Figure 2: RGSF-A reduces the severity of clinical and histopathological signs of arthritis in CIA mice. (a) CIA was induced in DBA1J mice and 8 days after booster dose CIA mice injected either with phosphate-buffered saline (control) or 0.2 mg/kg methotrexate intraperitoneal or with oral dose of RGSF-A 50 or 150 mg/kg daily for 5 weeks. Arthritic score was assessed for the indicated weeks. (b) Histology of paw joints from CIA mice treated with vehicle, MTX, or RGSF-A. Paw joints were collected on day 54 after booster dose of naïve unimmunized (A), vehicle CIA mice (B), 0.2 mg/kg MTX (C), 150 mg/kg RGSF-A (D), or 50 mg/kg RGSF-A (E) treated CIA mice. Joints are formalin fixed, decalcified, sectioned, and stained with hematoxylin-eosin stains. Extensive leukocyte infiltration and synovial expansion into the articular surface are observed in vehicle-treated CIA mice (B), with massive inflammatory cell infiltration (f), synovial hyperplasia (g), narrowed articular space (j), and cartilage erosions (downward arrow). RGSF-A treated groups developed a less cellular infiltration (f) with a reduced hyperplasia (g) and clear articular space (h), which is comparable to MTX (D) groups. Histopathological images are magnified at 50x. Symbols in (a) represent mean value with SEM shown. and , as compared with vehicle treatment; for each group.