Glutamine supplementation in sick children: is it beneficial?

Impact of Dietary Protein on the Management of Pediatric Short Bowel Syndrome

Essential amino acids (AAs) play a key role in stimulating intestinal adaptation after massive small gut resection. The nutritional effect of dietary amino acids during intestinal regrowth has received considerable attention in recent years. This review explores the significance of dietary amino acids in the nutritional management of infants and children with intestinal failure and short bowel syndrome (SBS) as reported in the medical literature over the last three decades. A literature search was conducted using electronic databases. Breast milk emerged as the first-line enteral regimen recommended for infants with SBS. Hydrolyzed formulas (HFs) or amino acid formulas (AAFs) are recommended when breast milk is not available or if the infant cannot tolerate whole protein milk. The superiority of AAFs over HFs has never been demonstrated. Although glutamine (GLN) is the main fuel for enterocytes, GLN supplementation in infants with SBS showed no difference in the child's dependence upon parenteral nutrition (PN). Circulating citrulline is considered a major determinant of survival and nutritional prognosis of SBS patients. Early enteral nutrition and dietary supplementation of AAs following bowel resection in children are essential for the development of intestinal adaptation, thereby eliminating the need for PN.

The influence of nutrition on white matter development in preterm infants: a scoping review

White matter (WM) injury is the most common type of brain injury in preterm infants and is associated with impaired neurodevelopmental outcome (NDO). Currently, there are no treatments for WM injury, but optimal nutrition during early preterm life may support WM development. The main aim of this scoping review was to assess the influence of early postnatal nutrition on WM development in preterm infants. Searches were performed in PubMed, EMBASE, and COCHRANE on September 2022. Inclusion criteria were assessment of preterm infants, nutritional intake before 1 month corrected age, and WM outcome. Methods were congruent with the PRISMA-ScR checklist. Thirty-two articles were included. Negative associations were found between longer parenteral feeding duration and WM development, although likely confounded by illness. Positive associations between macronutrient, energy, and human milk intake and WM development were common, especially when fed enterally. Results on fatty acid and glutamine supplementation remained inconclusive. Significant associations were most often detected at the microstructural level using diffusion magnetic resonance imaging. Optimizing postnatal nutrition can positively influence WM development and subsequent NDO in preterm infants, but more controlled intervention studies using quantitative neuroimaging are needed. IMPACT: White matter brain injury is common in preterm infants and associated with impaired neurodevelopmental outcome. Optimizing postnatal nutrition can positively influence white matter development and subsequent neurodevelopmental outcome in preterm infants. More studies are needed, using quantitative neuroimaging techniques and interventional designs controlling for confounders, to define optimal nutritional intakes in preterm infants.

Antioxidant-Rich Nutraceutical as a Therapeutic Strategy for Sickle Cell Disease

Sickle cell disease (SCD) is a genetically inherited disease in which the "SS" individual possesses two copies of the abnormal beta-globin gene. This disease is one of the most dominant genetic diseases in the world. SCD is marked by the propensity of red cell hemoglobin to polymerize and distort the red cell from a biconcave disk shape into a sickle shape, resulting in a typical vaso-occlusive episode and accelerated hemolysis. Plants are rich sources of bioactive compounds that are promising anti-sickling agents to scavenge free radicals, thereby ensuring oxidative balance. The current review highlights the potential therapeutic benefits of antioxidant-rich nutraceutical in the treatment and management of sickle cell disease. The anti-sickling potential of nutraceutical is attributed to the presence of antioxidant bioactive chemicals such as alkaloids, polyphenols, vitamins, and minerals, which acts as scavengers of free radicals that prevent oxidative damage of the hemoglobin and prevent hemolysis, facilitating longer erythrocyte lifespan. The challenges of current therapies for SCD and future directions are also discussed.KEY TEACHING POINTSSickle cell disease is a genetically inherited disease in which SS individuals possess two copies of the abnormal beta-globin gene.Oxidative stress contributes to the pathophysiology of secondary dysfunction in sickle cell patients.Antioxidants can play a vital role in maintaining a balance between oxidant and antioxidant defense systems.Nutraceutical rich in antioxidants such as alkaloids, polyphenols, vitamins, and minerals is potential therapeutic agents for sickle cell disease.An antioxidant-rich nutraceutical may act to reduce vaso-occlusive crises.

