Effects of intravenous supplementation with alpha-tocopherol in patients receiving total parenteral nutrition containing medium- and long-chain triglycerides

n-3 Polyunsaturated Fatty Acid Supplementation Affects Oxidative Stress Marker Levels in Patients with Type II Intestinal Failure: A Randomized Double Blind Trial

Type II intestinal failure (IF-II) is a condition in which the gastrointestinal tract is compromised. Liver complications may occur because of the pathology and/or prolonged use of parenteral nutrition (PN); oxidative stress has been implicated as one of the causes. Lipid emulsions containing n-3 polyunsaturated fatty acids (PUFAs) have been proposed for the treatment. We aimed to evaluate the effect of 7-day n-3 PUFA supplementation on oxidative stress in IF-II patients receiving PN. This was a randomized, controlled, double-blinded, pilot trial of adult patients with IF-II, receiving either conventional PN (control) or PN enriched with n-3 PUFAs (intervention). Twenty patients were included (14 men, 49 ± 16.9 years), with the ANCOVA analysis the glucose (p = 0.003), and direct bilirubin (p = 0.001) levels reduced; whereas the high-density lipoprotein cholesterol (HDL-C) increased (p = 0.017). In the random-effect linear regression analysis, a reduction (p < 0.0001) in the malondialdehyde (MDA) level was found in the intervention group when the covariables age, HDL-C level, and alanine aminotransferase activity were considered. After 1 week of PN supplementation with n-3 PUFAs, the marker levels of some oxidative stress, blood lipids, and hepatic biomarkers improved in patients with IF-II.

Fat soluble vitamin status in children on home parenteral nutrition in a tertiary paediatric intestinal rehabilitation unit

BACKGROUNDS & AIMS

Children with intestinal failure on home parenteral nutrition are at risk of fat malabsorption and fat soluble vitamin deficiency. Fish oil containing mixed lipid emulsions (SMOFlipid®) with higher vitamin E content, have a theoretical risk of exceeding current recommendations for vitamin E dosing and, may influence other fat soluble vitamin status in these children. The aim of this study was to assess for fat soluble vitamin status in children on long-term home parental nutrition receiving a mixed lipid emulsion (SMOFlipid®) compared with those receiving traditional soy or soy/olive oil based (non- SMOFlipid®) lipid emulsions and whether this is influenced by the underlying cause of intestinal failure.

METHODS

Retrospective longitudinal study in a tertiary referral paediatric hospital of children on home parental nutrition during the period January 2000 to June 2019. Data was retrieved using medical and pharmacy records, laboratory database, and summarised using inferential statistics.

RESULTS

111 patients (n = 58 female) received home parental nutrition in 121 discrete episodes (range 45-5329 days). N = 61 (55%) were diagnosed with anatomical short bowel syndrome, of which necrotising enterocolitis was the most common cause (n = 14). SMOFlipid® was used exclusively in n = 79 patients, non-SMOFlipid® exclusively in n = 19, and n = 13 changed from non-SMOFlipid® to SMOFlipid® during the study period. The median vitamin E level and vitamin E:lipid ratio were significantly higher for patients on SMOFlipid® compared to non-SMOFlipid® (27.9 vs 18.3 μmol/L respectively, p < 0.001; 7.10 vs 4.00 μmol/mmol; p < 0.001). Median vitamin A level was comparable (1.19 vs 1.12 μmol/L, p = 0.241), while median vitamin D level was significantly lower in the non-SMOFlipid® group consistent with mild deficiency (63.7 vs 43.0 nmol/L, p < 0.001).

CONCLUSION

The use of SMOFlipid® correlated with higher Vitamin E level in paediatric home parental nutrition patients. Lower vitamin D level appears to correlate with the use of non-SMOFlipid®. A larger prospective cohort is required to delineate any clinical significance from these findings.

Antioxidant balance in plasma of patients on home parenteral nutrition: A pilot study comparing three different lipid emulsions

BACKGROUND & AIMS

Parenteral nutrition (PN) can supply all essential nutrients to a patient with gastrointestinal insufficiency. However, the sensitivity to lipid peroxidation might increase in those receiving PN, especially home parenteral nutrition (HPN). This study aimed to investigate whether PN affects the antioxidant balance of plasma of HPN patients without comorbidities and whether this balance is influenced by comorbidities and according to the type of lipid emulsion included in the PN.

