A novel approach to develop an animal model for oral submucous fibrosis

Epidemiological data have proved the association of consumption of areca nut with the causation of oral submucous fibrosis (OSF). OSF is a chronic inflammatory disease with the potential for malignant transformation from 7 to 13%. The establishment of animal models makes it easier for researchers to focus on the therapeutic options to combat this disease further. We developed and compared two areca nut extract (ANE) administration methods in Swiss albino mice to establish OSF. This study compared an invasive intrabuccal injection technique with a non-invasive intraoral droplet administration. The duration of induction was around 12 weeks. Histopathology (H&E, Masson's trichrome staining) and gene expression analysis (COL-I, COL-II, and α-SMA) were performed using RT-PCR to confirm the OSF in animals. Our study showed that ANE administration through the intraoral droplet method exhibited significantly higher fibrosis than the intrabuccal injections, as evidenced by the H&E and Masson's trichrome staining. Furthermore, intraoral administration of ANE significantly upregulated the mRNA expression of COL-I, COL-II, and α-SMA, as revealed by the RT-PCR analysis. The non-invasive droplet method could simulate the absorption of areca nut seen in humans through daily dosing. This study establishes the intraoral droplet method as an efficient and non-invasive method to administer the ANE to develop OSF. These findings will aid in the efficient development of OSF animal models for interventional studies, including screening novel drugs in the reversal of the OSF.