In utero Therapy for the Treatment of Sickle Cell Disease: Taking Advantage of the Fetal Immune System

Sickle Cell Disease (SCD) is an autosomal recessive disorder resulting from a β-globin gene missense mutation and is among the most prevalent severe monogenic disorders worldwide. Haematopoietic stem cell transplantation remains the only curative option for the disease, as most management options focus solely on symptom control. Progress in prenatal diagnosis and fetal therapeutic intervention raises the possibility of in utero treatment. SCD can be diagnosed prenatally in high-risk patients using chorionic villus sampling. Among the possible prenatal treatments, in utero stem cell transplantation (IUSCT) shows the most promise. IUSCT is a non-myeloablative, non-immunosuppressive alternative conferring various unique advantages and may also offer safer postnatal management. Fetal immunologic immaturity could allow engraftment of allogeneic cells before fetal immune system maturation, donor-specific tolerance and lifelong chimerism. In this review, we will discuss SCD, screening and current treatments. We will present the therapeutic rationale for IUSCT, examine the early experimental work and initial human experience, as well as consider primary barriers of clinically implementing IUSCT and the promising approaches to address them.

Effect of amino-acid intake on physical conditions and skin state: a randomized, double-blind, placebo-controlled, crossover trial

The objective of this study is to elucidate the effect of a supplement enriched with l-leucine, l-arginine, and l-glutamine on body compositions/skin conditions. Healthy young women (n = 29) were allocated to a group (n = 14) receiving an amino-acid supplement (600 mg l-leucine, 250 mg l-arginine, and 300 mg l-glutamine) and a placebo group (n = 15) receiving a supplement not-containing the amino acids. The amino-acid supplement and placebo were given twice/day for 6 weeks. After a wash-out (2 months) from the 1st test, the amino-acid group received the placebo and the placebo group the amino-acid supplement. The body compositions/skin conditions were measured 4 times (day 1 and weeks 2, 4, and 6) in each test. Percentage-change of muscle mass in the amino-acid group increased up to 4 weeks (p = 0.05) and was higher than that in the placebo group (p = 0.09). Skin texture estimated by the image processing of neck skin replica tended to increase in the amino-acid group at 6 weeks compared with that at 0 week, though there was no significant intergroup difference. In conclusion, the young adult women having no fitness habit showed the significant increase of the muscle amount and improvement tendency of the skin texture by the continuous intake of the amino-acid supplement.

A Phase 3 Trial of l-Glutamine in Sickle Cell Disease

BACKGROUND

Oxidative stress contributes to the complex pathophysiology of sickle cell disease. Oral therapy with pharmaceutical-grade l-glutamine (USAN, glutamine) has been shown to increase the proportion of the reduced form of nicotinamide adenine dinucleotides in sickle cell erythrocytes, which probably reduces oxidative stress and could result in fewer episodes of sickle cell-related pain.

METHODS

In a multicenter, randomized, placebo-controlled, double-blind, phase 3 trial, we tested the efficacy of pharmaceutical-grade l-glutamine (0.3 g per kilogram of body weight per dose) administered twice daily by mouth, as compared with placebo, in reducing the incidence of pain crises among patients with sickle cell anemia or sickle β⁰-thalassemia and a history of two or more pain crises during the previous year. Patients who were receiving hydroxyurea at a dose that had been stable for at least 3 months before screening continued that therapy through the 48-week treatment period.

