Effect of a glutamine-supplemented enteral diet on methotrexate-induced enterocolitis

Potential roles of enteric glial cells in Crohn's disease: A critical review

Enteric glial cells in the enteric nervous system are critical for the regulation of gastrointestinal homeostasis. Increasing evidence suggests two-way communication between enteric glial cells and both enteric neurons and immune cells. These interactions may be important in the pathogenesis of Crohn's disease (CD), a chronic relapsing disease characterized by a dysregulated immune response. Structural abnormalities in glial cells have been identified in CD. Furthermore, classical inflammatory pathways associated with CD (e.g., the nuclear factor kappa-B pathway) function in enteric glial cells. However, the specific mechanisms by which enteric glial cells contribute to CD have not been summarized in detail. In this review, we describe the possible roles of enteric glial cells in the pathogenesis of CD, including the roles of glia-immune interactions, neuronal modulation, neural plasticity, and barrier integrity. Additionally, the implications for the development of therapeutic strategies for CD based on enteric glial cell-mediated pathogenic processes are discussed.

Whey protein concentrate ameliorates the methotrexate-induced liver and kidney damage

Methotrexate (MTX) is a cytotoxic immunosuppressant that is widely used in the treatment of tumours, rheumatoid arthritis and psoriasis. This study aims to evaluate the effects of whey proteins on MTX-induced liver and kidney damage by focusing on oxidant–antioxidant systems and eating habits. The study was conducted in four groups of thirty Sprague–Dawley rats (control, control + whey protein concentrate (WPC), MTX, MTX + WPC). A single dose of 20 mg/kg MTX was administered intraperitoneally to the MTX groups. Control and MTX groups were given 2 g/kg WPC by oral gavage every day for 10 d. At the end of day 10, blood samples were drawn and liver and kidney tissues were removed. MTX administration increased the lipid peroxidation level and decreased glutathione level, superoxide dismutase and glutathione-S-transferase activities in the liver and kidney. Administration of WPC significantly reduced the damage caused by MTX in the liver and kidney. While a decrease in serum urea level and an increase in serum creatinine level were detected in the MTX group, WPC administration reversed these results up to control group levels. Administration of WPC to the MTX group significantly reversed the histopathological damage scores of the liver and kidney. WPC administration ameliorated the MTX-induced oxidative damage in the liver and kidney tissues due to its antioxidant properties. Liver and kidney damage can be prevented by using whey proteins as a nutraceutical in MTX therapy. In conclusion, whey proteins demonstrated a protective effect against MTX-induced liver and kidney damage.

Poultry gut health and beyond

Intestinal health is critically important for the digestion and absorption of nutrients and thus is a key factor in determining performance. Intestinal health issues are very common in high performing poultry lines due to the high feed intake, which puts pressure on the physiology of the digestive system. Excess nutrients which are not digested and absorbed in the small intestine may trigger dysbiosis, i.e. a shift in the microbiota composition in the intestinal tract. Dysbiosis as well as other stressors elicit an inflammatory response and loss of integrity of the tight junctions between the epithelial cells, leading to gut leakage. In this paper, key factors determining intestinal health and the most important nutritional tools which are available to support intestinal health are reviewed.

The Protective Effects of Nutraceutical Components in Methotrexate-Induced Toxicity Models—An Overview

There are multiple concerns associated with methotrexate (MTX), widely recognized for anti-neoplastic and anti-inflammatory effects in life-threatening disease conditions, i.e., acute lymphoblastic leukemia, non-Hodgkin’s lymphoma, psoriasis, and rheumatoid arthritis, due to long-term side effects and associated toxicity, which limits its valuable potential. MTX acts as an inhibitor of dihydrofolate reductase, leading to suppression of purine and pyrimidine synthesis in high metabolic and turnover cells, targeting cancer and dysregulated immune cells. Due to low discrimination between neoplastic cells and naturally high turnover cells, MTX is prone to inhibiting the division of all fast-dividing cells, causing toxicity in multiple organs. Nutraceutical compounds are plant-based or food-derived compounds, used for their preventive and therapeutic role, ascertained in multiple organ dysfunctions, including cardiovascular disease, ischemic stroke, cancer, and neurodegenerative diseases. Gut microbiota and microbiota-derived metabolites take part in multiple physiological processes, their dysregulation being involved in disease pathogenesis. Modulation of gut microbiota by using nutraceutical compounds represents a promising therapeutic direction to restore intestinal dysfunction associated with MTX treatment. In this review, we address the main organ dysfunctions induced by MTX treatment, and modulations of them by using nutraceutical compounds. Moreover, we revealed the protective mechanisms of nutraceuticals in MTX-induced intestinal dysfunctions by modulation of gut microbiota.

Amino Acids May Have Protective Effects on Salivary Glands of 5-FU-administered Mice

BACKGROUND/AIM

This study aimed to identify the most useful components of Elental^® in the treatment of 5-fluorouracil (FU)-induced mucositis and salivary gland atrophy in mice.

MATERIALS AND METHODS

Mice (except the control group) were intraperitoneally injected with 5-FU. The mice received saline (control group and 5-FU group), dextrin (Dextrin group), amino acids (17AA group), or Elental^® (Elental^® group).

RESULTS

The volume and weight of salivary glands was higher in 17AA and Elental^® groups compared to 5-FU group. The number of mucous glands was higher, whereas the number of damaged granular ductal epithelial cells was lower in the salivary glands of all groups except the 5-FU group. Salivation was also decreased in the 5-FU group compared to the other groups.

CONCLUSION

Amino acids could be the most effective components of Elental^® for protecting mouse salivary glands from 5-FU-induced atrophic changes, and might be useful in the treatment of oral mucositis in cancer patients.

