Dietary ω‐6/ω‐3 Polyunsaturated Fatty Acid Ratios Affect the Homeostasis of Th/Treg Cells in Mice With Dextran Sulfate Sodium–Induced Colitis

Background: This study evaluated the effect of different dietary ω‐6/ω‐3 polyunsaturated fatty acid (PUFA) ratios on modulating helper T (Th) and regulatory T (Treg) lymphocytes in mice with dextran sulfate sodium (DSS)–induced colitis. Methods: There were 3 control and 3 colitis groups. Mice were fed for 24 days with diets with soybean oil (S), a mixture of soybean oil and low fish oil content (LF), or high fish oil content (HF). The ratio of ω‐6/ω‐3 PUFA in the LF diet was 4:1, and that in the HF diet was 2:1. The control groups drank distilled water while colitis groups were provided 2% DSS in drinking water during days 15–19. All mice drank distilled water from days 20–24 for recovery and were sacrificed on day 25. Results: Colitis resulted in higher blood Th1, Th2, and Th17 and lower Treg percentages. Also, plasma haptoglobin and proinflammatory chemokines were elevated in colon lavage fluid. Colitic groups with fish oil had lower inflammatory mediators in the plasma and colon lavage fluid. Furthermore, the percentages of blood Th1, Th2, and Th17 cells were lower, whereas Treg cell percentages were higher than those in the soybean oil group. The colitis group with an ω‐6/ω‐3 PUFA ratio of 2:1 had more pronounced effects than the group with a ratio of 4:1. Conclusions: Diets with an ω‐6/ω‐3 PUFA ratio of 2:1 or 4:1 regulate the Th/Treg balance and attenuate inflammatory mediator production in colitis. Compared with the ω‐6/ω‐3 PUFA ratio of 4:1, the ratio of 2:1 was more effective in reducing inflammatory reactions in DSS‐induced colitis.     

Effects of the ω‐6:ω‐3 Fatty Acid Ratio of Fat Emulsions on the Fatty Acid Composition in Cell Membranes and the Anti‐Inflammatory Action

Background: This study investigated the effects of parenterally administered fish oil (FO) on the fatty acid composition in rats to determine the optimal ω‐6:ω‐3 polyunsaturated fatty acid (PUFA) ratio of fat emulsions to achieve an anti‐inflammatory effect. Methods: Male Sprague‐Dawley rats were infused a parenteral nutrition (PN) solution containing fat emulsions with different ω‐6:ω‐3 PUFA ratios. The fatty acid content of phospholipids in the membranes of splenocytes was analyzed by gas chromatography (experiment 1). In addition, the amounts of leukotriene (LT) B₄ and LTB₅ released from peritoneal polymorphonuclear leukocytes (PMNs) were measured by high‐performance liquid chromatography (experiment 2). Results: In experiment 1, after infusion of the fat emulsion containing FO, the ω‐3 PUFA content in cell membranes rose to 70% of the peak value on day 1 and nearly reached a plateau on day 3. The highest ratio of eicosapentaenoic acid (EPA) to arachidonic acid (AA) was achieved by administrating a PN solution with the smallest ω‐6:ω‐3 PUFA ratio. In experiment 2, a larger amount of LTB₅ was released from Ca‐ionophore‐stimulated PMNs taken from rats given a larger quantity of FO. The ratio of LTB₅:LTB₄ released from PMNs correlated positively with the EPA:AA ratio in the membranous phospholipid and in serum. Conclusions: The ω‐3 PUFAs were readily incorporated into the cell membrane within 3 days of infusion with the fat emulsion. The EPA:AA ratio in membranous phospholipid in PMNs was positively correlated with the LTB₅:LTB₄ production ratio and was a good indicator of anti‐inflammatory effects.     

