Evaluation of the efficacy of Si-based agent in Rheumatoid Arthritis with complicating vestibular impairment

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent joint inflammation and progressive disability. Although current therapies have improved clinical outcomes, safer and more effective therapeutic approaches remain needed. Silicon (Si)-based agents have antioxidant and anti-inflammatory properties and have shown beneficial effects in several inflammatory disease models. METHODS: We evaluated the effects of oral administration of a Si-based agent in a type II collagen-induced arthritis mouse model. Arthritis severity was assessed using an arthritis index, hindlimb oedema, and the hindlimb extension reflex test. Serum type II collagen-specific autoantibody levels were also measured. Vestibular function was evaluated using the vestibulo-ocular reflex (VOR), and inner-ear structural changes were assessed by magnetic resonance imaging and histological analysis. RESULTS: The Si-based agent reduced arthritis-related outcomes, including the arthritis index, hindlimb oedema, and joint movement restriction, and reduced serum type II collagen-specific autoantibody levels. In contrast, no significant differences between the Si-based agent and control groups were detected in VOR-related outcomes, endolymphatic space measurements, or inner-ear histological findings. CONCLUSIONS: These findings suggest that the Si-based agent may have beneficial effects on arthritis-related manifestations. However, its effects on the vestibular function-related outcomes examined in this study were not evident. Further studies are needed to clarify the relationship between RA and vestibular dysfunction and to determine the potential therapeutic effects of Si-based agent on these complications.