CYT387 Inhibits the Hyperproliferative Potential of Fibroblast-like Synoviocytes via Modulation of IL-6/JAK1/STAT3 Signaling in Rheumatoid Arthritis.

Fibroblast-like synoviocytes (FLS) are the critical effector cells primarily involved in rheumatoid arthritis (RA) disease pathogenesis. Interleukin (IL)-6, a proinflammatory cytokine most abundantly expressed in the rheumatoid synovium, promotes Janus kinase (JAK)/signal transducer and transcriptional activator (STAT) signaling cascade activation in RA-FLS, thus leading to its aggressive phenotype, invasiveness, and joint destruction. Momelotinib (CYT387) is a selective small-molecule inhibitor of JAK1/2 and is clinically approved to treat myelofibrosis. However, the therapeutic efficacy of CYT387 in FLS mediated RA pathogenesis is less known. In the present study, we investigated the modulatory effect of CYT387 on IL6/JAK/STAT signaling cascade in FLS induced RA pathogenesis. CYT387 treatment inhibited IL-6 induced high proliferative and migratory potential of FLS cells isolated from adjuvant-induced arthritic (AA) rats. CYT387 reduced the expression of PRMT5, survivin, and HIF-1α mediated by IL-6/sIL-6R in AA-FLS in a dose-dependent manner. The IL-6/sIL-6R induced expression of angiogenic factors such as VEGF and PIGF in AA-FLS cells was found downregulated by CYT387 treatment. Importantly, CYT387 significantly reduced IL-6/sIL-6R dependent activation of JAK1 and STAT3 and increased SOCS3 expression in AA-FLS cells. Next, the S3I-201 mediated blockade of STAT3 activation supported the inhibitory effect of CYT387 on IL-6/JAK1/STAT3 signaling cascade in AA-FLS. Overall, this study proves that CYT387 inhibits proliferation, migration, and pathogenic disease potential of FLS isolated from adjuvant-induced arthritic (AA) rats via targeting IL-6/JAK1/STAT3 signaling cascade.

Inflammatory bowel diseases in Tamil Nadu: A survey of demographics, clinical profile, and practices.

BACKGROUND: Inflammatory bowel disease (IBD) is increasingly diagnosed in South Asia. This survey by the Tamil Nadu Chapter of the Indian Society of Gastroenterology (TNISG) documents the demography, clinical profile, and therapeutic practices related to IBD in Tamil Nadu. METHODS: TNISG members from 32 institutions completed an online cross-sectional questionnaire on IBD patients from March 2020 to January 2021. RESULTS: Of 1295 adult IBD patients, 654 had Crohn's disease (CD), 499 ulcerative colitis (UC), and 42 IBD-unclassified (IBD-U). CD and UC showed a unimodal age distribution. A total of 55% were graduates or postgraduates. A positive family history was noted in 30, other risk factors were uncommon. In CD, the pattern of involvement was ileocolonic (42.8%), ileal (34.7%), colonic (18.9%), and upper gastrointestinal (3.5%); while in UC, disease was characterized as extensive (44.9%), left-sided (41.7%), or proctitis (13.4%). Perineal disease, perianal fistulae, and bowel obstruction were noted in 4.3, 14.0, and 23.5%, respectively, of CD. The most widely used drugs were mesalamine, azathioprine, and corticosteroids. Surgery was undertaken in 141 patients with CD and 23 patients with UC. Of the 138 patients with pediatric IBD (≤16 years), 23 were characterized as very early onset IBD (VEO-IBD), 27 as early-onset, and 88 as adolescent IBD. VEO-IBD were more likely to have a positive family history of IBD and were more likely to have perineal disease and to have the IBD-U phenotype. Among pediatric IBD patients, corticosteroids, mesalamine, and azathioprine were the most commonly used medications, while 25 pediatric patients received biologics. CONCLUSION: This study provides important information on demography, clinical profile, and treatment practices of IBD in India.

Majoon Chobchini attenuates arthritis disease severity and RANKL-mediated osteoclastogenesis in rheumatoid arthritis.

