Integrated pharmacology reveals the mechanism of action of Bu-Shen-Tong-Du prescription against collagen-induced arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. Bu-Shen-Tong-Du prescription (BSP) has traditionally been used in to treat RA but its underlying mechanisms remain unclear. In this study, we explored the potential mechanisms of BSP in collagen-induced arthritis (CIA) rats, a classic animal model of RA. We employed an integrated pharmacology approach in combination with network pharmacology, 1H-nuclear magnetic resonance (NMR) metabolomics, and biochemical analyses to determine the mechanisms of BSP for treating RA. We found that BSP can regulate immunity and inflammation by decreasing the spleen index; inhibiting hyperplasia of the white pulp; reducing the levels of IL-1ß, IL-6, IL-17A, and IFN-γ; and increasing the levels of IL-10 in the serum. Network pharmacology was utilized to predict related signal transduction pathways of BSP in RA treatment. 1H NMR metabolomics of the serum confirmed that BSP regulated energy metabolism and amino acid metabolism. Finally, we validated the Toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signaling pathway using immunohistochemical methods, which demonstrated that BSP controlled RA-induced inflammation by inhibiting the TLR4/NF-κB signaling pathway. These results confirm the therapeutic effect of BSP in a CIA rat model, which is exerted via the inhibition of the inflammation and the improvement of the immune function, balancing energy metabolism and amino acid metabolism, and inhibiting the TLR4/NF-κB signaling pathway. This study provides an experimental basis for using BSP as a combinatorial drug to inhibit inflammation and regulate immunity in the treatment of RA.

Tetrahydropalmatine attenuates MSU crystal-induced gouty arthritis by inhibiting ROS-mediated NLRP3 inflammasome activation.

Activation of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome plays a crucial role in the inflammatory responses of monosodium urate (MSU) crystal-induced gouty arthritis. Therefore, the molecular basis of NLRP3 inflammasome is very valuable in developing potential therapeutic drugs for gout. Tetrahydropalmatine (THP), the main active component of the traditional Chinese medicinal herb Corydalis yanhusuo, has shown prominent anti-inflammatory and analgesic activities, but to date, these effects have not been investigated exhaustively on gout. This study indicated that THP attenuated pain and swelling in an MSU-induced acute gout model by decreasing pro-inflammatory cytokine production and inflammatory cell infiltration. THP exerted its actions by suppressing NLRP3 inflammasome activation and subsequent formation of caspase-1. Furthermore, results showed that THP alleviated MSU-induced reactive oxygen species (ROS) generation, upstream of NLRP3 inflammasome activation, by an increase in the activities of antioxidant enzymes both in vitro and in vivo. In conclusion, our study suggests that THP suppressed ROS-mediated NLRP3 inflammasome activation in MSU-induced inflammatory responses, which highlights its therapeutic potential in gouty arthritis.

Potential therapeutic compounds from traditional Chinese medicine targeting endoplasmic reticulum stress to alleviate rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease which affects about 0.5-1% of people with symptoms that significantly impact a sufferer's lifestyle. The cells involved in propagating RA tend to display pro-inflammatory and cancer-like characteristics. Medical drug treatment is currently the main avenue of RA therapy. However, drug options are limited due to severe side effects, high costs, insufficient disease retardation in a majority of patients, and therapeutic effects possibly subsiding over time. Thus there is a need for new drug therapies. Endoplasmic reticulum (ER) stress, a condition due to accumulation of misfolded proteins in the ER, and subsequent cellular responses have been found to be involved in cancer and inflammatory pathologies, including RA. ER stress protein markers and their modulation have therefore been suggested as therapeutic targets, such as GRP78 and CHOP, among others. Some current RA therapeutic drugs have been found to have ER stress-modulating properties. Traditional Chinese Medicines (TCMs) frequently use natural products that affect multiple body and cellular targets, and several medicines and/or their isolated compounds have been found to also have ER stress-modulating capabilities, including TCMs used in RA treatment by Chinese Medicine practitioners. This review encourages, in light of the available information, the study of these RA-treating, ER stress-modulating TCMs as potential new pharmaceutical drugs for use in clinical RA therapy, along with providing a list of other ER stress-modulating TCMs utilized in treatment of cancers, inflammatory diseases and other diseases, that have potential use in RA treatment given similar ER stress-modulating capacity.