Molecular Characterization and Nutrition Regulation of the Neutral Amino Acid Transporter ASCT2 in Triploid Crucian Carp

AlaSerCys Transporter 2 (ASCT2), encoded by the SLC1A5 gene, plays an important role in the absorption of glutamine. In this study, the full-length cDNA sequence of ASCT2 was cloned from triploid crucian carp. It encodes 539 amino acid residues and a stop codon. Phylogenetic analysis revealed that the sequences of the ASCT2 ORF region in cyprinid fishes shared high sequence homology. Comparing the abundance of ASCT2 in different tissues, we found its expression level in muscle was significantly higher than that in intestine (p < 0.05). In addition, the expression levels of ASCT2 also appeared different in diurnal variation. Then we found the addition of 2.5% glutamate in a feeding diet significantly increased the expression levels of ASCT2 in intestine and muscle (p < 0.05). However, in glutamine experiments, the muscle showed the highest expression level of ASCT2 when fish were fed the diet containing 3.0% glutamine (p < 0.05). In vitro, ASCT2 was sensitive to glutamine and its expression level appeared down-regulated when the addition of glutamine was added to 0.1 mg/mL. Finally, we found that the diet with 29% protein level significantly increased the expression level of ASCT2 in intestine (p < 0.05). Nevertheless, different protein sources (fish meal and soybean meal) had no significant effect on the expression levels of ASCT2 in intestine and muscle (p > 0.05). These results provided data for the study of ASCT2 in triploid crucian carp regulated by feeding nutrition, which had a potential application in improving feed formulation in aquaculture.

Effects of Immunonutrition on Chemoradiotherapy Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

We conducted a systematic review to assess the effects of immunonutrition on chemoradiotherapy patients.

METHODS

We searched the Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, CINAHL, and the Web of Science. We assessed the risk of bias using the Cochrane Risk of Bias tool. Our primary outcomes were the incidence of oral mucositis and diarrhea. The secondary outcomes were the incidence of esophagitis, grade ≥3 oral mucositis, grade ≥3 diarrhea, grade ≥3 esophagitis, and body weight loss.

RESULTS

A total of 1478 patients and 27 studies were included. There were no significant differences in the incidence of oral mucositis (relative risk [RR] = 0.91; 95% confidence interval [CI], 0.79-1.05), diarrhea (RR = 0.89; 95% CI, 0.76-1.05), or esophagitis (RR = 0.55; 95% CI, 0.11-2.86) between the immunonutrition group and standard nutrition/placebo group. Nevertheless, immunonutrition significantly reduced the incidence of grade ≥3 oral mucositis (RR = 0.45; 95% CI, 0.22-0.92), grade ≥3 diarrhea (RR = 0.56; 95% CI, 0.35-0.88), grade ≥3 esophagitis (RR = 0.15; 95% CI, 0.04-0.54), and losing >5% body weight (RR = 0.34; 95% CI, 0.18-0.64).

CONCLUSIONS

In this study, immunonutrition failed to reduce the incidence rates of oral mucositis, diarrhea, or esophagitis but was conducive to significantly improving the severity of oral mucositis and diarrhea esophagitis and reducing the rate of body weight loss.

The efficacy of sodium azulene sulfonate L-glutamine for managing chemotherapy-induced oral mucositis in cancer patients: a prospective comparative study

Background

The efficacy of sodium azulene sulfonate L-glutamine (GA) in treating oral mucositis caused by the administration of anticancer agents has not been previously elucidated. Therefore, this prospective comparative study was conducted to evaluate the efficacy of GA in treating oral mucositis caused by chemotherapy regimens involving fluorinated pyrimidine anticancer drugs.

Methods

The subjects of this study were patients with oral mucositis of grade 2 or higher while on outpatient chemotherapy regimens involving fluorinated pyrimidine anticancer drugs for colorectal or breast cancer. The subjects were randomly divided into a group that received GA (the GA group) or a group that did not receive GA (the control group) by using the closed-envelope method. GA was administered three times a day every day from the first day of the regimen until the final day. The primary endpoint was the development of oral mucositis of grade 2 or higher. The secondary endpoint was the severity of oral pain, which was judged using an 11-stage numerical rating scale (NRS) ranging from 0 to 10.

Results

The proportion of patients with oral mucositis of grade 2 or higher was 32.4% in the GA group and 57.6% in the control group. The GA group had a significantly lower frequency of occurrence. The changes in the NRS scores before and after the trial began were − 2.9 ± 0.6 in the GA group and − 1.2 ± 0.5 in the control group. The NRS score decreased more significantly in the GA group than in the control group (P = 0.046). One patient stopped GA treatment voluntarily due to nausea; other than nausea, no GA-related side effects were observed.

Conclusions

GA protects against oral mucositis and reduces the severity of prevailing oral mucositis symptoms. Our findings indicate that GA is a highly safe and convenient drug.

Oral Glutamine Ameliorates Chemotherapy-induced Changes of Intestinal Permeability and Does not Interfere with the Antitumor Effect of Chemotherapy in Patients with Breast Cancer: A Prospective Randomized Trial

Aims and Background

Sixty patients with breast cancer were randomly assigned to oral glutamine or placebo pre-neoadju-vant chemotherapy (CEF regimen).

Methods and Study Design

Oral glutamine supplementation was continued for at least 12 days. Patients kept a daily record of diarrhea and stomatitis. The plasma glutamine level, intestinal permeability (lactulose-mannitol test), and tumor size were analyzed. The expression of Ki-67 and PCNA antigens in breast carcinoma was assessed.

Results

The plasma glutamine level was significantly higher in the glutamine group than in the placebo group (420.39 ± 52.39 mmol/L vs 309.76 ± 42.34 mmoi/L, P <0.05). After one cycle of chemotherapy, the lactulose-mannitol ratio was higher in the placebo group than in the glutamine group (0.0630 ± 0.0091 vs 0.0471 ± 0.0094, P <0.05). No differences were observed in the grades of stomatitis and diarrhea, in the changes in tumor size, and in the expression of Ki-67 and PCNA antigens between the two groups.

Conclusions

Prophylactic oral glutamine could ameliorate the neoadjuvant chemotherapy-induced increase in intestinal permeability, but had no significant positive clinical effect on stomatitis and diarrhea and did not interfere with the antitumor effect of chemotherapy.

The Effect of Cisplatin on Blood Ammonia Elevation by Alanyl-Glutamine Supplementation

BACKGROUND

Although there are many clinical studies in which the beneficial effect of glutamine formulation on mucositis induced by chemo/radiotherapy was evaluated, the results are sometimes conflicting with the report of clinical deterioration. Then, we hypothesized that chemotherapy may increase the incidence of hyperammonemia without comparable change of major parameters of hepatic/renal disorder.

