The molecular immunology of mucositis: implications for evidence-based research in alternative and complementary palliative treatments

L-Glutamine Substantially Improves 5-Fluorouracil-Induced Intestinal Mucositis by Modulating Gut Microbiota and Maintaining the Integrity of the Gut Barrier in Mice

SCOPE

This study investigates the potential of glutamine to mitigate intestinal mucositis and dysbiosis caused by the chemotherapeutic agent 5-fluorouracil (5-FU).

METHODS AND RESULTS

Over twelve days, Institute of Cancer Research (ICR) mice are given low (0.5 mg kg-1) or high (2 mg kg-1) doses of L-Glutamine daily, with 5-FU (50 mg kg-1) administered between days six and nine. Mice receiving only 5-FU exhibited weight loss, diarrhea, abnormal cell growth, and colonic inflammation, correlated with decreased mucin proteins, increased endotoxins, reduced fecal short-chain fatty acids, and altered gut microbiota. Glutamine supplementation counteracted these effects by inhibiting the Toll-like receptor 4/nuclear factor kappa B (TLR4/NF-κB) pathway, modulating nuclear factor erythroid 2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) oxidative stress proteins, and increasing mammalian target of rapamycin (mTOR) levels, thereby enhancing microbial diversity and protecting intestinal mucosa.

CONCLUSIONS

These findings underscore glutamine's potential in preventing 5-FU-induced mucositis by modulating gut microbiota and inflammation pathways.

Pretreatment With L-Citrulline Positively Affects the Mucosal Architecture and Permeability of the Small Intestine in a Murine Mucositis Model

BACKGROUND

Mucositis is a common complication in patients undergoing radiotherapy and chemotherapy. It is associated with pain, poor quality of life, and malnutrition, leading to an increased number of hospital admissions and prolonged hospitalization. The use of immunonutrients may be an alternative treatment option, which may help to improve patient outcome.

OBJECTIVE

Here we assessed the impact of L-citrulline (CIT) on a murine model of 5-fluorouracil (5FU)-induced mucositis.

METHODS

Swiss male mice were randomized into 4 groups: control, CIT, 5FU, and 5FU+CIT. Mice were fed with commercial chow and supplemented with an oral solution of alanine (control and 5FU groups) or CIT (CIT and 5FU+CIT groups). On the seventh day, mice received intraperitoneal phosphate-buffered saline or 5FU (200 mg/kg, single dose) to induce mucositis. On the 10th day, mice were euthanized, and the blood and small intestines were harvested. Body weight, morphology, histopathology score (hematoxylin and eosin) of the small intestine (from 0-12), myeloperoxidase activity, oxidative stress level, and intestinal permeability were assessed.

RESULTS

We observed significant weight loss after the administration of 5FU in both treated and control animals. CIT administration contributed to a partial recovery of the mucosal architecture as well as an intermediate reduction of the histopathologic score, and functional intestinal permeability was partially rescued.

CONCLUSIONS

CIT administration attenuated 5FU-mediated damage to the mucosal architecture of the small intestine, decreasing the size of the injured areas and promoting decreased intestinal permeability.

Protective effect of amifostine on high-dose methotrexate-induced small intestinal mucositis in mice

BACKGROUND

Amifostine has been shown to be capable of minimizing radiotherapy-induced oral mucositis, but whether it protects small intestinal mucosae from high-dose methotrexate-induced damage is presently unknown.

AIM

We aimed to evaluate the protective effect of amifostine against high-dose methotrexate-induced small intestinal mucositis and its mechanism.

METHODS

Ninety Kunming mice were randomly divided into five experimental groups: saline control; high-dose methotrexate (HDMTX) group: treated with a single high dose of methotrexate; calcium folinate (CF) group: treated with high-dose methotrexate followed with CF; Amifostine group: treated with amifostine, followed with high-dose methotrexate; and amifostine-CF group: treated with amifostine pre-high-dose methotrexate and followed by CF post-high-dose methotrexate. Mouse weight, villus height and crypt depth, stool consistency, white blood cell count, death and survival were recorded. Bax and Bcl-2 mRNA expression were quantified by semi-quantitative PCR.

RESULTS

Compared to the mice treated with HDMTX, CF, and amifostine, mice treated with Amifostine-CF group were heavier and had greater villus height, crypt depth, and normal white blood cell count and lower diarrhea rate and mortality than the HDMTX, CF and amifostine groups. There was a significant decrease in enterocyte apoptosis in amifostine-CF mice compared with the HDMTX and CF groups.

CONCLUSIONS

The effect of amifostine plus CF was greater than amifostine or CF alone in preventing high-dose methotrexate-induced intestinal mucositis and improving intestinal recovery in mice.

