Methotrexate for inflammatory bowel disease: time for reconsideration

The Role of the Microbiome in the Pathogenesis and Treatment of Ulcerative Colitis-A Literature Review

Ulcerative colitis (UC) is a chronic inflammatory bowel disease affecting the colon and rectum. UC's pathogenesis involves colonic epithelial cell abnormalities and mucosal barrier dysfunction, leading to recurrent mucosal inflammation. The purpose of the article is to show the complex interplay between ulcerative colitis and the microbiome. The literature search was conducted using the PubMed database. After a screening process of studies published before October 2023, a total of 136 articles were selected. It has been discovered that there is a fundamental correlation of a robust intestinal microbiota and the preservation of gastrointestinal health. Dysbiosis poses a grave risk to the host organism. It renders the host susceptible to infections and has been linked to the pathogenesis of chronic diseases, with particular relevance to conditions such as ulcerative colitis. Current therapeutic strategies for UC involve medications such as aminosalicylic acids, glucocorticoids, and immunosuppressive agents, although recent breakthroughs in monoclonal antibody therapies have significantly improved UC treatment. Furthermore, modulating the gut microbiome with specific compounds and probiotics holds potential for inflammation reduction, while fecal microbiota transplantation shows promise for alleviating UC symptoms. This review provides an overview of the gut microbiome's role in UC pathogenesis and treatment, emphasizing areas for further research.

Pathological mechanism and targeted drugs of ulcerative colitis: A review

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with abdominal pain, diarrhea, and mucopurulent stools as the main symptoms. Its incidence is increasing worldwide, and traditional treatments have problems such as immunosuppression and metabolic disorders. In this article, the etiology and pathogenesis of ulcerative colitis are reviewed to clarify the targeted drugs of UC in the latest research. Our aim is to provide more ideas for the clinical treatment and new drug development of UC, mainly by analyzing and sorting out the relevant literature on PubMed, summarizing and finding that it is related to the main genetic, environmental, immune and other factors, and explaining its pathogenesis from the NF-κB pathway, PI3K/Akt signaling pathway, and JAK/STAT signaling pathway, and obtaining anti-TNF-α monoclonal antibodies, integrin antagonists, IL-12/IL-23 antagonists, novel UC-targeted drugs such as JAK inhibitors and SIP receptor agonists. We believe that rational selection of targeted drugs and formulation of the best dosing strategy under the comprehensive consideration of clinical evaluation is the best way to treat UC.

Dihydromyricetin Modulates Nrf2 and NF-κB Crosstalk to Alleviate Methotrexate-Induced Lung Toxicity

BACKGROUND

Methotrexate (MTX) is an effective anticancer, anti-inflammatory, and immunomodulatory agent. However, it induces a serious pneumonitis that leads to irreversible fibrotic lung damage. This study addresses the protective role of the natural flavonoid dihydromyricetin (DHM) against MTX-induced pneumonitis via modulation of Nrf2/NF-κB signaling crosstalk.

METHODS

Male Wistar rats were divided into 4 groups: control, which received the vehicle; MTX, which received a single MTX (40 mg/kg, i.p) at day 9 of the experiment; (MTX + DHM), which received oral DHM (300 mg/kg) for 14 days and methotrexate (40 mg/kg, i.p) on the 9th day; and DHM, which received DHM (300 mg/kg, p.o) for 14 days.

RESULTS

Lung histopathological examination and scoring showed a decline in MTX-induced alveolar epithelial damage and decreased inflammatory cell infiltration by DHM treatment. Further, DHM significantly alleviated the oxidative stress by decreasing MDA while increasing GSH and SOD antioxidant levels. Additionally, DHM suppressed the pulmonary inflammation and fibrosis through decreasing levels of NF-κB, IL-1β, and TGF-β1 while promoting the expression of Nrf2, a positive regulator of antioxidant genes, and its downstream modulator, HO-1.

CONCLUSION

This study identified DHM as a promising therapeutic target against MTX-induced pneumonitis via activation of Nrf2 antioxidant signaling while suppressing the NF-κB mediated inflammatory pathways.

Molecular manipulations and intestinal stem cell-derived organoids in inflammatory bowel disease

The pathogenesis of inflammatory bowel diseases (IBD) involves genetic predisposition, environmental factors, and a broadly dysregulated intestinal immune response to the commensal intestinal microflora. The interface between genetic predisposition and environmental factors is reflected in the epigenetic regulation at the transcriptional level. Treatment targets now involve mucosal and histological healing, but the future might additionally include normalization of intestinal cellular functions also at the molecular level, for example comprising complete restoration of phenotypic, genotypic, and epigenetic states. Recent developments in patient-derived epithelial intestinal stem cell (ISC) organoid technologies have opened exciting new therapeutic opportunities to potentially attain molecular healing by combining stem cell therapy with molecular manipulations using (epi)drugs and/or CRISPR/Cas9 genome editing. Here, we are the first to discuss the possibility for phenotypic, genotypic, and epigenetic restoration via molecular manipulations and stem cell therapy in IBD from a clinical perspective.

Methotrexate in inflammatory bowel disease: A primer for gastroenterologists

Methotrexate is an antineoplastic agent that is also used at lower doses for anti-inflammatory properties. Along with thiopurines (azathioprine and 6-mercaptopurine), it has historically been an important part of pharmacological treatment for patients with inflammatory bowel disease. Despite an increase in therapeutic options, these immunomodulators continue to play important roles in the management of inflammatory bowel disease, used either as a monotherapy in mild to moderate cases or in combination with monoclonal antibodies to prevent immunogenicity and maintain efficacy. In light of data linking the use of thiopurines with the risk of malignancies, methotrexate has regained attention as a potential alternative. In this article, we review data on the pharmacology, safety, and efficacy of methotrexate and discuss options for the positioning of methotrexate alone, or in combination, in therapeutic algorithms for Crohn's disease and ulcerative colitis.

Treatments of inflammatory bowel disease toward personalized medicine

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammatory disease characterized by intestinal inflammation and epithelial injury. For the treatment of IBD, 5-aminosalicylic acids, corticosteroids, immunomodulators, and biologic agents targeting tumor necrosis factor (TNF)-α, α4β7-integrin, and interleukin (IL)-12/23 have been widely used. Especially, anti-TNF-α antibodies are the first biologic agents that presently remain at the forefront. However, 10-30% of patients resist biologic agents, including anti-TNF-α agents (primary non-responder; PNR), and 20-50% of primary responders develop treatment resistance within one year (secondary loss of response; SLR). Nonetheless, the etiologies of PNR and SLR are not clearly understood, and predictors of response to biologic agents are also not defined yet. Numerous studies are being performed to discover prediction markers of the response to biologic agents, and this review will introduce currently available therapeutic options for IBD, biologics under investigation, and recent studies exploring various predictive factors related to PNR and SLR.