Chemotherapy-induced mucositis is associated with changes in proteolytic pathways

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.

Lactobacillus salivarius CPU-01 Ameliorates Temozolomide-Induced Intestinal Mucositis by Modulating Gut Microbiota, Maintaining Intestinal Barrier, and Blocking Pro-inflammatory Cytokines

Chemotherapy-induced intestinal mucositis is one of the major toxic side effects in the treatment of cancer patients. The purpose of this study is to screen lactic acid bacteria which could alleviate intestinal inflammation and damage induced by chemotherapeutic agents and explore the possible underlying mechanisms. Lactobacillus salivarius CPU-01 was selected from traditional Chinese fermented foods due to its protective effects on the toxicity of temozolomide in Caenorhabditis elegans. Eighteen ICR mice were randomly divided into 3 groups including control group, temozolomide-induced intestinal mucositis group, and temozolomide + L. salivarius CPU-01 group, and were used to investigate the effect of L. salivarius CPU-01 on chemotherapy-induced intestinal mucositis. It has been demonstrated that the administration of L. salivarius CPU-01 can prevent colon shortening and alleviate colon tissue damage caused by temozolomide-induced intestinal mucositis in mice. L. salivarius CPU-01 relieved the intestinal microbiota disorders caused by temozolomide and contributed to the growth of beneficial bacteria, such as Lactobacillus, Clostridia UCG - 014_norank, and Akkermansia. In vivo experiments also indicated that L. salivarius CPU-01 can suppress the level of temozolomide-induced pro-inflammatory cytokines in serum and mRNA expression in the small intestine tissues. It was also found that L. salivarius CPU-01 significantly increased the expressions of intestinal tight junction (TJ) proteins, ZO-1, and Occludin proteins in mice treated with temozolomide. These findings suggest that L. salivarius CPU-01 can ameliorate temozolomide-induced intestinal mucositis by modulating gut microbiota, blocking pro-inflammatory cytokines, and repairing the intestinal barrier. These findings suggest probiotics may serve as a potential alternative therapeutic strategy for the prevention of chemotherapy-induced intestinal mucositis in the future.

Clinical Impact of Highly Purified, Whey Proteins in Patients Affected With Colorectal Cancer Undergoing Chemotherapy: Preliminary Results of a Placebo-Controlled Study

Background and Aims: Sarcopenia, the loss of both lean body and skeletal muscle mass, may interfere in cancer patients outcome. As investigated, whey proteins could prevent the onset of sarcopenia. We have conducted a study to evaluate the effects of whey protein in colorectal cancer patients, undergoing 5-fluorouracil-based chemotherapy. Methods: After written informed consent, patients were blind randomized 1:1 to whey protein (ProLYOtin; arm A) versus placebo (arm B). The patients were assessed both physically and nutritionally before chemotherapy and after 3 (T2) and 6 months (T3) by body impedance assessment, L3-computed tomography scan, Mini Nutritional Assessment (MNA), and Malnutrition Universal Screening Tool (MUST) tests. Results: Forty-seven patients were included in this preliminary analysis. Baseline characteristics were well balanced between the 2 arms. During chemotherapy, 33 patients were reevaluated: anthropometric parameters (lean body mass from 68.5% to 71.2% vs 68.7% to 66.3%, and sarcopenia from 84% to 54% and 83% to 77% from baseline to T2 evaluation in arms A and B, respectively), nutritional status (MNA >24 = 100% [A] vs 73.7% [B]), and toxicity (no adverse effects in 86% [A] vs 29% [B] and 94% [A] vs 29% [B] for hematological and gastrointestinal toxicities, respectively) resulted to be significantly different. At univariate analysis, a condition of malnutrition risk according to MUST (relative risk [RR] = 7.5, P = .02) or MNA (RR = 1.45, P = .02) and ProLYOtin intake (RR = 0.12, P = .01) were found to be significantly predictive of chemotherapy toxicity. Conclusions: At present, our study shows how whey protein could be an important therapeutic option to improve nutritional status, and particularly to prevent severe toxicity during chemotherapy.