Yishen-tongbi decoction inhibits excessive activation of B cells by activating the FcγRIIb/Lyn/SHP-1 pathway and attenuates the inflammatory response in CIA rats.

Rheumatoid arthritis (RA) is a chronic autoimmune disease. Strong evidence supports that excessive activation of B cells plays a critical role in the pathogenesis of RA. Fc gamma receptor b (FcγRIIb) is the B cell inhibitory receptor and inhibits BCR (B cell receptor) signalling in part by selectively dephosphorylating CD19 which is considered a co-receptor for BCR and is essential for B cell activation. Our previous study demonstrated that a FcγRIIb I232T polymorphism presented a strong genetic link to RA and may lead to the excessive activation of B cells. Therefore, novel therapeutic strategies and drugs that can effectively inhibit the excessive activation of B cells by regulating the FcγRIIb are necessary for the treatment of RA. Therefore, we used Burkitt's lymphoma ST486 human B cells (lacking endogenous FcγRIIb) transfected with the 232Thr loss-of-function mutant to construct a FcγRIIb mutant cell line (ST486), and we demonstrated that YSTB treatment not only reduced proliferation and promoted apoptosis in ST486 cells but also did so in a dose-dependent manner. Furthermore, the intracellular Ca2+ flux of ST486 cells was decreased after treatment with YSTB, inhibiting the excessive activation of ST486 cells, and these effects correlated with the CD19/FcγRIIb-Lyn-SHP-1 pathways. Our data showed that YSTB treatment inhibited the expression of phosphorylated CD19 and upregulated the protein expression of FcγRIIb, Lyn, and SHP-1. Additionally, the CIA model was established to explore the anti-inflammatory and inhibitory effects of YSTB on bone destruction, and we found that YSTB decreased the paw oedema and arthritis index (AI) in CIA rats. It is worth mentioning that YSTB clearly decreased the AI earlier than methotrexate (MTX) (day 10 vs 16). Moreover, synovial hyperplasia, inflammatory cell infiltration and cartilage surface erosion in CIA rats were noticeably reduced after treatment with YSTB as evidenced by histopathological examination. Finally, we found that YSTB treatment suppressed bone erosion and joint space score (JNS) in CIA rats as evidenced by radiographic assessment. In summary, these data suggest that YSTB has great therapeutic potential for RA treatment.

A mechanistic insight of phytoestrogens used for Rheumatoid arthritis: An evidence-based review.

Assessment of the potential therapeutic benefits offered by naturally occurring phytoestrogens necessitate inspection of their potency and sites of action in impeding the chronic, systemic, autoimmune, joint destructing disorder Rheumatoid arthritis (RA). Possessing structural and functional similarity with human estrogen, phytoestrogen promisingly replaces the use of hormone therapy in eradicating RA symptoms with their anti-inflammatory, anti-oxidative, anti-proliferative, anti-angiogenesis, immunomodulatory, joint protection properties abolishing the harmful side effects of synthetic drugs. Scientific evidences revealed that use of phytoestrogens from different chemical categories including flavonoids, alkaloids, stilbenoids derived from different plant species manifest beneficial effects on RA through various cellular mechanisms including suppression of pro-inflammatory cytokines in particular tumor necrosis factor (TNF-α), interleukin(IL-6) and nuclear factor kappa B (NF-κB) and destructive metalloproteinases, inhibition of oxidative stress, suppressing inflammatory signalling pathways, attenuating osteoclastogenesis ameliorating cartilage degradation and bone erosion. This review summarizes the evidences of different phytoestrogen treatment and their pharmacological mechanisms in both in vitro and in vivo studies along with discussing clinical evaluations in RA patients showing phytoestrogen as a promising agent for RA therapy. Further investigations and more clinical trials are mandatory to clarify the utility of these plant derived compounds in RA prevention and in managing oestrogen deficient diseases in patients.

