOLE, FOLE recipients had a higher direct bilirubin level at baseline (5.8 mg/dL vs 3.0 mg/dL; P < .0001). Among FOLE recipients, 65% experienced cholestasis resolution vs 16% of SOLE recipients (P < .0001). The aspartate aminotransferase to platelet ratio index scores improved in FOLE recipients (1.235 vs 0.810 and 0.758, P < .02) but worsened in SOLE recipients (0.540 vs 2.564 and 2.098; P ≤ .0003) when baseline scores were compared with cholestasis resolution and end of study, respectively. Liver transplantation was reduced in FOLE vs SOLE (4% vs 12%; P = .0245). The probability of liver transplantation in relation to baseline direct or conjugated bilirubin (DB) was lower in FOLE vs SOLE recipients (1% vs 9% at DB of 2 mg/dL; 8% vs 35% at DB of 12.87 mg/dL; P = .0022 for both). Death rates were similar (FOLE vs SOLE: 10% vs 14% at DB of 2 mg/dL; 17% vs 23% at a DB of 12.87 mg/dL; P = .36 for both).

CONCLUSIONS

FOLE recipients experienced a higher rate of cholestasis resolution, lower aspartate aminotransferase to platelet ratio index, and fewer liver transplants compared with SOLE. This study demonstrates that FOLE may be the preferred parenteral lipid emulsion in children with intestinal failure-associated liver disease when DB reaches 2 mg/dL.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00910104 and NCT00738101.

Clinical application of fish-oil intravenous lipid emulsion in adult home parenteral nutrition patients

BACKGROUND

High-ω-6 polyunsaturated fatty acids (PUFAs) are noted to contribute to development of intestinal failure-associated liver disease (IFALD) in home parenteral nutrition (HPN). Fish oil (FO) has been added to latest generation of lipid injectable emulsion (ILE) to increase ω-3:ω-6 PUFA ratio; however, appropriate dose of FO to treat IFALD is unknown.

METHODS

After approval of exclusive FO ILE in the US for pediatric patients, we noted 2 adult patients with ongoing IFALD despite transition to mixed-oil (MO) ILE. They were transitioned to off-label FO ILE after review of literature regarding use of FO ILE in adult HPN patients was conducted to guide management.

RESULTS

The first case involves a 40-year-old female receiving HPN with IFALD refractory to MO ILE. MO ILE (with 15% FO) was provided at 50 g/d for 3 d/wk and combined with FO ILE at 50 g/d for 4 d/wk. This combination resulted in improvement in liver studies and allowed for decrease in dextrose calories. The second case involves a 49-year-old male receiving HPN (secondary to complications of necrotizing pancreatitis) who developed IFALD. FO ILE was used as the sole source of lipids and led to improvement in liver function tests. No evidence of essential fatty acid deficiency was found in either case.

CONCLUSIONS

Current case presentations and review of literature support the use of FO ILE to increase ω-3 PUFAs in patients with IFALD refractory to MO ILE. Additional research is necessary to delineate the dose of FO ILE necessary to achieve benefit.

High Dose Intravenous Fish Oil Reduces Inflammation-A Retrospective Tale from Two Centers

AIM

Patients on parenteral nutrition (PN) are prone to inflammation. This may aggravate an existing proinflammatory state and become a critical factor in the development of liver dysfunction (LD). Intravenous fish oil may attenuate this inflammatory state, but data on its use in adults are scarce. The aim of this study was to investigate the effects of adding a pure fish oil intravenous lipid emulsion (ILE) into short- and long-term PN in patients either at risk of, or with existing, inflammation.

METHODS

A retrospective analysis of 61 patients (32 female, 29 male, mean age 51.5 ± 12.6 years) who received all-in-one PN, including amino acids, glucose, and lipids supplemented with pure fish oil ILE, was performed. Pure fish oil ILE (Omegaven®, Fresenius Kabi, Bad Homburg, Germany) was used along with the standard ILE to reach a fish oil dose of 0.4-0.5 g fish oil/kg/d. Diagnoses were chronic intestinal failure (CIF, n = 20), Crohn's disease (CD, n = 22), and ulcerative colitis (UC, n = 19). The observation period was 12 months for CIF and 21 days for UC and CD.