METHODS

Adult patients on HPN (n = 86) received one of three types of lipid emulsion (based on 1) soyabean oil, 2) olive and soyabean oil or 3) soyabean, coconut, olive and fish oil) in all-in-one mixtures; in addition healthy controls (n = 66) were studied as comparators. HPN patients were classified to the following subgroups: 1) patients without (n = 58) or with (n = 28) comorbidities 2) patients on Intralipid (G_INTRA, n = 53), ClinOleic (G_CLIN, n = 17) or SMOFlipid (G_SMOFn = 16). The activities of total glutathione peroxidase (GSH-Px), selenium dependent glutathione peroxidase (Se-GSHPx) and glutathione S-transferase (GST) in plasma were determined spectrophotometrically. The antioxidant potential of plasma was determined using oxygen radical absorbance capacity (ORAC). The lipid peroxidation marker malondialdehyde (MDA) was analyzed with high performance liquid chromatography.

RESULTS

MDA concentration was the highest in G_INTRA and the lowest in G_SMOF (p < 0.05). G_SMOF also had the highest activity of GSH-Px. No differences in Se-GSHPx, GST and ORAC were observed among G_INTRA, G_CLIN and G_SMOF. Comparing with healthy controls, significantly lower GST (p = 0.0293) and ORAC (p < 0.0001) were observed in the HPN patients. Among all measured parameters only the concentration of MDA was significantly higher in patients with comorbidities compared to those without them. Comorbidities did not influence MDA level in G_INTRA and G_SMOF being still the lowest in G_SMOF (p = 0.0033). In contrast, significantly higher MDA level was observed for G_CLIN in those with vs. without comorbidities (p = 0.0262).

CONCLUSIONS

Patients on HPN have lower antioxidant defenses than healthy controls. The type of lipid emulsion used in HPN affects lipid peroxidation (even after taking into account comorbidities which often involve oxidative stress) being the highest in G_INTRA and the lowest in G_SMOF. Thus, to minimize the risk of oxidative stress, SMOFlipid can be considered in patients in HPN especially for those with comorbidities. ClinOleic can be considered in HPN patients without comorbidities. The observation should be confirmed in larger studies.

Nano-emulgel: Emerging as a Smarter Topical Lipidic Emulsion-based Nanocarrier for Skin Healthcare Applications

BACKGROUND

In recent decades, enormous efforts for different drug discovery processes have led to a number of drug molecules available today to overcome different challenges of the health care system. Unfortunately, more than half of these drugs are listed in either BCS (biopharmaceutical classification system) class II/ IV or both are eliminated from the development pipeline due to their limited clinical use. A nanotechnological approach bears much hope and lipoidal fabrication is found to be suitable for the delivery of such drugs. Nanoemulsion based gel i.e. nanoemulgel out of different nanolipoidal formulations has been found to be a suitable approach to successful drug delivery through topical routes. In past few years many herbal and synthetic active pharmaceutical ingredients (APIs) has been patented as nano sized emulsified gel for various therapeutic activities.

METHODS

Nanoemulgel is basically an emulsion-based topical gel formulation, where nanosized emulsion globules can be prepared with the help of high energy or low energy methods and further converted into nanoemulgel by adding a suitable gelling agent. Nanoemulgel fabrication enlists various kinds of polymeric materials, surfactants and fatty substances of natural, synthetic and semi-synthetic nature with a globule size range from 5 to 500 nm.

RESULTS

Nanoemulgel can be applicable to various acute and chronic diseases through topical routes.

CONCLUSION

Nanoemulgel preparations of many recently approved drugs are being used successfully in different areas of health care and have re-defined the significance of topical route of delivery as compared to other routes. However, along with various improvements in the current state of the delivery system, the safety factor needs to be taken into account by toxicological studies of the materials used in such formulations.

