Therapeutic effects of vitamin D and IL-22 on methotrexate-induced mucositis in mice

Vitamins and fatty acids against chemotherapy-induced intestinal mucositis

Chemotherapy has allowed an increase in cancer survivorship, but it causes important adverse effects. Mucositis affecting the gastrointestinal tract is one of the main problems acutely caused by many antineoplastic drugs, such as 5-fluorouracil or methotrexate. Mucositis may cause pain, diarrhea, anorexia, weight loss, systemic infections and even death. This narrative review focuses on intestinal mucositis and the role that some nutraceuticals, namely vitamins (both lipid- and water-soluble) as well as fatty acids (FAs) and lipid-based products, can have in it. In preclinical (cell cultures, animal models) and/or human studies, vitamins A, D, E, B2, B9 and C, omega-3 long-chain FAs (eicosapentaenoic, docosahexaenoic, conjugated linoleic acid), short-chain FAs (mainly butyrate), medium-chain FAs (capric acid), and different lipid-based products (emu oil, extra-virgin olive oil, lipid replacement therapy), enriched in beneficial FAs and natural antioxidants, were shown to exert beneficial effects (both preventative and palliative) against chemotherapy-induced intestinal mucositis. Although the exact mechanisms of action involved in these effects are not yet well known, our review highlights the interest of investigating on diet and nutrition to implement scientifically robust strategies to improve protection of cancer patients against chemotherapy-induced adverse effects.

Vitamin D is a potential treatment for the management of gastrointestinal mucositis

PURPOSE OF THE REVIEW

Gastrointestinal mucositis (GM) is a severe side effect of cancer treatments, negatively impacting the patient's quality of life, and has limited treatment. GM consists of complex biological processes involving apoptosis and inflammation, leading to damage and ulceration of the gastrointestinal system. Recently, vitamin D has been shown to have multiple roles in the gut, including immunomodulation, epithelial barrier regulation and microbiome regulation. Hence, this review aims to put forth vitamin D as a potential therapeutic due to its protective role in the intestine.

RECENT FINDINGS

Recent studies have shown that vitamin D can reduce intestinal inflammation by reducing NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation. Vitamin D also targets and maintains the intestinal epithelial barrier via the tight junction protein expression and the inhibition of microbiome translocation. Significant evidence also suggests that vitamin D exerts multiple therapeutic effects through binding to vitamin D receptors (VDRs), and the downregulation of VDR has been associated with the severity of the disease. Additionally, vitamin D deficiency is reported in cancer patients.

SUMMARY

There is a dire need for effective treatment for GM, and recent animal and human studies show that vitamin D may be a potential therapy to prevent or treat GM.

Anti-inflammaging effects of vitamin D in human gingival fibroblasts with advanced glycation end product stimulation

Background/purpose

:Both periodontal disease and diabetes mellitus (DM) are long-term inflammatory disorders that are highly prevalent and have a significant health impact. Inflammaging, a state of pre-aging and hyperinflammatory state has been acknowledged for its role in DM patients to have heightened risk of periodontitis. Numerous evidences revealed that inflammaging contributed by cell senescence, acceleration of inflammation and oxidative stress participates in the destruction of periodontium in DM. Abilities of vitamin D in suppressing inflammation and oxidative stress have been revealed in a range of tissues, however in DM’s gingival cells, the effect remain undefined.

Materials and methods

: Under the stimulation of advanced glycation end-products (AGEs), we assessed the cell proliferation in human gingival fibroblast (HGF), IL-6 and IL-8 secretions, cellular senescence expression and generation of reactive oxygen species (ROS) with or without vitamin D intervention. Following that, we examined the expression of Nrf2 and HO-1 to see if vitamin D was able to modulate the anti-oxidant signaling. A knockdown experiment was then conducted to proof the participation of Nrf2 on the secretion of pro-inflammatory IL-6 and IL-8.

Results

: Following the treatment of vitamin D, AGEs-elicited IL-6 and IL-8 production and cell senescence were dose-dependently repressed. Moreover, vitamin D attenuated AGEs-induced ROS in a dose-dependent pattern. Results from qRT-PCR demonstrated vitamin D reversed the suppression of Nrf2 and HO-1 induced by AGEs. Our findings revealed that the anti-inflammatory and anti-oxidant effect in vitamin D was mediated via the upregulation of Nrf2 expression.