RESULTS

A total of 230 patients (age range, 5 to 58 years; 53.9% female) were randomly assigned, in a 2:1 ratio, to receive l-glutamine (152 patients) or placebo (78 patients). The patients in the l-glutamine group had significantly fewer pain crises than those in the placebo group (P=0.005), with a median of 3.0 in the l-glutamine group and 4.0 in the placebo group. Fewer hospitalizations occurred in the l-glutamine group than in the placebo group (P=0.005), with a median of 2.0 in the l-glutamine group and 3.0 in the placebo group. Two thirds of the patients in both trial groups received concomitant hydroxyurea. Low-grade nausea, noncardiac chest pain, fatigue, and musculoskeletal pain occurred more frequently in the l-glutamine group than in the placebo group.

CONCLUSIONS

Among children and adults with sickle cell anemia, the median number of pain crises over 48 weeks was lower among those who received oral therapy with l-glutamine, administered alone or with hydroxyurea, than among those who received placebo, with or without hydroxyurea. (Funded by Emmaus Medical; ClinicalTrials.gov number, NCT01179217 .).

Insights into the pharmaceuticals and mechanisms of neurological orphan diseases: Current Status and future expectations

Several rare or orphan diseases have been characterized that singly affect low numbers of people, but cumulatively reach ∼6%-10% of the population in Europe and in the United States. Human genetics has shown to be broadly effective when evaluating subjacent genetic defects such as orphan genetic diseases, but on the other hand, a modest progress has been achieved toward comprehending the molecular pathologies and designing new therapies. Chemical genetics, placed at the interface of chemistry and genetics, could be employed to understand the molecular mechanisms of subjacent illnesses and for the discovery of new remediation processes. This review debates current progress in chemical genetics, and how a variety of compounds and reaction mechanisms can be used to study and ultimately treat rare genetic diseases. We focus here on a study involving Amyotrophic lateral sclerosis (ALS), Duchenne Muscular Dystrophy (DMD), Spinal muscular atrophy (SMA) and Familial Amyloid Polyneuropathy (FAP), approaching different treatment methods and the reaction mechanisms of several compounds, trying to elucidate new routes capable of assisting in the treatment profile.

l-Glutamine for sickle cell anemia: more questions than answers

In 2017, the Food and Drug Administration approved 2 medications for sickle cell anemia (SCA): hydroxyurea for children and l-glutamine for children and adults. The approval of hydroxyurea was long overdue, but the approval of l-glutamine was a surprise to many. Any effective new treatment for SCA is a welcome advance, but there are few published studies of l-glutamine as a specific treatment for SCA. Accordingly, there are many unanswered questions about its efficacy, safety, and role in current therapy.

Metabogenic and Nutriceutical Approaches to Address Energy Dysregulation and Skeletal Muscle Wasting in Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is a fatal genetic muscle wasting disease with no current cure. A prominent, yet poorly treated feature of dystrophic muscle is the dysregulation of energy homeostasis which may be associated with intrinsic defects in key energy systems and promote muscle wasting. As such, supplementative nutriceuticals that target and augment the bioenergetical expansion of the metabolic pathways involved in cellular energy production have been widely investigated for their therapeutic efficacy in the treatment of DMD. We describe the metabolic nuances of dystrophin-deficient skeletal muscle and review the potential of various metabogenic and nutriceutical compounds to ameliorate the pathological and clinical progression of the disease.

