An improved method for experimental induction of ulcerative colitis in Sprague Dawley rats

Ulcerative colitis (UC) is a chronic inflammatory manifestation of the human colon that is linked with colorectal cancer. Development of an appropriate animal model is crucial to study the immunopathophysiology of UC wherein chemical induction is the most popular method of choice. However, unavailability of an optimum experimental model limits the success of this method. The present study aims to establish an optimized model for acetic acid-induced colitis in Sprague Dawley rats. Response Surface Methodology (RSM) with a six-factors Box-Behnken design was employed to generate an improved method of inducing UC in rat, predicting the case statistics, apposite investigation of quadratic response surfaces, and construction of a second-order polynomial equation. UC was diagnosed through three responses viz. weight loss, severity of diarrhea, and appearance of blood in the stool. Analysis of variance alongside RSM jointly revealed that induction of UC can be achieved with highest probability using the combination of parameters that includes 120 gm body weight, 1.5 ml of 4% acetic-acid v/v in distilled water with a single dose of treatment for 24 h including a pre-induction of 5 mins. This optimized UC-induction model was validated in-vivo through disease scoring index and hematological assessments with satisfactory level of desirability. •An improved experimental method for inducing ulcerative colitis (UC) in Sprague Dawley rats has been developed.•Box-Behnken Design-fitted Response Surface Methodology (RSM) was implicated in optimizing the experimental parameters for generating UC.•This statistically optimized and experimentally validated method resembles the recipe for the generation of UC in animal model with the highest possible desirability.