Lipid peroxidation: Its effects on the formulation and use of pharmaceutical emulsions

Pharmaceutical delivery systems are developed to improve the physicochemical properties of therapeutic compounds. Emulsions are one of these drug delivering systems formulated using water, oils and lipids as main ingredients. Extensive data are usually generated on the physical and chemical characteristics of these oil-in-water and lipid emulsions. However, the oxidative tendency of emulsions is often overlooked. Oxidation impacts the overall quality and safety of these pharmaceutical emulsions. Additionally, introducing oxidatively unstable emulsions into biological systems further promotes oxidation in situ. Products of these reactions then continue to pose serious harm to cells and fuel other physiological oxidation reactions. Consequently, the increase of oxidation products leads to oxidative damage to biological systems. Thus, emulsions with lower lipid peroxidation are more stable and will reduce the negative effects of oxidation in situ. Preventive measures during the formulation of emulsions are important. Many naturally occurring and cost effective substances possess low oxidation tendencies and confer oxidative protection when used in emulsions. Additionally, certain preparatory methods should be employed to reduce or better control lipid peroxidation. Finally, emulsions must be evaluated for their oxidation susceptibility using the various techniques available. Careful attention to the preparation of emulsions and assessment of their oxidative stability will help produce safer emulsions without compromising efficacy.

New Parenteral Lipid Emulsions for Clinical Use

Routine use of parenteral lipid emulsions (LE) in clinical practice began in 1961, with the development of soybean oil (SO) - based LE. Although clinically safe, experimental reports indicated that SO-based LE could exert a negative influence on immunological functions. Those findings were related to its absolute and relative excess of omega-6 polyunsaturated fatty acids (PUFA) and the low amount of omega-3 PUFA and also to its high PUFA content with an increased peroxidation risk. This motivated the development of new LE basically designed along the reduction of omega-6 PUFA and the omega-3 PUFA addition in order to obtain balanced levels of the omega-6/omega-3 ratio. The new LE for clinical use (available in Europe and South America) are differentiated by their content in polyunsaturated (omega-6 and omega-3), monounsaturated, and saturated fatty acids (FA), as well as FA source of their origin, including soy, coconut, olive, and fish oil. This article presents the new LE nutrition and energy functions but also its biochemical, metabolic, and immunomodulating aspects, according to their FA content. LE at 20% when infused from 1.0 to 2.0 g/kg body weight/day rates, either alone or in association with amino acids and glucose, are safe and well tolerated in routine clinical practice. LE combining SO with medium-chain triglycerides and/or olive oil have less omega-6 PUFA and are better metabolized, with less inflammatory and immunosuppressive effects than in relation to pure SO-based LE. The omega-3 PUFA used alone or as component of a new and complex LE (soy, MCT, olive and fish oil) has demonstrated anti-inflammatory and immunomodulatory effects.

Plasma malondialdehyde levels in children on 12-hour cyclic parenteral nutrition: are there health risks?

In children undergoing total parenteral nutrition (PN), lipids provide a key source of calories preventing or correcting energy deficits and improving outcomes. However, some of these lipids may undergo oxidation leading to the formation of malondialdehyde (MDA), a cytotoxic byproduct found in these patients. This paper aims to describe a sensitive method for detecting MDA and discuss its role in certain diseases commonly found in children on regular PN. To quantify MDA levels in children benefitting from long-term cyclic PN, a reliable and sensitive high-performance liquid chromatographic method based on a 1-step derivatization/extraction procedure analysis with ultraviolet determination at 305 nm wavelength was achieved. In control children without PN, MDA levels were on average 3.30 ± 0.08 µM. However, in children nourished intravenously by fat emulsion for a long time, in which liver problems have been identified, the circulating concentrations of MDA ranged widely at both the start and the end of a session, 3- to 10-fold, respectively, in comparison with the levels measured in controls. This finding indicates that PN administrated long term raises plasma MDA levels, indicating chronic exposure and therefore a possible health risk, particularly liver damage. This preliminary study using a limited number of patients and controls showed that children undergoing long-term PN are strongly exposed to MDA, which must be considered as a potent toxic compound rather than a simple marker of lipid peroxidation.