Glutaminase activity determines cytotoxicity of L-asparaginases on most leukemia cell lines

L-Asparaginase (ASNase) is a front-line chemotherapy for acute lymphoblastic leukemia (ALL), which acts by deaminating asparagine and glutamine. To evaluate the importance of glutaminase activity, we exploited a recently developed mutant of Helicobacter pylori ASNase (dm HpA), with amino acid substitutions M121C/T169M. The mutant form has the same asparaginase activity as wild-type but lacks glutaminase activity. Wild-type and dm HpA were compared with the clinically used ASNases from Escherichia coli (l-ASP) and Erwinia chrysanthemi (ERWase). Asparaginase activity was similar for all isoforms, while glutaminase activity followed the rank order: ERWase>l-ASP>wild-type HpA>dm HpA. Cytotoxic efficacy of ASNases was tested on 11 human leukemia cell lines and two patient-derived ALL samples. Two cell lines which we had previously shown to be asparagine-dependent were equally sensitive to the asparaginase isoforms. The other nine lines and the two patient-derived samples were more sensitive to isoforms with higher glutaminase activities. ERWase was overall the most effective ASNase on all cell lines tested whereas dm HpA, having the lowest glutaminase activity, was the least effective. These data demonstrate that asparaginase activity alone may not be sufficient for ASNase cytotoxicity, and that glutaminase activity may be required for full anti-leukemic efficacy.

The need for evidence based nutritional guidelines for pediatric acute lymphoblastic leukemia patients: acute and long-term following treatment

High survival rates for pediatric leukemia are very promising. With regard to treatment, children tend to be able to withstand a more aggressive treatment protocol than adults. The differences in both treatment modalities and outcomes between children and adults make extrapolation of adult studies to children inappropriate. The higher success is associated with a significant number of children experiencing nutrition-related adverse effects both in the short and long term after treatment. Specific treatment protocols have been shown to deplete nutrient levels, in particular antioxidants. The optimal nutrition prescription during, after and long-term following cancer treatment is unknown. This review article will provide an overview of the known physiologic processes of pediatric leukemia and how they contribute to the complexity of performing nutritional assessment in this population. It will also discuss known nutrition-related consequences, both short and long term in pediatric leukemia patients. Since specific antioxidants have been shown to be depleted as a consequence of therapy, the role of oxidative stress in the pediatric leukemia population will also be explored. More pediatric studies are needed to develop evidence based therapeutic interventions for nutritional complications of leukemia and its treatment.

Dietary glutamine supplementation prevents mucosal injury and modulates intestinal epithelial restitution following acetic acid induced intestinal injury in rats

Beneficial effects of glutamine (GLN) have been described in many gastrointestinal disorders. The aim of the present study was to evaluate the preventative effect of oral GLN supplementation against acetic acid (AA) induced intestinal injury in a rat. Male Sprague-Dawley rats were divided into four experimental groups: control (CONTR) rats underwent laparotomy, control-glutamine (CONTR-GLN) rats were treated with enteral glutamine given in drinking water (2%) 48 hours before and five days following laparotomy, AA rats underwent laparotomy and injection of AA into an isolated jejunal loop, and acetic acid-glutamine (AA-GLN) rats underwent AA-induced injury and were treated with enteral GLN 48 hours before and 5 days following laparotomy. Intestinal mucosal damage (Park's injury score), mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined five days following intestinal injury. Western blotting was used to determine p-ERK and bax protein levels. AA-induced intestinal injury resulted in a significantly increased intestinal injury score with concomitant inhibition of cell turnover (reduced proliferation and enhanced apoptosis). Treatment with dietary GLN supplementation resulted in a decreased intestinal injury score with concomitant stimulation of cell turnover (enhanced proliferation and reduced apoptosis). In conclusion, pre-treatment with oral GLN prevents mucosal injury and improves intestinal recovery following AA-induced intestinal injury in rats.

Plasma arginine levels and blood glucose control in very preterm infants receiving 2 different parenteral nutrition regimens

BACKGROUND

Improving parenteral nutrition (PN) amino acid (AA) intake in very preterm infants is associated with less hyperglycemia. AAs stimulate newborn insulin secretion with arginine, demonstrating a specific effect. We hypothesized that low arginine levels would be associated with increased insulin-treated hyperglycemia and higher mean daily blood glucose levels in very preterm infants.

