Increased frequency of oral plasma cell mucositis/plasma cell gingivitis after the COVID-19 pandemic: a 23-year retrospective analysis and review of diagnostic challenges relating to this condition.

OBJECTIVE: Oral plasma cell mucositis (PCM) or localized plasma cell gingivitis (PCG) is an idiopathic inflammatory condition often associated with hypersensitivity reactions. This study aimed to evaluate the frequency and features of PCM/PCG in a large biopsy service over a time period of more than 20 years. STUDY DESIGN: The biopsy archives at University of Florida College of Dentistry were searched from 2000 through the first quarter of 2023 for cases of oral PCM or PCG. Case data were aggregated and analyzed. RESULTS: A total of 107 cases were included. Between 2000 and 2019, PCM/PCG was diagnosed in 0.03% of all biopsy cases. Starting in 2020 through 2023, the percentage of biopsies diagnosed as PCM/PCG increased threefold to 0.10% of all biopsy cases, and the mean patient age increased by 3 years. There were no statistically significant differences between cases diagnosed from 2000 to 2019 and those from 2020 to 2023 regarding age, sex, location, or histology. CONCLUSIONS: A significant increase in PCM/PCG was identified in this study at one institution coinciding with the start of the COVID-19 pandemic. Further investigation is recommended to determine if this is a widespread phenomenon and identify possible etiologic mechanisms.

Retrospective Case Series of Cocaine-Associated Plasma Cell Orificial Mucositis.

Importance: Plasma cell orificial mucositis (PCOM) associated with cocaine use is an emerging, rare condition that has become a concern in Spain in recent years. Limited knowledge exists regarding this novel condition. Objectives: To delineate the clinicopathologic characteristics of this emerging entity and establish a novel approach in the differential diagnosis of cocaine-associated lesions. Design, Setting, and Participants: A descriptive, retrospective, multicenter case series of 10 patients diagnosed with cocaine-associated PCOM was conducted in Spain from April 2020 to March 2023. Main Outcomes and Measures: Patient demographic, clinical, histopathologic, and treatment data were collected. Results: A total of 10 patients (6 [60%] male; median [range] age, 45.5 [36-66] years) presenting with exudative ulcerated plaques were identified for this study. The lesions had raised and erythematous edges over the nostril and a median (range) evolution time of 9 (2-24) months. Septal or palate perforations were observed in 4 (40%) of the patients. Biopsies revealed a dense inflammatory infiltrate of plasma cells in the dermis without atypia and with eosinophils. All patients reported recent cocaine use. Three urine tests detected cocaine but found no presence of amphetamines or opiates. Six patients improved with corticosteroid therapy. Up to 60% of patients were lost to follow-up. Conclusions and Relevance: This case series describes the clinicopathologic characteristics of PCOM, an emerging entity associated with cocaine use in Spain, and demonstrates a novel approach in the differential diagnosis of cocaine-associated lesions. To date, cocaine-associated skin lesions have been reported as neutrophilic dermatoses and vasculitis. The appearance of a plasma cell infiltrate changes what has been described in the medical literature so far. PCOM is a benign condition of unknown cause characterized by a proliferative polyclonal plasma cell infiltrate. A comprehensive differential diagnosis workup is required to reach this exclusionary diagnosis. Several irritants have been documented in cases of PCOM, and a hypersensitivity mechanism has been proposed. Since the initial report of cocaine-associated PCOM in Spain, its incidence has experienced a surge in the country. The cause of this phenomenon may be attributed to newly unidentified adulterants. The administration of corticosteroids and discontinuation of cocaine use are the sole treatments that have demonstrated efficacy. Clinicians should be vigilant regarding this emerging condition and conduct inquiries into cocaine use. Additional research is required to clarify the pathophysiology of this emerging condition.

Investigation of the efficacy of systemic N-Acetyl Cysteine therapy preventing nasal mucositis following radiotherapy.