Fish oil emulsions in the management of intestinal failure-associated liver disease

The role of parenteral lipid emulsions in the treatment of intestinal failure-associated liver disease (IFALD) is both topical and controversial. There is strong evidence supporting plant-based (soy, olive) lipid emulsions as a key cause for IFALD, especially in neonates. As a result, alternate lipid formulations, most notably fish oil emulsions (FOE) have come into widespread use despite somewhat limited clinical data on their overall benefit and potential long-term consequences. This review examines putative mechanisms of action of FOE in reversing cholestasis associated with IFALD, and critically reviews published clinical studies of the use of FOE in pediatric patients with IFALD. From these works, it appears the mechanism of action of FOE is most likely related to the reduction of serum phytosterols associated with plant-based lipid emulsions rather than a specific positive benefit of the fish oils themselves. Although the use of FOE seems to correlate with a reduction in cholestasis, their actual individual benefit is not established, and data on long-term outcomes and safety are not yet available.

Injectable lipid emulsions-advancements, opportunities and challenges

Injectable lipid emulsions, for decades, have been clinically used as an energy source for hospitalized patients by providing essential fatty acids and vitamins. Recent interest in utilizing lipid emulsions for delivering lipid soluble therapeutic agents, intravenously, has been continuously growing due to the biocompatible nature of the lipid-based delivery systems. Advancements in the area of novel lipids (olive oil and fish oil) have opened a new area for future clinical application of lipid-based injectable delivery systems that may provide a better safety profile over traditionally used long- and medium-chain triglycerides to critically ill patients. Formulation components and process parameters play critical role in the success of lipid injectable emulsions as drug delivery vehicles and hence need to be well integrated in the formulation development strategies. Physico-chemical properties of active therapeutic agents significantly impact pharmacokinetics and tissue disposition following intravenous administration of drug-containing lipid emulsion and hence need special attention while selecting such delivery vehicles. In summary, this review provides a broad overview of recent advancements in the field of novel lipids, opportunities for intravenous drug delivery, and challenges associated with injectable lipid emulsions.

Lipid emulsions in parenteral nutrition of intensive care patients: current thinking and future directions

Background

Energy deficit is a common and serious problem in intensive care units and is associated with increased rates of complications, length of stay, and mortality. Parenteral nutrition (PN), either alone or in combination with enteral nutrition, can improve nutrient delivery to critically ill patients. Lipids provide a key source of calories within PN formulations, preventing or correcting energy deficits and improving outcomes.

Discussion

In this article, we review the role of parenteral lipid emulsions (LEs) in the management of critically ill patients and highlight important biologic activities associated with lipids. Soybean-oil-based LEs with high contents of polyunsaturated fatty acids (PUFA) were the first widely used formulations in the intensive care setting. However, they may be associated with increased rates of infection and lipid peroxidation, which can exacerbate oxidative stress. More recently developed parenteral LEs employ partial substitution of soybean oil with oils providing medium-chain triglycerides, ω-9 monounsaturated fatty acids or ω-3 PUFA. Many of these LEs have demonstrated reduced effects on oxidative stress, immune responses, and inflammation. However, the effects of these LEs on clinical outcomes have not been extensively evaluated.

Conclusions

Ongoing research using adequately designed and well-controlled studies that characterize the biologic properties of LEs should assist clinicians in selecting LEs within the critical care setting. Prescription of PN containing LEs should be based on available clinical data, while considering the individual patient’s physiologic profile and therapeutic requirements.