Effects of ω‐3 Polyunsaturated Fatty Acids on the Homeostasis of CD4+ T Cells and Lung Injury in Mice With Polymicrobial Sepsis

Background: Sepsis is a common cause of death in critically ill patients. An overwhelming inflammatory response and imbalance of helper T (Th) cells and regulatory T (Treg) cells are thought to be involved in the progression of sepsis. ω‐3 Polyunsaturated fatty acids (PUFAs) were found to have anti‐inflammatory and immunomodulatory properties. This study investigated the effects of ω‐3 PUFAs on the balance of Th subsets, Treg cells, and the inflammatory response in septic mice. Methods: Mice were randomly assigned to soybean oil (SO) and fish oil (FO) groups. The 2 groups received an identical nutrient distribution except for the sources of the fat. The SO group was fed soybean oil, while part of the soybean oil was replaced by fish oil in the FO group. The FO group had an ω‐6/ω‐3 PUFA ratio of 2:1. After feeding the diets for 3 weeks, sepsis was induced by cecal ligation and puncture (CLP), and mice were sacrificed on days 0, 1, and 3. Results: Compared with the SO group, the FO group had lower inflammatory mediator levels in the plasma and peritoneal lavage fluid after CLP. Also, the FO group had lower Th1, Th2, and Th17 percentages and a higher Th1/Th2 ratio in blood. In lung tissues, neutrophil infiltration was reduced, whereas peroxisome proliferator–activated receptor γ expression was upregulated. Conclusions: A fish oil diet with an ω‐6/ω‐3 PUFA ratio of 2:1 may elicit more balanced Th polarization, alleviate inflammatory responses, and attenuate lung injury in CLP‐induced sepsis.     

Intravenous ω‐3 Fatty Acids Plus Gemcitabine

Background: Marine‐derived ω‐3 fatty acids (ω‐3FAs) have proven antitumor activity in vivo and in vitro and improve quality of life (QOL) in clinical cancer studies. These changes may be mediated by reduction in circulating proangiogenic and proinflammatory factors. In this first study of intravenous ω‐3FAs as a therapy in cancer patients, we aimed to assess if it could augment the antitumor activity of gemcitabine in patients with advanced pancreatic cancer and improve QOL. Materials and Methods: Patients were administered gemcitabine 1000 mg/m³ weekly followed by up to 100 g (200 mg/mL) of ω‐3 rich lipid emulsion for 3 weeks followed by a rest week. This was continued for up to 6 cycles, progression, unacceptable toxicity, patient request, or death. The primary outcome measure was objective response rate, with secondary outcome measures of overall and progression free survival, QOL scores, and adverse events. Results: Fifty patients were recruited. Response rate was 14.3% and disease control rate was 85.7%. Overall and progression free survival were 5.9 and 4.8 months, respectively. Increase in global health of > 10% over baseline was seen in 47.2% of patients. More than 50% of patients had > 10% increase in QOL scores in generic symptom scores and both disease‐specific domains. Grade 3/4 adverse events were thrombocytopenia (8%), neutropenia (12%), nausea or vomiting (4%), and chills (6%). Conclusion: Intravenous ω‐3FAs in combination with gemcitabine shows evidence of improved activity and benefit to QOL in patients with advanced pancreas cancer and is worthy of investigation in a randomized phase III trial.     

ω‐3 Fatty Acids Reduce Chemotherapy‐Induced Hematological Toxicity by Bone Marrow Stimulation in Mice

Background: ω‐3 Fatty acids exert several benefits during chemotherapy, such as preventing intestinal mucosal damage and improving response to chemotherapy. However, little is known about the effect of ω‐3 fatty acids on chemotherapy‐induced hematological toxicities. Methods: Mice that had consumed either an ω‐3–rich or an ω–3‐poor diet for 2 weeks were intraperitoneally administered cisplatin. The resultant changes in blood cell count, bone marrow cell count, and cytokine levels in bone marrow supernatant were analyzed. The effect of ω‐3 fatty acids on human peripheral blood mononuclear cells (PBMCs) exposed to cisplatin was also examined. Results: Although peripheral blood cell counts decreased after cisplatin treatment in both groups of mice, the decrease in white blood cell count was significantly lower in mice that consumed the ω‐3–rich diet. The decrease in bone marrow cells after cisplatin treatment was also reduced in mice that consumed the ω‐3–rich diet. Levels of stem cell factor (SCF) and fibroblast growth factor 1 (FGF‐1) were significantly higher in bone marrow supernatants from mice that consumed the ω‐3–rich diet. The rate of apoptosis in PBMCs (after exposure to cisplatin) cultured in medium containing ω‐3 fatty acids was significantly lower than in PBMCs cultured in control medium. Conclusion: ω‐3–Rich diets reduced chemotherapy‐induced leukopenia in mice. This may be the result of increased numbers of bone marrow cells due to higher levels of SCF and FGF‐1 in the bone marrow.     

