Triptolide Prevents Bone Destruction in the Collagen-Induced Arthritis Model of Rheumatoid Arthritis by Targeting RANKL/RANK/OPG Signal Pathway
Inhibitory effects of triptolide in periarticular bone erosion in knee joints of collagen-induced arthritis (CIA) mice. Mice were orally administered triptolide (Trip, 8, 16, and 32 μg/kg, resp.), methotrexate (MTX, 0.1 mg/kg), or vehicle for 21 days from the first day of the onset of the clinical symptoms of arthritis. At the end of the experiment, Micro-CT scan was performed to validate the efficiency of triptolide in CIA mice. (a) The two-dimensional reconstructed bones of knee joints in different groups. Compared with vehicle-treated CIA mice, dose of 32 μg/(kg·day) triptolide markedly reduced the extent of joint destruction in triptolide-treated CIA mice. (b) The values of four parameters including bone volume, bone mineral density (BMD), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) of proximal end of the tibia facing the articular cavity in different groups. Compared with vehicle-treated and methotrexate-treated CIA mice, triptolide significantly increased BMD, bone volume fraction (BVF), and Tb.Th of inflamed joints and decreased Tb.Sp of inflamed joints. Data are represented as the mean ± SD (). in comparison with the normal control. , and in comparison with the vehicle control. , and in comparison with methotrexate-treated CIA mice.