Majoon Chobchini, a polyherbal Unani compound, has been used holistically in India to treat rheumatoid arthritis. However, the potential mechanism underlying the antiarthritic efficacy of Majoon Chobchini has not been elucidated so far. This study was aimed to explore the underlying molecular mechanism and scientifically validate the therapeutic basis of Majoon Chobchini in rheumatoid arthritis (RA). The anti-arthritic efficacy of Majoon Chobchini was demonstrated in vivo using complete Freund's adjuvant-induced arthritic rat model and adjuvant-induced arthritic fibroblast-like synoviocytes (AA-FLS). The expression of pro-inflammatory mediators and enzymes was evaluated in the serum and synovial tissues of adjuvant-induced arthritis (AIA) rats. In-vitro, AA-FLS, and bone marrow macrophages (BMMs) were co-cultured to evaluate the formation and activity of osteoclasts using TRAP staining analysis and pit formation assay, respectively. RANKL and OPG levels were detected using western blotting and qRT-PCR analysis. Furthermore, the involvement of JAK-STAT-3 signaling in the therapeutic efficacy of Majoon Chobchini was evaluated both in vivo and in vitro. Majoon Chobchini significantly reversed the physical symptoms in AIA rats with reduced expression of pro-inflammatory cytokines and enzymes. Notably, Majoon Chobchini alleviated cartilage degradation and bone erosion in AIA rats via inhibiting the activation of the JAK-STAT-3 signaling pathway in the AIA rats. Consistent with its effect in vivo, Majoon Chobchini decreased osteoclast inducing potential of AA-FLS and thus attenuated osteoclast formation and bone resorption in vitro. Taken together, our findings suggest that the JAK/STAT-3 signaling inhibition may underlie the mechanism through which Majoon Chobchini provides relief against RA symptoms. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02985-4.

Cyanidin prevents the hyperproliferative potential of fibroblast-like synoviocytes and disease progression via targeting IL-17A cytokine signalling in rheumatoid arthritis.

The hyperplastic phenotype of fibroblast-like synoviocytes (FLSs) plays an important role for synovitis, chronic inflammation and joint destruction in rheumatoid arthritis (RA). Interleukin 17A (IL-17A), a signature pro-inflammatory cytokine effectively influences the hyperplastic transformation of FLS cells and synovial pannus growth. IL-17A cytokine signalling participates in RA pathology by regulating an array of pro-inflammatory mediators and osteoclastogenesis. Cyanidin, a key flavonoid inhibits IL-17A/IL-17 receptor A (IL-17RA) interaction and alleviates progression and disease severity of psoriasis and asthma. However, the therapeutic efficacy of cyanidin on IL-17A cytokine signalling in RA remains unknown. In the present study, cyanidin inhibited IL-17A induced migratory and proliferative capacity of FLS cells derived from adjuvant-induced arthritis (AA) rats. Cyanidin treatment reduced IL-17A mediated reprogramming of AA-FLS cells to overexpress IL-17RA. In addition, significantly decreased expression of IL-17A dependent cyr61, IL-23, GM-CSF, and TLR3 were observed in AA-FLS cells in response to cyanidin. At the molecular level, cyanidin modulated IL-17/IL-17RA dependent JAK/STAT-3 signalling in AA-FLS cells. Importantly, cyanidin activated PIAS3 protein to suppress STAT-3 specific transcriptional activation in AA-FLS cells. Cyanidin treatment to AA rats attenuated clinical symptoms, synovial pannus growth, immune cell infiltration, and bone erosion. Cyanidin reduced serum level of IL-23 and GM-CSF and expression of Cyr 61 and TLR3 in the synovial tissue of AA rats. Notably, the level of p-STAT-3 protein was significantly decreased in the synovial tissue of AA rats treated with cyanidin. This study provides the first evidence that cyanidin can be used as IL-17/17RA signalling targeting therapeutic drug for the treatment of RA and this need to be investigated in RA patients.

Ferulic acid inhibits interleukin 17-dependent expression of nodal pathogenic mediators in fibroblast-like synoviocytes of rheumatoid arthritis.