ω‐3 Fatty Acids Prevent Hepatic Steatosis,Independent of PPAR‐α Activity,in a Murine Model of Parenteral Nutrition–Associated Liver Disease

Objectives: ω‐3 Fatty acids (FAs), natural ligands for the peroxisome proliferator‐activated receptor–α (PPAR‐α), attenuate parenteral nutrition–associated liver disease (PNALD). However, the mechanisms underlying the protective role of ω‐3 FAs are still unknown. The aim of this study was to determine the effects of ω‐3 FAs on hepatic triglyceride (TG) accumulation in a murine model of PNALD and to investigate the role of PPAR‐α and microsomal triglyceride transfer protein (MTP) in this experimental setting. Methods: 129S1/SvImJ wild‐type or 129S4/SvJaePparatm/Gonz/J PPAR‐α knockout mice were fed chow and water (controls); oral, fat‐free PN solution only (PN‐O); PN‐O plus intraperitoneal (IP) ω‐6 FA‐predominant supplements (PN–ω‐6); or PN‐O plus IP ω‐3 FA (PN–ω‐3). Control and PN‐O groups received sham IP injections of 0.9% NaCl. Hepatic histology, TG and cholesterol, MTP activity, and PPAR‐α messenger RNA were assessed after 19 days. Results: In all experimental groups, PN feeding increased hepatic TG and MTP activity compared with controls. Both PN‐O and PN–ω‐6 groups accumulated significantly greater amounts of TG when compared with PN–ω‐3 mice. Studies in PPAR‐α null animals showed that PN feeding increases hepatic TG as in wild‐type mice. PPAR‐α null mice in the PN‐O and PN–ω‐6 groups demonstrated variable degrees of hepatic steatosis, whereas no evidence of hepatic fat accumulation was found after 19 days of oral PN plus IP ω‐3 FAs. Conclusions: PN induces TG accumulation (steatosis) in wild‐type and PPAR‐α null mice. In PN‐fed wild‐type and PPAR‐α null mice given IP ω‐3 FAs, reduced hepatic TG accumulation and absent steatosis are found. Prevention of steatosis by ω‐3 FAs results from PPAR‐α–independent pathways.     

Parenteral ω‐3 Fatty Acid Lipid Emulsions for Children With Intestinal Failure and Other Conditions

Background: There is growing interest in the use of ω‐3 fatty acid (n‐3FA) lipid emulsions to prevent complications associated with parenteral nutrition. The authors systematically reviewed the evidence on the benefits and safety of n‐3FA compared with standard lipid emulsions in children with intestinal disease, critical illness, trauma, or postoperative complications. Materials and Methods: The authors searched 4 bibliographic databases from their inception to March 2011, conference proceedings, trial registries, and reference lists. Two reviewers independently selected studies, assessed methodological quality, and rated the strength of the evidence. One reviewer extracted and a second reviewer verified data. The authors summarized findings qualitatively and conducted meta‐analysis when appropriate. Results: Five randomized controlled trials with unclear risk of bias and 3 high‐quality prospective cohort studies were included. The studies examined premature, low birth weight infants (n = 6) and children with heart disease (n = 1) or intestinal failure (n = 1). The strength of evidence was consistently low or very low across all lipid emulsion comparisons and outcomes. In young children, n‐3FA emulsions resulted in improvement in some biochemical outcomes of intestinal failure–associated liver disease but no difference in mortality. Few studies examined patient‐important outcomes, such as length of hospital and intensive care stay; need for transplantation, growth, and cognitive development; or the long‐term effects and potential harms associated with these therapies. Conclusions: Currently, there is a lack of sufficient high‐quality data to support the use of parenteral n‐3FA lipid emulsions in children. Future trials examining long‐term clinical outcomes and harms are needed.     

Rapid Incorporation of ω‐3 Fatty Acids Into Colonic Tissue After Oral Supplementation in Patients With Colorectal Cancer

