Effects of acid antisecretory drugs on mucus barrier of the rat against 5-fluorouracil-induced gastrointestinal mucositis

Chemotherapy-induced gastrointestinal toxicity: Pathogenesis and current management

Chemotherapy is the most common treatment for malignant tumors. However, chemotherapy-induced gastrointestinal toxicity (CIGT) has been a major concern for cancer patients, which reduces their quality of life and leads to treatment intolerance and even cessation. Nevertheless, prevention and treatment for CIGT are challenging, due to the prevalence and complexity of the condition. Chemotherapeutic drugs directly damage gastrointestinal mucosa to induce CIGT, including nausea, vomiting, anorexia, gastrointestinal mucositis, and diarrhea, etc. The pathogenesis of CIGT involves multiple factors, such as gut microbiota disorders, inflammatory responses and abnormal neurotransmitter levels, that synergistically contribute to its occurrence and development. In particular, the dysbiosis of gut microbiota is usually linked to abnormal immune responses that increases inflammatory cytokines' expression, which is a common characteristic of many types of CIGT. Chemotherapy-induced intestinal neurotoxicity is also a vital concern in CIGT. Currently, modern medicine is the dominant treatment of CIGT, however, traditional Chinese medicine (TCM) has attracted interest as a complementary and alternative therapy that can greatly alleviate CIGT. Accordingly, this review aimed to comprehensively summarize the pathogenesis and current management of CIGT using PubMed and Google Scholar databases, and proposed that future research for CIGT should focus on the gut microbiota, intestinal neurotoxicity, and promising TCM therapies, which may help to develop more effective interventions and optimize managements of CIGT.

An elemental diet protects mouse salivary glands from 5‑fluorouracil‑induced atrophy

An elemental diet (ED) reduces adverse effects of chemotherapy, including oral mucositis, in patients with cancer. However, the detailed mechanism(s) of the healing effects of an ED remains unclear. In the present study, the protective effects of the ED, Elental^®, were examined against 5-fluorouracil (5-FU)-induced oral mucositis and salivary gland atrophy in mice. Mucositis was induced in female ICR mice by injection of 5-FU. The mice were orally administered Elental^® (ED group) or saline (control group). After treatment, the mice body weight, salivary gland weight and the histological changes in the salivary gland granular duct area were monitored. The mice body weight remained stable in the ED group, but was significantly decreased in the control group. Moreover, the salivary gland weight was higher in the ED group compared with the control group. In addition, the salivary gland granular duct area cells were larger in the ED group compared with the control group. Whole transcriptome analysis and network analysis were conducted to understand the mechanisms of action of Elental^® against oral mucositis. Whole transcriptome analysis and Ingenuity Pathways Analysis data suggested that Elental^® contributed to the recovery of mitochondrial function in 5-FU-damaged salivary glands. Immunohistochemical analysis of salivary gland tissue demonstrated that the expression of cytochrome c oxidase subunit 4 and epidermal growth factor were higher in the ED group compared with the control group. Next, the rate of apoptosis in the salivary glands was examined using terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assays. The number of TUNEL-positive cells in the salivary glands was lower in the ED group compared with the control group. These findings suggested that Elental^® may protect mouse salivary glands from 5-FU-induced atrophic changes, which suggests that ED treatment may improve xerostomia and alleviate oral mucositis in patients with cancer receiving 5-FU-based chemotherapy.

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.