Interleukin 17 (IL-17), a proinflammatory cytokine produced by T helper (Th) 17 cells, potentially controls fibroblast-like synoviocytes (FLS)-mediated disease activity of rheumatoid arthritis (RA) via IL-17/ IL-17 receptor type A (IL-17RA)/signal transducer and activator of transcription 3 (STAT-3) signaling cascade. This has suggested that targeting IL-17 signaling could serve as an important strategy to treat FLS-mediated RA progression. Ferulic acid (FA), a key polyphenol, attenuates the development of gouty arthritis and cancer through its anti-inflammatory effects, but its therapeutic efficiency on IL-17 signaling in FLS-mediated RA pathogenesis remains unknown. In the current study, FA markedly inhibited the IL-17-mediated expression of its specific transmembrane receptor IL-17RA in FLS isolated from adjuvant-induced arthritis (AA) rats. Importantly, FA dramatically suppressed the IL-17-mediated expression of toll-like receptor 3 (TLR-3), cysteine-rich angiogenic inducer 61 (Cyr61), IL-23, granulocyte-macrophage colony stimulating factor (GM-CSF) in AA-FLS via the inhibition of IL-17/IL-17RA/STAT-3 signaling cascade. In addition, FA significantly decreased the formation of osteoclast cells and bone resorption potential in a coculture system consisting of IL-17 treated AA-FLS and rat bone marrow derived monocytes/macrophages. Furthermore, FA remarkably inhibited the IL-17-mediated expression of receptor activator of nuclear factor κ-Β ligand (RANKL) and increased the expression of osteoprotegerin (OPG) in AA-FLS via the regulation of IL-17/IL-17RA/STAT-3 signaling cascade. The therapeutic efficiency of FA on IL-17 signaling was further confirmed by knockdown of IL-17RA using small interfering RNA or blocking of STAT-3 activation with S3I-201. The molecular docking analysis revealed that FA manifests significant ligand efficiency toward IL-17RA, STAT-3, IL-23, and RANKL proteins. This study provides new evidence that FA can be used as a potential therapeutic agent for inhibiting IL-17-mediated disease severity and bone erosion in RA.

Interleukin 17 under hypoxia mimetic condition augments osteoclast mediated bone erosion and expression of HIF-1α and MMP-9.

Interleukin 17 (IL-17) and hypoxia have been implicated to play a key role in rheumatoid arthritis (RA). In this study, the combined treatment of IL-17 and cobalt chloride (CoCl2), a hypoxia mimetic significantly increased the osteoclast formation and the expression of TRAP and MMP-9 in RAW 264.7 macrophage cells in the presence of RANKL and M-CSF. The unified effect of IL-17 and CoCl2 markedly increased osteoclast mediated bone erosion through the activation of RANKL/NF-κB/NFATc1 signaling pathway. The treatment of IL-17 in combination with CoCl2 further potentiated the protein and mRNA expression of HIF-1α and MMP-9 in rat synovial macrophages. Conversely, the blockage of HIF-1α expression with BAY87-2243 abrogated the IL-17 and CoCl2 mediated expression of HIF-1α and MMP-9. Further, the knockdown of IL-17RA using siRNA reversed the IL-17 and CoCl2 induced expression of HIF-1α in synovial macrophages. In conclusion, IL-17 synergizes with CoCl2 induced hypoxic condition to augment osteoclast mediated bone erosion and synovial macrophages mediated RA pathogenesis.

Ferulic acid, a dietary polyphenol suppresses osteoclast differentiation and bone erosion via the inhibition of RANKL dependent NF-κB signalling pathway.

AIMS: Bone erosion induced by enhanced osteoclast formation is a debilitating pathological phenomenon in rheumatoid arthritis (RA). Recent finding has revealed that ferulic acid is associated with reduced osteoclast differentiation and bone erosion. However, the underlying mechanism through which ferulic acid inhibited osteoclast differentiation and bone erosion still remains to be elucidated. This study assessed the therapeutic effects of ferulic acid on osteoclast differentiation and bone erosion by targeting RANKL dependent NF-κB pathway. MAIN METHODS: RAW 264.7 monocyte/macrophage cells were left untreated/treated with 25, 50 and 100 µM ferulic acid prior to stimulation with/without RANKL and M-CSF. Osteoclast differentiation and formation was assessed by SEM and TRAP analysis whereas its functional activity of bone erosion was determined by pit formation assay. Crucial transcription factors (NF-κBp-65, NFATc1 and c-Fos) and osteoclast specific genes (TRAP, MMP-9 and Cathepsin K) were evaluated by quantitative RT-PCR. Further, the protein level expression of NF-κBp-65, NFAtc1, c-Fos and MMP-9 was assessed using western blot analysis. KEY FINDINGS: Our results demonstrated that ferulic acid significantly attenuated RANKL induced osteoclast differentiation as evidenced from SEM and TRAP staining analysis. A remarkable decrease in the bone resorption activity of osteoclasts was also noticed upon ferulic acid treatment. In addition, the down-regulation of RANKL induced NF-κB activation and its associated downstream factors like NFATc1, c-Fos, TRAP, Cathepsin K and MMP-9 was also observed upon ferulic acid treatment. SIGNIFICANCE: Thus, our findings evidence the anti-stimulatory and anti-resorptive role of ferulic acid via the inhibition of RANKL dependent NF-κB signalling pathway.

