Abstract
BACKGROUND/OBJECTIVES: Steamed ginger extract (GGE03) has been proposed as a complementary treatment for osteoarthritis (OA). On the other hand, the efficacy and mechanism are incompletely understood. This study examined the anti-osteoarthritic effects of GGE03 in monosodium iodoacetate (MIA)-induced OA Sprague-Dawley (SD) rats. MATERIALS/METHODS: The rats were divided into the following groups: normal control group (NC); OA control group (OC); OA+30, 50, or 100 mg/kg body weight (BW)/day GGE03 group (O+G30, O+G50, or O+G100); OA+150 mg/kg BW/day methyl sulfonyl methane (MSM, positive control group (O+M). The SD rats were given GGE03 or MSM orally for 5 weeks. MIA was injected intra-articularly into the knee joints on day 15 to induce OA. The exercise performance test, pain behavior test, micro-computed tomography, histological examination, and immunofluorescence staining were performed on the knee joint. The inflammatory mediators, cytokines, and matrix metalloproteinase (MMP) mRNA expression were measured in the knee joint synovial fluid. RESULTS: The OC group had significantly shorter exercise times to exhaustion and withdrawal threshold according to the von Frey test, more severe knee joint swelling and subchondral bone erosion than the NC group, and reduced type II collagen and aggrecan expression in the articular cartilage. The OC group showed a significantly higher mRNA expression of inflammatory mediators, cytokines, and MMPs than the NC group. In OA rats, GGE03 administration reduced knee swelling and cartilage degradation and increased type II collagen and aggrecan expression in the articular cartilage. GGE03 administration reduced the expression of inducible nitric oxide synthase, cyclooxygenase-2, 5-lipoxygenase, interleukin (IL)-1β, IL-6, tumor necrosis factor-α, MMP-2, MMP-3, MMP-9, and MMP-13 in the synovia of the knee joints. CONCLUSION: GGE03 administration is a useful supplementary agent for anti-OA treatment.