Pathological mechanism of joint destruction in haemophilic arthropathy.

Haemophilic arthropathy (HA), caused by intra-articular haemorrhage, is one of the most common complications in patients with haemophilia. Factor replacement therapy provides missing coagulation factors to prevent children with haemophilia from joint bleeding and decreases their risk for HA. However, haemophilia patients in developing countries are still suffering from HA due to insufficient replacement therapy. Symptoms such as pain and activity limitations caused by HA seriously affect the functional abilities and quality of life of patients with HA, causing a high disability rate in the haemophilia cohort. The pathological mechanism of HA is complicated because the whole pathological mainly involves hypertrophic synovitis, osteopenia, cartilage and bone destruction, and these pathological changes occur in parallel and interact with each other. Inflammation plays an important role in the whole complex pathological process, and iron, cytokines, growth factors and other factors are involved. This review summarizes the pathological mechanism of HA to provide background for clinical and basic research.

Combinatmarion treatment with Lactobacillus acidophilus LA-1, vitamin B, and curcumin ameliorates the progression of osteoarthritis by inhibiting the pro-inflammatory mediators.

Disease-modifying osteoarthritis (OA) therapy is not yet available. Several adjuvant therapies have demonstrated promising results in the treatment of OA. The present study aimed to investigate the therapeutic effects and underlying mechanisms of a combination of Lactobacillus acidophilus, vitamin B, and curcumin in the treatment of OA. Monosodium iodoacetate (MIA)-induced arthritis of the knee joint in rat was used as an animal model of human OA. The combination of L. acidophilus LA-1, vitamin B, and curcumin or a saline solution was given orally. Pain was measured according to the paw withdrawal latency, and paw withdrawal threshold. Cartilage destruction was analyzed using histomorphological techniques and the Mankin scoring system. Protein expression in the joint was examined using immunohistochemistry. The effects of the combination of L. acidophilus LA-1, vitamin B, and curcumin on mRNA levels in chondrocytes stimulated with interleukin (IL)-1ß were analyzed using real-time polymerase chain reaction. The combination of L. acidophilus, vitamin B, and curcumin effectively downregulated Th17 cells and the related cytokine IL-17, thereby maintained the Treg population, and increased the expression of the Treg-related cytokine IL-10 in human peripheral blood mononuclear cells. The OA animal model exhibited reduced pain and preservation of cartilage in response to the combination treatment. The expression levels of pro-inflammatory cytokines and the catabolic, matrix metalloproteinase-13 (MMP-13), were decreased, whereas the expression of the anabolic tissue inhibitors of metalloproteinases (TIMPs) were upregulated in response to the drug combination. The combination of L. acidophilus, vitamin B, and curcumin was beneficial in OA treatment, controlling the inflammatory response via regulation of the Th17/Treg population and reducing the expression of pro-inflammatory cytokines in human peripheral blood mononuclear cells. The combination treatment also preserved cartilage, suppressed osteoclastogenesis, and regulated the anabolic/catabolic imbalance. These findings indicate the therapeutic potential of combination use of L. acidophilus, vitamin B, and curcumin in patients with OA.

Cathelicidin and Calprotectin Are Disparately Altered in Murine Models of Inflammatory Arthritis and Airway Inflammation.