Curcumin induces apoptosis and cell cycle arrest via the activation of reactive oxygen species-independent mitochondrial apoptotic pathway in Smad4 and p53 mutated colon adenocarcinoma HT29 cells.

Curcumin is a natural dietary polyphenol compound that has various pharmacological activities such as antiproliferative and cancer-preventive activities on tumor cells. Indeed, the role reactive oxygen species (ROS) generated by curcumin on cell death and cell proliferation inhibition in colon cancer is poorly understood. In the present study, we hypothesized that curcumin-induced ROS may promote apoptosis and cell cycle arrest in colon cancer. To test this hypothesis, the apoptosis-inducing potential and cell cycle inhibition effect of ROS induced by curcumin was investigated in Smd4 and p53 mutated HT-29 colon adenocarcinoma cells. We found that curcumin treatment significantly increased the level of ROS in HT-29 cells in a dose- and time-dependent manner. Furthermore, curcumin treatment markedly decreased the cell viability and proliferation potential of HT-29 cells in a dose- and time-dependent manner. Conversely, generation of ROS and inhibitory effect of curcumin on HT-29 cells were abrogated by N-acetylcysteine treatment. In addition, curcumin treatment did not show any cytotoxic effects on HT-29 cells. Furthermore, curcumin-induced ROS generation caused the DNA fragmentation, chromatin condensation, and cell nuclear shrinkage and significantly increased apoptotic cells in a dose- and time-dependent manner in HT-29 cells. However, pretreatment of N-acetylcysteine inhibited the apoptosis-triggering effect of curcumin-induced ROS in HT-29 cells. In addition, curcumin-induced ROS effectively mediated cell cycle inhibition in HT-29 cells. In conclusion, our data provide the first evidence that curcumin induces ROS independent apoptosis and cell cycle arrest in colon cancer cells that carry mutation on Smad4 and p53.

Interleukin 17 regulates SHP-2 and IL-17RA/STAT-3 dependent Cyr61, IL-23 and GM-CSF expression and RANKL mediated osteoclastogenesis by fibroblast-like synoviocytes in rheumatoid arthritis.

Interleukin (IL)-17 predominately produced by the Th17 cells, plays a crucial role in the fibroblast-like synoviocytes (FLS) mediated disease process of rheumatoid arthritis (RA). IL-17 exerts its pathogenic effects in RA-FLS by IL-17/IL-17RA/STAT-3 signaling. Recent studies have shown that RA-FLS produces SHP-2, Cyr61, IL-23, GM-CSF and RANKL which results in worsening of the disease. However, whether IL-17/IL-17RA/STAT-3 signaling regulates SHP-2, Cyr61, IL-23, GM-CSF and RANKL expressions in RA-FLS remains unknown. In this study, IL-17 treatment dramatically induced the production of Cyr61, IL-23 and GM-CSF in FLS isolated from adjuvant induced arthritis (AA) rats. Conversely, IL-17 mediated production of Cyr61, IL-23 and GM-CSF was abrogated by knockdown of IL-17RA using a small interfering RNA or blockade of STAT-3 activation with S3I-201 in AA-FLS. Interestingly, IL-17 treatment noticeably increased the expression of IL-17RA and SHP-2 in AA-FLS. However, silencing of IL-17RA reversed the effect of IL-17 on the expression of IL-17RA and SHP-2 in AA-FLS. In addition, an increased number of TRAP-positive multinucleated cells were observed in a coculture system consisting of IL-17 treated AA-FLS and rat bone marrow derived monocytes/macrophages. Further, mechanistically we found that IL-17 upregulated RANKL expression in AA-FLS that was dependent on the IL-17/IL-17RA/STAT-3 signaling cascade. Knockdown of IL-17RA or inhibition of STAT-3 activation decreased the IL- 17 induced RANKL expression by AA-FLS and their osteoclastogenic potential. Taken together, our findings demonstrate that IL-17 regulates SHP-2 expression and IL-17RA/STAT-3 dependent production of Cyr61, IL-23, GM-CSF and RANKL in AA-FLS and may reveal a new insight into the pathogenesis of RA.