Increased Ghrelin but Low Ghrelin-Reactive Immunoglobulins in a Rat Model of Methotrexate Chemotherapy-Induced Anorexia

Background and aims

Cancer chemotherapy is commonly accompanied by mucositis, anorexia, weight loss, and anxiety independently from cancer-induced anorexia–cachexia, further aggravating clinical outcome. Ghrelin is a peptide hormone produced in gastric mucosa that reaches the brain to stimulate appetite. In plasma, ghrelin is protected from degradation by ghrelin-reactive immunoglobulins (Ig). To analyze possible involvement of ghrelin in the chemotherapy-induced anorexia and anxiety, gastric ghrelin expression, plasma levels of ghrelin, and ghrelin-reactive IgG were studied in rats treated with methotrexate (MTX).

Methods

Rats received MTX (2.5 mg/kg, subcutaneously) for three consecutive days and were killed 3 days later, at the peak of anorexia and weight loss. Control rats received phosphate-buffered saline. Preproghrelin mRNA expression in the stomach was analyzed by in situ hybridization. Plasma levels of ghrelin and ghrelin-reactive IgG were measured by immunoenzymatic assays and IgG affinity kinetics by surface plasmon resonance. Anxiety- and depression-like behaviors in MTX-treated anorectic and in control rats were evaluated in the elevated plus-maze and the forced-swim test, respectively.

Results

In MTX-treated anorectic rats, the number of preproghrelin mRNA-producing cells was found increased (by 51.3%, p < 0.001) as well were plasma concentrations of both ghrelin and des-acyl-ghrelin (by 70.4%, p < 0.05 and 98.3%, p < 0.01, respectively). In contrast, plasma levels of total IgG reactive with ghrelin and des-acyl-ghrelin were drastically decreased (by 87.2 and 88.4%, respectively, both p < 0.001), and affinity kinetics of these IgG were characterized by increased small and big Kd, respectively. MTX-treated rats displayed increased anxiety- but not depression-like behavior.

Conclusion

MTX-induced anorexia, weight loss, and anxiety are accompanied by increased ghrelin production and by a decrease of ghrelin-reactive IgG levels and affinity binding properties. Such changes of ghrelin-reactive IgG may underlie their decreased ghrelin-transporting capacities compromising ghrelin orexigenic and anxiolytic effects and contributing to chemotherapy-induced loss of appetite.

Steamed root of Rehmannia glutinosa Libosch (Plantaginaceae) alleviates methotrexate-induced intestinal mucositis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Intestinal mucositis induced by chemotherapy is a severe clinical problem in cancer patients that currently lack effective interventions. In traditional Chinese medicine, chemotherapeutic toxicity is diagnosed as Qi and Yin deficiency, and steamed rehmannia root (SRR) is frequently prescribed to these patients. Whether SRR can prevent the adverse effects remains to be confirmed experimentally. The present study used a rat model to investigate potential efficacy and action mechanisms of SRR in attenuating the adverse effects caused by chemotherapy.

MATERIALS AND METHODS

Intraperitoneal injection of a single dose of anti-metabolite methotrexate (MTX, 25mg/kg) was given to adult Wistar rats, which also received oral gavage of water or SRR (1.08g/kg twice daily 3 days before and 4 days after MTX treatment), or calcium folinate (CF, a clinically used MTX antidote as a comparison, at 1mg/kg twice daily 36h after MTX treatment), or SRR and CF in combination. Animals were sacrificed 4 days after MTX treatment. Complete blood cell counting was carried out. Jejunum was analyzed histologically for mucosal damage, immunohistochemically for proliferating cell nuclear antigen (PCNA), and biochemically for thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH), as well as for tumor necrosis factor alpha (TNF-α).

RESULTS

MTX treatment led to weight loss, leucopenia, polycythemia, increase in large thrombocyte ratio, intestinal villus atrophy, crypt loss and reduction in PCNA positive crypt cells, increases in mucosal TBARS and TNF-α and decrease in GSH. All these alterations were inhibited by SRR administration except leucopenia, and the effects of CF or CF plus SRR supplementation were found to be inferior to those of SRR.

CONCLUSIONS

SRR can alleviate MTX-induced gut mucositis, which may be achieved by inhibiting MTX-induced oxidative stress and inflammatory response. These findings support the application of SRR in chemotherapy but not the combined application of SRR and CF.