Background: The purpose of the study was to examine whether a preoperative supplement with ω‐3 fatty acids (FAs) leads to their incorporation into colonic tissue in patients scheduled for colorectal cancer surgery. This would be of interest because ω‐3 FAs have potential beneficial (local) immunological effects that might benefit these patients. Methods: In a randomized, double‐blind, prospective, placebo‐controlled, single‐center intervention trial, patients referred for elective colorectal cancer surgery received either an ω‐3 FA–enriched oral nutrition supplement (ONS) (200 mL twice daily) providing 2.0 g of eicosapentaenoic acid (EPA) and 1.0 g of docosahexaenoic acid (DHA) per day or a standard ONS for 7 days before surgery. Tissue samples from healthy colonic tissue (mucosa and muscular layer) were obtained during surgery, and tissue fatty acid composition was analyzed by gas chromatography. Results: EPA was significantly higher in colonic mucosa (P = .001) and in the colonic muscular layer (P = .004) in the ω‐3 FA group compared with controls. Patients in the ω‐3 FA group also tended to have higher docosapentaenoic acid and DHA levels in colonic tissue. Conclusions: EPA is incorporated rapidly into colonic mucosa and colonic muscular layer in patients given 3 g of ω‐3 FA daily for 7 days before surgery for colorectal cancer. This may lead to potential beneficially effects on (local) immune function, which might benefit these patients.     

Rapid Enrichment of Cell Phospholipids in Long‐Chain Polyunsaturated ω‐3 Fatty Acids After a Bolus Intravenous Injection of a Medium‐Chain Triacylglycerol

The present review aims at highlighting the use of a recently developed medium‐chain triacylglycerol:fish oil (MCT:FO) emulsion for the rapid and sustained enrichment of long‐chain polyunsaturated ω‐3 fatty acids in cell phospholipids. Preclinical in vitro, in vivo, and ex vivo experiments are briefly considered with emphasis on the changes in the fatty acid pattern of cell phospholipids in several organs, the partial correction of liver steatosis, and the cardiovascular modification of cationic and functional variables observed in ω‐3‐depleted rats examined 60–120 minutes after a bolus intravenous (IV) injection (1.0 mL) of the MCT:FO emulsion. The clinical findings collected in healthy male volunteers before or after the bolus IV injection (50.0 mL) of either the MCT:FO emulsion or a control medium‐chain triacylglycerol:long‐chain triacylglycerol emulsion are also reviewed, with emphasis on the rapid (within 60 minutes) and sustained (up to 2–3 days) enrichment of platelet and white blood cell phospholipids in long‐chain polyunsaturated ω‐3 fatty acids and hemostatic safety of the present procedure proposed as a tool for the rapid prevention or correction of metabolic and functional disturbances in humans with a relative deficiency in such ω‐3 fatty acids.     

Effects on Varying Intravenous Lipid Emulsions on the Small Bowel Epithelium in a Mouse Model of Parenteral Nutrition

Background: Injectable fat emulsions (FEs) are a clinically dependable source of essential fatty acids (FA). ω‐6 FA is associated with an inflammatory response. Medium‐chain triglycerides (MCT, ω‐3 FA), fish oil, and olive oil are reported to decrease the inflammatory response. However, the effect of these lipids on the gastrointestinal tract has not been well studied. To address this, we used a mouse model of parenteral nutrition (PN) and hypothesized that a decrease in intestinal inflammation would be seen when either fish oil and MCT or olive oil were added. Methods: Three FEs were studied in adult C57BL/6 mice via intravenous cannulation: standard soybean‐based FE (SBFE), 80% olive oil ‐supplemented FE (OOFE), or a combination of a soybean oil, MCT, olive oil, and fish oil emulsion (SMOF). PN was given for 7 days, small bowel mucosa‐derived cytokines, animal survival rate, epithelial cell (EC) proliferation and apoptosis rates, intestinal barrier function and mucosal FA composition were analyzed. Results: Compared to the SBFE and SMOF groups, the best survival, highest EC proliferation and lowest EC apoptosis rates were observed in the OOFE group; and associated with the lowest levels of tumor necrosis factor‐α, interleukin‐6, and interleukin‐1β expression. Jejunal FA content showed higher levels of eicosapentaenoic and docosapentaenoic acid in the SMOF group and the highest arachidonic acid in the OOFE group. Conclusion: The study showed that PN containing OOFE had beneficial effects to small bowel health and animal survival. Further investigation may help to enhance bowel integrity in patients restricted to PN.     