Cationic host defense peptides (CHDP) are immunomodulatory molecules that control infections and contribute to immune homeostasis. CHDP such as cathelicidin and calprotectin expression is altered in the arthritic synovium, and in the lungs of asthma and COPD patients. Recent studies suggest a link between airway inflammation and the immunopathology of arthritis. Therefore, in this study we compared the abundance of mouse cathelicidin (CRAMP), defensins, and calprotectin subunits (S100A8 and S100A9) in murine models of collagen-induced arthritis (CIA) and allergen house dust mite (HDM)-challenged airway inflammation. CRAMP, S100A8, and S100A9 abundance were significantly elevated in the joint tissues of CIA mice, whereas these were decreased in the lung tissues of HDM-challenged mice, compared to naïve. We further compared the effects of administration of two different synthetic immunomodulatory peptides, IG-19 and IDR-1002, on cathelicidin and calprotectin abundance in the two models. Administration of IG-19, which controls disease progression and inflammation in CIA mice, significantly decreased CRAMP, S100A8, and S100A9 levels to baseline in the joints of the CIA mice, which correlated with the decrease in cellular influx in the joints. However, administration of IDR-1002, which suppresses HDM-induced airway inflammation, did not prevent the decrease in the levels of cathelicidin and calprotectin in the lungs of HDM-challenged mice. Cathelicidin and calprotectin levels did not correlate with leukocyte accumulation in the lungs of the HDM-challenged mice. Results of this study suggest that endogenous cathelicidin and calprotectin abundance are disparately altered, and may be differentially regulated, within local tissues in airway inflammation compared to arthritis.

Andrographolide attenuates complete freund's adjuvant induced arthritis via suppression of inflammatory mediators and pro-inflammatory cytokines.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional plant-derived medicines have enabled the mankind in curing the wide spectrum of diseases throughout the ages. Andrographis paniculata (Burm.f.) Nees, is one of the traditional plant used as a folk medicine for the management of inflammation, arthritis, viral-bacterial infections and other ailments in India, China, Malaysia and other South-East Asian countries. Its major bioactive compound; andrographolide, a diterpenoid, also exerts cytoprotective properties and is reported to be effective in neuroprotection, hepatoprotection, etc. AIM: The study is aimed to explore the role of andrographolide in treatment of complete freund's adjuvant (CFA) induced arthritis. MATERIALS AND METHODS: The influx of immune cells, release of pro-inflammatory cytokines and subsequent accumulation of synovial fluid (swelling) and pain manifest into the disease. The present study used CFA induced Balb/c mice model and treated them intraperitoneally with andrographolide and dexamethasone (used as a positive control) on alternate days for six days. After 6 days, blood and peritoneal macrophages were collected to evaluate the expression of various arthritic markers and paw edema was measured on all days. RESULTS: The in vitro and ex vivo experiments showed that andrographolide treated animal group had reduced paw edema, cell cytotoxicity and nitric oxide production than dexamethasone treated animal group. Further, the study revealed the mechanistic role of andrographolide in treatment of arthritis by suppressing battery of molecules like COX-2, NF-κB, p-p38, CD40, TNF-α, IL-1ß and IL-6 involved in arthritis. CONCLUSION: The study showed the potent anti-arthritic effects of andrographolide and warrants further investigations on andrographolide for the development of safe and effective anti-arthritic drug.

Theacrine alleviates chronic inflammation by enhancing TGF-ß-mediated shifts via TGF-ß/SMAD pathway in Freund's incomplete adjuvant-induced rats.

