Dinitrochlorobenzene (DNCB) + Ethanol-Induced Crohn's Disease Model

Overview

Model Description	The DNCB-ethanol model is used to simulate Crohn's disease (CD) in mice, mimicking the disease's pathological characteristics. This model involves applying DNCB, a chemical irritant, in combination with ethanol to the skin of mice, which induces an inflammatory response similar to that seen in human CD.
Modeling Mechanism	DNCB, as a chemical irritant, can trigger an immune response in the body, leading to intestinal inflammation. Ethanol acts as a solvent, facilitating the penetration of DNCB into intestinal tissues and enhancing its effect. By administering a DNCB-ethanol solution via colonic infusion, an animal model exhibiting the pathological features of Crohn’s disease can be successfully induced.
Model Characteristics	The DNCB combined with ethanol-induced Crohn's disease model effectively replicates key pathological features of human Crohn’s disease, including intestinal inflammatory cell infiltration, ulcer formation, and bowel wall thickening. This model is also characterized by its relatively simple induction procedure and low cost.
Model Applications	This model is widely used in studies of Crohn’s disease pathogenesis, drug screening, and evaluation of therapeutic strategies. It provides a valuable platform for identifying anti-inflammatory and immunomodulatory agents and assessing their efficacy and safety.
Modeling Method	Experimental animals are maintained in controlled environmental conditions to ensure health prior to induction. Animals are anesthetized to reduce pain and stress. A DNCB solution is prepared by dissolving DNCB powder in absolute ethanol at the required concentration. The solution is then administered intrarectally via a catheter, with insertion depth adjusted for the animal’s species and size. After injection, animals are briefly inverted to prevent leakage. Post-procedure, animals recover in an incubator and are monitored daily for body weight, stool characteristics, activity, and clinical symptoms such as diarrhea or bloody stools to track disease progression.
Therapeutic Areas	Inflammatory bowel disease (IBD)
Readouts	• Body weight and food intake changes: A decrease in body weight and reduced food intake are commonly indicative of disease progression. • Clinical symptom observation: Monitor experimental animals for typical symptoms such as diarrhea, bloody stools, and weight loss. Additionally, observe their general behavior and activity levels to assess overall health status. • Histopathological analysis: At the end of the experiment or at designated time points, animals are sacrificed, and colon tissues are collected for histopathological analysis. Key pathological features include inflammatory cell infiltration, ulcer formation, and bowel wall thickening. • Inflammatory cytokine detection: The expression levels of inflammatory cytokines in colon tissues are measured using techniques such as ELISA and PCR to evaluate the degree of inflammation. Commonly assessed cytokines include TNF-α and IL-6.