RESULTS

A reduction in inflammation was noticeable in all patients and became statistically significant in CD (hsCRP p < 0.0001, ESR p = 0.0034, procalcitonin p = 0.0014, Il-6 p = 0.001) and UC groups (hsCRP and ESR p < 0.0001, Il-6 p = 0.0001, TNF-α p = 0.0113). In the CIF group, the total bilirubin concentration (p = 0.2157) and aspartate transaminase SGOT (p = 0.1785) did not vary over time.

CONCLUSIONS

PN with pure fish oil ILE reduces some inflammatory parameters in IBD and maintains liver function parameters in CIF patients. Fish oil might become a valuable ingredient in both short- and long-term PN in patients at risk of liver dysfunction.

Case Report: Transitioning to a Mixed-Oil Intravenous Lipid Emulsion in an Adult Patient Receiving Home Parenteral Nutrition

A potential risk of long-term parenteral nutrition (PN) is intestinal failure-associated liver disease (IFALD). One recommendation for mitigating risk is limiting the fat dose to reduce the harmful effects of the ω-6 fatty acids, which are the main ingredient in traditional fats. SMOFlipid (SMOF) (Kabi-Fresenius, Bad Homburg, Germany) is a combination of soybean oil, medium-chain triglycerides, olive oil, and fish oil emulsion. This fat source may alleviate the risk of IFALD and improve liver function tests. A patient with a long history of PN reliance and IFALD is presented in this case report. After 4 months on SMOF, total and direct bilirubin levels improved.

Fish oil protects the liver from parenteral nutrition-induced injury via GPR120-mediated PPARγ signaling

Intravenous fish oil lipid emulsions (FOLE) can prevent parenteral nutrition (PN)-induced liver injury in murine models and reverse PN-induced cholestasis in pediatric patients. However, the mechanisms by which fish oil protects the liver are incompletely characterized. Fish oil is rich in omega-3 fatty acids, which are ligands for the G-protein coupled receptor 120 (GPR120), expressed on hepatic Kupffer cells. This study tested the hypothesis that FOLE protects the liver from PN-induced injury through GPR120 signaling. Utilizing a previously described murine model of PN-induced liver injury in which mice develop steatosis in response to an oral parenteral nutrition diet, FOLE was able to preserve normal hepatic architecture in wild type mice, but not in congenic GPR120 knockout (gpr120-/-) mice. To further characterize the requirement of intact GPR120 for FOLE-mediated hepatic protection, gene expression profiles of key regulators of fat metabolism were measured. PPARγ was identified as a gene that is up-regulated by the PN diet and normalized with the addition of FOLE in wild type, but not in gpr120-/- mice. This was confirmed at the protein expression level. A PPARγ expression array further identified CD36 and SCD1, both down-stream effectors of PPARγ, to be up-regulated in PN-fed wild type mice yet normalized upon FOLE administration in wild type but not in gpr120-/- mice. Together, these results suggest that FOLE protects the liver, in part, through activation of GPR120 and the downstream effectors PPARγ and CD36. Identification of key genetic determinants of FOLE-mediated hepatic protection may provide targets for small molecule-based hepatic protection strategies.

Effect of n-3 long-chain polyunsaturated fatty acids on wound healing using animal models – a review

The present review summarizes results of experiments, mostly performed on rodents, regarding the effects of fish oil (FO) and its biologically active constituents, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the healing of cutaneous wounds, but also of selected other types of injury. Structure, metabolism and functions of EPA/DHA in an organism are briefly mentioned, with an emphasis on the ability of these long-chain polyunsaturated fatty acids to modulate inflammation. Wound healing as a complex programmed sequence of cellular and molecular processes including inflammation, cell migration, angiogenesis, synthesis of provisional matrix, collagen deposition and reepithelialisation is briefly described. Markers for evaluation of the healing process include planimetry indices, tensile strength, quantification of collagen synthesis including hydroxyproline determination, histopathology/immunohistochemistry and genomic/proteomic markers. As far as effects on wound healing are concerned, the main emphasis is put on the outcomes of experiments using a dietary FO/DHA/EPA administration, but the results of experiments with a parenteral application are also mentioned, together with selected relevantin vitrostudies. An important conclusion from the above-mentioned studies is an inconsistency of FO/DHA/EPA effects on wound healing: decreased/increased collagen deposition; lower/higher counts of the inflammatory cells in the healing tissue; increased/decreased concentration of both pro- and anti-inflammatory cytokines; DHA accelerated/delayed wound healing process. Some experiments indicate superiority of DHA over EPA regarding wound healing.