METHODS

To verify our hypothesis, we examined the increase in blood ammonia level with 1-h intravenous infusion of alanyl-glutamine on day 1-4 after cisplatin (CDDP) administration in rats and assessed the correlation with hepatic/renal parameters.

RESULTS

Hepatic parameters (glutamate-oxaloacetic transaminase [GOT] and glutamic-pyruvic transaminase [GPT]) with CDDP did not change until day 3 and only GOT increased on day 4. Renal parameters (plasma creatinine, blood urea nitrogen) with CDDP continuously increased up to day 4. Alanyl-glutamine infusion significantly elevated blood ammonia level of CDDP rats with the peak on day 3, although the same dose did not change that of control rats.

CONCLUSION

These results indicates that CDDP enhances the increase in blood ammonia level by glutamine supplementation without correlating with primary parameters for hepatic/renal dysfunction.

Elemental Diet Accelerates the Recovery From Oral Mucositis and Dermatitis Induced by 5-Fluorouracil Through the Induction of Fibroblast Growth Factor 2

Mucositis and dermatitis induced by anticancer agents are common complications of anticancer therapies. In this study, we evaluated the efficacy of Elental (Ajinomoto Pharmaceutical Ltd, Tokyo, Japan), an elemental diet with glutamine in the treatment of 5-fluorouracil (5-FU)-induced oral mucositis and dermatitis in vivo and tried to clarify the underlying mechanisms of its action. Oral mucositis and dermatitis was induced through a combination of 5-FU treatment and mild abrasion of the cheek pouch in hamsters and the dorsal skin in nude mice respectively. These animals received saline, dextrin or Elental suspension (18 kcal/100 g) by a gastric tube daily until sacrifice. Elental reduced oral mucositis and dermatitis more effectively than dextrin in the animal model. Moreover, growth facilitating effects of Elental on HaCaT cells were examined in vitro. MTT assay, wound healing assay, and migration assay revealed that Elental could enhance the growth, invasion, and migration ability of HaCaT. ELISA and Western blotting showed upregulated FGF2 in Elental-treated HaCaT. These findings suggest that Elental is effective for the treatment of mucositis and dermatitis, and may accelerate mucosal and skin recovery through FGF2 induction and reepithelization.

The Dipeptide Alanyl-Glutamine Prevents Intestinal Mucosal Atrophy in Parenterally Fed Rats

This study was performed to determine whether the addition of alanyl-glutamine (Ala-Gln) can prevent intestinal mucosal atrophy induced by standard solution of total parenteral nutrition (S-TPN). Forty-one male Sprague-Dawley rats weighing 250 g were randomly divided into four groups: group I was killed after overnight fasting; group II received S-TPN. The other groups received S-TPN supplemented with amino acids other than glutamine (group III) or supplemented with Ala-Gln 2 g/100 mL (group IV); both solutions were isocaloric and isonitrogenous. After 1 week of TPN the rats were killed, and the duodenum, proximal jejunum, mid-small bowel, and distal ileum were obtained for morphologic and functional analysis. Weight gain did not differ significantly among these four groups, and there was no difference in nitrogen balance between groups III and IV. Serum glutamine in group IV (102.8 +/- 13.3 mumol/dL) was significantly increased (p less than .05) compared with groups I, II, and III (66.2 +/- 3.9, 55.7 +/- 7.8, and 61.3 +/- 10.8 mumol/dL, respectively). Mucosal wet weight, protein, RNA, sucrase, and maltase of group IV were significantly increased (p less than .05) compared with groups II and III. Villus height was significantly increased (p less than .05) in the jejunum of group IV rats compared with groups II and III, but not in any other segments of the intestine. No significant changes were observed in crypt depth among all groups. Diamine oxidase in groups II, III, and IV was significantly decreased (p less than .05) compared with group I in all segments except for the ileum.(ABSTRACT TRUNCATED AT 250 WORDS)

Glutamine for induction of remission in Crohn's disease

BACKGROUND

Crohn's disease is a chronic relapsing condition of the alimentary tract with a high morbidity secondary to bowel inflammation. Glutamine plays a key role in maintaining the integrity of the intestinal mucosa and has been shown to reduce inflammation and disease activity in experimental models of Crohn's disease.

OBJECTIVES

To evaluate the efficacy and safety of glutamine supplementation for induction of remission in Crohn's disease.

SEARCH METHODS

We searched the following databases from inception to November 15, 2015: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane IBD Group Specialised Register. Study references were also searched for additional trials. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared glutamine supplementation administered by any route to a placebo, active comparator or no intervention in people with active Crohn's disease were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed the methodological quality of the included studies. The Cochrane risk of bias tool was used to assess methodological quality. The primary outcome measure was clinical or endoscopic remission. Secondary outcomes included intestinal permeability, clinical response, quality of life, growth in children and adverse events. Risk ratios and 95% confidence intervals were calculated for dichotomous outcomes. The overall quality of the evidence supporting the primary outcome was evaluated using the GRADE criteria.

MAIN RESULTS

Two small RCTs (total 42 patients) met the inclusion criteria and were included in the review. One study (18 patients) compared four weeks of treatment with a glutamine-enriched polymeric diet (42% amino acid composition) to a standard polymeric diet (4% amino acid composition) with low glutamine content in paediatric patients (< 18 years of age) with active Crohn's disease. The other study (24 patients) compared glutamine-supplemented total parenteral nutrition to non-supplemented total parenteral nutrition in adult patients (> 18 years of age) with acute exacerbation of inflammatory bowel disease. The paediatric study was rated as low risk of bias. The study in adult patients was rated as unclear risk of bias for blinding and low risk of bias for all other items. It was not possible to pool data for meta-analysis because of significant differences in study populations, nature of interventions, and the way outcomes were assessed. Data from one study showed no statistically significant difference in clinical remission rates at four weeks. Forty-four per cent (4/9) of patients who received a glutamine-enriched polymeric diet achieved remission compared to 56% (5/9) of patients who received a standard low-glutamine polymeric diet (RR 0.80, 95% CI 0.31 to 2.04). A GRADE analysis indicated that the overall quality of evidence for this outcome was low due to serious imprecision (9 events). In both included studies, no statistically significant changes in intestinal permeability were found between patients who received glutamine supplementation and those who did not. Neither study reported on clinical response, quality of life or growth in children. Adverse event data were not well documented. There were no serious adverse events in the paediatric study. The study in adult patients reported three central catheter infections with positive blood cultures in the glutamine group compared to none in the control group (RR 7.00, 95% CI 0.40 to 122.44).

