Sprague-Dawley rats are a sustainable and reproducible animal model for induction and study of oral submucous fibrosis

Abstract

Background: Oral submucous fibrosis (OSF) is a chronic debilitating disease predominantly affecting the oral cavity and oropharynx. Characteristic histological traits of OSF include epithelial atrophy, inflammation, and a generalized submucosal fibrosis. Several studies and epidemiological surveys provide substantial evidence that areca nut is the main etiological factor for OSF. Hesitance of patients to undergo biopsy procedure together with clinicians becoming increasingly reluctant to take biopsies in cases of OSF has prompted researchers to develop animal models to study the disease process. Materials and Methods: The present study evaluates the efficacy, sustainability, and reproducibility of using Sprague-Dawley (SD) rats as a possible model in the induction and progression of OSF. Buccal mucosa of SD rats was injected with areca nut and pan masala solutions on alternate days over a period of 48 weeks. The control group was treated with saline. The influence of areca nut and pan masala on the oral epithelium and connective tissue was evaluated by light microscopy. Results: Oral submucous fibrosis-like lesions were seen in both the areca nut and pan masala treated groups. The histological changes observed included: Atrophic epithelium, partial or complete loss of rete ridges, juxta-epithelial hyalinization, inflammation and accumulation of dense bundles of collagen fibers subepithelially. Conclusions: Histopathological changes in SD rats following treatment with areca nut and pan masala solutions bears a close semblance to that seen in humans with OSF. The SD rats seem to be a cheap and efficient, sustainable and reproducible model for the induction and development of OSF.