Protective effects of aqueous extract of Solanum nigrum Linn. leaves in rat models of oral mucositis

Oral mucositis is one of the most debilitating side effects in patient undergoing chemotherapy or chemoradiotherapy. Leaves of the plant Solanum nigrum are used in folklore medicine to treat oral ulcers in India. However, no pharmacological investigation has been carried out till date. Aqueous extract of Solanum nigrum leaves (AESN) was prepared and subjected to various phytochemical screening. HPLC analysis of the ethyl acetate fraction was carried out. The aqueous extract (100 and 200 mg/kg) was further evaluated for its protective effect on two rat models: (a) busulfan plus infrared radiation (chemoradiotherapy) induced oral mucositis and (b) methotrexate (chemotherapy) induced oral mucositis. Various parameters including body weight change, food intake, and mortality were measured. AESN showed protective effect in both models of oral mucositis; however, the higher dose was more effective in chemotherapy induced oral mucositis. A reduction in oral mucositis score (P < 0.05) was observed in the treatment groups. Significant (P < 0.05) improvement in food intake was also observed in AESN treated groups. Aqueous extract of Solanum nigrum leaves has protective effect on chemotherapy and chemoradiotherapy induced oral mucositis in rats.

Supplementation of fish oil augments efficacy and attenuates toxicity of 5-fluorouracil in 1,2-dimethylhydrazine dihydrochloride/dextran sulfate sodium-induced colon carcinogenesis

PURPOSE

5-Fluorouracil (5-FU) is used for the treatment of colorectal cancer, but has low therapeutic response rate and severe side effects. Recently, fish oil (FO) rich in n-3 polyunsaturated fatty acids has been preferred to chemosensitize tumor cells to anticancer drugs. Therefore, the current study is designed to evaluate chemotherapeutic efficacy and toxicity profile of 5-FU in combination with FO in 1,2-dimethylhydrazine dihydrochloride/dextran sulfate sodium (DMH/DSS)-induced colon cancer model.

METHODS

The therapeutic efficacy of 5-FU along with FO was analyzed through assessment of survival rate, tumor burden, volume, serum sialic acid levels, cytokeratin 19 (CK19) expression and index of cell proliferation such as cell cycle progression. Toxicological aspects were evaluated by standard functional and structural parameters related to spleen, gastrointestinal, liver and kidney.

RESULTS

In the present study, 5-FU in combination with FO increased the survival rate in carcinogen-treated animals. Synergism of 5-FU and FO was also reflected in significant inhibition in tumor growth and serum sialic acid levels in DMH/DSS model. Moreover, the combination dosage significantly augmented the inhibition of cell cycle progression, as shown by CK19 expression. Additionally, FO ameliorated hematologic depression, gastrointestinal, hepatic and renal toxicity caused by 5-FU as substantiated by a marked improvement in structural and functional alterations of these organs.

CONCLUSION

The supplementation of FO is potentially a promising option for increasing the therapeutic potential and mitigating the side effects of 5-FU.

New pharmacotherapy options for chemotherapy-induced alimentary mucositis

INTRODUCTION

Chemotherapy-induced alimentary mucositis is an extremely common condition that is caused by a breakdown of the mucosal barrier. It occurs in between 40 - 100% of cancer patients depending on the treatment regimen. Symptoms typically include pain from oral ulceration, vomiting and diarrhoea. Alimentary mucositis often necessitates chemotherapy reductions or treatment breaks, overall potentially compromising survival outcomes. Consequently, alimentary mucositis creates a burden not only on patients' quality of life but also on healthcare costs. Despite this, currently, there is no clinically effective localised/pharmacological therapy intervention strategy to prevent alimentary mucositis.

AREAS COVERED

Over recent years, a number of novel pharmacotherapy agents have been trialed in various preclinical and clinical settings. This critical review will therefore provide an overview of emerging pharmacotherapies for the treatment of alimentary mucositis following chemotherapy with particular emphasis on studies published in the last 2 years. A Pubmed literature search was conducted to identify eligible articles published before 30 November 2013 and each article was reviewed by all authors. All articles were written in English.

EXPERT OPINION

Currently, there is no clinically effective localised therapeutic intervention strategy to prevent the condition. New emerging areas of research have recently been proposed to play key roles in the development of alimentary mucositis and these areas may provide researchers and clinicians with new research directions. Hopefully this will continue, and evidence-based informed guidelines can be produced to improve clinical practice management of this condition.