Neonatology/Paediatrics - Guidelines on Parenteral Nutrition, Chapter 13

There are special challenges in implementing parenteral nutrition (PN) in paediatric patients, which arises from the wide range of patients, ranging from extremely premature infants up to teenagers weighing up to and over 100 kg, and their varying substrate requirements. Age and maturity-related changes of the metabolism and fluid and nutrient requirements must be taken into consideration along with the clinical situation during which PN is applied. The indication, the procedure as well as the intake of fluid and substrates are very different to that known in PN-practice in adult patients, e.g. the fluid, nutrient and energy needs of premature infants and newborns per kg body weight are markedly higher than of older paediatric and adult patients. Premature infants <35 weeks of pregnancy and most sick term infants usually require full or partial PN. In neonates the actual amount of PN administered must be calculated (not estimated). Enteral nutrition should be gradually introduced and should replace PN as quickly as possible in order to minimise any side-effects from exposure to PN. Inadequate substrate intake in early infancy can cause long-term detrimental effects in terms of metabolic programming of the risk of illness in later life. If energy and nutrient demands in children and adolescents cannot be met through enteral nutrition, partial or total PN should be considered within 7 days or less depending on the nutritional state and clinical conditions.

Lipid emulsions - Guidelines on Parenteral Nutrition, Chapter 6

The infusion of lipid emulsions allows a high energy supply, facilitates the prevention of high glucose infusion rates and is indispensable for the supply with essential fatty acids. The administration of lipid emulsions is recommended within ≤7 days after starting PN (parenteral nutrition) to avoid deficiency of essential fatty acids. Low-fat PN with a high glucose intake increases the risk of hyperglycaemia. In parenterally fed patients with a tendency to hyperglycaemia, an increase in the lipid-glucose ratio should be considered. In critically ill patients the glucose infusion should not exceed 50% of energy intake. The use of lipid emulsions with a low phospholipid/triglyceride ratio is recommended and should be provided with the usual PN to prevent depletion of essential fatty acids, lower the risk of hyperglycaemia, and prevent hepatic steatosis. Biologically active vitamin E (α-tocopherol) should continuously be administered along with lipid emulsions to reduce lipid peroxidation. Parenteral lipids should provide about 25–40% of the parenteral non-protein energy supply. In certain situations (i.e. critically ill, respiratory insufficiency) a lipid intake of up to 50 or 60% of non-protein energy may be reasonable. The recommended daily dose for parenteral lipids in adults is 0.7–1.3 g triglycerides/kg body weight. Serum triglyceride concentrations should be monitored regularly with dosage reduction at levels >400 mg/dl (>4.6 mmol/l) and interruption of lipid infusion at levels >1000 mg/dl (>11.4 mmol/l). There is little evidence at this time that the choice of different available lipid emulsions affects clinical endpoints.

Prospective analysis of serum carotenoids, vitamin A, and tocopherols in adults with short bowel syndrome undergoing intestinal rehabilitation

OBJECTIVE

Carotenoids, vitamin A, and tocopherols serve important roles in many key body functions. However, availability of these compounds may be decreased in patients with short bowel syndrome (SBS) due to decreased oral intake of fruits and vegetables and/or decreased intestinal absorption. Little information is available on serum concentrations of carotenoids, vitamin A, and tocopherols during chronic parenteral nutrition (PN) or during PN weaning. The aim of this study was to prospectively examine serum concentrations of a wide variety of carotenoids, vitamin A, and tocopherols in patients with SBS undergoing an intensive 12-wk intestinal rehabilitation program.

METHODS

Twenty-one PN-dependent adult patients with SBS were enrolled in a 12-wk intestinal rehabilitation program, which included individualized dietary modification, multivitamin supplementation, and randomization to receive subcutaneous placebo (n = 9) or human growth hormone (0.1 mg . kg(-1) . d(-1); n = 12). PN weaning was initiated after week 4 and advanced as tolerated. Serum concentrations of carotenoids, vitamin A, and tocopherols were determined at baseline and at weeks 4 and 12.

RESULTS

A significant percentage of subjects exhibited low serum concentrations for carotenoids and alpha-tocopherol at study entry, and a few subjects had low concentrations of retinol (5%). Carotenoid and vitamin A valves did not improve over time, while alpha-tocopherol levels rose. Serum alpha-tocopherol concentration was negatively associated with PN lipid dose (r = -0.34, P < 0.008).

CONCLUSION

Patients with SBS are depleted in diet-derived carotenoids despite oral and intravenous multivitamin supplementation and dietary adjustment during intestinal rehabilitation and PN weaning. Reduction of PN lipid infusion may improve serum alpha-tocopherol concentrations.

