Inflammation in the Pathogenesis of Rheumatoid Arthritis and in Experimental Arthritis: Evaluation of Combinations of Carnosic Acid and Extract of Rhodiola rosea L. with Methotrexate

The host immune response generates the pro-inflammatory immune response as a protective measure against invading pathogens, allergens, and/or trauma. However, dysregulated and chronic inflammation may result in secondary damage to tissues and immune pathology to the host. Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease which primarily involves synovial inflammation, joint pain, immobility, and stiffness. Increased infiltration of inflammatory immune cells and fibroblast-like synoviocytes into joints, form pannus and small blood vessels that lead to synovium and cartilage destruction. In this chapter we will focus on the role of inflammatory cytokines (IL-1β, IL-6 and IL-17), chemokine monocyte chemotactic protein-1 and matrix metalloproteinase-9 in the pathogenesis of experimental arthritis in animals and in human RA. Further, we will be discussing about methotrexate’s (cornerstone of anti-rheumatic therapy) immune suppressing activity, anti-inflammatory properties of carnosic acid and extract of Rhodiola rosea L., and their innovative combination treatments with methotrexate in rat adjuvant arthritis.