Methotrexate modulates tight junctions through NF-κB, MEK, and JNK pathways

OBJECTIVES

Chemotherapy often induces intestinal mucositis, which is associated with an increase in intestinal permeability; however, underlying mechanisms remain incompletely understood. Thus, we aimed to study the regulation of 3 tight junction (TJ) proteins, claudin-1, occludin, and zonula occludens-1, after anticancer treatment.

METHODS

Methotrexate (MTX) was subcutaneously injected for 3 consecutive days in Sprague-Dawley rats to induce intestinal mucositis and was applied on Caco-2 cell monolayers. TJ protein expression and cellular distribution were studied by Western blot and microscopy, respectively. In Caco-2 cells, the paracellular permeability was evaluated by both transepithelial electrical resistance and flux of fluorescein isothiocyanate-dextran marker. Cytokine production and signaling pathways were also assessed.

RESULTS

In MTX-treated rats, the cellular distribution of the 3 TJ proteins was altered and claudin-1 and occludin expression was reduced during the acute phase of mucositis compared with controls. During the recovery phase, these parameters were restored. In vitro, MTX treatment led to an increase in proinflammatory cytokine production at the apical side but did not affect Caco-2 cell apoptosis and necrosis. Increase in paracellular permeability was associated with altered occludin and zonula occludens-1 expression and cellular distribution. All of these alterations were prevented by MEK1 and 2, JNK, and NF-κB inhibitors.

CONCLUSIONS

MTX treatment induced an increase in intestinal permeability partially related to alteration of TJs protein expression and cellular distribution that may be mediated by MAPK and NF-κB pathways. These are potential targets to limit the adverse effects of chemotherapy.

Progress towards the development of animal models of chemotherapy-induced gastrointestinal mucositis

The pathogenesis of chemotherapy-induced gastrointestinal mucositis is not fully elucidated, which makes it extremely difficult to develop effective interventions. Recently, the use of animal models of chemotherapy-induced gastrointestinal mucositis has led to advances in the understanding of cellular mechanisms and clinical pharmacology of various types of chemotherapy drugs. Tumor-bearing models, non-tumor-bearing models, transgenic models and gene knockout models have been developed to assess the effect of chemotherapy on chemotherapy-induced gastrointestinal mucositis. In this paper, we comprehensively analyze the advantages and disadvantages of various methods for developing chemotherapy-induced gastrointestinal mucositis to provide a reference for the choice of animal models for future research of chemotherapy-associated mucosal toxicity and the underlying mechanisms.

Intestinal inflammation influences α-MSH reactive autoantibodies: relevance to food intake and body weight

Autoantibodies reacting with alpha-melanocyte-stimulating hormone (α-MSH), an anorexigenic neuropeptide, are involved in regulation of feeding. In this work we studied if intestinal inflammation (mucositis) may influence α-MSH autoantibodies production relevant to food intake and body weight. Mucositis and anorexia were produced in Sprague-Dawley rats by methotrexate (MTX, 2.5mg/kg/day, for three days, subcutaneously). Plasma levels of total IgG and of α-MSH autoantibodies were measured during and after MTX-induced mucositis and were compared with pair-fed and ad libitum-fed controls. Effects of intraperitoneal injections of rabbit anti-α-MSH IgG (3 or 10 μg/day/rat) on MTX-induced anorexia and on plasma α-MSH peptide concentration were separately studied. Here we show that in MTX rats, intestinal mucositis and anorexia were accompanied by decreased plasma levels of both total IgG and of α-MSH autoantibodies while refeeding was characterized by their elevated levels. In spite of similar food intake in MTX and pair-fed rats, recovery of body weight was delayed by at least 1 week in the MTX group. During refeeding and body weight deficit in MTX rats, α-MSH IgG autoantibody levels correlated negatively with food to water intake ratios. Injections of anti-α-MSH IgG induced a dose-dependent attenuation of food intake and body weight regain in MTX-treated rats accompanied by increased concentrations of α-MSH peptide which correlated positively with plasma levels of α-MSH autoantibodies. These data show that intestinal inflammation, independently from food restriction, affects general humoral immune response which may influence food intake and body weight control via modulation of α-MSH plasma concentration by α-MSH reactive autoantibodies.

