Therapeutic efficacy of brown propolis from Araucaria sp. in modulating rheumatoid arthritis.

Rheumatoid arthritis is a systemic inflammatory autoimmune disease with prevalence estimated at 0.5% to 1% of the population. As one of the treatment routes of rheumatoid arthritis is based on the use of nonsteroidal anti-inflammatory drugs, the use of natural products with anti-inflammatory potential becomes relevant. Brown propolis has several biological properties, including immunomodulatory and anti-inflammatory effects. Thus, the present study evaluated the therapeutic efficacy of the crude extract of brown propolis from Araucaria sp. through experimental models of analgesia, anti-inflammatory activity, and rheumatoid arthritis. Hyperalgesia was evaluated by mechanical and thermal sensitivity. Anti-inflammatory activity was evaluated by plantar volume, cell migration and NF-kB expression in carrageenan-induced paw oedema. In collagen-induced rheumatoid arthritis, it was evaluated by mechanical and thermal nociception on the plantar surface, and mechanical nociception in the femorotibial and caudal joints, evaluation of plantar volume, radiography, weight gain and biochemical profile. The results demonstrated that the oral administration of brown propolis can modulate the course of rheumatoid arthritis, and it can inhibit pain through the modulation of mechanical sensitivity. The anti-arthritic effect of propolis may be due to its anti-inflammatory capacity, which includes inhibiting oedema formation, cell migration, and NF-kB expression, as well as preserving joint space and normalizing urea levels. This was an animal model study. Therefore, brown propolis should be evaluated in studies of human RA to determine efficacy.