No evidence for oxidative stress in patients on home parenteral nutrition

BACKGROUND & AIMS

Patients on total parenteral nutrition depend on the composition of the nutritional formulation for maintenance of their oxidant-antioxidant balance. The present observational study was conducted to evaluate a substantial part of our patient population for evidence of oxidative stress.

METHODS

Venous blood samples were obtained from 41 patients on home parenteral nutrition (HPN) and 41 healthy controls. Glutathione in plasma and whole blood, glutathione peroxidase and superoxide dismutase in erythrocytes and total plasma antioxidant capacity were measured to assess the antioxidant status. Oxidant status was evaluated by measuring the production of reactive oxygen species by leukocytes. Oxidative damage was assessed by measuring lipid peroxidation and protein oxidation products.

RESULTS

Patients on HPN showed some signs of increased oxidative stress, however, there were no signs for oxidative damage, compared with healthy controls. In addition, activity of any underlying disease was not associated with increased oxidative stress.

CONCLUSIONS

The current treatment regime for patients on HPN at our center apparently prevents the development of significant oxidative damage, despite signs of some oxidative stress. Based on these data, adaptations in the composition of parenteral nutritional formulations do not seem mandatory.

Pilot study on the effect of parenteral vitamin E on ischemia and reperfusion induced liver injury: a double blind, randomized, placebo-controlled trial

BACKGROUND AND AIMS

Liver surgery usually involves ischemia and reperfusion (I/R) which results in oxidative stress and cell damage. The administration of antioxidants should diminish or prevent this damage. The purpose of this study was to investigate the effect of the antioxidant vitamin E on I/R injury.

METHODS

We carried out a placebo-controlled double-blind study on 68 patients undergoing elective, tumor-related, partial liver resection. 47 patients were qualified for the per protocol population based evaluation. The patients were randomly assigned to two groups. The day before surgery one group received three infusions containing vitamin E (600 IU=540 mg vitamin E emulsion). The other group received three infusions of placebo.

RESULTS

Length of stay in the intensive care unit (ICU) was significantly shorter in the verum group than in the placebo group (P<0.05). There were signs of improvement for AUC AST (P<0.05), ALT and GLDH in the verum group after surgery. Serum vitamin E concentration increased after administration of vitamin E infusion and declined in both treatment groups after surgery (P<0.01). In the verum group vitamin E deficiency was prevented while vitamin E concentration remained low in the placebo group (P<0.01).

CONCLUSIONS

The findings from this study indicate that preoperative administration of vitamin E is safe and that this treatment may have beneficial effects by reducing the impact of I/R injury in liver surgery.

Vitamin E: absorption, plasma transport and cell uptake

PURPOSE OF REVIEW

Large-scale clinical trials have failed to demonstrate a benefit for vitamin E supplementation in cardiovascular prevention. This contrasts with previous epidemiological studies indicating that individuals with high vitamin E status benefit from protection against chronic illnesses, including cardiovascular diseases. These conflicting results suggest that the metabolism of supplemental versus naturally delivered vitamin E and their potential roles, other than a potent antioxidant action, are not fully understood. The purpose of this review is to provide an update on current knowledge on the intestinal absorption of vitamin E, its plasma transport and its supply to cells. The review will also discuss the intravascular metabolism of intravenously delivered vitamin E.

RECENT FINDINGS

Although the luminal digestion of vitamin E is fairly well understood, several pathways regulating net vitamin E absorption remain to be elucidated. In several cell types, cholesterol and vitamin E share common mechanisms for cellular uptake (scavenger receptor B type I and LDL receptors) and efflux (ABCA1 transporters). The role of specific binding proteins in alpha-tocopherol intracellular trafficking is increasingly being understood, leading to new insights into the non-antioxidant functions of vitamin E.

SUMMARY

Substantial progress has been made in characterizing the plasma transport of vitamin E and its delivery to cells. Mechanisms regulating the balance between the cellular uptake and efflux of vitamin E are under investigation. Vitamin E is not only an antioxidant but may also modulate pathways of cell signalling and gene expression. The translation of this new knowledge into clinical studies will help define future indications for vitamin E supplementation.