AUTHORS' CONCLUSIONS

Currently there is insufficient evidence to allow firm conclusions regarding the efficacy and safety of glutamine for induction of remission in Crohn's disease. Data from two small studies suggest that glutamine supplementation may not be beneficial in active Crohn's disease but these results need to be interpreted with caution as they are based on small numbers of patients. This review highlights the need for adequately powered randomised controlled trials to investigate the efficacy and safety of glutamine for induction of remission in Crohn's disease.

Key Roles of Glutamine Pathways in Reprogramming the Cancer Metabolism

Glutamine (GLN) is commonly known as an important metabolite used for the growth of cancer cells but the effects of its intake in cancer patients are still not clear. However, GLN is the main substrate for DNA and fatty acid synthesis. On the other hand, it reduces the oxidative stress by glutathione synthesis stimulation, stops the process of cancer cachexia, and nourishes the immunological system and the intestine epithelium, as well. The current paper deals with possible positive effects of GLN supplementation and conditions that should be fulfilled to obtain these effects. The analysis of GLN metabolism suggests that the separation of GLN and carbohydrates in the diet can minimize simultaneous supply of ATP (from glucose) and NADPH2 (from glutamine) to cancer cells. It should support to a larger extent the organism to fight against the cancer rather than the cancer cells. GLN cannot be considered the effective source of ATP for cancers with the impaired oxidative phosphorylation and pyruvate dehydrogenase inhibition. GLN intake restores decreased levels of glutathione in the case of chemotherapy and radiotherapy; thus, it facilitates regeneration processes of the intestine epithelium and immunological system.

Myelosuppressive and hepatotoxic potential of leflunomide and methotrexate combination in a rat model of rheumatoid arthritis

BACKGROUND

Safety of the combination of leflunomide and methotrexate was examined in several studies with inconclusive results. The present study was designed to compare the efficacy and safety of the combination of leflunomide and methotrexate in adjuvant-induced arthritis (AIA) in rats focusing on immunosuppressive and hepatotoxic effects.

METHODS

Eighty four rats were divided into seven groups. Group 1: Sham control, group 2: the vehicle control, group 3: methotrexate group, group 4-5: leflunomide (5 and 10mg/kg/day) groups, group 6-7: combination 1 and 2 [methotrexate+leflunomide (5 and 10mg/kg/day)] groups, respectively.

RESULTS

The current results indicated that combination therapies improved the ankle circumference and clinical scores compared to monotherapies; histopathological examination confirmed these findings. The myelosuppressive effect of leflunomide (10mg/kg/day) was comparable to that produced by methotrexate as indicated by the complete blood count and bone marrow cellularity; however their combination resulted in greater toxicity. Furthermore, methotrexate greatly affected the splenic histopathology compared to leflunomide and the combination therapy produced a greater effect compared to leflunomide not methotrexate. Differently, assessment of the hepatotoxic potential of the two drugs highlighted that leflunomide induced a dose-dependent increase in the fibrosis score which was higher in their magnitude than that induced by methotrexate. Leflunomide (10mg/kg/day) and combination 2 groups showed the greatest degree of liver fibrosis.

CONCLUSIONS

In rats with AIA, current drug combinations provided higher therapeutic benefit compared to monotherapies, however, greater toxicities were observed. Therefore, continuous monitoring of hematologic parameters and liver function will be recommended in clinical settings.

Lutein protects against methotrexate-induced and reactive oxygen species-mediated apoptotic cell injury of IEC-6 cells

Purpose

High-dose chemotherapy using methotrexate (MTX) frequently induces side effects such as mucositis that leads to intestinal damage and diarrhea. Several natural compounds have been demonstrated of their effectiveness in protecting intestinal epithelial cells from these adverse effects. In this paper, we investigated the protection mechanism of lutein against MTX-induced damage in IEC-6 cells originating from the rat jejunum crypt.

Methods

The cell viability, induced-apoptosis, reactive oxygen species (ROS) generation, and mitochondrial membrane potential in IEC-6 cells under MTX treatment were examined in the presence or absence of lutein. Expression level of Bcl2, Bad and ROS scavenging enzymes (including SOD, catalase and Prdx1) were detected by quantitative RT-PCR.

Results

The cell viability of IEC-6 cells exposed to MTX was decreased in a dose- and time-dependent manner. MTX induces mitochondrial membrane potential loss, ROS generation and caspase 3 activation in IEC-6 cells. The cytotoxicity of MTX was reduced in IEC-6 cells by the 24 h pre-treatment of lutein. We found that pre-treatment of lutein significantly reduces MTX-induced ROS and apoptosis. The expression of SOD was up-regulated by the pre-treatment of lutein in the MTX-treated IEC-6 cells. These results indicated that lutein can protect IEC-6 cells from the chemo-drugs induced damage through increasing ROS scavenging ability.

Conclusion

The MTX-induced apoptosis of IEC-6 cells was shown to be repressed by the pre-treatment of lutein, which may represent a promising adjunct to conventional chemotherapy for preventing intestinal damages.

Effects of glutamine on brain development in very preterm children at school age

OBJECTIVES

The amino acid glutamine has been shown to reduce the number of serious neonatal infections in very preterm children, which may benefit long-term brain development. The aims of the current follow-up study were to (1) determine the long-term effects of glutamine-enriched feeding in the first month after birth in very preterm children on measures of brain development at school age, and (2) elucidate a potential mediating role of serious neonatal infections.

METHODS

Fifty-two very preterm children who originally took part in a randomized controlled trial on enteral glutamine supplementation between day 3 and 30 after birth participated at a mean (SD) age of 8.6 (0.3) years. Measures of brain development included volumetric outcomes of major brain structures, as well as fractional anisotropy (FA) values of major white matter tracts.