BACKGROUND: Radiotherapy (RT) is one of the main methods used in the treatment of head and neck cancers but may cause mucosal side effects in the tumor area and surrounding structures. These include nasal mucosal disorders and chronic rhinosinusitis due to disruption of the mucociliary system. This situation seriously affects the quality of life of the patients and there is no accepted effective method for its treatment yet. In our study, we aimed to examine the side effects of RT on the nasal mucosa and mucociliary system and to investigate histopathologically and immunohistochemically the effectiveness of N-acetyl cysteine (NAC) in preventing these side effects of RT. METHODOLOGY: The study was carried out with 30 female Sprague Dawley rats devided in three groups. No intervention was made in the control group. On the second day of the experiment, 30 Gy radiotherapy was applied to the head area in the RT group. NAC was administered intraperitoneally at a dose of 1 g/kg/day for 14 days from the first day of the study to the RT+ NAC group. On the second day, 30 Gy of radiotherapy was applied to the head area 1 hour after the NAC application. On the 14th day, 1 hour after NAC was applied to the RT+NAC group, all animals were sacrificed. The nasal mucosa samples were stained with hematoxylin-eosin, and the intensity and extent of staining sentan in the nasopharyngeal tissue samples were evaluated by immunohistochemical staining using anti-SNTN antibody. RESULTS: The loss of cilia in the nasal tissue was lower in the RT+NAC group than in the RT group. The intensity and extent of staining in the nasopharyngeal tissue of Sentan was higher in the RT+NAC group than in the RT group. Mucosal neutrophil and mononuclear inflammatory cell infiltration in the nasal tissue, vascular dilatation, hyperemia and hemorrhage, erosion and shedding of the mucosal epithelium, mucosal ulceration were found to be similar in the RT+NAC group and the control group. It was milder in the RT+NAC group than in the RT group, but not statistically significant. CONCLUSIONS: Radiotherapy caused pathological changes in the nasal mucosa, caused loss of cilia and a decrease in the level of Sentan, the cilia apical protein. The results of our study showed that NAC treatment can reduce the side effects of RT on the nasal mucosa. It also showed that NAC was effective in preventing the loss of cilia, which is the building block of the mucociliary system, and improving the expression of Sentan.

Mucoprotective effect of ellagic acid in 5 fluorouracil-induced intestinal mucositis model.

Intestinal mucositis (IM) is a common side effect of several anticancer medications, including 5-fluorouracil (5-FU), and can lead to treatment disruptions and compromised outcomes. IM has severe clinical effects such as diarrhea, erythematous mucosal lesions, and the development of ulcers accompanied by excruciating pain. This study aimed to evaluate the mucoprotective effects of ellagic acid on 5-FU-induced IM in mice. Mice were administered normal saline intraperitoneally for six days, followed by intraperitoneal injection of 5-FU for four days at a dose of 50 mg per kilogram. Ellagic acid was orally administered to the mice in groups III and IV in two doses (5 mg and 10 mg), with a one-hour time separation from 5-FU for ten days. At the end of the experiment, small intestine tissue was collected to measure the levels of antioxidant enzymes superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), and inflammatory cytokines (IL-6, IL-B, TNF) using ELISA assay. Pre-treatment with ellagic acid led to a significant decrease in pro-inflammatory cytokines and improved antioxidant enzyme levels compared to the 5-FU group. Histopathological analysis demonstrated the mucoprotective effect of ellagic acid against 5-FU-induced intestinal changes, including villi atrophy, damage to stem cells, infiltration of inflammatory cells in the mucosal layer, edema, damage to muscular mucosa, and decreased oxidative stress production, such as MDA. These results suggest that ellagic acid may be a potential candidate for treating IM induced by antineoplastic drugs.

Unusual clinical presentations of plasma cell mucositis involving oral mucosa: Presentation of 2 cases and review of the literature.