A New Intravenous Fat Emulsion Containing Soybean Oil,Medium‐Chain Triglycerides,Olive Oil,and Fish Oil

Background: SMOFlipid 20% is an intravenous lipid emulsion (ILE) containing soybean oil, medium‐chain triglycerides, olive oil, and fish oil developed to provide energy, essential fatty acids (FAs), and long‐chain ω‐3 FAs as a mixed emulsion containing α‐tocopherol. The aim was to assess the efficacy and safety of this new ILE in pediatric patients receiving home parenteral nutrition (HPN) compared with soybean oil emulsion (SOE). Methods: This single‐center, randomized, double‐blind study included 28 children on HPN allocated to receive either SMOFlipid 20% (n = 15) or a standard SOE (Intralipid 20%, n = 13). ILE was administered 4 to 5 times per week (goal dose, 2.0 g/kg/d) within a parenteral nutrition regimen. Assessments, including safety and efficacy parameters, were performed on day 0 and after the last study infusion (day 29). Lipid peroxidation was determined by measurement of thiobarbituric acid reactive substances (TBARS). Results: There were no significant differences in laboratory safety parameters, including liver enzymes, between the groups on day 29. The mean ± standard deviation changes in the total bilirubin concentration between the initial and final values (day 29 to day 0) were significantly different between groups: SMOFlipid group ?1.5 ± 2.4 µmol/L vs SOE group 2.3 ± 3.5 µmol/L, P < .01; 95% confidence interval [CI], ?6.2 to ?1.4). In plasma and red blood cell (RBC) phospholipids, the ω‐3 FAs C20:5ω‐3 (eicosapentaenoic acid) and + C22:6ω‐3 (docosahexaenoic acid) increased significantly in the SMOFlipid group on day 29. The ω‐3:ω‐6 FA ratio was significantly elevated with SMOFlipid 20% compared with SOE group (plasma, day 29: 0.15 ± 0.06 vs 0.07 ± 0.02, P < .01, 95% CI, 0.04–0.11; and RBC, day 29: 0.23 ± 0.07 vs 0.14 ± 0.04, P < .01, 95% CI, 0.04–0.13). Plasma α‐tocopherol concentration increased significantly more with SMOFlipid 20% (15.7 ± 15.9 vs 5.4 ± 15.2 µmol/L, P < .05; 95% CI, ?2.1 to 22.6). The low‐density lipoprotein–TBARS concentrations were not significantly different between both groups, indicating that lipid peroxidation did not differ between groups. Conclusions: SMOFlipid 20%, which contains 15% fish oil, was safe and well tolerated, decreased plasma bilirubin, and increased ω‐3 FA and α‐tocopherol status without changing lipid peroxidation.     

Effect of Dietary Fatty Acid Composition on Th1/Th2 Polarization in Lymphocytes

Background: It has become increasingly clear that polyunsaturated fatty acids (PUFAs) have immunomodulatory effects. However, the intake of these fatty acids used in animal studies often greatly exceeds dietary human intake. Whether differences in the composition of fatty acids that are consumed in amounts consistent with normal dietary intake can influence immune function remains uncertain. Methods: We manufactured 3 types of liquid diet, related to modified fatty acid composition (ω‐6/ω‐3 = 0.25, 2.27 and 42.9), but excluding eicosapentaenoic acid and docosahexaenoic acid, based upon a liquid diet used clinically in humans. We assessed CD3‐stimulated cytokine production of splenocytes in female BALB/c mice (n = 4 per group) fed 1 of 3 liquid diets for 4 weeks. We also measured the cytokine production of peripheral blood mononuclear cells stimulated with phorbol myristate acetate and ionomycin in humans at the end of a 4‐week period of consumption of 2 different liquid diets (ω‐6/ω‐3 = 3 and 44). Results: We found that the ratio of interfero ω‐γ (IFN‐γ) / interleukin‐4 (IL‐4) was significantly higher in mice fed theω ‐3 rich diet than in others. In humans, IFN‐γ / IL‐4 was significantly higher after the ω‐3 versus the ω‐6 enhanced diet. Conclusions: Differences in the composition of ω‐3 andω ‐6 PUFAs induces a shift in the Th1/Th2 balance in both mouse and human lymphocytes, even when ingested in normal dietary amounts. An ω‐3 rich diet containing α‐linolenic acid modulates immune function.     