Transitioning Toward Evidence-Based Research in the Health Sciences for the XXI Century

This article discusses some of the misconceptions of evidence-based research in the health sciences. It proposes that since not all treatments in medicine and dentistry can be evidence-based, clinical applications of the evidence-based process should become a specialty. The case is particularly evident in dentistry. Therefore dentistry is taken in this article as a model for discussion. We propose that to approach dentistry from the viewpoint of the patient-oriented evidence that matters (POEM) is perfectly acceptable so far as we also engage in the process of research evaluation and appraisal in dentistry (READ). We distinguish between dentistry based on the evidence, and evidence-based dentistry. We argue that when invoking an evidence-based approach to dentistry or medicine, it is not sufficient to establish the 'levels of evidence', but rather that all evidence-based clinical intervention must undergo the stringent process of evidence-based research so that clinical practice guidelines be revised based on the best available evidence.

Administration of Ratanhia-based herbal oral care products for the prophylaxis of oral mucositis in cancer chemotherapy patients: a clinical trial

Oral complications are a common side effect of cancer chemotherapy, as antineoplastic agents affect both the immune system and the oral mucosa. This study demonstrates preventive and therapeutic effects of dental treatment and regular use of Weleda Ratanhia-Mundwasser((R)) (herbal mouthwash) and Weleda Pflanzen-Zahngel((R)) (herbal toothgel) on oral mucositis during chemotherapy. Thirty-two female patients with breast cancer starting on chemotherapy were evaluated in this study. Plaque index, gingival index, degree of mucositis and 10 single symptoms were monitored once weekly for four consecutive weeks. After four weeks, plaque and gingival indexes were slightly decreased compared to baseline values. The degree of mucositis was increased by one grade in 15.6 % of the patients and over 70 % remained without symptoms. On the whole, single symptoms decreased from day 7 since beginning of chemotherapy to day 28. Mucositis symptoms were moderate in severity, and the results indicate a positive influence of using Weleda Ratanhia-Mundwasser and Weleda Pflanzen-Zahngel. Further studies might be promising.

Prospective evaluation of HSV, Candida spp., and oral bacteria on the severity of oral mucositis in pediatric acute lymphoblastic leukemia

BACKGROUND

Oral mucositis is a common collateral effect among the secondary complications resulting from chemotherapy. The objective of this study was to prospectively evaluate the association of HSV-1, Candida spp., and oral bacteria on the severity of oral mucositis in pediatric acute lymphoblastic leukemia (ALL).

PROCEDURE

Seventy-one prospective patients were included. Analyses of oral microbiota were conducted on days 14 (D14) and 56 (D56) of the Brazilian GBTLI-99 treatment protocol. Herpes simplex virus (HSV) identification was performed by PCR followed by DNA sequencing analysis. Bacteria and fungi identification was obtained by standard microbiological culture tests.

RESULTS

HSV-1 was found in 10.37% of individual patient samples. One sample was positive for HSV-4. On D14, we found an association between the severity of mucositis and the presence of HSV (p = 0.0347) and Candida spp. (p = 0.0078). At D56, we found an association between the severity of mucositis and the presence of HSV on D14 (p < 0.0001) and HSV presence (p = 0.0317).

CONCLUSION

The presence of HSV, mainly HSV-1, and Candida spp. was associated with mucositis severity in pediatric ALL. No association could be found between bacterial CFU and severity of mucositis.

Colchicine mouth washings to improve oral mucositis in patients with hematological malignancies: a clinical trial

OBJECTIVE

Oral mucositis (OM) is a frequently encountered problem as a complication of cancer treatment. We investigated whether daily washings with colchicine solution improved mucositis in patients with hematological malignancies undergoing chemotherapy.

METHODS

This study was a one-arm, nonrandomized clinical trial that used a historical control group. Patients were included in the study from the first day of mucositis and followed up until discharge. Patients received 2 mg colchicine mouthwashes daily for 5 days or saline solution. OM was assessed once daily until symptom resolution, using the WHO grading scale of 0-4 and a visual analogue scale. We determined that at least 40 patients in the colchicine group would be needed to detect a 20% difference in the duration of OM between Groups A and B, with a 95% confidence level and a power of 80%.

RESULTS

82 patients were included in the final analysis, 40 in the colchicine group and 42 in the control group. Median duration of OM was significantly different among groups; 9 days (range 1-17 days) for the control group versus 6 days (range 3-13 days) for those exposed to colchicine mouthwash (p = .028). The median days of regression of mucosal lesions were significantly different (p = .047) among the control group (7 days [range 3-20]) compared to the colchicine group (4 days [range 2-14]).

SIGNIFICANCE OF RESULTS

Although our findings suggest that colchicine mouthwash is helpful in reducing the severity and duration of chemotherapy-induced OM, randomized trials are needed to confirm these results.

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.