RESULTS

Glutamine supplementation in the first month was associated with medium-sized increases in white matter (d = 0.54, P = .03), hippocampus (d = 0.47, P = .02), and brain stem (d = 0.54, P = .04) volumes at school age. Exploratory analyses using an uncorrected P value indicated higher FA values of the bilateral cingulum hippocampal tract in the glutamine group. All differences were either strongly associated (hippocampus volume, brain stem volume, and FA values of cingulum hippocampal tract) or completely mediated (white matter volume) by the lower number of serious neonatal infections in the glutamine group.

CONCLUSIONS

Short-term glutamine supplementation after birth increases white matter, hippocampus, and brain stem volumes in very preterm children at school age, mediated by a decrease in serious neonatal infections.

Glutamine: A novel approach to chemotherapy-induced toxicity

Treatment of cancer is associated with short- and long-term side-effects. Cancer produces a state of glutamine deficiency, which is further aggravated by toxic effects of chemotherapeutic agents leading to increased tolerance of tumor to chemotherapy as well as reduced tolerance of normal tissues to the side-effects of chemotherapy. This article reviews the possible role of glutamine supplementation in reducing the serious adverse events in patients treated with anticancer drugs. The literature related to the possible role of glutamine in humans with cancer and the supportive evidence from animal studies was reviewed. Searches were made and the literature was retrieved using PUBMED, MEDLINE, COCHRANE LIBRARY, CENAHL and EMBASE, with a greater emphasis on the recent advances and clinical trials. Glutamine supplementation was found to protect against radiation-induced mucositis, anthracycline-induced cardiotoxicity and paclitaxel-related myalgias/arthralgias. Glutamine may prevent neurotoxicity of paclitaxel, cisplatin, oxaplatin bortezomib and lenolidamide, and is beneficial in the reduction of the dose-limiting gastrointestinal toxic effects of irinotecan and 5-FU-induced mucositis and stomatitis. Dietary glutamine reduces the severity of the immunosuppressive effect induced by methotrexate and improves the immune status of rats recovering from chemotherapy. In patients with acute myeloid leukemia requiring parenteral nutrition, glycyl-glutamine supplementation could hasten neutrophil recovery after intensive myelosuppressive chemotherapy. Current data supports the usefulness of glutamine supplementation in reducing complications of chemotherapy; however, paucity of clinical trials weakens the clear interpretation of these findings.

Effects of neonatal enteral glutamine supplementation on cognitive, motor and behavioural outcomes in very preterm and/or very low birth weight children at school age

In very preterm ( < 32 weeks of gestation) and/or very low birth weight (VLBW, < 1500 g birth weight) children, serious neonatal infections are among the main causes of poor developmental outcomes later in childhood. The amino acid glutamine has been shown to reduce the incidence of serious neonatal infections in very preterm and/or VLBW children, while developmental effects beyond 24 months are unknown. We determined the cognitive, motor and behavioural outcomes at school age of a cohort of sixty-four very preterm and/or VLBW children (aged 7·5 (sd 0·4) years) who participated in a randomised placebo-controlled trial using enteral glutamine between day 3 and day 30 of life. Cognitive and motor outcomes were studied using the Wechsler Intelligence Scale for Children-III, the Movement Assessment Battery for Children (MABC), the Attention Network Test and a visual working memory task. Behavioural outcomes were evaluated using parent- and teacher-rated questionnaires. Intelligence quotient, processing speed, attentional functioning, working memory and parent- and teacher-rated behavioural outcomes were not different between children treated with glutamine or placebo; only visuomotor abilities as measured by the Ball Skills scale of the MABC (P = 0·002; d = 0·67) were poorer in the glutamine group. This effect persisted after taking into account the beneficial effects of lower serious neonatal infections rates in children treated with glutamine (P = 0·005). In conclusion, glutamine supplementation between day 3 and day 30 of life had neither beneficial nor detrimental effects on long-term cognitive, motor and behavioural outcomes of very preterm and/or VLBW children at school age, although visuomotor abilities were poorer in children that received glutamine.

Chemotherapy-induced diarrhea: pathophysiology, frequency and guideline-based management

Diarrhea is one of the main drawbacks for cancer patients. Possible etiologies could be radiotherapy, chemotherapeutic agents, decreased physical performance, graft versus host disease and infections. Chemotherapy-induced diarrhea (CID) is a common problem, especially in patients with advanced cancer. The incidence of CID has been reported to be as high as 50-80% of treated patients (≥30% CTC grade 3-5), especially with 5-fluorouracil bolus or some combination therapies of irinotecan and fluoropyrimidines (IFL, XELIRI). Regardless of the molecular targeted approach of tyrosine kinase inhibitors and antibodies, diarrhea is a common side effect in up to 60% of patients with up to 10% having severe diarrhea. Furthermore, the underlying pathophysiology is still under investigation. Despite the number of clinical trials evaluating therapeutic or prophylactic measures in CID, there are just three drugs recommended in current guidelines: loperamide, deodorized tincture of opium and octreotide. Newer strategies and more effective agents are being developed to reduce the morbidity and mortality associated with CID. Recent research focusing on the prophylactic use of antibiotics, budesonide, probiotics or activated charcoal still have to define the role of these drugs in the routine clinical setting. Whereas therapeutic management and clinical work-up of patients presenting with diarrhea after chemotherapy are rather well defined, prediction and prevention of CID is an evolving field. Current research focuses on establishing predictive factors for CID like uridine diphosphate glucuronosyltransferase-1A1 polymorphisms for irinotecan or dihydropyrimidine-dehydrogenase insufficiency for fluoropyrimidines.

GCMS-based metabolomic study in mice with colitis induced by dextran sulfate sodium

BACKGROUND

Metabolomics provides data about all the metabolic processes of a cell or organism. So far, the changes that occur in the levels of metabolites during the development of colitis have not been fully elucidated. Here we examined the changes of metabolite levels in the serum and colon tissue of colitis mice using gas chromatography mass spectrometry (GC/MS) with the aim of achieving a detailed understanding of the pathogenesis of inflammatory bowel disease (IBD).

METHODS

To induce colitis, C57BL/6J mice were administered 3.0% dextran sulfate sodium (DSS) in their drinking water for 5 days and were subsequently given drinking water alone.