Prefeeding With ω‐3 Fatty Acids Suppresses Inflammation Following Hemorrhagic Shock

Background: Hemorrhagic shock followed by resuscitation stimulates an inflammatory response. This study tests the hypothesis that prefeeding with fish oil rich in ω‐3 fatty acids (FAs) will attenuate that response. Methods: Male Sprague‐Dawley rats (n = 60; 350 ± 30 g) were randomly but unequally assigned to 3 groups: sham (n = 12), control (n = 24), and fish oil (n = 24). In the fish oil group, rat chow was supplemented with fish oil (600 mg/kg/d, 25% ω‐3 FA). Control and sham group diets were supplemented with corn oil. Under fluothane, hemorrhagic shock was induced, and arterial pressure was maintained at 25 to 30 mm Hg for 30 minutes. Resuscitation was carried out by giving 21 mL/kg lactated Ringer's solution and returning shed blood to the animal. Half of each group was killed at 30 minutes and at 4 hours postresuscitation. Liver samples were assayed for indicators of inflammation and heat shock protein 25 (Hsp25). Lung edema was measured. Results: All animals survived. At 30 minutes postresuscitation, expression of mRNA for inducible nitric oxide synthase (iNOS) was significantly elevated in the control group but normal in the fish oil group. At 4 hours, expression of mRNA for Hsp25 was significantly increased in the fish oil group. Lung edema index was significantly lower in the fish oil group than in either sham or control groups. Conclusions: Fish oil prefeeding in a rodent model of hemorrhagic shock was associated with increased liver mRNA expression of Hsp25, reduced liver mRNA expression of iNOS, and decreased lung edema. These findings support the validity of the study hypothesis.     

Pilot Experimental Study on the Effect of Arginine,Glutamine, and β‐Hydroxy β‐Methylbutyrate on Secondary Wound Healing

Background: Wound healing is a complex process, dependent on available nutrition substrates. When used together with β‐hydroxy β‐methylbutyrate, arginine and glutamine have been shown to increase collagen deposition in human subjects. However, there are no experimental investigations on the influence of this amino acid mixture with regard to secondary wound healing. The aim of this study is to investigate the effects of the supplementation of these 3 amino acids on the healing of open wounds in otherwise healthy animals. Materials and Methods: Twelve rats were divided into control and treatment groups. Two 2‐cm × 1‐cm full‐thickness skin defects were prepared on each subject. The rats in both groups received a diet containing 1.2 g of protein per 100 g of body weight per day. The treatment group, in addition, received 200 mg/kg L‐arginine, 200 mg/kg L‐glutamine, and 40 mg/kg β‐hydroxy β‐methylbutyrate every day. Wound sizes were measured every 2 days. On the 10th day, tissue samples were taken for histopathologic evaluation and also for the measurement of hydroxyproline concentrations. Results: There was no statistically significant difference between mean wound sizes for the 2 groups (P > .05). There was also no statistically significant difference between the groups with regard to histological healing parameters (reepithelialization [P = 1.00], granulation tissue [P = 1.00], collagen accumulation [P = .455], inflammatory cell accumulation [P = .455], angiogenesis [P = .242]) or tissue hydroxyproline concentrations (P = .240). Conclusion: Diet supplemented with arginine, glutamine, and β‐hydroxy β‐methylbutyrate is not beneficial in enhancing secondary healing of open wounds in rats. Further research regarding this topic is warranted.     

Mixture of Arginine,Glutamine, and β‐hydroxy‐β‐methyl Butyrate Enhances the Healing of Ischemic Wounds in Rats

Background: This study investigated the effects of an amino acid mixture containing arginine, glutamine, and β‐hydroxy‐β‐methyl butyrate on secondary healing of ischemic wounds in a rat model (N = 18). Methods: After the formation of a bipediculated flap on each rat, 2 full‐thickness excisional skin wounds (2 × 2 cm) were created on every flap. The rats were then randomized into the control and treatment groups. Every rat received standardized rat food throughout the study. The rats in the treatment group were administered an extra 200 mg/kg of L‐arginine, 200 mg/kg of L‐glutamine, and 40 mg/kg of β‐hydroxy‐β‐methyl butyrate per day. Wound sizes were measured on days 0, 4, 10, and 14. The rats were sacrificed, and the wounds were excised for biochemical and histologic examination on the 14th day. Results: As compared with the control group, the treatment group's wound sizes were significantly smaller on days 10 and 14 (P < .001), as was its inflammatory cell accumulation score (P = .008). There was no significant difference between the 2 groups in collagen accumulation (P = .340), granulation tissue maturation (P = .161), angiogenesis (P = .387), or reepithelialization (P = .190) and no significant difference between hydroxyproline concentrations in wounds (P = .287). Discussion: This amino acid combination seems to have a positive impact on the secondary healing of experimental ischemic wounds when introduced as a supplement to the standard diet, and the reduction in the inflammatory process appears to play a role in this effect.     

