(1) Background: Rheumatoid arthritis is a chronic autoimmune disease that causes progressive articular damage and functional loss. It is characterized by synovial inflammation that leads to progressive cartilage destruction. For this reason, research on functional foods that reduce the inflammatory response are under progress. (2) Methods: We focused on the anti-inflammatory effects of Sargassum muticum, and confirmed the effect of the extract on the collagen-induced arthritis (CIA) DBA/1J mice model. (3) Results: The extract was given at concentrations of 50, 100, and 200 mg/kg, and the arthritis score and edema volume of the experimental group were significantly different from the CIA group. The level of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ were determined in serum and lymphocytes. The expression of these cytokines in the serum remarkably decreased from S. muticum extract (SME)100 mg/kg, and decreased from SME 200 mg/kg in lymphocytes. Also, immunohistochemical analysis of IL-6 and TNF-α in the joints revealed that the inflammatory response was noticeably lower when treated with S. muticum extract. (4) Conclusions: This study provides results of the experiment of S. muticum extract treatment in a mouse model. The treatment was found to contribute to the alleviation of edema and symptoms by reducing the expression of inflammatory cytokines. It was concluded that it may be a useful substance to help in the mitigation of arthritis symptoms.
Keywords: Sargassum muticum; anti-inflammation; collagen-induced arthritis; functional food; rheumatoid arthritis.