Effect of vitamin supplementation on cisplatin-induced intestinal epithelial cell apoptosis in Wistar/NIN rats

OBJECTIVE

Chemotherapeutic agents induce small intestinal mucositis that is characterized structurally by crypt loss and villus atrophy and functionally by absorptive and barrier impairments. We studied the effect of selected individual vitamins and multiple-vitamin mixture supplementation in modulating cisplatin-induced intestinal damage and apoptosis.

METHODS

Thirty-six male Wistar/NIN rats 20 wk old and fed the control diet (AIN-93G) were randomly divided into six groups. Five groups were administered cisplatin (2.61 mg/kg of body weight) once a week for 3 wk and were concomitantly provided the control diet or riboflavin, folate, α- tocopherol, or a multiple-vitamin mixture supplemented diet. The sixth group served as a control for cisplatin and received saline as the vehicle. Intestinal epithelial cell apoptosis was monitored by morphometry, M30 staining, DNA fragmentation, and caspase-3 activity. Functional and structural integrities were determined by measuring activities of alkaline phosphatase and lysine ala-dipeptidyl aminopeptidase and the villus height/crypt depth ratio. Oxidative burden was assessed as the formation of thiobarbituric acid-reactive substances and protein carbonyls. Plasma levels of selected vitamins were also measured.

RESULTS

Cisplatin administration significantly increased intestinal apoptosis in the villus and crypt regions that correlated with increased oxidative damage, decreased Bcl-2/Bax, and compromised functional integrity. Riboflavin, folate, and the multiple-vitamin mixture supplementation attenuated the cisplatin-induced increase in apoptotic indices, with a decrease in oxidative burden, increased Bcl-2/Bax, and improved functional and structural integrities. The α-tocopherol supplementation, although effective in attenuating oxidative stress and improving functional integrity, failed to lower the apoptotic indices.

CONCLUSIONS

Riboflavin, folate, and the multiple-vitamin supplementation proved to be more efficacious in attenuating the cisplatin-induced intestinal damage and associated changes in apoptosis.

Anti-inflammatory and anti-angiogenic effect of long chain n-3 polyunsaturated fatty acids in intestinal microvascular endothelium

BACKGROUND & AIMS

The role of endothelial cells in inflammatory bowel disease has been recently emphasized. Endothelial activation and expression of adhesion molecules are critical for leukocytes recruitment into the inflammatory wall. Compelling evidence demonstrated anti-inflammatory effects of long chain n-3 PUFA in inflammatory models. We previously showed that long chain n-3 PUFA (EPA and DHA) inhibited inflammatory response in epithelial and dendritic cells. As long chain n-3 PUFA treatment led to a decreased expression of adhesion molecules in endothelial cells from other organs, we have now investigated their effect on intestinal endothelial cells in vitro and in colitic rats.

METHODS

In vitro study: Primary culture of human intestinal microvascular endothelial cells (HIMEC) were pre-treated with DHA and then incubated with IL-1β. In vivo study: Colitis was induced in 2 groups at day0 by intrarectal injection of 2-4-6-trinitrobenzen sulfonic acid (TNBS). Rats received by gavage either fish oil, rich in EPA and DHA (TNBS+n-3) or an isocaloric isolipidic oil formula for 14 days.

RESULTS

DHA led to a decreased VCAM-1, TLR4, cyclooxygenase-2 and VEGFR2 expression and a decreased production of IL-6, IL-8 and GM-CSF and a reduced production of PGE(2) and LTB(4) (p < 0.001) in IL-1β-induced HIMEC. Similarly, dietary intervention with fish oil rich in EPA and DHA significantly decreased colon production of PGE(2) and LTB(4,) endothelial VCAM-1 and VEGFR2 in rats with colitis.

CONCLUSIONS

Data obtained from in vitro and in vivo studies reveal a potential anti-angiogenic role of long chain n-3 PUFA in intestinal endothelial cells. This protective effect of long chain n-3 PUFA may partly explain the observed benefit of dietary intake of long chain n-3 PUFA in IBD development.

