Malvidin attenuates pain and inflammation in rats with osteoarthritis by suppressing NF-κB signaling pathway

Malvidin is one of the most widespread anthocyanidins which exhibits significant antioxidant and anti-inflammatory activity. The aim of this paper is to investigate the effects of Malvidin on osteoarthritis (OA). We created an animal model of OA using Wistar rats administered by monosodium iodoacetate (MIA). Effects of Malvidin on hyperalgesia were evaluated by paw pressure tests and compression threshold test. Articular chondrocytes were isolated from the OA rats to detect the apoptotic chondrocytes using senescence-associated beta-galactosidase (SA-beta-gal) staining kit. The expression levels of pro-inflammatory cytokines and matrix metalloproteinase (MMPs) were assessed by western blot and qPCR. Luciferase assay was used to determine the impact of Malvidin on nuclear factor-kappa B (NF-kappa B) pathway. Malvidin treatment exhibited significant pain-relieving effects in OA rats and decreased the expression level of apoptotic marker SA-beta-gal in chondrocytes. We found that the upregulated expressions of interleukin (IL)-1 beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), and MMPs induced by MIA in cartilage tissues were significantly reversed by Malvidin. Furthermore, Malvidin inhibited NF-kappa B pathway via an NF-kappa B inhibitor (I kappa B alpha)-independent manner through suppressing p65 nuclear transportation in vitro. Our findings suggest that Malvidin significantly attenuates the OA-induced pain and inflammation by inhibiting NF-kappa B signaling pathway and suppressing pro-inflammatory cytokine expression and chondrocyte apoptosis.