Rheumatoid arthritis (RA) is a systemic autoimmune disorder characterized by polyarticular symmetrical arthritis. The prevalence of RA is consistent worldwide, affecting about 0.5%-1.0% of the population. The aim of this study was to investigate whether Saussurea lappa (costus) could ameliorate adjuvant arthritis (AA) in the rat for 21 days.
Animals were divided into eight groups (n=5/group). Group 1 acted as control, group 2 presented the AA rats (positive control), and groups 3, 4, and 5 were treated with different doses of S. lappa (200, 400, and 600 mg/kg, respectively), whereas groups 6, 7, and 8 were AA rats and orally administered with S. lappa (200, 400, and 600 mg/kg, respectively). The changes caused by chronic inflammation were evaluated through the measurement of ankle circumference (AC). Serum C-reactive protein (CRP), interleukins (IL-1β and IL-6), tumor necrosis factor α (TNF-α), total oxidative capacity (TOC), and total antioxidant capacity (TAC) were determined.
Saussurea lappa dose-dependently alleviated the severity of the disease based on the reduction in AC and on the clinical scores of the histological study. Histopathological examination proved that S. lappa decreased the infiltration of inflammatory cells and synovial hyperplasia as well as protected joint destruction. Saussurea lappa reduced the serum levels of CRP, TNF-α, IL-1β, and IL-6, reduced the TOC, and improved the TAC as compared with AA rats.
The S. lappa extract has potentially useful anti-arthritic activity as well as improves the immune and antioxidant responses of adjuvant-induced monoarthritis in rats.