Technological advances in mucositis research: new insights and new issues

The last decade has seen a significant acceleration in the introduction of molecular tools used in cancer diagnosis and treatment. Driving factors have been the movement of advanced technologies from the laboratory to the clinic and the shift to a more genetically individualised patient approach. With this has followed an increased ability to study the toxic side effects of cancer treatment, some of which are newly emerging, by utilising many of the same technologies. Mucositis research in particular has reached a golden period of investigation and understanding of the pathobiological mechanisms that contribute to the development of the condition. This paper has selected a few of the emerging technologies that are highly relevant to mucositis research to discuss in detail. These technologies include target therapies, toxicogenomics, nanomedicine, pharmacogenetics and pharmacogenomics, with a particular focus on microarray technology. These technologies are critical to discuss in the context of mucositis research not only because they are widely applicable to cutting edge research, but they also provide opportunities for further advances both in the laboratory and clinical setting. In addition, some of these technologies have the potential to be implemented immediately in the field of mucositis research.

Lactobacillus fermentum BR11 and fructo-oligosaccharide partially reduce jejunal inflammation in a model of intestinal mucositis in rats

Although probiotics are beginning to enter mainstream medicine for disorders of the colon, their effects on the small bowel remain largely unexplored. We investigated the recently identified probiotic, Lactobacillus fermentum (L. fermentum) BR11 (BR11) and the prebiotic, fructo-oligosaccharide (FOS), both individually and in synbiotic combination, for their potential to alleviate intestinal mucositis. From Days 0-9, rats consumed skim milk (SM; saline + SM), low dose (LD-BR11; 1 x 10(6)cfu/ml), high dose (HD-BR11; 1 x 10(9)cfu/ml), LD-FOS (3%), HD-FOS (6%), or synbiotic (HD-BR11/FOS). On Day 7, rats were injected with 5-fluorouracil (5-FU; 150 mg/kg). All rats were sacrificed on Day 10. Intestinal tissues were collected for quantitative histology, sucrase, and myeloperoxidase (MPO) determinations. 5-FU decreased sucrase activity, villus height, crypt depth, and crypt cell proliferation compared to controls. Compared to 5-FU + SM, histological damage severity scores were increased for all treatments, although all were effective at reducing jejunal inflammation, indicated by reduced MPO activity (P < 0.05). The combination of BR11 and FOS did not provide additional protection. Moreover, HD-FOS and the synbiotic actually increased clinical mucositis severity (P < 0.05). We conclude that L. fermentum BR11 has the potential to reduce inflammation of the upper small intestine. However, its combination with FOS does not appear to confer any further therapeutic benefit for the alleviation of mucositis.

Regulatory T cells, a potent immunoregulatory target for CAM researchers: modulating tumor immunity, autoimmunity and alloreactive immunity (III)

Regulatory T (T(reg)) cells are the major arbiter of immune responses, mediating actions through the suppression of inflammatory and destructive immune reactions. Inappropriate T(reg) cell frequency or functionality potentiates the pathogenesis of myriad diseases with ranging magnitudes of severity. Lack of suppressive capability hinders restraint on immune responses involved in autoimmunity and alloreactivity, while excessive suppressive capacity effectively blocks processes necessary for tumor destruction. Although the etiology of dysfunctional T(reg) cell populations is under debate, the ramifications, and their mechanisms, are increasingly brought to light in the medical community. Methods that compensate for aberrant immune regulation may not address the underlying complications; however, they hold promise for the alleviation of debilitating immune system-related disorders. The dominant immunoregulatory nature of T(reg) cells, coupled with recent mechanistic knowledge of natural immunomodulatory compounds, highlights the importance of T(reg) cells to practitioners and researchers of complementary and alternative medicine (CAM).

Mucositis pain induced by radiation therapy: prevalence, severity, and use of self-care behaviors

Pain from radiation therapy (RT)-induced mucositis is a significant clinical problem for patients with head and neck cancer (HNC). The purpose of this study was to determine the pattern, severity, and time course of RT-induced mucositis pain; self-care behaviors (SCBs) used to manage mucositis pain; and the effectiveness of these behaviors in relieving such pain. Forty-nine patients with HNC were assessed using the MacDibbs Mouth Assessment Tool to determine the severity of RT-induced mucositis pain over their course of RT and at a one-month follow-up visit. All patients developed pain due to RT-induced mucositis. A Self-Care Diary was used weekly by patients to record SCBs and their effectiveness. The most effective SCBs for RT-induced mucositis pain were mouth rinsing and using oral analgesics. However, more severe pain with swallowing was not managed well throughout the study. Future studies need to test more effective strategies to manage RT-induced mucositis pain.

Regulatory T Cells, a Potent Immunoregulatory Target for CAM Researchers: Modulating Allergic and Infectious Disease Pathology (II)

Regulatory T (T_reg) cells maintain dominant control of immune responses to foreign materials and microbes. Appropriate T_reg cell suppression of immune responses is essential for the maintenance of efficacious defensive responses and the limitation of collateral tissue damage due to excess inflammation. Allergy and infection are well studied and frequent afflictions in which T_reg cells play an essential role. As such, they provide excellent models to communicate the significance and relevance of T_reg cells to complementary and alternative medicine (CAM).