Rheumatoid arthritis is a chronic and systemic autoimmune disease, which affects approximately 1% of the adult population worldwide. The present study investigated the therapeutic effect of theacrine (TC) on arthritis and its mechanisms in Freund's incomplete adjuvant (FIA)-induced SD rats. Rats were randomly divided into 5 groups: i) healthy control; ii) model; iii) positive control with methotrexate (MTX); iv) treatment with 12.5 mg/kg TC; and v) treatment with 25.0 mg/kg TC. The apparent scores, including changes in body weights, degree of paw swelling and arthritis indicators, were analyzed to evaluate the anti-chronic inflammatory effect of TC. The levels of interleukin (IL)-6 and transforming growth factor-ß (TGF-ß) in serum were measured by enzyme-linked immunosorbent assay. The protein and RNA expression levels of the critical factors in rats were measured to elucidate the mechanisms responsible for chronic inflammation and to verify molecular indexes of chronic inflammatory conditions. TC notably suppressed the severity of FIA-induced rat by attenuating the apparent scores, animal weight and inflammatory indexes in the 25 mg/kg TC group compared with the FIA rat model. Furthermore, TC significantly decreased the levels of IL-6 and increased the levels of TGF-ß. Histopathological examinations indicated that TC rescued the synovial hyperplasia and inflammatory cell infiltration in joint tissues. In addition, TC enhanced TGF-ß-mediated shifts in inflammatory marker expression in joint tissue. Overall, the present study demonstrated that TC exerted a superior anti-arthritic effect via the suppression of IL-6 and the activation of TGF-ß by the TGF-ß/SMAD pathway.

Curcumin attenuates collagen-induced rat arthritis via anti-inflammatory and apoptotic effects.

Curcumin is a natural herbal product that has been popularly used to treat autoimmune diseases in China; however, its effects on rheumatoid arthritis and its mechanism are not clear. The main purposes of this study are to explore the therapeutic effects of curcumin on collagen-induced arthritis (CIA) rats and the pharmacological mechanism. In the present study, CIA rats were established by injecting bovine type II collagen. Curcumin and methotrexate were then orally administered daily, and the swelling degree of the hind limb joints was scored every two days. Histopathological changes were observed by hematoxylin-eosin staining. The levels of cytokines (TNF-α, IL-1ß, IL-17 and TGF-ß) were detected by radioimmunoassay, while the expression of IκBα and COX-2 was detected by Western blot. In addition, cell viability was detected by CCK-8 assay, and the effect of curcumin on macrophage apoptosis was detected by flow cytometry and TUNEL assay. The results indicated that in vivo curcumin attenuated the degree of joint swelling of rats and the further development of joint histopathology. Moreover, it downregulated the levels of cytokines. In vitro curcumin inhibited the degradation of IκBα and reduced the production of COX-2 in LPS-induced inflammatory RAW264.7 cells. Importantly, curcumin significantly induced macrophage apoptosis. In conclusion, in this study, we have demonstrated that curcumin exerts therapeutic effects on arthritis in CIA rats and has a strong pharmacological activity on reducing the inflammatory response in macrophages. Its mechanism may be related to the inhibition of the NF-κB signaling pathway and the promotion of macrophage apoptosis.

Theaflavin-3, 3'-Digallate Attenuates Rheumatoid Inflammation in Mice Through the Nuclear Factor-κB and MAPK Pathways.

Rheumatoid arthritis (RA) is a common autoimmune disease which impacts a large number of patients worldwide, and new drugs are required for lower the disease burden. Theaflavin-3, 3'-digallate (TFDG) is polyphenol exhibiting inhibition on inflammatory factors. This study aimed to explore the attenuation of TFDG on RA. The collagen-induced arthritis (CIA) mouse model was established and administered with TFDG. The arthritis score and incidence was recorded to assess the amelioration of TFDG on arthritis. Histopathological change of the mouse joint tissues was evaluated by haemotoxylin and eosin staining. The expression of pro-inflammatory mediators including interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-6 was quantified by ELISA. The activation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathways in the synovium were determined by Western blotting. In comparison with the control, administration of TFDG significantly reduced arthritis score and incidence in the CIA mouse model. TFDG significantly suppressed the expression of IL-1ß, TNF-α, and IL-6, as well as the levels of MMP-1, MMP-2, and MMP-3 in the synovium. TFDG also showed remarkable inhibition on the activation of NF-κB and the phosphorylation of P38, JNK2, and ERK. This study puts up evidence that TFDG exerts protection on RA via inhibiting the activation of NF-κB- and MAPK-signaling pathways.