Irinotecan induces enterocyte cell death and changes to muc2 and muc4 composition during mucositis in a tumour-bearing DA rat model

Irinotecan-induced mucositis is a major oncological problem. Goblet cells secrete mucus, protecting the intestinal mucosa, with secretion altered during mucositis. The enteric nervous system is involved in regulating gut motility and secretion. The aim of this study was to determine whether enteric neural cells and goblet cells are altered following irinotecan treatment. Tumour-bearing Dark Agouti rats were administered a single dose of 175 mg/kg of irinotecan intraperitoneally and 0.01 mg/kg atropine subcutaneously. Experimental and untreated control rats were killed at times 6, 24, 48, 72, 96 and 120 h after treatment. Jejunum and colon samples were formalin fixed. Haematoxylin and eosin staining, Alcian Blue-PAS staining, and immunohistochemistry with S-100 antibody (neural cell marker) were carried out. Statistical analyses were carried out using Kruskal-Wallis test with Dunns post test, Mann Whitney U test, and nonlinear regression. Total goblet cells decreased at 72 h compared with controls in the colon (p < 0.05). The percentage of cavitated goblet cells decreased compared to all other time points at 120 h in the colon. The number of S-100-positive cells in the submucosal plexus decreased in the colon (p = 0.0046) and in the myenteric plexus of the jejunum and colon (p = 0.0058 and p = 0.0022, respectively), on comparing treated with control. Enteric ganglia in the myenteric plexus of the jejunum decreased at 24 h and 96 h. Irinotecan-induced mucositis is associated with increases in mucus secretion and enteric neural cell change. These changes may contribute to the pathophysiology of mucositis through the dysregulation of neural signalling.

5-Fluororacil-Induced Gastrointestinal Damage Impairs the Absorption and Anticoagulant Effects of Dabigatran Etexilate

Fluoropyrimidines, including 5-fluororacil (5-FU), cause gastrointestinal damage in the clinical setting and might affect the gastrointestinal absorption of concomitantly administered drugs. We aimed to evaluate the effects of fluoropyrimidine-induced gastrointestinal damage on the pharmacokinetics and pharmacodynamics of dabigatran etexilate (DABE), an anticoagulant, in rats with gastrointestinal damage induced by the repeated oral administration of 5-FU. Rats were administered DABE orally or dabigatran (DAB), an active moiety of DABE, intravenously. The plasma DAB concentration was determined using liquid chromatography-tandem mass spectrometry. The activated partial thromboplastin time (APTT) was measured before and 30 min after the administration of each drug, and the APTT ratio was calculated. In 5-FU-treated rats, the maximum plasma concentration, the area under the concentration-time curve of DAB after the oral administration of DABE, and the oral bioavailability of DABE were significantly decreased to 18.3%, 22.9%, and 16.3% of the respective control values. The 5-FU-treated rats' APTT ratio was also significantly lower than the control value. Fluoropyrimidine-induced gastrointestinal damage might reduce the plasma concentration of DAB by impairing DABE absorption and might attenuate the anticoagulant effects of DABE in the clinical setting.

5-Fluorouracil treatment alters the expression of intestinal transporters in rats

5-Fluorouracil (5-FU), an anticancer drug, causes severe gastrointestinal damage, which may affect the absorption of orally administered drugs including the substrates of intestinal uptake and efflux transporters. This study aimed to investigate quantitatively the effect of 5-FU-induced intestinal damage on the expression of intestinal transporters: P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and peptide transporter 1 (PEPT1) in rats. The rats were treated with 5-FU (30 mg/kg/day, p.o.) for 5 days to induce intestinal damage, and then the upper, middle and lower intestinal segments were removed. The mRNA and protein expression levels of these transporters in each segment were determined using quantitative real-time PCR and Western blotting, respectively. In the 5-FU-treated rats, the protein levels of P-gp and Bcrp in the upper segment were significantly increased to 15- and 2.6-fold of the control, respectively, while those in other segments were unaffected. Pept1 expression was increased by 5-FU in almost all segments. A remarkable increase in P-gp expression was shown, the uptake of digoxin, a P-gp substrate, in each intestinal segment was measured using a rat everted sac. As a result, the uptake of digoxin in the upper segments of 5-FU-treated rats was decreased compared with that of the control. In conclusion, 5-FU-induced intestinal damage was shown to alter the expression of these transporters, especially in the upper intestinal segment, while the characteristics of the influence varied among the transporters. The 5-FU-induced intestinal damage may affect transporter-mediated drug absorption of orally administered drugs in the clinical setting.

