A new constituent against rheumatoid arthritis from the flower buds of Lonicera japonica

In this study, two new compounds named as 8,4′-di-O-methylquercetin-3′-O-β-galactosyl-3-O-β-glucopyranoside (1) and 6-formyl-5-hydroxyl-4-ethyl-2-hydroxymethyl-1H-indene (2), were isolated from the flower buds of Lonicera japonica. Structures of compound 1 and 2 were determined by spectroscopic methods. Additionally, compound 1 showed therapeutic effects against rheumatoid arthritis (RA) in collagen-induced arthritis (CIA) mice through significantly reducing the inflammatory responses in the joint tissues. These results suggested that compound 1 exerted potent chondroprotective and anti-inflammatory effects against RA.