Effect of treatment with a Jianpi herbal formula on disease-free survival in patients with gastric cancer after radical gastrectomy

AIM: To investigate the effect of treatment with a Jianpi herbal formula on disease-free survival (DFS) in patients with gastric cancer after radical gastrectomy.

METHODS: A total of 474 gastric cancer patients after radical gastrectomy were assigned to treatment group (n = 196; undergoing treatment with the Jianpi herbal formula and chemotherapy) and control group (n = 278; undergoing chemotherapy only). Independent factors influencing DFS in gastric cancer patients after radical gastrectomy were analyzed using the Kaplan-Meier method and Cox proportional hazards model. A stratified analysis was performed by clinicopathologic stage.

RESULTS: Cox analysis showed that clinicopathologic stage (P = 0.000) and treatment with the Jianpi herbal formula (P = 0.000) were independent factors influencing DFS in gastric cancer patients after radical gastrectomy. Stratified analysis indicated that treatment with the Jianpi herbal formula was an independent factor influencing DFS in patients with stage IV (M0) gastric cancer after radical gastrectomy (P = 0.034). Patients of the treatment group had a significantly longer DFS than those of the control group (39.78 mo vs 18.38 mo, P = 0.023). Treatment with the Jianpi herbal formula was also an independent factor influencing DFS in patients with stage III gastric cancer after radical gastrectomy (P = 0.000). The 1-, 3-, and 5-year DFS rates were significantly higher in the treatment group than in the control group (94% vs 82%, 76% vs 47%, 67% vs 39%).

CONCLUSION: Treatment with the Jianpi herbal formula can prolong DFS in stages III and IV (M0) gastric cancer patients after radical gastrectomy.

Interleukin-10 and -12 predict chemotherapy-associated toxicity in esophageal adenocarcinoma

INTRODUCTION

Chemotherapy-associated mucositis often prevents completion of an entire chemotherapy cycle. The underlying pathophysiology of chemotherapy-associated mucositis has not been well established. The individual immunologic predisposition of patients seems to play an important role.

METHODS

One hundred fifty-six patients with locally advanced or metastatic esophageal adenocarcinoma received neoadjuvant chemotherapy with cisplatin, 5-fluorouracil, and leucovorin followed by resection. Before the neoadjuvant therapy, monocytes were isolated from blood samples and were stimulated with lipopolysaccharide and interferon. An enzyme-linked immunosorbent assay was used to measure interleukin (IL)-10 and -12 levels and correlated with patients' clinical course.

RESULTS

Twenty-two patients (14,1%) developed grade III to IV mucositis (according to the NCI-Common toxicity criteria scales) within the neoadjuvant chemotherapy. Pretherapeutic low IL-10 (<24.1 pg/ml) and high IL-12 (>5500 pg/ml) levels were significantly associated with mucositis causing a therapy interruption or even cessation. Patients with high IL-10 (>43.6 pg/ml) and low IL-12 (<4408.5 pg/ml) levels had an uneventful neoadjuvant chemotherapy.

CONCLUSIONS

Pretherapeutic individual monocyte function is correlated with the development and the grade of chemotherapy induced mucositis. This knowledge might help us in predicting the grade of mucositis and in understanding the genesis regarding the association to pro- and anti-inflammatory effects of monocyte cytokines.

An α-linolenic acid-rich formula reduces oxidative stress and inflammation by regulating NF-κB in rats with TNBS-induced colitis