Liver Disease,Systemic Inflammation,and Growth Using a Mixed Parenteral Lipid Emulsion,Containing Soybean Oil,Fish Oil,and Medium Chain Triglycerides,Compared With Soybean Oil in Parenteral Nutrition–Fed Neonatal Piglets

Background: The optimal parenteral lipid emulsion for neonates should reduce the risk of intestinal failure–associated liver disease and inflammation, while supporting growth and development. This could be best achieved by balanced content of ω‐6 and ω‐3 polyunsaturated fatty acids (PUFAs). Using a neonatal piglet model of parenteral nutrition (PN), we compared a 100% soy oil–based emulsion (ω‐6:ω‐3 PUFA: 7:1) with a mixed lipid emulsion comprising 30% soy oil, 30% medium‐chain triglycerides, 25% olive oil, and 15% fish oil (ω‐6:ω‐3 PUFA: approximately 2.5:1) with regard to liver disease, inflammation, and fatty acid content in plasma and brain. Method: Neonatal piglets, 3–6 days old, underwent jugular catheter insertion for isonitrogenous, isocaloric PN delivery over 14 days. The IL group (n = 8) was treated with Intralipid; the ML group (n = 10) was treated with the mixed lipid (SMOFlipid). Bile flow, liver chemistry, C‐reactive protein (CRP), and PUFA content in plasma phospholipids and brain were compared. Results: Compared with the IL group, ML‐treated piglets had increased bile flow (P = .008) and lower total bilirubin (P = .001) and CRP (P = .023) concentrations. The ω‐6 long‐chain PUFA content was lower in plasma and brain for the ML group. The key ω‐3 long‐chain PUFA for neonatal development, docosahexaenoic acid (DHA), was not different between groups. Conclusion: The mixed lipid, having less ω‐6 PUFA and more ω‐3 PUFA, was able to prevent liver disease and reduce systemic inflammation in PN‐fed neonatal piglets. However, this lipid did not increase plasma or brain DHA status, which would be desirable for neonatal developmental outcomes.     

Restoration of Mannose‐Binding Lectin Complement Activity Is Associated With Improved Outcome in Patients With Advanced Pancreatic Cancer Treated With Gemcitabine and Intravenous ω‐3 Fish Oil

Background: Pancreatic cancer has an extremely poor clinical outcome. Surrogate biomarkers for outcome are scarce. There is mixed evidence for the association of high mannose‐binding lectin (MBL) complement activity with cancer outcomes, including reduced survival and increased infectious complications. ω‐3–rich fatty acids (ω‐3FA) attenuate production of proinflammatory cytokines and potentially manipulate complement activity. Materials and Methods: As part of a single‐arm phase II trial in a university hospital, patients with advanced pancreatic adenocarcinoma were treated with weekly ω‐3FA–rich intravenous infusion (Lipidem [B. Braun Melsungen AG, Melsungen, Germany]: up to 100 g/wk) plus gemcitabine chemotherapy until withdrawal or tumor progression. Primary outcome measure was objective response rate. Changes in complement activity, which were a secondary outcome measure, were analyzed and relation to clinical outcome determined. Results: Twenty‐three patients were assessable for time to progression (TTP), overall survival (OS), and complement activity. No hypoactivity in alternative and classical pathways was demonstrated. Baseline MBL was low in 10 of 23 patients (43.5%). There was no difference in OS or TTP between low‐ and high‐baseline MBL patients. Of these 10 patients, 5 were classified as MBL responders. MBL responders had a tendency toward improved OS over nonresponders (8.9 vs 4.4 months, P = .07). MBL responders had significantly improved TTP over nonresponders (10.6 vs 5.3 months, P = .03). Conclusion: MBL restoration had an association with improved outcome in the cohort of patients with low MBL activity at baseline. The independent contribution of ω‐3FA to this effect warrants further investigation in the form of randomized clinical trials.     