OBJECTIVE: Plasma cell mucositis (PCM) is a non-neoplastic plasma cell disorder of the upper aerodigestive tract with a high impact on life quality. Less than 70 cases were reported in the literature. The objective of this study was to report 2 cases of PCM. A concise review of the literature is also presented. STUDY DESIGN: Two cases of PCM that presented during the COVID-19 quarantine are reported. The inclusion criteria for the literature review were English-indexed case reports of the last 20 years. RESULTS: Cases were treated with meprednisone. As mechanical trauma was proposed as a triggering factor, its control was also considered. Patients were followed with no relapses. There were 29 studies included. The mean age was 57 years, with a male predominance, different clinical phenotypes, and intensely erythematous mucosa as a classical finding. The most frequent site was the lip, followed by the buccal mucosa. The final diagnosis is clinicopathologic. CD138 expression is a hallmark of plasma cells, frequently aiding PCM diagnosis. Plasma cell mucositis treatment is mostly symptomatic, and several therapeutic modalities have been mostly unsuccessful. CONCLUSIONS: Diagnosing plasma cell mucositis becomes challenging as many lesions may mimic other conditions. Consequently, in these cases, the diagnostic process should gather clinical, histopathologic, and immunohistochemical data.

From Pathogenesis to Intervention: The Importance of the Microbiome in Oral Mucositis.

Oral mucositis (OM) is a common and impactful toxicity of standard cancer therapy, affecting up to 80% of patients. Its aetiology centres on the initial destruction of epithelial cells and the increase in inflammatory signals. These changes in the oral mucosa create a hostile environment for resident microbes, with oral infections co-occurring with OM, especially at sites of ulceration. Increasing evidence suggests that oral microbiome changes occur beyond opportunistic infection, with a growing appreciation for the potential role of the microbiome in OM development and severity. This review collects the latest articles indexed in the PubMed electronic database which analyse the bacterial shift through 16S rRNA gene sequencing methodology in cancer patients under treatment with oral mucositis. The aims are to assess whether changes in the oral and gut microbiome causally contribute to oral mucositis or if they are simply a consequence of the mucosal injury. Further, we explore the emerging role of a patient's microbial fingerprint in OM development and prediction. The maintenance of resident bacteria via microbial target therapy is under constant improvement and should be considered in the OM treatment.

Guiqi Baizhu prescription ameliorates cytarabine-induced intestinal mucositis by targeting JAK2 to inhibit M1 macrophage polarization.

BACKGROUND: Intestinal mucositis (IM) is characterized by damage to the intestinal mucosa resulting from inhibition of epithelial cell division and loss of renewal capacity following anticancer chemotherapy and radiotherapy. Cytarabine (Ara-C), the main chemotherapy drug for the treatment of leukemia and lymphoma, is a frequent cause of IM. Guiqi Baizhu prescription (GQBZP) is a traditional Chinese medicine with anti-cancer and anti-inflammatory effects. PURPOSE: To determine if GQBZP can ameliorate Ara-C induced IM and identify and characterize the pharmacologic and pharmacodynamic mechanisms. STUDY DESIGN AND METHODS: IM was induced in mice with Ara-C and concurrently treated with orally administered GQBZP. Body weight and food intake was monitored, with HE staining to calculate ileal histomorphometric scoring and villus length/crypt depth. Immunoblotting was used to detect intestinal tissue inflammatory factors. M1 macrophages (M1) were labeled with CD86 by flow cytometry and iNOS + F4/80 by immunofluorescence. Virtual screening was used to find potentially active compounds in GQBZP that targeted JAK2. In vitro, RAW264.7 cells were skewed to M1 macrophage polarization by lipopolysaccharide (LPS) and interferon-γ (INF-γ) and treated orally with GQBZP or potential active compounds. M1 was labeled with CD86 by flow cytometry and iNOS by immunofluorescence. ELISA was used to detect inflammatory factor expression. Active compounds against JAK2, p-JAK2, STAT1 and p-STAT1 were identified by western blotting and HCS fluorescence. Molecular dynamics simulations and pharmacokinetic predictions were carried out on representative active compounds. RESULTS: Experimental results with mice in vivo suggest that GQBZP significantly attenuated Ara-C-induced ileal damage and release of pro-inflammatory factors by inhibiting macrophage polarization to M1. Molecular docking was used to identify potentially active compounds in GQBZP that targeted JAK2, a key factor in macrophage polarization to M1. By examining the main components of each herb and applying Lipinski's rules, ten potentially active compounds were identified. In vitro experimental results suggested that all 10 compounds of GQBZP targeted JAK2 and could inhibit M1 polarization in RAW264.7 cells treated with LPS and INF-γ. Among them, acridine and senkyunolide A down-regulated the expression of JAK2 and STAT1. MD simulations revealed that acridine and senkyunolide A were stable in the active site of JAK2 and exhibited good interactions with the surrounding amino acids. CONCLUSIONS: GQBZP can ameliorate Ara-C-induced IM by reducing macrophage polarization to M1, and acridine and senkyunolide A are representative active compounds in GQBZP that target JAK2 to inhibit M1 polarization. Targeting JAK2 to regulate M1 polarization may be a valuable therapeutic strategy for IM.