YinYang1 deficiency ameliorates joint inflammation in a murine model of rheumatoid arthritis by modulating Th17 cell activation.

Yin Yang 1 (YY1) is a ubiquitously expressed transcription factor that functions in cooperation with various cofactors to regulate gene expression. In the immune system, YY1 enhances cytokine production and T helper (Th) 2 effector cell differentiation, resulting in the activation of inflammation. However, no studies have reported the role of YY1 in Th17 cell regulation, which is implicated in rheumatoid arthritis (RA). We investigated the expression of YY1 in Th17 cells in vitro and revealed increased levels of YY1 mRNA and protein. To elucidate the function of YY1 pathogenesis in RA, we used a collagen-induced arthritis (CIA) mouse model with YY1 deficiency. Deficiency of YY1 reduced the severity of arthritis and joint destruction. Moreover, Th17 cells were dramatically reduced in YY1-deficient mice. The cytokine interleukin (IL)-17 was decreased in YY1-deficient CD4+ T cells ex vivo and in vivo. Interestingly, the level of signal transducer and activator of transcription 3 (STAT3), tumor necrosis factor-α, IL-17, IL-6, and IL-1ß were markedly decreased in YY1-deficient mice with CIA. The cytokine-inducing function of YY1 was more specific to IL-17 than to interferon-γ. YY1 plays a role in Th17 cell differentiation and RA pathogenesis. Our findings suggest that future RA therapies should target the regulatory mechanism involved in Th17 cell differentiation, in which YY1 may cooperate with the STAT3 signaling pathway.

Intra-articular lentivirus-mediated gene therapy targeting CRACM1 for the treatment of collagen-induced arthritis.

Abnormal store-operated calcium uptake has been observed in peripheral T lymphocytes of rheumatoid arthritis (RA) patients, and sustained intracellular calcium signalling is known to mediate the functions of many types of immune cells. Thus, it is hypothesized that regulating calcium entry through CRACM1 (the pore-forming subunit of calcium release-activated calcium (CRAC) channels; also known as ORAI1) may be beneficial for the management of RA. Localized CRACM1 knockdown in the joints and draining lymph nodes (DLNs) of mice with collagen-induced arthritis (CIA) was achieved via lentiviral-based delivery of shRNA targeting mouse CRACM1. Consistent with CRACM1 knockdown, calcium influx in synovial cells and the histopathological features of CIA were reduced. These effects were also associated with reduced levels of several notable inflammatory cytokines, such as IL-6, IL-17A, and IFN-γ, in the joints. Additionally, CRACM1-shRNA reduced the number of bone marrow-derived osteoclasts in vitro as well as osteoclasts in CIA joints, which was associated with reduced RANKL levels in the serum and joints. In summary, inhibiting calcium entry by CRACM1 knockdown suppressed arthritis development and may be therapeutically beneficial for RA patients.

Periplocoside A ameliorated type II collagen-induced arthritis in mice via regulation of the balance of Th17/Treg cells.

Periplocoside A (PSA) has been extracted from the Chinese herbal medicine Periploca sepium Bge to treat rheumatoid arthritis (RA) via immune regulation. We previously found that PSA exhibits immunosuppressive activity both in vitro and in vivo. Balanced regulation of helper T 17 (Th17)/regulatory T (Treg) cells is the current therapeutic direction for the treatment of RA. The present study investigated the mechanism of PSA in treating collagen-induced arthritis (CIA). The therapeutic effects and potential pharmacological mechanisms of PSA were specifically clarified by examining its effects on CIA in DBA/1 mice. PSA administration significantly relieved the severity of the arthritis, and preventive administration of PSA reduced the incidence of arthritis in the mice with CIA and relieved joint damage in terms of morphology. PSA was also able to reduce the levels of anti-collagen II (CII) antibodies and pro-inflammatory cytokines in the serum. As a result, the proportion of Th17 cells decreased, and the proportion of Treg cells increased. A follow-up study of the ex vivo immunological reactions induced by a specific antigen found that PSA suppressed lymphocyte proliferation, inhibited the differentiation and reactivity of Th17 cells, and promoted the proportion of Treg cells among helper T cells. PSA also exhibited pharmacological effect in regulating the balance between Th17 and Treg cells in CIA through relevant signalling pathways. Thus, PSA played a specific role in CIA treatment. In particular, our results suggest that the therapeutic effects of PSA on RA are partially realized via the regulation of the balance of Th17/Treg cells.