The cirrhotic liver is depleted of docosahexaenoic acid (DHA), a key modulator of NF-κB and TGFβ pathways in hepatic stellate cells

Liver cirrhosis results from chronic hepatic damage and is characterized by derangement of the organ architecture with increased liver fibrogenesis and defective hepatocellular function. It frequently evolves into progressive hepatic insufficiency associated with high mortality unless liver transplantation is performed. We have hypothesized that the deficiency of critical nutrients such as essential omega-3 fatty acids might play a role in the progression of liver cirrhosis. Here we evaluated by LC-MS/MS the liver content of omega-3 docosahexaenoic fatty acid (DHA) in cirrhotic patients and investigated the effect of DHA in a murine model of liver injury and in the response of hepatic stellate cells (HSCs) (the main producers of collagen in the liver) to pro-fibrogenic stimuli. We found that cirrhotic livers exhibit a marked depletion of DHA and that this alteration correlates with the progression of the disease. Administration of DHA exerts potent anti-fibrogenic effects in an acute model of liver damage. Studies with HSCs show that DHA inhibits fibrogenesis more intensely than other omega-3 fatty acids. Data from expression arrays revealed that DHA blocks TGFβ and NF-κB pathways. Mechanistically, DHA decreases late, but not early, SMAD3 nuclear accumulation and inhibits p65/RelA-S536 phosphorylation, which is required for HSC survival. Notably, DHA increases ADRP expression, leading to the formation of typical quiescence-associated perinuclear lipid droplets. In conclusion, a marked depletion of DHA is present in the liver of patients with advanced cirrhosis. DHA displays anti-fibrogenic activities on HSCs targeting NF-κB and TGFβ pathways and inducing ADPR expression and quiescence in these cells.

Long-Term Outcomes in Children With Intestinal Failure-Associated Liver Disease Treated With 6 Months of Intravenous Fish Oil Followed by Resumption of Intravenous Soybean Oil

BACKGROUND

Intravenous soybean oil (SO) is a commonly used lipid emulsion for children with intestinal failure (IF); however, it is associated with IF-associated liver disease (IFALD). Studies have demonstrated that intravenous fish oil (FO) is an effective treatment for IFALD. However, there is a lack of long-term data on children who stop FO and resume SO. This study's objective was to investigate our institution's outcomes for children with IFALD treated with 6 months of FO and who then restarted SO.

METHODS

Inclusion criteria for FO included children with IFALD. Parenteral nutrition (PN)-dependent children resumed SO after FO and were prospectively followed for 4.5 years or until death, transplant, or PN discontinuation. The primary outcome was the cumulative incidence rate (CIR) for cholestasis after FO.

RESULTS

Forty-eight subjects received FO, and conjugated bilirubin decreased over time (-0.22 mg/dL/week; 95% confidence interval [CI]: -0.25, -0.19; P < .001). The CIR for cholestasis resolution after 6 months of FO was 71% (95% CI: 54%, 82%). Twenty-seven subjects resumed SO and were followed for a median of 16 months (range 3-51 months). While the CIR for enteral autonomy after 3 years of follow-up was 40% (95% CI: 17%, 26%), the CIR for cholestasis and transplant was 26% (95% CI: 8%, 47%) and 6% (95% CI: 0.3%, 25%), respectively.

CONCLUSION

In this study, FO effectively treated cholestasis, and SO resumption was associated with cholestasis redevelopment in nearly one-fourth of subjects. Long-term FO may be warranted to prevent end-stage liver disease.