Petroselinum Crispum is Effective in Reducing Stress-Induced Gastric Oxidative Damage

Background:

Oxidative stress has been shown to play a principal role in the pathogenesis of stress-induced gastric injury. Parsley (Petroselinum crispum) contains many antioxidants such as flavanoids, carotenoids and ascorbic acid.

Aims:

In this study, the histopathological and biochemical results of nutrition with a parsley-rich diet in terms of eliminating stress-induced oxidative gastric injury were evaluated.

Study Design:

Animal experimentation

Methods:

Forty male Wistar albino rats were divided into five groups: control, stress, stress + standard diet, stress + parsley-added diet and stress + lansoprazole (LPZ) groups. Subjects were exposed to 72 hours of fasting and later immobilized and exposed to the cold at +4 degrees for 8 hours to create a severe stress condition. Samples from the animals’ stomachs were arranged for microscopic and biochemical examinations.

Results:

Gastric mucosal injury was obvious in rats exposed to stress. The histopathologic damage score of the stress group (7.00±0.57) was higher than that of the control group (1.50±0.22) (p<0.05). Significant differences in histopathologic damage score were found between the stress and stress + parsley-added diet groups (p<0.05), the stress and stress + standard diet groups (p<0.05), and the stress and stress + LPZ groups (p<0.05). The mean tissue malondialdehyde levels of the stress + parsley-added group and the stress + LPZ group were lower than that of the stress group (p<0.05). Parsley supported the cellular antioxidant system by increasing the mean tissue glutathione level (53.31±9.50) and superoxide dismutase (15.18±1.05) and catalase (16.68±2.29) activities.

Conclusion:

Oral administration of parsley is effective in reducing stress-induced gastric injury by supporting the cellular antioxidant defence system.

Pharmacokinetic Properties of Oral Lafutidine Tablets and the Effect of Food on its Pharmacokinetics in Healthy Chinese Subjects

INTRODUCTION

The aim of this study was to evaluate the pharmacokinetics (PK) of single and multiple doses of oral lafutidine tablets and the effect of food on the PK properties in healthy Chinese subjects. The tolerability and the effect of gender on the PK properties were also evaluated to acquire more PK information.

METHODS

Three PK studies were conducted in 12 healthy Chinese subjects (6 male, 6 female). Study 1 was a single-dose, three-period, three-dose level (10, 20, and 40 mg), three-sequence cross-over study under fasting conditions. Study 2 was a repeat-dose study (10 mg twice daily over 6 days; all 12 subjects). Study 3 was a two-period, two-sequence cross-over single-dose (10 mg) food interaction study. All randomizations (study 1, study 3) were done to ascertain 1:1 gender ratio per sequence. A validated liquid chromatography tandem mass spectrometry (LC/MS/MS) method was used to determine plasma lafutidine concentrations. PK parameters were calculated by the non-compartmental method.

RESULTS

The area under the time-concentration curve (AUC) and maximum plasma concentration (C _max) of lafutidine tablets were dose-independent in the single-dose study among these healthy volunteers. The PK parameters of the multiple-dose study were inconsistent with the single study. After administration of a single dose of 10 mg under either fed or fasting conditions, we found that food may not affect the degree of absorption of the lafutidine tablets, but it may slow down the absorption rate. This is shown by the fact that the AUC showed no significant difference while the peak time was significantly delayed under fed conditions.

CONCLUSION

The PK of lafutidine showed dose proportionality. There was no significant accumulation of lafutidine tablets with multiple dosing. Food did not affect the degree of lafutidine absorption, but it did reduce the rate of absorption. Further study is needed regarding the effect of gender on lafutidine. Lafutidine was well tolerated within the dose range 10-40 mg, and no serious adverse events were observed.