Fibroblast-like synoviocytes-dependent effector molecules as a critical mediator for rheumatoid arthritis: Current status and future directions.

Rheumatoid arthritis (RA) is a systemic-autoimmune-mediated disease characterized by synovial hyperplasia and progressive destruction of joint. Currently available biological agents and inhibitor therapy that specifically target tumor necrosis factor-α, interleukin 1ß (IL-1ß), IL-6, T cells, B cells, and subcellular molecules (p38 mitogen-activated protein kinase and janus kinase) cannot facilitate complete remission in all patients and are unable to cure the disease. Therefore, further potent therapeutic targets need to be identified for effective treatment and successful clinical outcomes in patients with RA. Scientific breakthroughs have brought new insights regarding fibroblast-like synoviocytes (FLS), a major constituent of the synovial hyperplasia. These play a pivotal role in RA invading cartilage and bone tissue. Currently there are no effective therapies available that specifically target these aggressive cells. Recent evidences indicate that FLS-dependent effector molecules (toll-like receptors, nodal effector molecules, hypoxia-inducible factor, and IL-17) have emerged as important mediators of RA. In this review, we discuss the pathological features and recent advances in understanding the role of FLS-dependent effector molecules in the disease onset of RA. Pharmacological inhibition of FLS-dependent effector molecules might be a promising option for FLS-targeted therapy in RA.

Curcumin inhibits growth potential by G1 cell cycle arrest and induces apoptosis in p53-mutated COLO 320DM human colon adenocarcinoma cells.

Curcumin, a natural polyphenolic compound and it is isolated from the rhizome of Curcuma longa, have been reported to possess anticancer effect against stage I and II colon cancer. However, the effect of curcumin on colon cancer at Dukes' type C metastatic stage III remains still unclear. In the present study, we have investigated the anticancer effects of curcumin on p53 mutated COLO 320DM human colon adenocarcinoma cells derived from Dukes' type C metastatic stage. The cellular viability and proliferation were assessed by trypan blue exclusion assay and MTT assay, respectively. The cytotoxicity effect was examined by lactate dehydrogenase (LDH) cytotoxicity assay. Apoptosis was analyzed by DNA fragmentation analysis, Hoechst and propidium iodide double fluorescent staining and confocal microscopy analysis. Cell cycle distribution was performed by flow cytometry analysis. Here we have observed that curcumin treatment significantly inhibited the cellular viability and proliferation potential of p53 mutated COLO 320DM cells in a dose- and time-dependent manner. In addition, curcumin treatment showed no cytotoxic effects to the COLO 320DM cells. DNA fragmentation analysis, Hoechst and propidium iodide double fluorescent staining and confocal microscopy analysis revealed that curcumin treatment induced apoptosis in COLO 320DM cells. Furthermore, curcumin caused cell cycle arrest at the G1 phase, decreased the cell population in the S phase and induced apoptosis in COLO 320DM colon adenocarcinoma cells. Together, these data suggest that curcumin exerts anticancer effects and induces apoptosis in p53 mutated COLO 320DM human colon adenocarcinoma cells derived from Dukes' type C metastatic stage.

Trikatu, an herbal compound ameliorates rheumatoid arthritis by the suppression of inflammatory immune responses in rats with adjuvant-induced arthritis and on cultured fibroblast like synoviocytes via the inhibition of the NFκB signaling pathway.