Contribution of Blood Vessel Activation, Remodeling and Barrier Function to Inflammatory Bowel Diseases.

Inflammatory bowel diseases (IBDs) consist of a group of chronic inflammatory disorders with a complex etiology, which represent a clinical challenge due to their often therapy-refractory nature. In IBD, inflammation of the intestinal mucosa is characterized by strong and sustained leukocyte infiltration, resulting in the loss of epithelial barrier function and subsequent tissue destruction. This is accompanied by the activation and the massive remodeling of mucosal micro-vessels. The role of the gut vasculature in the induction and perpetuation of mucosal inflammation is receiving increasing recognition. While the vascular barrier is considered to offer protection against bacterial translocation and sepsis after the breakdown of the epithelial barrier, endothelium activation and angiogenesis are thought to promote inflammation. The present review examines the respective pathological contributions of the different phenotypical changes observed in the microvascular endothelium during IBD, and provides an overview of potential vessel-specific targeted therapy options for the treatment of IBD.

Therapeutic effect and mechanism of Daikenchuto in a model of methotrexate-induced acute small intestinal mucositis.

BACKGROUND: Daikenchuto (DKT) has positive therapeutic effects on improving various gastrointestinal disorders. The present study investigated whether or not DKT has a potential therapeutic effect on chemotherapy-induced acute small intestinal mucositis (CIM) in a rat model. METHODS: Intraperitoneal injection of 10 mg/kg methotrexate (MTX) every 3 days for a total of 3 doses was used for induction of CIM in a rat model. The MTX and DKT-MTX groups were injected with MTX as above from the first day, and the DKT-MTX and DKT groups were administered 2.7% DKT via the diet at the same time. The rats were euthanized on day 15. RESULTS: The DKT-MTX group showed an improvement in the body weight and conditions of gastrointestinal disorders as well as increased levels of diamine oxidase in plasma and in the small intestinal villi. The pathology results showed that small intestinal mucosal injury in the DKT-MTX group was less severe than that in the MTX group. Immunohistochemistry for myeloperoxidase and malondialdehyde and quantitative real-time polymerase chain reaction (RT-qPCR) for TGF-ß1 and HIF-1α showed that DKT attenuated peroxidative damage. The crypts in the DKT-MTX group contained more Ki-67-positive cells than MTX group. The zonula occluden-1 and claudin-3 results showed that DKT promoted repair of the mucosal barrier. RT-qPCR for the amino acid transporters EAAT3 and BO+AT also confirmed that DKT promoted mucosal repair and thus promoted nutrient absorption. CONCLUSION: DKT protected against MTX-induced CIM in a rat model by reducing inflammation, stimulating cell proliferation, and stabilizing the mucosal barrier.

Characterization of a novel dual murine model of chemotherapy-induced oral and intestinal mucositis.

