The novel lipid emulsion Vegaven is well tolerated and elicits distinct biological actions compared with a mixed-oil lipid emulsion containing fish oil:a parenteral nutrition trial in piglets

BACKGROUND

Vegaven is a novel lipid emulsion for parenteral nutrition (PN) based on 18-carbon n-3 fatty acids, which elicits liver protection via interleukin-10 (IL10) in the murine model of PN.

OBJECTIVE

In a preclinical model of PN in neonatal piglets, Vegaven was tested for efficacy and safety and compared with a mixed-oil lipid emulsion containing fish-oil (SMOFlipid).

METHODS

4-5-day-old male piglets were randomly allocated to isocaloric isonitrogenous PN for 14 days that varied only by the type of lipid emulsion (Vegaven, N=8; SMOFlipid, N=8). Hepatic IL10 tissue concentration served as primary outcome. Secondary outcomes were organ weights, bile flow, blood analyses, plasma insulin and glucagon concentrations, insulin signaling, proinflammatory cytokines, tissue lipopolysaccharide concentrations, and fatty acid composition of phospholipid fractions in plasma, liver, and brain.

RESULTS

Total weight gain on trial, organ weights, and bile flow were similar between the Vegaven and the SMOFlipid group. Vegaven elicited higher hepatic IL10 (Δ=148 pg/mg protein, p<0.001) and insulin receptor substrate-2 levels (Δ=0.08 O.D., p=0.012). Plasma insulin concentrations (Δ=1.46 mU/L, p=0.003) and fructosamine (glycated albumin, Δ=12.4 μmol/g protein, p=0.003) were increased in SMOFlipid as compared with Vegaven group, indicating insulin resistance. Higher hepatic injury markers were observed more frequently in the SMOFlipid group compared with the Vegaven group. Lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-6 were increased in pancreatic and brain tissues of SMOFlipid- vs Vegaven-treated piglets. Insulin signaling was reduced in the brains of SMOFlipid-treated piglets. Vegaven and SMOFlipid elicited distinct fatty acid profiles in the phospholipid fractions of the rapidly growing brains, but showed similar accretion of docosahexaenoic acid and arachidonic acid after two weeks of PN.

CONCLUSIONS

Vegaven was well tolerated in this piglet model of PN and demonstrated distinct biological actions compared with SMOFlipid, namely lower liver, pancreas, and brain inflammation, enhanced insulin signaling, and improved whole-body glucose control.

Pig Models in Retinal Research and Retinal Disease

The pig has been used as a large animal model in biomedical research for many years and its use continues to increase because induced mutations phenocopy several inherited human diseases. In addition, they are continuous breeders, can be propagated by artificial insemination, have large litter sizes (on the order of mice), and can be genetically manipulated using all of the techniques that are currently available in mice. The pioneering work of Petters and colleagues set the stage for the use of the pig as a model of inherited retinal disease. In the last 10 years, the pig has become a model of choice where specific disease-causing mutations that are not phenocopied in rodents need to be studied and therapeutic approaches explored. The pig is not only used for retinal eye disease but also for the study of the cornea and lens. This review attempts to show how broad the use of the pig has become and how it has contributed to the assessment of treatments for eye disease. In the last 10 years, there have been several reviews that included the use of the pig in biomedical research (see body of the review) that included information about retinal disease. None directly discuss the use of the pig as an animal model for retinal diseases, including inherited diseases, where a single genetic mutation has been identified or for multifactorial diseases such as glaucoma and diabetic retinopathy. Although the pig is used to explore diseases of the cornea and lens, this review focuses on how and why the pig, as a large animal model, is useful for research in neural retinal disease and its treatment.

In parenteral nutrition-fed piglets, fatty acids vary by lipid emulsion and tissue sampled

BACKGROUND

Children with intestinal failure without liver disease may be given soy-based lipid emulsion (SLE) or mixed lipid emulsion (MLE; containing soy, medium-chain triglyceride, olive, and/or fish oils). Both differ in essential fatty acid content: MLE has added arachidonic acid (AA) and docosahexaenoic acid (DHA). The aim of this study, in neonatal piglets, was to compare serum and tissue fatty acid composition when the emulsions were given at unrestricted doses.

METHODS

We compared SLE (n = 15) and MLE (n = 15) at doses of 10-15 g/kg/day in parenteral nutrition (PN). On day 14 we collected serum and tissues. Using gas-liquid chromatography, percentage fatty acids were measured in serum, brain, and liver phospholipid. Comparisons were made to reference values from litter-matched controls (n = 8).