In-vivo quantitative assessment of the therapeutic response in a mouse model of collagen-induced arthritis using 18 F-fluorodeoxyglucose positron emission tomography.

Mouse collagen-induced arthritis (CIA) is the most commonly used animal model to investigate underlying pathogenesis of autoimmune arthritis and to demonstrate the therapeutic efficacy of novel drugs in autoimmune arthritis. The conventional read-outs of CIA are clinical score and histopathology, which have several limitations, including (i) subjected to observer bias; and (ii) longitudinal therapeutic efficacy of a new drug cannot be determined. Thus, a robust, non-invasive, in-vivo drug screening tool is currently an unmet need. Here we have assessed the utility of 18 F-fluorodeoxyglucose positron emission tomography (18 F-FDG) as an in-vivo screening tool for anti-inflammatory drugs using the mouse CIA model. The radiotracer 18 F-FDG and a PET scanner were employed to monitor CIA disease activity before and after murine anti-tumour necrosis factor (TNF)-α antibody (CNTO5048) therapy in the mouse CIA model. Radiotracer concentration was derived from PET images for individual limb joints and on a per-limb basis, and Spearman's correlation coefficient (ρ) was determined with clinical score and histology of the affected limbs. CNTO5048 improved arthritis efficiently, as evidenced by clinical score and histopathology. PET showed an increased uptake of 18 F-FDG with the progression of the disease and a significant decrease in the post-treatment group. 18 F-FDG uptake patterns showed a strong correlation with clinical score (ρ = 0·71, P < 0·05) and histopathology (ρ = 0·76, P < 0·05). This study demonstrates the potential of 18 F-FDG PET as a tool for in-vivo drug screening for inflammatory arthritis and to monitor the therapeutic effects in a longitudinal setting.

Anti-inflammatory activity of green versus black tea aqueous extract in a rat model of human rheumatoid arthritis.

AIM: Recently, there has been an increasing interest in tea (Camellia sinensis) as a protective agent against inflammatory diseases. Here, we evaluated/compared the anti-inflammatory activity of two different doses (0.5 and 1.0 g/kg body weight) of green tea aqueous extract (GTE, rich in catechins) and black tea aqueous extract (BTE, rich in theaflavins and thearubigins) in rat adjuvant-induced arthritis (AIA). METHODS: Adjuvant-induced arthritis rat model received orally/daily distilled water as vehicle, indomethacin (1.0 mg/kg body weight; a non-steroidal/anti-inflammatory drug), or tea aqueous extracts (for 28 or 14 consecutive days starting from day 0 or 14 of arthritis induction, respectively). RESULTS: The present study showed that only the high dose of GTE (from day 0) significantly alleviated (P < 0.05-0.001) all complications shown in arthritic rats, including synovial joint inflammation, elevation in erythrocyte sedimentation rate, blood leukocytosis (due to lymphocytosis and neutrocytosis), and changes in weight/cellularity of lymphoid organs. The anti-arthritic activity of the high dose of GTE (from day 0) was comparable (P > 0.05) with that of indomethacin (12.9-53.8 vs. 9.5-48.4%, respectively) and mediated by significantly decreasing and down-regulating (P < 0.001) the systemic production of pro-inflammatory cytokines and the expression of chemokine receptor-5 in synovial tissues, respectively. Moreover, the anti-arthritic activity of tea aqueous extracts was in the following order: high dose of GTE > low dose of GTE ≥ high dose of BTE > low dose of BTE. CONCLUSION: The present study proved the anti-inflammatory activity of GTE over BTE and equal to that of indomethacin in AIA rat model.