Oral and intestinal mucositis are debilitating inflammatory diseases observed in cancer patients undergoing chemo-radiotherapy. These are devastating clinical conditions which often lead to treatment disruption affecting underlying malignancy management. Although alimentary tract mucositis involves the entire gastrointestinal tract, oral and intestinal mucositis are often studied independently utilizing distinct organ-specific pre-clinical models. This approach has however hindered the development of potentially effective whole-patient treatment strategies. We now characterize a murine model of alimentary tract mucositis using 5-Fluorouracil (5-FU). Mice were given 5-FU intravenously (50 mg/kg) or saline every 48 h for 2 weeks. Post initial injection, mice were monitored clinically for weight loss and diarrhea. The incidence and extent of oral mucositis was assessed macroscopically. Microscopical and histomorphometric analyses of the tongue and intestinal tissues were conducted at 3 interim time points during the experimental period. Repeated 5-FU treatment caused severe oral and intestinal atrophy, including morphological damage, accompanied by body weight loss and mild to moderate diarrhea in up to 77.8% of mice. Oral mucositis was clinically evident throughout the observation period in 88.98% of mice. Toluidine blue staining of the tongue revealed that the ulcer size peaked at day-14. In summary, we have developed a model reproducing the clinical and histologic features of both oral and intestinal mucositis, which may represent a useful in vivo pre-clinical model for the study of chemotherapy-induced alimentary tract mucositis and the development of preventative therapies.

A Rat Model for Oral Mucositis Induced by a Single Administration of 5-Fluorouracil.

BACKGROUND/AIM: This study aimed to develop a reliable chemotherapy-induced oral mucositis (CIOM) rat model by intraperitoneally administering a single dosage of 5-fluorouracil (5-FU) combined with a chemical stimulus. MATERIALS AND METHODS: The 5-FU dosage for CIOM development was determined by the survival rate of rats administrated 160 mg/kg, 200 mg/kg, and 240 mg/kg of 5-FU. Thirty rats were assigned to normal control (NC) and three experimental groups: i) ulcer formation without 5-FU administration (PBS/U+), ii) 5-FU administration without ulcer formation (5-FU/U-), and iii) ulcer formation after 5-FU administration (5-FU/U+). White blood cell count and weight were measured at the day of 5-FU administration (D0), ulcer formation (D2), and two days after ulcer formation (D4). The oral mucosa for histologic evaluations was obtained two (D4) and five days (D7) after ulcer formation. RESULTS: The 5-FU dosage for CIOM development was 200 mg/kg. White blood cell count (WBC) counts and weight of rats were significantly lower in 5-FU/U- (WBC, p<0.001; weight, p=0.002) and 5-FU/U+ (WBC, p<0.001; weight, p<0.001) groups compared to those in the NC group at D4. The number of Ki-67 positive cells in the oral epithelium was lower in 5-FU/U+ group compared to that in NC (p<0.001) and PBS/U+ (p=0.047) groups at D7. CONCLUSION: Single administration of 200 mg/kg of 5-FU combined with a chemical stimulus can lead to an immune-suppressive status, failure of weight gain, and impairment of epithelium regeneration as observed in a CIOM rat model.

Association of Fructo-oligosaccharides and Arginine Improves Severity of Mucositis and Modulate the Intestinal Microbiota.

Mucositis is defined as inflammatory and ulcerative lesions along of the gastrointestinal tract that leads to the imbalance of the intestinal microbiota. The use of compounds with action on the integrity of the intestinal epithelium and their microbiota may be a beneficial alternative for the prevention and/or treatment of mucositis. So, the aim of this study was to evaluate the effectiveness of the association of fructo-oligosaccharides (FOS) and arginine on intestinal damage in experimental mucositis. BALB/c mice were randomized into five groups: CTL (without mucositis + saline), MUC (mucositis + saline), MUC + FOS (mucositis + supplementation with FOS-1st until 10th day), MUC + ARG (mucositis + supplementation with arginine-1st until 10th day), and MUC + FOS + ARG (mucositis + supplementation with FOS and arginine-1st until 10th day). On the 7th day, mucositis was induced with an intraperitoneal injection of 300 mg/kg 5-fluorouracil (5-FU), and after 72 h, the animals were euthanized. The results showed that association of FOS and arginine reduced weight loss and oxidative stress (P < 0.05) and maintained intestinal permeability and histological score at physiological levels. The supplementation with FOS and arginine also increased the number of goblet cells, collagen area, and GPR41 and GPR43 gene expression (P < 0.05). Besides these, the association of FOS and arginine modulated intestinal microbiota, leading to an increase in the abundance of the genera Bacteroides, Anaerostipes, and Lactobacillus (P < 0.05) in relation to increased concentration of propionate and acetate. In conclusion, the present results show that the association of FOS and arginine could be important adjuvants in the prevention of intestinal mucositis probably due to modulated intestinal microbiota.

