Mediators of Inflammation-Induced Bone Damage in Arthritis and Their Control by Herbal Products
OBJECTIVES We aimed to determine the anti-arthritis effect and its mechanism of a combination of herbal extracts from Trachelospermi caulis (TC) and Moutan cortex radicis (MC) (TCMC). METHODS The anti-arthritis activity of TCMC was assessed using a mouse model of type II collagen-induced arthritis (CIA). Reverse transcriptase-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), electrophoretic mobility shift assay (EMSA) and other biological assays were performed. KEY FINDINGS TCMC significantly ameliorated various inflammatory parameters, such as clinical arthritis index, histological deformation of joints, serum levels of rheumatoid arthritis biomarkers (cartilage oligomeric matrix protein, serum amyloid P and anti-collagen type II IgG antibody), and Th1-related responses (T cell proliferation, and production of Interferon-γ and interleukin (IL)-2 in splenocytes isolated from CIA mice). The production of matrix metalloproteinases (MMPs), pro-inflammatory cytokines (tumour necrosis factor-α, IL-1β and IL-6) and chemokines (macrophage inflammatory protein-1, monocyte chemoattractant protein-1, and Regulated upon Activation, Normal T-cell Expressed, and Secreted) was suppressed by TCMC in CIA mice. In addition, the number of osteoclasts in the hind tibia was significantly decreased. With regard to the mechanism, TCMC suppressed the activation of the transcription factors nuclear factor (NF)-κB and activator protein (AP)-1. CONCLUSIONS TCMC exerts an anti-arthritis effect in CIA mice by suppression of the production of various inflammatory factors and the formation of osteoclasts through the inhibition of NF-κB and AP-1 activation.