Backgroundand Purpose: Inflammatory Bowel Disease (IBD) is a persistent bio-psychological disorder with the absence of actual pathological reason. Association between IBD and isotretinoin has been reported by many human and in vitro studies. However, in this study, our focus is on finding the causal relationship between IBD and isotretinoin for the development of a new animal model. MethodsTwenty-eight Sprague Dawley rats were taken for this study and divided into five groups (i.e. Group 1: Normal control, Group 2: Standard IBD Model Group (Indomethacin treated), Group 3: Isotretinoin low dose (7 mg/kg), Group 4: Isotretinoin medium dose (35 mg/kg), Group 5: Isotretinoin high dose (70 mg/kg). The rats were treated according to assigned treatment and observed on different days to evaluate the severity of IBD with the help of symptomatical (nausea, diarrhea, stool consistency, etc.) activity, biochemical parameters, macroscopy, and histological analyses. Key resultsDuring the entire study period, body weight, stool consistency and frequency of the animals had been observed daily. No significant reduction in body weight was observed between the disease induced and normal control animals; however, it was observed that the stool consistency of the animals became less (mucus in stool) day by day and stool frequency increased (frequent defecation) in the different isotretinoin groups compared to the control group. There was statistically significant increase in TBARS levels of isotretinoin low (p < 0.05), medium (p < 0.001) and high dose (p < 0.01) treated group was observed, as compared to control group. Similarly, statistically significant effects of isotretinoin on GSH level (p < 0.01), CAT activity (p < 0.01), and SOD (p < 0.01) were also observed. Increase in TNF-α levels found significantly higher in isotretinoin medium dose (35 mg/kg) treated group (p < 0.001) as compared with control group as well as standard IBD model group. All the three-isotretinoin treated groups (Isotretinoin low dose: p < 0.001; Isotretinoin medium dose: p < 0.001; Isotretinoin high dose: p < 0.001) depicted significant difference in macroscopic scores as compared with control group; these results are comparable with standard IBD model group. Histological analyses revealed that, among three-dose groups of isotretinoin, there was excessive amount of crypt abscesses, infiltration of inflammatory cells, and formation of ulceration observed in isotretinoin medium dose treated group. ConclusionAs standard indomethacin treated group, isotretinoin also caused significant damage to intestinal mucosa, and form ulceration in gastrointestinal tract. Compared to control group, isotretinoin significantly worsens the disease condition, which were comparable to the indomethacin-treated group; however, isotretinoin at the dose of 35 mg/kg caused maximum severe damage to the intestinal mucosa.
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