Year‐long Changes in Protein Metabolism in Elderly Men and Women Supplemented With a Nutrition Cocktail of β‐Hydroxy‐β‐methylbutyrate (HMB), L‐Arginine,and L‐Lysine

Background: A major contributing factor to the loss of mobility in elderly people is the gradual and continuous loss of lean body mass. Objectives: To determine whether supplementation of an amino acid cocktail daily for 1 year could improve the age‐associated changes in protein turnover and lean body mass in elderly people. Design: Elderly (76± 1.6 years) women (n = 39) and men (n = 38) were recruited for a double‐blinded controlled study. Study participants were randomly assigned to either an isonitrogenous control‐supplement (n = 37) or a treatment‐supplement (HMB/Arg/Lys) consisting of β‐hydroxy‐β‐methylbutyrate, L‐arginine, and L‐lysine (n = 40) for the 1‐year study. Lean tissue mass was measured using both bioelectrical‐impedance analysis (BIA) and dual energy x‐ray absorptiometry (DXA). Rates of whole‐body protein turnover were estimated using primed/intermittent oral doses of ¹⁵N‐glycine. Results: In subjects taking the HMB/Arg/Lys supplement, lean tissue increased over the year of study while in the control group, lean tissue did not change. Compared with control, HMB/Arg/Lys increased body cell mass (BIA) by 1.6% (P = .002) and lean mass (DXA) by 1.2% (P = .05). The rates of protein turnover were significantly increased 8% and 12% in the HMB/Arg/Lys‐supplemented group while rates of protein turnover decreased 11% and 9% in the control‐supplemented subjects (P < .01), at 3 and 12 months, respectively. Conclusions: Consumption of a simple amino acid‐related cocktail increased protein turnover and lean tissue in elderly individuals in a year‐long study.     

Parenteral but Not Enteral Omega‐3 Fatty Acids (Omegaven) Modulate Intestinal Regrowth After Massive Small Bowel Resection in Rats

Background: The purpose of the present study was to evaluate the effects of ω‐3 fatty acids (Omegaven) on early intestinal adaptation in rats with short bowel syndrome (SBS). Methods: Male Sprague‐Dawley rats were randomly assigned to 1 of 4 groups: sham rats underwent bowel transection; SBS rats underwent 75% bowel resection; SBS‐O ω‐3 rats underwent bowel resection and were treated with oral Omegaven given by gavage; and SBS‐I ω‐3 rats underwent bowel resection and were treated with Omegaven given intraperitoneally. Rats were killed on day 14. Parameters of intestinal adaptation (bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depths, cell proliferation and apoptosis) were determined at time of death. Real‐time polymerase chain reaction was used to determine the level of Bax and Bcl‐2 messenger RNA (mRNA). Statistical analysis was performed using Kruskal‐Wallis test followed by post hoc test, with P < .05 considered statistically significant. Results: Oral ω‐3 supplementation did not significantly change intestinal regrowth. In contrast, parenteral ω‐3 in rats that underwent resection resulted in higher bowel and mucosal weights, mucosal DNA and protein in ileum, villus height in ileum, crypt depth in jejunum and ileum, and greater rates of cell proliferation in jejunum and ileum compared with SBS animals. The initial decreased levels of apoptosis corresponded with the early decrease in Bax and increase in Bcl‐2 mRNA levels. Conclusions: Parenteral but not enteral Omegaven augments and accelerates structural bowel adaptation in a rat model of SBS. Increased cell proliferation and decreased apoptosis reflect increased cell turnover in Omegaven‐treated animals.     

ω-3 Fatty acids have no impact on serum lactate levels after major gastric cancer surgery

Background: Preoperative and intraoperative nutrition support in patients undergoing major surgery results in decreased incidence of morbidity and mortality. Studies investigating the role of ω‐3 fatty acids in these patients are increasing. Some are focused on perfusion at the cellular level. This study was undertaken to address the effect of postoperative administration of ω‐3 fatty acids on cellular hypoperfusion associated with major gastric surgery. Methods: Twenty‐six patients undergoing gastric cancer surgery were randomly assigned to receive parenteral nutrition (PN) supplemented with a combination of ω‐6 and ω‐3 fatty acids (Omegaven, 0.2 g/kg/d; Lipovenoes 10%, 0.6 g/kg/d) or with ω‐6 fatty acid (Lipovenoes 10%, 0.8 g/kg/d) for 5 days. Blood samples were taken preoperatively, postoperative day 1, and on the last day of PN therapy (day 5). Results: Patients receiving ω‐3 and ω‐6 fatty acids showed neither lower serum lactate levels nor lower rates of complications compared with patients receiving ω‐6 only. There were no statistically significant differences between the groups in other biochemical parameters, complications, or length of hospital stay or mortality. Conclusion: PN with ω‐3 fatty acid supplementation does not have a significant impact on cellular hypoperfusion and lactate clearance after major gastric surgery.