The progression of doxorubicin-induced intestinal mucositis in rats.

Chemotherapy-induced intestinal mucositis is a severe side effect contributing to reduced quality of life and premature death in cancer patients. Despite a high incidence, a thorough mechanistic understanding of its pathophysiology and effective supportive therapies are lacking. The main objective of this rat study was to determine how 10 mg/kg doxorubicin, a common chemotherapeutic, affected jejunal function and morphology over time (6, 24, 72, or 168 h). The secondary objective was to determine if the type of dosing administration (intraperitoneal or intravenous) affected the severity of mucositis or plasma exposure of the doxorubicin. Morphology, proliferation and apoptosis, and jejunal permeability of mannitol were examined using histology, immunohistochemistry, and single-pass intestinal perfusion, respectively. Villus height was reduced by 40% after 72 h, preceded at 24 h by a 75% decrease in proliferation and a sixfold increase in apoptosis. Villus height recovered completely after 168 h. Mucosal permeability of mannitol decreased after 6, 24, and 168 h. There were no differences in intestinal injury or plasma exposure after intraperitoneal or intravenous doxorubicin dosing. This study provides an insight into the progression of chemotherapy-induced intestinal mucositis and associated cellular mucosal processes. Knowledge from this in vivo rat model can facilitate development of preventive and supportive therapies for cancer patients.

Protective Effect of Plumeria Pudica Latex Proteins on Intestinal Mucositis Induced by 5-Fluorouracil.

Intestinal mucositis is characterized by inflammation and ulceration of the mucosa that affects the gastrointestinal tract and is associated with administering some drugs, such as 5- Fluorouracil (5-FU), conventional chemotherapy used in clinics for cancer therapy. Inside intestinal mucosa, the 5-FU acts, leading to oxidative stress, stimulating the production/release of proinflammatory cytokines, local accumulation of neutrophils and consequent tissue damage. These alterations favor bacterial proliferation, triggering secondary infections, and are responsible for undesired effects such as myelosuppression and diarrhea. These factors negatively impact oncological patients' quality of life and explain why they commonly interrupt their treatment prematurely. Currently, there is no specific drug with the ability to completely avoid this condition, so the search for new molecules with pharmacological properties that can be used for preventing or ameliorating intestinal mucositis is important. Plumeria pudica is a plant that produces latexcontaining molecules with therapeutic potential. A protein fraction obtained from this latex (LPPp), which comprises a well-defined mixture of chitinases, proteinases proteinase inhibitors, was demonstrated to have antioxidant and anti-inflammatory activities, preserving tissue glutathione and malondialdehyde concentration, reducing superoxide dismutase and myeloperoxidase activity, and reducing the level of proinflammatory cytokines in different experimental models. Given this scenario, inflammation and oxidative stress are directly involved in the pathogenesis of intestinal mucositis promoted by 5-FU. So, the hypothesis is that LPPp could inhibit these factors to attenuate the cytotoxicity of this pathology associated with 5-FU-treatment. This article brings new insights into the potential of the laticifer proteins extracted from the latex of P. pudica and opens new perspectives for the treatment of this type of intestinal mucositis with LPPp.

Evaluation and validation of chemotherapy-specific diarrhoea and histopathology in rats.

