Metformin Repurposing in Oral Submucous Fibrosis: Unveiling In Vitro Signaling Pathways, Progressing to Clinical Trial

Overview

OSF is a widespread health issue in Asian countries, notably Pakistan, linked to the consumption of pan, chalia, and gutka, affecting a rising number of young individuals as an epidemic. This condition significantly impairs oral function, resulting in ulcers and chronic lesions, often progressing to oral cancer. Current treatments focus on symptom relief and halting disease progression. This study explores the repurposing of metformin, an FDA-approved drug with antifibrotic properties, for OSF treatment. Our objective is to unveil its therapeutic potential and comprehend its impact on the dysregulated signaling pathways associated with OSF. This research offers promising insights for an enhanced management approach, providing hope for those grappling with this debilitating condition

OSF stands as a persistent inflammatory and potentially malignant condition affecting the oral cavity, marked by progressive fibrosis of the oral mucosa. The spectrum of its manifestations spans from initial inflammation to the gradual emergence of fibrous bands, leading to restricted mouth opening and mucosal rigidity. Common symptoms encompass burning sensations, difficulty in swallowing, and alterations in taste perception. This health concern has gained prominence in Pakistan, experiencing a worrisome surge in prevalence from 8.3/105 to 16.2/105 in recent years. Formerly confined to Southeast Asia, OSF has now transcended borders, manifesting in Asian immigrant communities in Britain and America, evolving into a global oral potential malignant disorder (OPMD) with a malignant rate of 9.13% . Presently, the corticosteroid-based approach effectively reduces inflammation in OSF but falls short in addressing the underlying molecular mechanisms contributing to fibrosis. Furthermore, the prolonged use of corticosteroids raises concerns about adverse effects, including mucosal atrophy and compromised tissue integrity. This study aims to investigate the potential of metformin, a recognized emerging drug for treating fibrosis, and its anti-fibrotic properties in various organs. The established safety profile of metformin adds an advantageous aspect to its potential applications. Numerous studies indicate that metformin exhibits anti-fibrotic effects by inhibiting TGF-β1 production, reducing phosphorylation and nuclear translocation of Smad2/3. Additionally, metformin inhibits Smad2/3 phosphorylation independently and activates AMPK, hindering Smad3 phosphorylation. The impact on reactive oxygen species (ROS) generation moderates TGF-β1-induced Smad2/3 phosphorylation and myofibroblast differentiation.Metformin has shown promise in hindering collagen production and promoting trans differentiation in various organ, including the lung, kidney, heart and adipose tissue. A clinical trial reported metformin therapy's impact on postmenopausal ovaries, patients with type 2 diabetes mellitus (T2DM) exhibited isotropic collagen organization and reduced fibrosis during oophorectomy.The observed risk reduction for ovarian cancer in T2DM women using metformin suggests its potential as an ovarian cancer prophylaxis. Despite conflicting clinical trial results in liver fibrosis, metformin consistently improves hepatocyte damage and inflammation. Clinical trials have explored the role of metformin antitumor activity when combined with conventional chemotherapeutic drugs and in idiopathic pulmonary fibrosis it inhibits TGFβ1, suppressing collagen formation, activating PPARγ signaling and inducing lipogenic differentiation.