In summary, our study showed that the oral administration of SMS significantly alleviated the symptoms of arthritis and decreased the progression of CIA by suppressing oxidative stress damage and regulating proinflammatory mediators, including the reduced production of MDA and MPO, enhanced SOD and CTA levels, and decreased IL-6, TNF-α, COX-2, and PGE2 levels. The gene discussed is MPO; the disease is Arthritis.