RESULTS

A total of 77 and 92 metabolites were detected in serum and colon tissue, respectively, and among the metabolites the compositions of TCA cycle intermediates and amino acids changed depending on the degree of colitis. Then, partial least square discriminant analysis (PLS-DA), a multiple classification analysis, showed distinct clustering and clear separation of the groups according to the degree of colitis. Furthermore, PLS-DA loadings plots revealed that succinic acid, indole-3-acetic acid, glutamic acid, and glutamine were the main contributors to the separation of each stage of colitis. In addition, it was revealed that supplementation with glutamine, the level of which was significantly decreased in the acute phase of colonic inflammation, attenuated colitis induced by DSS.

CONCLUSIONS

Our results suggest that metabolomics is capable of representing the various degrees of colitis, and our findings will aid in the discovery of therapeutic agents for IBD and other inflammatory disorders by metabolomic approaches.

Nutritional therapy in critically ill and injured patients

Nutritional support of critically ill or injured patients has undergone significant advances in the last few decades. These advances are the direct result of the growing scientific progress and increased knowledge of the biology and biochemistry of key metabolic and nutrient changes induced by injury, sepsis, and other critical illnesses, both in adults and children. As this knowledge has increased, the science of nutritional support has become more disease based and disorder based. This article discusses protein and nitrogen metabolism in critically ill patients, immunomodulation, and the key nutrients involved in an immune-enhancing diet.

Nutrition modulation of gastrointestinal toxicity related to cancer chemotherapy: from preclinical findings to clinical strategy

Chemotherapy-induced gut toxicity is a major dose-limiting toxicity for many anticancer drugs. Gastrointestinal (GI) complications compromise the efficacy of chemotherapy, promote overall malnutrition, aggravate cancer cachexia, and may contribute to worsened prognosis. The GI tract is an attractive target for nutrition modulation, owing to its direct exposure to the diet, participation in uptake and metabolism of nutrients, high rate of cell turnover, and plasticity to nutrition stimuli. Glutamine, ω-3 polyunsaturated fatty acids, and probiotics/prebiotics are therapeutic factors that potentially modulate GI toxicity related to cancer treatments. Preclinical and clinical evidence are reviewed to critically define plausible benefits of these factors and their potential development into adjuncts to cancer chemotherapy. Mechanisms underlying the action of these nutrients are being unraveled in the laboratory. Optimal strategies to translate these findings into clinical care still remain to be elucidated. Key questions that remain to be answered include the following: which nutrient or combination of nutrients is selected for which patient and chemotherapy regimen? What mechanisms are responsible for modulation, and how are nutrient(s) administered in a clinically optimal manner? Research exploring interactions between different nutrients in GI protection is ongoing and demands further understanding. How nutrition preparations given to chemotherapy-treated patients are formulated in terms of component selection and dose optimization should be carefully studied and justified.

Evaluation of current and upcoming therapies in oral mucositis prevention

Cancer chemotherapy has evolved from a few therapeutic agents in three drug classes to more than 50 drugs in over ten drug classes. With generally cytotoxic mechanisms of action, there is continued research interest in preventing and managing adverse events of chemotherapy. Although treatment-induced symptom management has made significant progress, most therapies lead to intolerable reactions that result in a dose reduction or discontinuation of therapy. Mucositis is a common adverse event that can occur after administration of systemic chemotherapy and/or radiation therapy leading to inflammatory lesions anywhere from the oral cavity to the GI tract. Although pathophysiologically similar, gastrointestinal mucositis and oral mucositis (OM) differ in terms of symptom presentation and offending therapies. The focus of the article will be on OM; gastrointestinal mucositis will be mentioned when therapy efficacy is relevant to OM. OM prophylaxis has been a subject of interest for at least the past 30 years, yet progress has been limited due to a lack of understanding of the condition. With the recent introduction of palifermin (Kepivance™), novel therapies continue to be developed that may significantly reduce the incidence, duration and/or severity of OM. In addition, outcomes including an improvement in patient quality of life, increasing treatment dose intensity or reducing healthcare costs may result from successful management of OM prophylaxis. This article will review currently available OM prophylactic therapies. Agents in preclinical or clinical development and natural supplements will also be discussed.

Cisplatin upregulates glutamine transport in human intestinal epithelial cells: the protective mechanism of glutamine on intestinal mucosa after chemotherapy

BACKGROUND

Glutamine (GLN) prevents the intestinal mucosal injury induced by chemotherapy, although the mechanism of this protective action has not yet been elucidated. Amino acid transport across the plasma membrane is essential for supplying enterocytes with amino acids for cellular metabolism. It was hypothesized that chemotherapy stimulates GLN transport, which enables GLN to be used more efficiently as a metabolic fuel.

METHODS

A rat model was used to examine the effect of enteral GLN on intestinal mucosal injury induced by intraperitoneal injection of cisplatin (7.0 mg/kg of body weight). The effects of cisplatin on amino acid transport and the expression of messenger RNA and protein were evaluated by real-time polymerase chain reaction and Western blot analysis, respectively, in the human intestinal epithelial cell line Caco-2. The effects of cisplatin on glutaminase activity and intracellular glutathione were also studied.

RESULTS

GLN prevented mucosal atrophy induced by cisplatin in rats. In Caco-2 cells, cisplatin significantly increased GLN transport and the expression of GLN transporter ASCT2 messenger RNA and protein. Leucine, but not glutamate, transport significantly increased in the cisplatin-treated group due to the increase in LAT1 (leucine transporter) protein expression. Glutaminase activity and intracellular glutathione increased significantly in the cisplatin-treated group.

CONCLUSIONS

Bolus enteral GLN prevents intestinal mucosal injury induced by cisplatin in rats, as demonstrated by increased GLN transport and increased GLN transporter expression after cisplatin administration.

Protective mechanism of glutamine on the expression of proliferating cell nuclear antigen after cisplatin-induced intestinal mucosal injury

BACKGROUND

Glutamine prevents the intestinal mucosal injury induced by chemotherapy. However, the mechanism has not yet been elucidated. Proliferating cell nuclear antigen (PCNA) is expressed in the nuclei of cells during the DNA synthesis phase of the cell cycle, and PCNA is also involved in the DNA damage tolerance pathway known as post-replication repair. We hypothesized that glutamine supplementation might stimulate the intestinal epithelial cell cycle interruption induced by chemotherapy. The effect of supplemental glutamine after cisplatin-induced intestinal mucosal injury on the expression of PCNA was investigated.