Elemental diet moderates 5-fluorouracil-induced gastrointestinal mucositis through mucus barrier alteration

PURPOSE

There are reports that elemental diet (ED) ameliorates oral mucositis caused by antineoplastic chemotherapy. Although this effectiveness may be partly due to high nutrient absorption, the effects of chemotherapy on mucosal defense mechanisms remain unclear. We investigated the effects of oral supplementation with ED on mucin in 5-fluorouracil (5-FU)-induced intestinal mucositis.

METHODS

5-FU was administered to rats orally once daily, and ED was supplied orally twice daily for 5 days. The severity of mucositis was assessed by length, dry tissue weight, and villus height of the intestinal tract. Using anti-mucin monoclonal antibody, we compared the immunoreactivity in the gastrointestinal (GI) tract and mucin content by histological and biochemical examinations.

RESULTS

Oral supplementation with ED reduced histological damage and loss of length, dry tissue weight, and villus height induced by 5-FU administration. ED markedly altered PGM34 antibody immunoreactivity and mucin contents in the small intestine of rats with 5-FU-induced mucositis.

CONCLUSIONS

ED may possibly be more effective for the prevention of antineoplastic chemotherapy-induced mucositis through the activation of GI mucus cells.

Efficacy of Lafutidine Versus Famotidine in Patients with Reflux Esophagitis: A Multi-Center, Randomized, Double-Blind, Non-inferiority Phase III Trial

BACKGROUND

There has been no study on the efficacy of lafutidine for patients with reflux esophagitis in Korea.

AIM

To evaluate the efficacy of a new-generation histamine-2 receptor antagonist, lafutidine, in comparison with famotidine in patients with reflux esophagitis.

METHODS

This was a randomized, double-blind, non-inferiority trial enrolling patients with erosive esophagitis. The efficacy and safety of 20 mg lafutidine (treatment group) were compared with those of 40 mg famotidine (control group) and 20 mg omeprazole (reference group). The primary endpoint was the complete healing rates of reflux esophagitis on endoscopy after 8 weeks of treatment. The non-inferiority margin was assumed to be -15 %.

RESULTS

The healing rates of reflux esophagitis on endoscopy after 8 weeks of treatment were 70.14 % (101/144) in the lafutidine, 63.45 % (92/145) in the famotidine, and 85.71 % (126/147) in the omeprazole group. The difference in healing rates between the lafutidine and famotidine groups was 6.69 % (95 % confidence interval = [-4.14 to 17.52]). In addition, lafutidine was superior to famotidine in clinical improvement (53.73 % vs. 39.55 %, P = 0.0200).

CONCLUSIONS

Lafutidine was non-inferior to famotidine in healing of reflux esophagitis. Lafutidine, however, was superior to famotidine in terms of symptom relief of reflux esophagitis.

Human uridine phosphorylase-1 inhibitors: a new approach to ameliorate 5-fluorouracil-induced intestinal mucositis

PURPOSE

5-fluorouracil (5-FU) has been broadly used to treat solid tumors for more than 50 years. One of the major side effects of fluoropyrimidines therapy is oral and intestinal mucositis. Human uridine phosphorylase (hUP) inhibitors have been suggested as modulators of 5-FU toxicity. Therefore, the present study aimed to test the ability of hUP blockers in preventing mucositis induced by 5-FU.

METHODS

We induced intestinal mucositis in Wistar rats with 5-FU, and the intestinal damage was evaluated in presence or absence of two hUP1 inhibitors previously characterized. We examined the loss of weight and diarrhea following the treatment, the villus integrity, uridine levels in plasma, and the neutrophil migration by MPO activity.

RESULTS

We found that one of the compounds, 6-hydroxy-4-methyl-1H-pyridin-2-one-3-carbonitrile was efficient to promote intestinal mucosa protection and to inhibit the hUP1 enzyme, increasing the uridine levels in the plasma of animals. However, the loss of body weight, diarrhea intensity or neutrophil migration remained unaffected.

CONCLUSION

Our results bring support to the hUP1 inhibitor strategy as a novel possibility of prevention and treatment of mucositis during the 5-FU chemotherapy, based on the approach of uridine accumulation in plasma and tissues.