The present study was designed to investigate the potential therapeutic effect of trikatu, an herbal compound and its underlying molecular mechanism in rats with adjuvant-induced arthritis (AIA). Our results indicate that trikatu (1000 mg/kg/b.wt. oral) administration suppressed the production of pro-inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, and monocyte chemoattractant protein (MCP)-1) and downregulated the mRNA expression levels of inflammatory mediators (TNF-α, IL-1ß, IL-6, IL-17, MCP-1, receptor activator of nuclear factor kappa B ligand (RANKL), cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS)) and transcription factors (nuclear factor kappa B 65 (NFкB-p65) and activator protein-1 (AP-1)) in cultured AIA-fibroblast like synoviocytes and synovial tissue of AIA rats. Consistently, the protein expression of NFкB-p65, IL-17, TNF-α, COX-2, and RANKL was also dramatically reduced in cultured AIA-fibroblast like synoviocytes and synovial tissue of AIA rats by trikatu treatment. In addition, trikatu suppressed the expression and phosphorylation of NFкB-p65 similar to the Bay 11-7082 (NFкB inhibitor) in cultured AIA-fibroblast like synoviocytes. Furthermore, trikatu alleviated the histopathology of joint of arthritic rats. Overall, these data highlights that trikatu could be a promising alternative modality for the possible treatment of rheumatoid arthritis and other inflammatory diseases.

Majoon ushba, a polyherbal compound, suppresses pro-inflammatory mediators and RANKL expression via modulating NFкB and MAPKs signaling pathways in fibroblast-like synoviocytes from adjuvant-induced arthritic rats.

Fibroblast-like synoviocytes (FLS) are inhabitant mesenchymal cells of synovial joints and have been recognized to play an imperative role in the immunopathogenesis of rheumatoid arthritis (RA). Blocking these pathological roles of FLS provides a potentially important therapeutic strategy for the treatment for RA. A recent study had confirmed that majoon ushba (MU), a polyherbal unani compound, possesses anti-arthritic effects in in vivo. Toward this direction, an effort has been made to understand the effect of MU on FLS derived from adjuvant-induced arthritis (AIA) rats. Here, we observed that MU administration (100-300 µg/ml) significantly inhibited the expression and phosphorylation of NFкB-p65 protein similar to that of the Bay 11-7082 (NFкB inhibitor) in NFкB signaling pathway and suppressed the protein expression of ERK1/2 and JNK1/2 in MAPKs signaling pathway in AIA-FLS. In addition, the protein expression of TNF-α, IL-17, RANKL, and iNOS was also found reduced. MU treatment significantly inhibited the mRNA expression of pro-inflammatory mediators (TNF-α, IL-1ß, IL-6, MCP-1, IL-17, iNOS, and COX-2), transcription factors (NFкB-p65 and AP-1), and RANKL and attenuated the overproduction of TNF-α, IL-1ß, IL-6, and MCP-1 (ELISA) in AIA-FLS. Furthermore, MU treatment significantly inhibited the level of lipid peroxidation, lysosomal enzymes release, and glycoproteins and increased antioxidant status (superoxide dismutase and catalase) in AIA-FLS. In conclusion, the results of this study provide evidence that MU possesses anti-inflammatory effect against AIA-FLS through the decrease in pro-inflammatory mediators expression by suppressing NFкB and MAPKs signaling pathways.

Majoon ushba, a polyherbal compound ameliorates rheumatoid arthritis via regulating inflammatory and bone remodeling markers in rats.

The present study was aimed to investigate the anti-arthritic effect of majoon ushba (MU) and its underlying mechanism in adjuvant induced arthritis (AIA) rats. Arthritis was induced by intradermal injection of complete freund's adjuvant (0.1ml) into the right hind paw of the Wistar albino rats. MU (1000mg/kg/b.wt) and methotrexate (3mg/kg/b.wt) were administered from day 11 to day 18th for 8days after adjuvant induction. We have found that MU treatment significantly increased the level of anti-inflammatory cytokine (IL-10) and inhibited the over production of pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6) and monocyte chemoattractant protein-1 (MCP-1) (ELISA) in the serum of adjuvant-induced arthritic rats. The mRNA expression of pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6, and IL-17), inflammatory enzymes (inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2)), MCP-1, receptor activator of nuclear factor-kB ligand (RANKL) and transcription factors (NF-кB and AP-1) (Real-Time PCR) was found significantly downregulated in the synovial tissues of MU treated arthritic rats. In addition, the protein expression of NF-кB, IL-17, COX-2, and RANKL (western blotting and immunohistochemistry analysis) was found reduced. On the other hand, osteoprotegerin (OPG), a bone remodeling marker was found to be elevated in synovial tissues of MU treated arthritic rats. Furthermore, MU treatment prevented body weight loss and reduced the joint paw edema, cell infiltration, cartilage and bone degradation as evidenced by the histopathological and radiological analysis. In conclusion, our current findings provide scientific evidence for the traditional claim of MU as an anti-arthritic drug.