METHODS

We performed a secondary analysis on previous study data comparing high-protein/calorie PN (HPC-PN) and control groups in infants <29 weeks' gestation. Infants were substratified (within original groups) according to high (highARG) and low (lowARG) plasma arginine levels on days 8-10 using a reference population-derived threshold for high/low arginine (57 µmol/L). Daily protein, arginine, carbohydrate intake, mean daily blood glucose, and insulin treatment data from the first 15 days of life were collected.

RESULTS

Control group infants (n = 60) were stratified into lowARG (n = 41) and highARG (n = 19) groups. There were no differences in basic demographic data or carbohydrate intake. LowARG infants had higher mean daily blood glucose levels ( P .05) and a trend to more insulin treatment on days 610. HPC-PN group infants (n = 55) were stratified into lowARG (n = 33) and highARG (n = 22) GROUPS. LowARG infants had lower gestation and birth weight and were sicker than highARG infants. There were no differences in carbohydrate intake. LowARG infants had higher mean daily blood glucose levels (p .01) and more insulin treatment (p .01) on days 15 and 610. Insulin-treated hyperglycemia was also associated with low plasma glutamine levels.

CONCLUSION

Low plasma arginine levels (≤57 µmol/L) in very preterm infants are associated with poorer blood glucose control.

Glutamine randomized studies in early life: the unsolved riddle of experimental and clinical studies

Glutamine may have benefits during immaturity or critical illness in early life but its effects on outcome end hardpoints are controversial. Our aim was to review randomized studies on glutamine supplementation in pups, infants, and children examining whether glutamine affects outcome. Experimental work has proposed various mechanisms of glutamine action but none of the randomized studies in early life showed any effect on mortality and only a few showed some effect on inflammatory response, organ function, and a trend for infection control. Although apparently safe in animal models (pups), premature infants, and critically ill children, glutamine supplementation does not reduce mortality or late onset sepsis, and its routine use cannot be recommended in these sensitive populations. Large prospectively stratified trials are needed to better define the crucial interrelations of “glutamine-heat shock proteins-stress response” in critical illness and to identify the specific subgroups of premature neonates and critically ill infants or children who may have a greater need for glutamine and who may eventually benefit from its supplementation. The methodological problems noted in the reviewed randomized experimental and clinical trials should be seriously considered in any future well-designed large blinded randomized controlled trial involving glutamine supplementation in critical illness.

Effect of L-arginine supplement on liver regeneration after partial hepatectomy in rats

Background

Nitric oxide (NO) has been reported to be a key mediator in hepatocyte proliferation during liver regeneration. NO is the oxidative metabolite of L-arginine, and is produced by a family of enzymes, collective termed nitric oxide synthase (NOS). Thus, administration of L-arginine might enhance liver regeneration after a hepatectomy. Another amino acid, L-glutamine, which plays an important role in catabolic states and is a crucial factor in various cellular and organ functions, is widely known to enhance liver regeneration experimentally. Thus, the present study was undertaken to evaluate the effects of an L-arginine supplement on liver regeneration, and to compared this with supplementation with L-glutamine and L-alanine (the latter as a negative control), using a rat partial hepatectomy model.

Methods

Before and after a 70% hepatectomy, rats received one of three amino acid solutions (L-arginine, L-glutamine, or L-alanine). The effects on liver regeneration of the administered solutions were examined by assessment of restituted liver mass, staining for proliferating cell nuclear antigen (PCNA), and total RNA and DNA content 24 and 72 hours after the operation.

Results

At 72 hours after the hepatectomy, the restituted liver mass, the PCNA labeling index and the DNA quantity were all significantly higher in the L-arginine and L-glutamine groups than in the control. There were no significant differences in those parameters between the L-arginine and L-glutamine groups, nor were any significant differences found between the L-alanine group and the control.

Conclusion

Oral supplements of L-arginine and L-glutamine enhanced liver regeneration after hepatectomy in rats, suggesting that an oral arginine supplement can clinically improve recovery after a major liver resection.