Conclusion

: These data showed that high levels of AGEs in the gingiva lead to inflammaging reflected by increased pro-inflammatory cytokines, cell senescence expression and oxidative stress. Vitamin D supplementation can reduce oxidative stress and inflammation via the upregulation of Nrf2 signaling and hence, may be a potential approach for treatment of diabetes-associated periodontitis.

Vitamin D influences gut microbiota and acetate production in zebrafish (Danio rerio) to promote intestinal immunity against invading pathogens

Although evidence has shown that vitamin D (VD) influences gut homeostasis, limited knowledge is available how VD regulates intestinal immunity against bacterial infection. In the present study, cyp2r1 mutant zebrafish, lacking the capacity to metabolize VD, and zebrafish fed a diet devoid of VD, were utilized as VD-deficient animal models. Our results confirmed that the expression of antimicrobial peptides (AMPs) and IL-22 was restrained and the susceptibility to bacterial infection was increased in VD-deficient zebrafish. Furthermore, VD induced AMP expression in zebrafish intestine by activating IL-22 signaling, which was dependent on the microbiota. Further analysis uncovered that the abundance of the acetate-producer Cetobacterium in VD-deficient zebrafish was reduced compared to WT fish. Unexpectedly, VD promoted the growth and acetate production of Cetobacterium somerae under culture in vitro. Importantly, acetate treatment rescued the suppressed expression of β-defensins in VD-deficient zebrafish. Finally, neutrophils contributed to VD-induced AMP expression in zebrafish. In conclusion, our study elucidated that VD modulated gut microbiota composition and production of short-chain fatty acids (SCFAs) in zebrafish intestine, leading to enhanced immunity.

Experimental Chemotherapy-Induced Mucositis: A Scoping Review Guiding the Design of Suitable Preclinical Models

Mucositis is a common and most debilitating complication associated with the cytotoxicity of chemotherapy. The condition affects the entire alimentary canal from the mouth to the anus and has a significant clinical and economic impact. Although oral and intestinal mucositis can occur concurrently in the same individual, these conditions are often studied independently using organ-specific models that do not mimic human disease. Hence, the purpose of this scoping review was to provide a comprehensive yet systematic overview of the animal models that are utilised in the study of chemotherapy-induced mucositis. A search of PubMed/MEDLINE and Scopus databases was conducted to identify all relevant studies. Multiple phases of filtering were conducted, including deduplication, title/abstract screening, full-text screening, and data extraction. Studies were reported according to the updated Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. An inter-rater reliability test was conducted using Cohen's Kappa score. After title, abstract, and full-text screening, 251 articles met the inclusion criteria. Seven articles investigated both chemotherapy-induced intestinal and oral mucositis, 198 articles investigated chemotherapy-induced intestinal mucositis, and 46 studies investigated chemotherapy-induced oral mucositis. Among a total of 205 articles on chemotherapy-induced intestinal mucositis, 103 utilised 5-fluorouracil, 34 irinotecan, 16 platinum-based drugs, 33 methotrexate, and 32 other chemotherapeutic agents. Thirteen articles reported the use of a combination of 5-fluorouracil, irinotecan, platinum-based drugs, or methotrexate to induce intestinal mucositis. Among a total of 53 articles on chemotherapy-induced oral mucositis, 50 utilised 5-fluorouracil, 2 irinotecan, 2 methotrexate, 1 topotecan and 1 with other chemotherapeutic drugs. Three articles used a combination of these drugs to induce oral mucositis. Various animal models such as mice, rats, hamsters, piglets, rabbits, and zebrafish were used. The chemotherapeutic agents were introduced at various dosages via three routes of administration. Animals were mainly mice and rats. Unlike intestinal mucositis, most oral mucositis models combined mechanical or chemical irritation with chemotherapy. In conclusion, this extensive assessment of the literature revealed that there was a large variation among studies that reproduce oral and intestinal mucositis in animals. To assist with the design of a suitable preclinical model of chemotherapy-induced alimentary tract mucositis, animal types, routes of administration, dosages, and types of drugs were reported in this study. Further research is required to define an optimal protocol that improves the translatability of findings to humans.

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

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