The Areca Nut and Oral Submucosal Fibrosis: A Narrative Review

Area of Science:

• Oral pathology
• Fibrotic disorders
• Areca nut-related diseases

Background:

• Oral submucosal fibrosis (OSF) affects ~5% of areca nut (AN) chewers, causing progressive oral cavity fibrosis.
• OSF leads to restricted mouth opening, impaired mastication, deglutition, speech, and diminished quality of life.
• OSF patients have a 4% increased risk of developing oral cancer, often linked to AN chewing and tobacco use.

Purpose of the Study:

• To investigate the mechanisms underlying AN-induced oral submucosal fibrosis (OSF).
• To identify key molecular players and cellular effectors involved in OSF pathogenesis.
• To underscore the need for novel diagnostic markers and therapeutic strategies for OSF.

Main Methods:

• In vitro studies using cultured fibroblasts exposed to arecoline.
• In vivo studies involving mice exposed to AN extract or arecoline.
• Analysis of pro-fibrotic gene and protein expression (TGF-β1, CCN2, α-SMA, Col1A1).

Main Results:

• Arecoline, a key AN alkaloid, induces fibroblast differentiation into α-smooth muscle actin (α-SMA)-expressing myofibroblasts in vitro.
• Arecoline promotes expression of profibrotic mediators like transforming growth factor-β 1 (TGF-β1) and cellular communication network factor 2 (CCN2).
• In vivo studies demonstrate submucosal collagen accumulation and myofibroblast differentiation with upregulated pro-fibrotic genes in response to AN or arecoline.

Conclusions:

• Areca nut (AN) chewing is a significant cause of oral submucosal fibrosis (OSF), driven by arecoline's fibrogenic properties.
• Myofibroblasts are key effector cells in OSF, with arecoline promoting their activation and profibrotic mediator release.
• Urgent need for mechanism-focused research to develop diagnostics and therapeutics for the global burden of OSF.