RESULTS

Comparing median values, linoleic acid (LA) was lower for MLE vs SLE in serum (-27%), liver (-45%), and brain (-33%) (P < 0.001). AA was lower for MLE in serum (-25%), liver (-40%), and brain (-10%). DHA was higher for MLE in serum (+50%), liver (+200%), and brain (+10%). AA levels were lower for MLE vs control piglets in serum (-81%), liver (-63%), and brain (-9%). DHA levels were higher in serum (+41%), liver (+38%), and brain (+19%).

CONCLUSION

This study in piglets has shown that, at unrestricted doses, MLE treatment is associated with low serum and tissue AA compared with SLE and healthy litter-matched controls. Although not yet proven, low tissue AA levels may have functional consequences, and these data support current practice avoiding MLE dose restriction.

Use of aromatic root vegetables in the technology of freshwater fish preserves

The expediency of using freshwater fish and aromatic root vegetables in the technology of preserves has been substantiated. Based on the organoleptic analysis, the compatibility of freshwater fish and aromatic vegetables as part of preserves has been determined. The conditions for pretreatment of salted semi-finished products to ensure their maturation as part of preserves have been theoretically substantiated and experimentally determined. It has been found that pretreatment of freshwater fish flesh with 1.0% and 1.5% malic acid for 60 minutes provides soft, tender and juicy consistency, which corresponds to an organoleptic rating of 5 points. Changes in the fatty acid composition of preserves are mainly associated with an increase in the amount of polyunsaturated fatty acids that have been introduced with linseed oil, which is a positive factor. It has been found that, in comparison with the control sample, the level of all mineral elements in preserves with aromatic root vegetables is significantly increased, with fiber present, which indicates the expediency of introducing aromatic root vegetables into this product to enrich it with essential mineral and carbohydrate elements to obtain a high-value and healthy food product. Enriching the formulation of preserves made of freshwater fish with a variety of herbal additives increases their nutritional value and allows to get a product of high value enriched with such vital nutrients as carbohydrates, calcium, potassium, phosphorus, sulfur, sodium, magnesium, manganese, and iron. Aromatic root vegetables such as horseradish, parsley, and ginger have been found to exhibit antiseptic properties and delay the activity of microbial enzymes as they content phenol. Therefore, the use of aromatic root vegetables helps to inhibit the oxidation and hydrolysis of fats, which may be due to the presence of phenols in their composition.

Mixed Lipid, Fish Oil, and Soybean Oil Parenteral Lipids Impact Cholestasis, Hepatic Phytosterol, and Lipid Composition

OBJECTIVES

In parenteral nutrition-dependent infants and children, intestinal failure (IF)-associated liver disease (IFALD) remains an important problem. A comparative study was undertaken of parenteral mixed lipid (ML), ω-3 predominant fish oil (FO), and ω-6 predominant soybean oil (SO) emulsions in regards to hepatic phytosterol, neutral lipid, fatty acid (FA) content, and the relationship to cholestasis in piglets.

METHODS

Neonatal piglets received parenteral nutrition, varying in lipid dose (5 or 10 g· kg · day) and formulation: SO5 (n = 5), SO10 (n = 5), FO5 (n = 5), and ML10 (n = 5). On day 14, liver chemistry, bile flow, histology and neutral lipid staining were assessed. Hepatic triglyceride FA content was determined using thin layer and gas chromatography, and phytosterol content was assessed using gas chromatography-mass spectrometry.

RESULTS

SO groups had higher prevalence of biochemical cholestasis (P < 0.04) and lower bile flow (P < 0.0001). Hepatic campesterol, stigmasterol, and β-sitosterol were highest in SO10 (P < 0.0001). Hepatic FA (P < 0.03) and ω-6/ω-3 FA ratio (P < 0.0001) were higher in the SO groups. Neutral lipid accumulation (P = 0.3) and liver histology (P = 0.16) were not different between groups. Univariate predictors of bile flow were: campesterol (r = -0.77, P = 0.001), β-sitosterol (r = -0.74, P = 0.002), stigmasterol (r = -0.74, P = 0.002), ω-6 FA (r = -0.72, P = 0.002), and ω-3 FA (r = 0.59, P = 0.02). Only campesterol independently predicted bile flow.

CONCLUSIONS

ML and FO lipid emulsions reduce cholestasis in association with lowered hepatic phytosterol and lipid content. Lower hepatic phytosterol and ω-6 FA content, and higher ω-3 FA content are hepatoprotective. Multivariate analysis suggests reduced phytosterol accumulation may best explain the hepatoprotective effect of fish oil-containing lipids.