| چکیده انگلیسی مقاله |
Introduction: Osteoarthritis is a public health concern that leads to disability due to chronic pain, stiffness, sleep disturbance, and depression. D-limonene is a racemic mixture of limonene, a natural cyclic monoterpene, and the major component of the oil extracted from the citrus rind with chemo-preventive and anti-inflammatory activities. The purpose of this study was to investigate the anti-inflammatory properties of D-limonene compared with dexamethasone and ibuprofen in bovine fibroblast-like synoviocyte cells (BFLSc) as well as Human THP-1 monocyte/macrophage-like cells. Materials and Methods: BFLSc was isolated from the synovial membrane of the metacarpal joint cartilage of an 8-month-old Holstein. THP-1 cells were prepared by the Pasteur Institute of Iran. Cells were cultivated and exposed to 20 ng/ml lipopolysaccharide (LPS) stimulation without, or in the presence of, ibuprofen, dexamethasone, or D-limonene (7.5µg/ml). The gene expressions of cyclooxygenase-2 (COX-2), Interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS), and Tumor necrosis factor alpha (TNF-α) were evaluated by real-time PCR. Concentrations of Nitric Oxide (NO), and Prostaglandin-E2 (PGE2) were measured by ELISA methods. Results: The inhibitory effects of D-limonene included dose-dependent decreases in the expression of iNOS and COX-2 proteins (P < 0.05). The treated cells secreted increased amounts of COX-2, IL-1β, iNOS, TNF-α, NO, and PGE2 in response to LPS stimulation in all conditions. D-limonene quenched the gene expression of COX-2, iL-1β, iNOS, and TNF-α, in BFLSc, and the production of PGE2 and NO in monocyte/macrophage cells alike dexamethasone, and ibuprofen. Conclusion: The results obtained in this study show that D-limonene probably exerts anti-inflammatory effects through the suppression of TNF-α, IL-1β, COX-2, and iNOS and NO, PGE2 production. |