Therapeutic Mechanism of Santeng Dingtong Recipe (三藤定痛方) on Monosodium Urate Crystal-Induced Rabbit Arthritis

Objective: To study the therapeutic mechanism of Santeng Dingtong recipe (STDT) on monosodium urate crystal (MSU) induced rabbit arthritis Methods: Forty-two rabbits were randomly divided into six groups, 7 in each group. Group 1 received 0.9% saline 2. 5 ml/kg per day by gastrogavage (ig) for 10 days; Group 2, 3 and 4 received STDT 0.125 g/kg, 1.0 g/kg and 8.0 g/kg per day respectively by ig for 10 days; Group 5 received colchicine 4. 5 mg/kg per day by ig for 4 days; and Group 6 was untreated. MSU crystals 10 mg /500ul containing polymyxin B 10 u/ml was injected into the knee joints of Group 1-5 to make rabbit arthritis models. Leukocytes in synovial lavage fluids was then counted and differentiated; pathological injury of synovial membranes was observed under HE staining; interleukin-1 beta (IL-1B), tumor necrosis factor alpha (TNFa) and leukotriene B4 (LTB4) content in synovial lavage fluids were determined by ELISA. Results: MSU caused a rapid leukocyte infiltration and increased production of IL-1B, TNFa and LTB4 2 hrs after intra-articular injection. STDT inhibited neutrophil infiltration in synovial fluids dose-dependently, protected the synovial membrane against pathological injury and reduced the production of IL-1B, TNFa and LTB4; while colchicine did not decrease the level of TNFa, but significantly inhibited neutrophil infiltration in synovial fluid and reduced the production of IL-11B and LTB4. Conclusion: STDT exerts an anti-inflammatory effect in rabbit model of acute MSU arthritis, its mechanism being probably due to the decrease of XL-1B, TNFa and LTB4 synthesis.

Anti-inflammatory effects of traditional mixed extract of medicinal herbs(MEMH)on monosodium urate crystal-induced gouty arthritis

Korean oriental medicine prescription is widely used for the treatment of gouty diseases. In the present study, we investigated anti-inflammatory effects of modified Korean herbal formulation, mixed extract of medicinal herbs(MEMH), and its modulatory effects on inflammatory mediators associated with gouty arthritis. Both in vitro and in vivo studies were carried out to assess the anti-inflammatory efficacy of MEMH on monosodium urate(MSU) crystals-induced gouty inflammation. MSU crystals stimulated human chondrosarcoma cell line, SW1353, and human primary chondrocytes were treated with MEMH in vitro. The expression levels of pro-inflammatory mediators and metalloproteases were analyzed. The effect of MEMH on NFκB signaling pathway in SW1353 cells was examined. Effect of MEMH on the mR NA expression level of pro-inflammatory mediators and chemotactic factor from human monocytic cell line, THP-1, was also analyzed. The probable role of MEMH in the differentiation process of osteoblast like cells, SaO S-2, after MSU treatment was also observed. To investigate the effects of MEMH in vivo, MSU crystals-induced ankle arthritic model was established. Histopathological changes in affected joints and plasma levels of pro-inflammatory mediators(IL-1β and TNFα) were recorded. MEMH inhibited NFκB signaling pathway and COX-2 protein expression in chondrocytes. MSU-induced mR NA expressions of pro-inflammatory mediators and chemotactic cytokines were suppressed by MEMH. In MSU crystals-induced ankle arthritic mouse model, administration of MEMH relieved inflammatory symptoms and decreased the plasma levels of IL-1β and TNFα. The results indicated that MEMH can effectively inhibit the expression of inflammatory mediators in gouty arthritis, demonstrating its potential for treating gouty arthritis.

Suppression of monosodium urate crystal-induced inflammation by inhibiting TGF-β-activated kinase 1-dependent signaling:role of the ubiquitin proteasome system

Monosodium urate(MSU)crystals activate inflammatory pathways that overlap with interleukin-1β(IL-1β)signaling.However,the post-translational mechanisms involved and the role of signaling proteins in this activation are unknown.In the present study,we investigated the intracellular signaling mechanisms involved in MSU-induced activation of THP-1 macrophages and human nondiseased synovial fibroblasts(NLSFs)and the in vivo efficacy of an inhibitor of tumor grovArth factor-β(TGF-β)-activated kinase 1(TAK1),5Z-7-oxozeaenoI,in MSU-induced paw inflammation in C57BL76 mice.THP-1 macrophage activation with MSU crystals(25-200 ng/ml)resulted in the rapid and sustained phosphorylation of interleukin-1 receptor-activated kinase 1(IRAK1 Thr^(209))and TAK1(Thr^(184/187))and their association with the E3 ubiquitin ligase TRAF6.At the cellular level,MSU inhibited the deubiquitinases A20 and UCHL2 and increased 20s proteasomal activity,leading to a global decrease in K^(63)-linked ubiquitination and increase in K^(48)-linked ubiquitination in THP-1 macrophages.While MSU did not stimulate cytokine produaion in NLSFs,it significantly amplified IL-1β-induced IL-6,IL-8,and ENA-78/CXCL5 production.Docking studies and MD simulations followed by TAK1 in vitro kinase assays revealed that uric acid molecules are capable of arresting TAK1 in an active-state conformation,resulting in sustained TAK1 kinase activation.Importantly,MSU-induced proinflammatory cytokine production was completely inhibited by 5Z-7-oxozeaenol but not IRAK1/4 or TRAF6 inhibitors.Administration of 5Z-7-oxozeaenol(5 or 15 mg/kg;orally)significantly inhibited MSU-induced paw inflammation in C57BL/6 mice.Our study identifies a novel post-translational mechanism of TAK1 activation by MSU and suggests the therapeutic potential of TAK1 in regulating MSU-induced Inflammation.

Case Report: Gouty Tophus of the Larynx

Gout is a metabolic disorder that is characterized by a deposition of monosodium urate crystals in the joint or soft tissue. Gout manifestations in head and neck region are rare, and larynx is an infrequently affected location. We recently managed a case of a gouty tophus over the larynx. A 65-year-old male with a long history of gout without medical control. He has suffered from increasing hoarseness for six months. Laryngoscopy revealed a mass lesion over the right vocal process region without vocal paralysis. Laryngo-micro-surgery biopsy was taken, and pathology confirmed laryngeal gouty tophus without evidence of malignancy.