Chemotherapy-induced mucositis is characterized by diarrhoea and villous atrophy. However, it is not well-understood why diarrhoea arises, why it only occurs with some chemotherapeutics and how it is related to villus atrophy. The objectives in this study were to determine (i) the relationship between chemotherapy-induced diarrhoea and villus atrophy and to (ii) establish and validate a rat diarrhoea model with clinically relevant endpoints. Male Wistar Han IGS rats were treated with saline, doxorubicin, idarubicin, methotrexate, 5-fluorouracil, irinotecan or 5-fluorouracil+irinotecan. After 72 h, jejunal tissue was taken for morphological, apoptotic and proliferative analyses, and faecal water content and change in body weight were determined. All treatments except methotrexate caused a similar reduction (≈42%) in villus height, but none of them altered mucosal crypt cell proliferation or apoptosis. Doxorubicin, idarubicin, irinotecan and 5-fluorouracil+irinotecan caused body weight reduction, but only irinotecan and idarubicin caused diarrhoea. No direct correlation between diarrhoea and villus height or body weight loss was observed. Therefore, studies of the mechanisms for chemotherapy-induced diarrhoea should focus on functional factors. Finally, the irinotecan and idarubicin diarrhoea models established in this study will be useful in developing supportive treatments of this common and serious adverse effect in patients undergoing chemotherapy.

Taurine Treatment Alleviates Intestinal Mucositis Induced by 5-Fluorouracil in Mice.

Taurine (Tau), a ß-amino acid, exists in red goji fruit (Lycium barbarum L.). It exerts many cellular physiological functions such as anti-inflammation and oxidation resistance. The chemotherapy drug 5-fluorouracil (5FU) can cause intestinal mucositis. However, current therapeutic approaches for mucositis have limited efficacy and are associated with various side effects. It is still unknown whether Tau can alleviate intestinal mucositis. This study aimed to investigate the protective effect of the Tau in a mucositis mouse model and elucidate the underlying molecular mechanisms. The intestinal mucositis symptoms were alleviated by the Tau administration as evidenced by decreased body weight loss, histopathological score, oxidative stress, and improved glutathione (GSH). The Tau supplementation strengthened intestinal epithelial tight junction and reduced serum lipopolysaccharide (LPS) levels in intestinal mucositis mice. Moreover, the 5FU-induced inflammatory responses were alleviated by Tau treatment via the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) and nuclear factor kappa-B/inducible nitric oxide synthase (NF-κB/iNOS) signaling pathway. Tau administration modulated short chain fatty acids (SCFAs) in the colon of mice. The results indicated that the Tau might be a new dietary strategy for intestinal mucositis caused by 5FU.

The Intestinal Redox System and Its Significance in Chemotherapy-Induced Intestinal Mucositis.

Chemotherapy-induced intestinal mucositis (CIM) is a significant dose-limiting adverse reaction brought on by the cancer treatment. Multiple studies reported that reactive oxygen species (ROS) is rapidly produced during the initial stages of chemotherapy, when the drugs elicit direct damage to intestinal mucosal cells, which, in turn, results in necrosis, mitochondrial dysfunction, and ROS production. However, the mechanism behind the intestinal redox system-based induction of intestinal mucosal injury and necrosis of CIM is still undetermined. In this article, we summarized relevant information regarding the intestinal redox system, including the composition and regulation of redox enzymes, ROS generation, and its regulation in the intestine. We innovatively proposed the intestinal redox "Tai Chi" theory and revealed its significance in the pathogenesis of CIM. We also conducted an extensive review of the English language-based literatures involving oxidative stress (OS) and its involvement in the pathological mechanisms of CIM. From the date of inception till July 31, 2021, 51 related articles were selected. Based on our analysis of these articles, only five chemotherapeutic drugs, namely, MTX, 5-FU, cisplatin, CPT-11, and oxaliplatin were shown to trigger the ROS-based pathological mechanisms of CIM. We also discussed the redox system-mediated modulation of CIM pathogenesis via elaboration of the relationship between chemotherapeutic drugs and the redox system. It is our belief that this overview of the intestinal redox system and its role in CIM pathogenesis will greatly enhance research direction and improve CIM management in the future.

Possible cytoprotective mechanisms of oxytocin against 5-fluorouracil-induced gastrointestinal mucositis.