MATERIALS AND METHODS

The male Wister rats were divided into three groups; a control group (control n = 5), which received standard rat diet; the Cis group (cisplatin 6 mg/kg i.p., n = 5), and the Cis + Gln group [cisplatin + Ala-Glutamine (0.5 g/day × 3 days p.o., n = 5)]. After 1, 3, and 7 days of chemotherapy, PCNA, and glutamine transporter (ASCT2) expression in the small intestine (jejunum and ileum) was investigated.

RESULTS

The expression of PCNA in the crypt of the small intestine (jejunum and ileum) decreased after chemotherapy, while the expression strongly increased by glutamine administration, even if it was after chemotherapy. On day 1, both the mRNA expression of the glutamine transporter (ASCT2) and PCNA expression in crypt cells were significantly increased by administration of glutamine (Cis + Gln group). The increased expression of ACST2 appeared earlier than in the Cis group. In the Cis + Gln group, the PCNA expression was normalized on day 3, and the expression was same as that in the control group on day 3.

CONCLUSION

Glutamine supplementation rapidly improved the expression of PCNA after cisplatin-induced intestinal mucosal injury. The effects of glutamine may be due to an anti-oxidant effect, but the amino acid might also attenuate the initial mucosal injury and improve intestinal cell turnover.

A diet containing whey protein, free glutamine, and transforming growth factor-beta ameliorates nutritional outcome and intestinal mucositis during repeated chemotherapeutic challenges in rats

Anticancer chemotherapy often induces side effects such as mucositis. Recent data suggest that a diet, Clinutren Protect (CP), containing whey proteins, glutamine, and transforming growth factor-beta (TGFbeta)-rich casein limits intestinal mucositis and improves recovery after a single methotrexate (MTX) challenge in rats. Chemotherapy consists of alternating periods of treatment and rest. Thus, our study evaluated the effects of CP on nutritional outcome and intestinal mucositis in rats receiving repeated chemotherapeutic challenges. Thirty-six Sprague-Dawley rats received 3 cycles of MTX at 8-d intervals. Rats had free access to CP or control diet (Co) from 7 d before the first MTX injection until the end of the experiment at d 27. In Co, whey proteins and TGFbeta-rich casein were replaced by TGFbeta-free casein. L-Glutamine was replaced by L-alanine. Body composition was assessed by dual energy X-ray absorptiometry. Before MTX challenges, food intake and body weight were similar in both groups but became higher during MTX challenges in CP (P < 0.05). Fat mass decreased similarly in both groups. In contrast, the decrease of fat free mass between d -1 and d 27 was less pronounced in the CP group (-9.5 g) than in the Co group (-57.2 g) (P < 0.05). The intestinal damage score was lower in the CP group (0.6 +/- 0.3 vs. 2.1 +/- 0.6; P < 0.05). Fecal IgA increased over time in the CP group (P < 0.05) but not in the Co group. A diet containing whey proteins, glutamine, and TGFbeta improves nutritional outcome by limiting the reduction of fat free mass and reduces intestinal mucositis during repeated chemotherapeutic challenges in rats.

Symposium 4: Hot topics in parenteral nutrition A review of the use of glutamine supplementation in the nutritional support of patients undergoing bone-marrow transplantation and traditional cancer therapy

The relationship between glutamine and malignancy can be traced back to the 1950s and the requirement for glutamine for malignant-cell growth in culture. Later studies demonstrated an association between the rate of proliferation of the malignant cells and glutamine usage. The excessive use of glutamine by malignant cells was seen as an opportunity for the development of a treatment using glutamine analogues, but unfortunately excessive toxicity was observed during clinical studies. In animal models glutamine supplementation, initially thought to increase tumour growth, actually causes tumour regression as a result of improved immune clearance of the tumour and appears to reduce the severity of the side effects of chemo- and radiotherapy. This finding led to human studies in both traditional cancer therapy and bone-marrow transplantation, which are reviewed here. Unfortunately, the majority of the studies performed are small and have poor methodological reporting. There is clinical heterogeneity in terms of routes of administration, dosing schedules, chemotherapy regimens and diseases. Studies of glutamine in non-bone-marrow transplantation chemo- and/or radiotherapy treatment suggest a possible trend towards reductions in objective mucositis but no effect on subjective symptoms. There is no evidence for its effect on other clinical outcomes. For bone-marrow transplantation there appears to be some benefit from oral glutamine in reducing mucositis and graft v. host disease, while intravenous glutamine may reduce infections but at the expense of an increased relapse rate. Good-quality studies are required in this area.

Effect of glutamine on intestinal mucosal integrity and bacterial translocation after abdominal radiation

This study evaluates the effect of oral glutamine on intestinal mucosal integrity and bacterial translocation in rats. 80 animals were randomised into four groups: group 1 (chow diet and water), group 2 (chow diet and glutamine 3%), group 3 (radiation, chow diet and water), group 4 (radiation, chow diet and glutamine 3%). Groups 1 and 2 were fed for 5 days, then sacrificed. Groups 3 and 4 were fed for 12 days, irradiated on the 5th day and sacrificed on 1st, 3rd and 7th post-radiation days. Cultures from the mesenteric lymph nodes (MLN), portal vein (PV) and aorta (A) were taken and two tissue samples were also taken from the terminal ileum for light and electron microscopic examination. In non-radiated rats glutamine did not alter the histologic parameters of villous height (VH), mitoses per crypt (M/C) and muscle thickness (MT). Group 3 rats had severe mucosal damage associated with a significant decrease of VH (p < 0.0001) and M/C (p < 0.01) on 1st and 3rd post-radiation days respectively. In contrast, group 4 rats maintained their mucosal structure and had a significant increase of VH and M/C (p < 0.0001) on post-radiation days 1 and 3. Bacterial translocation in MLN was 87.5% (p < 0.002) and 75% (p < 0.04) on 1st and 3rd post-radiation days respectively in group 3, and fell significantly to 12.5% (p < 0.002) in group 4. The data demonstrate that glutamine helps maintain the integrity of the intestinal mucosa and thereby reduces the incidence of bacterial translocation following abdominal irradiation.

