TNF and rheumatoid arthritis: In a study investigating the effects and mechanisms of LBP in rheumatoid arthritis (RA) model rats, LBP (i.g., 200 and 400 mg/kg) treatment reduced paw swelling and arthritis scores, increased mechanical pain threshold and thermal withdrawal latency, alleviated histopathological changes in synovial tissues, and lowered serum levels of TNF-α, IL-1β, and IL-6.