Gastrointestinal mucositis is a common and dose-limiting side effect characterized by ulcerative lesions in the mucosa of the digestive tract in patients receiving anticancer drugs such as 5-fluorouracil (5-FU), a potent antineoplastic drug. Several protocols have reported the efficacy of therapeutic interventions to prevent this side effect, although complete success has not yet been achieved and mucositis remains one of the most serious complications associated with 5-FU therapy. Oxytocin, a well-known antistress agent, has been reported to have comparable effects to ranitidine. Previous studies have shown that oxytocin inhibits gastric acid secretion and the expression of proinflammatory cytokines in rats. If oxytocin can reduce stress-induced ulcers via antioxidant, antiapoptotic, and anti-inflammatory pathways, then it may have a dose-dependent effect on gastrointestinal mucositis caused by 5-FU.

Simotang Alleviates the Gastrointestinal Side Effects of Chemotherapy by Altering Gut Microbiota.

Simotang oral liquid (SMT) is a traditional Chinese medicine (TCM) consisting of four natural plants and is used to alleviate gastrointestinal side effects after chemotherapy and functional dyspepsia (FD). However, the mechanism by which SMT helps cure these gastrointestinal diseases is still unknown. Here, we discovered that SMT could alleviate gastrointestinal side effects after chemotherapy by altering gut microbiota. C57BL/6J mice were treated with cisplatin (DDP) and SMT, and biological samples were collected. Pathological changes in the small intestine were observed, and the intestinal injury score was assessed. The expression levels of the inflammatory factors IL-1ß and IL-6 and the adhesive factors Occludin and ZO-1 in mouse blood or small intestine tissue were also detected. Moreover, the gut microbiota was analyzed by high-throughput sequencing of 16S rRNA amplicons. SMT was found to effectively reduce gastrointestinal mucositis after DDP injection, which lowered inflammation and tightened the intestinal epithelial cells. Gut microbiota analysis showed that the abundance of the anti-inflammatory microbiota was downregulated and that the inflammatory microbiota was upregulated in DDP-treated mice. SMT upregulated anti-inflammatory and anticancer microbiota abundance, while the inflammatory microbiota was downregulated. An antibiotic cocktail (ABX) was also used to delete mice gut microbiota to test the importance of gut microbiota, and we found that SMT could not alleviate gastrointestinal mucositis after DDP injection, showing that gut microbiota might be an important mediator of SMT treatment. Our study provides evidence that SMT might moderate gastrointestinal mucositis after chemotherapy by altering gut microbiota.

Paraprobiotic Enterococcus faecalis EC-12 prevents the development of irinotecan-induced intestinal mucositis in mice.

AIMS: This study tested the protective effect of purified paraprobiotic Enterococcus faecalis (EC-12) and an E. faecalis-based formulation (Med LanS) on irinotecan-induced intestinal mucositis murine model. MAIN METHODS: C57BL/6 male mice received saline, irinotecan (75 mg/Kg, i.p.), EC-12 (0.3, 1, or 3 × 107 CFU/Kg, p.o.) + irinotecan or Med Lan-S (3 × 107 CFU/Kg, p.o.) + irinotecan. Body mass variation was assessed daily, and blood samples were collected for evaluating bacteremia and leukocyte count. The ileum was harvested for myeloperoxidase assay, histopathology, quantitative PCR, and immunofluorescence for macrophages (F4/80), TLR4, and IL-18 binding protein (IL-18BP). KEY FINDINGS: The best therapeutic strategy was EC-12 administration at 3 × 107 CFU/Kg, starting 1 week before irinotecan. EC-12 and Med Lan-S did not prevent the irinotecan-induced body mass loss or leukopenia but attenuated the neutrophil infiltration in the intestine and increased the villus/crypt ratio (P < 0.05). Additionally, EC-12 and Med Lan-S reduced the mRNA expression of Cldn-2, Ocln, and Tlr4 versus the irinotecan group (P < 0.05). Irinotecan also augmented the expression of Il-18, IL-18BP, the immunofluorescence of F4/80, and TLR4, while only EC-12 prevented the expression of all these markers. Remarkably, EC-12 and Med Lan inhibited the irinotecan-induced bacterial translocation to the blood. SIGNIFICANCE: Paraprobiotic E. faecalis EC-12 prevents the development of intestinal mucositis by downregulating the inflammatory response. Med Lan-S also protects from mucositis. Possibly, the complexity of the formulation accounts for an innate immune-driven protective mechanism.