Intra-articular injection of Mg2+combined with VC reduced the productions of inflammatory cytokines (TNF-α and PGE2) as well as the pain related neuropeptides (SP and CGRP) in the synovium. (A) Left, IHC staining showed the expressions of TNF-α and PGE2 in synovium at week 6 and 12 post-treatment. Scale bar, 100 μm. Right, quantification of TNF-α and PGE2 positive cells in synovium at the indicated time points. *P < 0.05, **P < 0.01, ***P < 0.001, n = 5–6 animals per group. (B) Left, IHC showed the expressions of SP and CGRP in synovium at week 6 and 12 post-treatment. Scale bar, 100 μm. Right, quantification of SP and CGRP positive cells in synovium at the indicated time points. *P < 0.05, **P < 0.01, ***P < 0.001, n = 5–6 animals per group.