Reversal of intestinal failure associated liver disease fibrosis in a patient receiving long term home parenteral nutrition

Intestinal failure associated liver disease (IFALD) is frequent problem encountered when managing patients receiving parenteral nutrition (PN). Its occurrence is often multifactorial and modification of these factors is vital for the management of such hepatic dysfunction. The use of novel lipid preparations can form part of this management strategy. We present a case whereby such modification of contributing factors, including lipid preparations, led to improvements in IFALD and reversal of hepatic fibrosis.

Parenteral Nutrition and Lipids

Lipids have multiple physiological roles that are biologically vital. Soybean oil lipid emulsions have been the mainstay of parenteral nutrition lipid formulations for decades in North America. Utilizing intravenous lipid emulsions in parenteral nutrition has minimized the dependence on dextrose as a major source of nonprotein calories and prevents the clinical consequences of essential fatty acid deficiency. Emerging literature has indicated that there are benefits to utilizing alternative lipids such as olive/soy-based formulations, and combination lipids such as soy/MCT/olive/fish oil, compared with soybean based lipids, as they have less inflammatory properties, are immune modulating, have higher antioxidant content, decrease risk of cholestasis, and improve clinical outcomes in certain subgroups of patients. The objective of this article is to review the history of IVLE, their composition, the different generations of widely available IVLE, the variables to consider when selecting lipids, and the complications of IVLE and how to minimize them.

Intravenous Treatment with a Long-Chain Omega-3 Lipid Emulsion Provides Neuroprotection in a Murine Model of Ischemic Stroke - A Pilot Study

Single long-chain omega-3 fatty acids (e.g. docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA)) are known for their neuroprotective properties associated with ischemic stroke. This pilot study aimed to test the effectiveness of an acute treatment with a long-chain omega-3 lipid emulsion (Omegaven 10%^®, OGV) that contains fish oil (DHA 18 mg/ml; EPA 21 mg/ml) and α-tocopherol (0.2 mg/ml) in a transient middle cerebral artery occlusion (MCAO) model of ischemic stroke in mice. For this purpose, female CD-1 mice were anesthetized and subjected to 90 minutes of MCAO. To reflect a clinically relevant situation for an acute treatment, either after induction of stroke or after reperfusion, a single dose of OGV was injected intravenously into the tail vein (5 ml/kg b.w.). A neurological severity score was used to assess motor function and neurological outcome. Stroke-related parameters were determined 24 hours after MCAO. Microdialysis was used to collect samples from extracellular space of the striatum. Mitochondrial function was determined in isolated mitochondria or dissociated brain cells. Inflammation markers were measured in brain homogenate. According to control experiments, neuroprotective effects could be attributed to the long-chain omega-3 content of the emulsion. Intravenous injection of OGV reduced size and severity of stroke, restored mitochondrial function, and prevented excitotoxic glutamate release. Increases of pro-inflammatory markers (COX-2 and IL-6) were attenuated. Neurological severity scoring and neurochemical data demonstrated that acute OGV treatment shortly after induction of stroke was most efficient and able to improve short-term neurological outcome, reflecting the importance of an acute treatment to improve the outcome. Summarising, acute treatment of stroke with a single intravenous dose of OGV provided strong neuroprotective effects and was most effective when given immediately after onset of ischemia. As OGV is an approved fishoil emulsion for parenteral nutrition in humans, our results may provide first translational data for a possible early management of ischemic stroke with administration of OGV to prevent further brain damage.

Intravenous Lipid Emulsions in Parenteral Nutrition

Fat is an important macronutrient in the human diet. For patients with intestinal failure who are unable to absorb nutrients via the enteral route, intravenous lipid emulsions play a critical role in providing an energy-dense source of calories and supplying the essential fatty acids that cannot be endogenously synthesized. Over the last 50 y, lipid emulsions have been an important component of parenteral nutrition (PN), and over the last 10-15 y many new lipid emulsions have been manufactured with the goal of improving safety and efficacy profiles and achieving physiologically optimal formulations. The purpose of this review is to provide a background on the components of lipid emulsions, their role in PN, and to discuss the lipid emulsions available for intravenous use. Finally, the role of parenteral fat emulsions in the pathogenesis and management of PN-associated liver disease in PN-dependent pediatric patients is reviewed.