title: Suppression of NF-kappaB activation by curcumin leads to inhibition of expression of cyclo-oxygenase-2 and matrix metalloproteinase-9 in human articular chondrocytes: Implications for the treatment of osteoarthritis.
abstract: Pro-inflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) play a key role in the pathogenesis of osteoarthritis (OA). Anti-inflammatory agents capable of suppressing the production and catabolic actions of these cytokines may have therapeutic potential in the treatment of OA and a range of other osteoarticular disorders. The purpose of this study was to examine the effects of curcumin (diferuloylmethane), a pharmacologically safe phytochemical agent with potent anti-inflammatory properties on IL-1beta and TNF-alpha signalling pathways in human articular chondrocytes maintained in vitro. The effects of curcumin were studied in cultures of human articular chondrocytes treated with IL-1beta and TNF-alpha for up to 72h. Expression of collagen type II, integrin beta1, cyclo-oxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9) was monitored by western blotting. The effects of curcumin on the expression, phosphorylation and nuclear translocation of protein components of the NF-kappaB system were studied by western blotting and immunofluorescence, respectively. Treatment of chondrocytes with curcumin suppressed IL-1beta-induced NF-kappaB activation via inhibition of IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 phosphorylation and p65 nuclear translocation. Curcumin inhibited the IL-1beta-induced stimulation of up-stream protein kinase B Akt. These events correlated with down-regulation of NF-kappaB targets including COX-2 and MMP-9. Similar results were obtained in chondrocytes stimulated with TNF-alpha. Curcumin also reversed the IL-1beta-induced down-regulation of collagen type II and beta1-integrin receptor expression. These results indicate that curcumin has nutritional potential as a naturally occurring anti-inflammatory agent for treating OA through suppression of NF-kappaB mediated IL-1beta/TNF-alpha catabolic signalling pathways in chondrocytes.
authors.affiliation: Institute of Anatomy, Ludwig-Maximilians-University Munich, Pettenkoferstrasse 11, D-80336 Munich, Germany. mehdi.shakibaei@med.uni-muenchen.de
authors.forename: Mehdi
authors.initials: M
authors.lastname: Shakibaei
authors.forename: Thilo
authors.initials: T
authors.lastname: John
authors.forename: Gundula
authors.initials: G
authors.lastname: Schulze-Tanzil
authors.forename: Ingo
authors.initials: I
authors.lastname: Lehmann
authors.forename: Ali
authors.initials: A
authors.lastname: Mobasheri
mesh_terms: D001692:Biological Transport; D002467:Cell Nucleus / Q000378:metabolism; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism; D003474:Curcumin / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051058:Oncogene Protein v-akt / Q000378:metabolism; D010003:Osteoarthritis / Q000188:drug therapy; D010766:Phosphorylation; D015398:Signal Transduction / Q000187:drug effects; D050863:Synaptotagmin I / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D053583:Interleukin-1beta; D008565:Membrane Proteins; D016328:NF-kappa B; D050863:Synaptotagmin I; D014409:Tumor Necrosis Factor-alpha; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D051058:Oncogene Protein v-akt; D020780:Matrix Metalloproteinase 9; D003474:Curcumin