Changes in the mucus barrier during cisplatin-induced intestinal mucositis in rats

AIM

Gastrointestinal mucositis is a frequent complication of antineoplastic chemotherapy, but the effects of chemotherapy on mucosal defense mechanisms remain poorly understood. We studied the effects of cisplatin on mucin, one of the principal defense factors of the gastrointestinal mucosa, and evaluated the efficacy of two different types of H2-receptor antagonists against cisplatin-induced mucositis.

METHODS

Cisplatin (6 mg/kg) was administered intravenously to rats (day 0). The rats were sacrificed 1, 3, 7, and 11 days after treatment, and their stomach, jejunum, ileum, and colon were removed. Immunoreactivity of the mucosa was compared with the use of anti-mucin monoclonal antibody. To evaluate the efficacy of H2-receptor antagonists, either famotidine (3 mg/kg) or lafutidine (30 mg/kg) was given orally once daily on days 0, 1, and 2. Histological and biochemical findings were compared among the groups to assess effects on cisplatin-induced injury.

RESULTS

Cisplatin significantly altered the immunoreactivity and content of mucin in the small intestinal mucosa, especially in the ileum. Lafutidine protected against cisplatin-induced mucosal injury and attenuated decreased mucin accumulation.

CONCLUSION

Cisplatin appears to alter the mucus barrier function in the intestinal mucosa. Lafutidine might effectively prevent chemotherapy-induced mucositis by activating intestinal mucus cells.

Possible involvement of host defense mechanism in the suppression of rat acute reflux esophagitis by the particular histamine H2 receptor antagonist lafutidine

AIMS

Gastroesophageal reflux disease is considered to be caused primarily by gastric juice refluxed into the esophagus. Here, we investigated the possible involvement of host defense mechanisms in the development of acute reflux esophagitis using lafutidine, a histamine H(2) receptor antagonist (H(2)RA) with proven gastric mucosal protective effects.

METHODS AND RESULTS

The ligation of both the pylorus and the forestomach of SD rats under anesthesia caused hemorrhagic lesions in the esophageal mucosa at 6 h. Lesion formation was significantly inhibited by treatment with H(2)RAs, including the conventional H(2)RAs famotidine and cimetidine as well as lafutidine. The maximum suppressive abilities of these agents were similar to that of the proton pump inhibitor lansoprazole. Interestingly, unlike famotidine, lafutidine at low doses significantly suppressed esophagitis without inhibiting gastric acid secretion. Note that neither lafutidine nor famotidine inhibited hexosamine output in gastric juice samples obtained 3 h after ligation. Additionally, the protective effect of lafutidine, but not of famotidine, was partly attenuated by the denervation of capsaicin-sensitive afferent nerves with a large dose of capsaicin.

CONCLUSION

The present results indicate that esophageal host-defense via capsaicin-sensitive afferent nerves may contribute to the therapeutic action of lafutidine.

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.

Nippostrongylus brasiliensis: increase of sialomucins reacting with anti-mucin monoclonal antibody HCM31 in rat small intestinal mucosa with primary infection and reinfection

Infections with the parasitic helminth, Nippostrongylus brasiliensis, cause changes in rat small intestinal goblet cell mucin, particularly in the peripheral sugar residues of oligosaccharide. These changes may correlate with expulsion. In this study, we examined changes in mucin oligosaccharides caused by primary infection and reinfection with N. brasiliensis, using two monoclonal antibodies, HCM31 and PGM34, that react with sialomucin and sulfomucin, respectively. Enzyme-linked immunosorbent assay of jejunal mucins showed that the relative reactivity of mucins with HCM31, but not PGM34, increased up to 16 days after primary infection and 6 days after reinfection, the times when the worms were expelled from the rats. Immunohistochemical studies confirmed that goblet cells stained with HCM31 greatly increased at the time of worm expulsion. These results indicate that the marked increase observed in HCM31-reactive sialomucins may be related to expulsion of the worms.