Dietary glutamine and oral antibiotics each improve indexes of gut barrier function in rat short bowel syndrome

Short bowel syndrome (SBS) is associated with gut barrier dysfunction. We examined effects of dietary glutamine (GLN) or oral antibiotics (ABX) on indexes of gut barrier function in a rat model of SBS. Adult rats underwent a 60% distal small bowel + proximal colonic resection (RX) or bowel transection (TX; control). Rats were pair fed diets with or without l-GLN for 20 days after operation. Oral ABX (neomycin, metronidazole, and polymyxin B) were given in some RX rats fed control diet. Stool secretory immunoglobulin A (sIgA) was measured serially. On day 21, mesenteric lymph nodes (MLN) were cultured for gram-negative bacteria. IgA-positive plasma cells in jejunum, stool levels of flagellin- and lipopolysaccharide (LPS)-specific sIgA, and serum total, anti-flagellin- and anti-LPS IgG levels were determined. RX caused gram-negative bacterial translocation to MLN, increased serum total and anti-LPS IgG and increased stool total sIgA. After RX, dietary GLN tended to blunt bacterial translocation to MLN (-29%, P = NS) and significantly decreased anti-LPS IgG levels in serum, increased both stool and jejunal mucosal sIgA and increased stool anti-LPS-specific IgA. Oral ABX eliminated RX-induced bacterial translocation, significantly decreased total and anti-LPS IgG levels in serum, significantly decreased stool total IgA and increased stool LPS-specific IgA. Partial small bowel-colonic resection in rats is associated with gram-negative bacterial translocation from the gut and a concomitant adaptive immune response to LPS. These indexes of gut barrier dysfunction are ameliorated or blunted by administration of dietary GLN or oral ABX, respectively. Dietary GLN upregulates small bowel sIgA in this model.

Enteral glutamine pretreatment does not decrease plasma endotoxin level induced by ischemia-reperfusion injury in rats

AIM: To investigate whether oral glutamine pretreatment prevents impairment of intestinal mucosal integrity during ischemia-reperfusion (I/R) in rats.

METHODS: The study was performed as two series with 40 rats in each. Each series of animals was divided into four groups. The first group was used as a control. Animals in the second group were only pretreated with oral glutamine, 1 g/kg for 4 d. The third group received a normal diet, and underwent intestinal I/R, while the fourth group was pretreated with oral glutamine in the same way, and underwent intestinal I/R. Intestinal mucosal permeability to ⁵¹Cr-labeled EDTA was measured in urine in the first series of animals. In the second series, histopathological changes in intestinal tissue and plasma endotoxin levels were evaluated.

RESULTS: Intestinal I/R produced a significant increase in intestinal permeability, plasma endotoxin level and worsened histopathological alterations. After intestinal I/R, permeability was significantly lower in glutamine-treated rats compared to those which received a normal diet. However, no significant change was observed in plasma endotoxin levels or histopathological findings.

CONCLUSION: Although glutamine pretreatment seems to be protective of intestinal integrity, upon I/R injury, such an effect was not observable in the histopathological changes or plasma endotoxin level.

Molecular mechanisms contributing to glutamine-mediated intestinal cell survival

Glutamine, the most abundant amino acid in the bloodstream, is the preferred fuel source for enterocytes and plays a vital role in the maintenance of mucosal growth. The molecular mechanisms regulating the effects of glutamine on intestinal cell growth and survival are poorly understood. Here, we show that addition of glutamine (1 mmol/l) enhanced rat intestinal epithelial (RIE)-1 cell growth; conversely, glutamine deprivation increased apoptosis as noted by increased DNA fragmentation and caspase-3 activity. To delineate signaling pathways involved in the effects of glutamine on intestinal cells, we assessed activation of extracellular signal-related kinase (ERK), protein kinase D (PKD), and phosphatidylinositol 3-kinase (PI3K)/Akt, which are important pathways in cell growth and survival. Addition of glutamine activated ERK and PKD in RIE-1 cells after a period of glutamine starvation; inhibition of ERK, but not PKD, increased cell apoptosis. Conversely, glutamine starvation alone increased phosphorylated Akt; inhibition of Akt enhanced RIE-1 cell DNA fragmentation. The role of ERK was further delineated using RIE-1 cells stably transfected with an inducible Ras. Apoptosis was significantly increased following ERK inhibition, despite Ras activation. Taken together, these results identify a critical role for the ERK signaling pathways in glutamine-mediated intestinal homeostasis. Furthermore, activation of PI3K/Akt during periods of glutamine deprivation likely occurs as a protective mechanism to limit apoptosis associated with cellular stress. Importantly, our findings provide novel mechanistic insights into the antiapoptotic effects of glutamine in the intestine.

The effect of glutamine-enriched enteral nutrition on intestinal microflora in very low birth weight infants: A randomized controlled trial

BACKGROUND & AIMS

In a previous study, we have found that glutamine supplementation decreased the infection rate in very low birth weight (VLBW) infants. In this study, we investigated whether this beneficial effect originated from increased number of bifidobacteria and lactobacilli in the intestinal microflora of these infants.

METHODS

In a randomized controlled trial, VLBW infants (gestational age <32 weeks and/or birth weight <1500g) received enteral glutamine supplementation (0.3g/kg/day) or isonitrogenous placebo supplementation between d3 and d30 of life. Faecal microflora was determined by fluorescent in situ hybridization <48h, at d7, d14 and d30 of life.

RESULTS

In 43/52 (glutamine group) and 43/50 (control group) infants, > or = 2 samples were analyzed. Baseline characteristics were not different between groups. The prevalence of bifidobacteria, lactobacilli, Escheria coIi, streptococci and clostridia was not different between groups (p>0.05). In both groups, colonization with bifidobacteria was delayed, whereas potentially pathogenic bacteria such as E. coli, appeared rapidly after birth. Antibiotic treatment decreased the prevalence of all faecal bacteria (p<0.05).

CONCLUSIONS

Decreased infectious morbidity in VLBW infants that received glutamine supplementation was not associated with alterations in the prevalence of bifidobacteria, lactobacilli, E. coIi, streptococci and clostridia. In general, colonization with health-promoting bacteria was delayed, whereas potentially pathogenic bacteria appeared rapidly after birth. Antibiotic treatment delayed the bacterial colonization.