We have previously shown that α-linolenic acid (ALA), a (n-3) PUFA exerts in vitro antiinflammatory effects in the intestine. In this study, we aimed to evaluate its effect on inflammatory and oxidative stress in a colitis model. Colitis was induced in 2 groups at d 0 by intrarectal injection of 2-4-6-trinitrobenzen sulfonic acid (TNBS), whereas the control group received the vehicle. Rats we fed 450 mg . kg(-1) . d(-1) of ALA (TNBS+ALA) while the other colitic group (TNBS) and the control group were fed an isocaloric corn oil formula for 14 d (from d -7 to d 7). RBC fatty acid composition was assessed. Oxidative stress was studied by measuring urinary 8-isoprostanes (8-IP) and colon glutathione (GSH) concentration and inducible nitric oxide synthase (iNOS) expression. Colitis was assessed histologically, by production of proinflammatory mediators, including cytokines, leukotrienes B(4) (LTB(4)), and cyclooxygenase-2 (COX-2) and by nuclear factor-κB (NF-κB) activation. The ALA-rich diet significantly increased the RBC levels of ALA, eicosapentaenoic acid, and docosapentaenoic acid (n-3) compared with the TNBS group (P < 0.01 for all). The beneficial effect of ALA supplementation on oxidative stress was reflected by lower urinary 8-IP levels (P < 0.05), a normalized colon GSH concentration (P < 0.01), and reduced colon iNOS expression (P < 0.05) compared with the TNBS group. ALA also protected against colon inflammation as assessed by lower tumor necrosis factor-α secretion and mRNA level (P < 0.05), reduced NF-κB activation (P = 0.01), and lower colon lipid mediator concentrations such as LTB(4) and COX-2 (P < 0.05) compared with the TNBS group. These findings show that an ALA-rich formula is beneficial to TNBS-induced colitic rats via inhibition of oxidative and inflammatory stress.

Beneficial effects of cathepsin inhibition to prevent chemotherapy-induced intestinal mucositis

One of the main secondary toxic side effects of anti-mitotic agents used to treat cancer patients is intestinal mucositis. Previous data showed that cathepsin D activity, contributing to the proteolytic lysosomal pathway, is up-regulated during intestinal mucositis in rats. At the same time, cathepsin inhibition limits intestinal damage in animal models of inflammatory bowel diseases. The aim of this study was to evaluate the effects of cathepsin inhibition on methotrexate-induced mucositis in rats. Male Sprague-Dawley rats received saline solution subcutaneously as the control group or 2·5 mg/kg of methotrexate for 3 days (D0-D2). From D0 to D3 methotrexate-treated rats also received intraperitoneal injections of pepstatin A, a specific inhibitor of cathepsin D or E64, an inhibitor of cathepsins B, H and L, or vehicle. Rats were euthanized at D4 and jejunal samples were collected. Body weight and food intake were partially preserved in rats receiving E64 compared with rats receiving vehicle or pepstatin A. Cathepsin D activity, used as a marker of lysosomal pathway, was reduced both in E64 and pepstatin-treated rats. However, villus atrophy and intestinal damage observed in methotrexate-treated rats were restored in rats receiving E64 but not in rats receiving pepstatin A. The intramucosal concentration of proinflammatory cytokines, interleukin-1β and cytokine-induced neutrophil chemoattractant (CINC)-2, was markedly increased in methotrexate-treated rats receiving vehicle or pepstatin A but not after E64 treatment. In conclusion, a large broad inhibition of cathepsins could represent a new potential target to limit the severity of chemotherapy-induced mucositis as opposed to the inhibition of cathepsin D alone.

A diet containing whey protein, glutamine, and TGFbeta modulates gut protein metabolism during chemotherapy-induced mucositis in rats

BACKGROUND

Mucositis, a common side effect of chemotherapy, is characterized by compromised digestive function, barrier integrity and immune competence.

AIMS

Our aim was to evaluate the impact of a specifically designed diet Clinutren Protect (CP), which contains whey proteins, TGFbeta-rich casein, and free glutamine, on mucositis in rats.

METHODS

Mucositis was induced by three consecutive injections (day 0, day 1, day 2) of methotrexate (2.5 mg/kg). Rats had free access to CP or placebo diets from days -7 to 9. In the placebo diet, whey proteins and TGFbeta-rich casein were replaced by TGFbeta-free casein and glutamine by alanine. Intestinal parameters were assessed at day 3 and 9. Values, expressed as mean +/- SEM, were compared using two-way ANOVA.

RESULTS

At day 3, villus height was markedly decreased in the placebo (296 +/- 11 microm) and CP groups (360 +/- 10 microm) compared with controls (464 +/- 27 microm), but more markedly in the placebo as compared to CP group. The intestinal damage score was also reduced in the CP compared with the placebo group. Glutathione content increased in the CP compared with the placebo group (2.2 +/- 0.2 vs. 1.7 +/- 0.2 micromol/g tissue). Gut protein metabolism was more affected in the placebo than in the CP group. The fractional synthesis rate was decreased in the placebo group (93.8 +/- 4.9%/day) compared with controls (121.5 +/- 12.1, P < 0.05), but not in the CP group (106.0 +/- 13.1). In addition, at day 9, rats exhibited improved body weight and food intake recovery in the CP compared to the placebo group.

CONCLUSIONS

Clinutren Protect feeding reduces intestinal injury in the acute phase of methotrexate-induced mucositis in rats and improves recovery.

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.

Oxidative stress and protective effect of erythropoietin on methotrexate-induced esophageal damage

INTRODUCTION

An experimental study was conducted to investigate the role of oxidative stress and effects of erythropoietin (EPO) on methotrexate-induced esophageal damage.

MATERIALS AND METHODS

Twenty-four female Sprague-Dawley rats were equally divided into 3 groups: Sham operation animals (group S) were administered subcutaneous injections of 0.2 mL of 0.9% NaCl; control animals (group MTX) were administered subcutaneous injections of methotrexate (5 mg/kg) and EPO-treated animals (group EPO) were administered subcutaneous injections of methotrexate (5 mg/kg) and EPO (2000 IU/kg) once daily for 4 consecutive days. At the fifth day, the distal 1.5-cm esophageal segments were harvested for biochemical and histologic investigations. Oxidative damage was assessed by measuring the levels of malondialdehyde and nitric oxide, and activities of superoxide dismutase and catalase in homogenized samples of esophageal tissue. Histologic damage to esophageal tissue was scored and total tissue damage scores were calculated.

RESULTS

Malondialdehyde levels in the S and EPO groups were significantly lower than those in the MTX group (P<0.05). Catalase and superoxide dismutase activities, and nitric oxide levels in the S and EPO groups were significantly higher than those in the MTX group (P<0.05). Esophageal tissue damage was significantly less in the EPO group than that in the MTX group (P<0.05).

CONCLUSIONS

Free radicals elevate in methotrexate given rats' esophagus and EPO has significant preventive effects on methotrexate-induced oxidative damage of esophagus in a rat model.

Methotrexate induces intestinal mucositis and alters gut protein metabolism independently of reduced food intake

One of the main secondary toxic side effects of antimitotic agents used to treat cancer patients is intestinal mucositis. This one is characterized by compromised digestive and absorptive functions, barrier integrity, and immune competence. At the same time, food intake is decreased, which may induce intestinal damages per se. The aim of the study was to characterize which alterations are specific to methotrexate, independently of the anorexic effect of the drug. Male Sprague-Dawley rats received subcutaneously saline solution as control group or 2.5 mg/kg of methotrexate during 3 days (D0-D2). Methotrexate-treated rats were compared with ad libitum and pair-fed controls. Histological examinations and specific markers of the immune and nonimmune gut barrier function were assessed at D4 or D7. Compared with ad libitum and pair-fed controls, methotrexate induced at D4 villus atrophy associated with epithelial necrosis. Mucosal protein synthesis rate and mucin contents of methotrexate treated rats were reduced. At the same time, cathepsin D proteolytic activity was increased compared with ad libitum and pair-fed controls, whereas calpain activity was increased when compared with the only pair-fed controls. These intestinal lesions were associated with various metabolic disturbances such as increased TNF-alpha level and inflammation score in the jejunum but also disturbances of amino acid concentrations in the duodenum and plasma. At D7, these alterations were partially or completely normalized. In addition to the consequences of a low food intake, methotrexate further impairs different biological processes leading to a dramatic loss of gut homeostasis. Targeted nutritional management of chemotherapy receiving patients should be set up to prevent or limit such alterations.

New pathways for alimentary mucositis

Alimentary mucositis is a major dose-limiting toxicity associated with anticancer treatment. It is responsible for reducing patient quality of life and represents a significant economic burden in oncology. The pathobiology of alimentary mucositis is extremely complex, and an increased understanding of mechanisms and pathway interactions is required to rationally design improved therapies. This review describes the latest advances in defining mechanisms of alimentary mucositis pathobiology in the context of pathway activation. It focuses particularly on the recent genome-wide analyses of regimen-related mucosal injury and the identification of specific regulatory pathways implicated in mucositis development. This review also discusses the currently known alimentary mucositis risk factors and the development of novel treatments. Suggestions for future research directions have been raised.