Trikatu, a herbal compound mitigates the biochemical and immunological complications in adjuvant-induced arthritic rats.

AIM: Rheumatoid arthritis is a chronic inflammatory autoimmune disorder with multi-factorial factors influencing disease alleviation in synovial joints. The aim of this study was to investigate the anti-arthritic efficacy of trikatu, a herbal compound, on biochemical and immunological complications in adjuvant-induced arthritic rats. METHODS: Arthritis was induced in rats by a single intradermal injection of complete Freund's adjuvant (0.1 mL) into the foot pad of the right hind paw. Trikatu (1000 mg/kg body weight, oral) and indomethacin (3 mg/kg body weight, intrap intraperitoneal) were administered for 8 days from days 11 to 18 after adjuvant injection. RESULTS: Our present study results evidenced a significant alteration in the activities/levels of lysosomal enzymes, protein bound carbohydrates, bone collagen, urinary constituents like hydroxyproline and total glycosaminoglycans, lipid peroxidation, antioxidant status, lipid profiles, rheumatoid factor and inflammatory mediators in adjuvant-induced arthritic rats. Trikatu treatment (1000 mg/kg/body weight) reverted back all the above biochemical and immunological parameters to near normal levels in arthritic rats as evidenced by the radiological and histopathological assessements . CONCLUSION: These results suggest that trikatu could be a promising alternative drug for the control and management of rheumatoid arthritis.

Resolvin D3 Is Dysregulated in Arthritis and Reduces Arthritic Inflammation.

Uncontrolled inflammation is a unifying component of many chronic inflammatory diseases, such as arthritis. Resolvins (Rvs) are a new family from the endogenous specialized proresolving mediators (SPMs) that actively stimulate resolution of inflammation. In this study, using lipid mediator metabololipidomics with murine joints we found a temporal regulation of endogenous SPMs during self-resolving inflammatory arthritis. The SPMs present in self-resolving arthritic joints include the D-series Rvs, for example, RvD1, RvD2, RvD3, and RvD4. Of note, RvD3 levels were reduced in inflamed joints from mice with delayed-resolving arthritis when compared with self-resolving inflammatory arthritis. RvD3 was also reduced in serum from rheumatoid arthritis patients compared with healthy controls. RvD3 administration reduced joint leukocytes as well as paw joint eicosanoids, clinical scores, and edema. Taken together, these findings provide evidence for dysregulated endogenous RvD3 levels in inflamed paw joints and its potent actions in reducing murine arthritis.

Spatiotemporal expression of endogenous TLR4 ligands leads to inflammation and bone erosion in mouse collagen-induced arthritis.

Increased expression of endogenous Toll-like receptor 4 (TLR4) ligands (e.g., Tenascin-C, S100A8/A9, citrullinated fibrinogen (cFb) immune complexes) has been observed in patients with rheumatoid arthritis (RA). However, their roles in RA pathogenesis are not well understood. Here, we investigated the expression kinetics and role of endogenous TLR4 ligands in the murine model of collagen-induced arthritis (CIA). Tenascin-C was upregulated in blood early in CIA, and correlated positively with the clinical score at day 56. Levels of S100A8/A9 increased starting from day 28, peaking at day 42, and correlated positively with joint inflammation. Levels of anti-cFb antibodies increased during the late phase of CIA and correlated positively with both joint inflammation and cartilage damage. Blockade of TLR4 activation at the time of the first TLR4 ligand upregulation prevented clinical and histological signs of arthritis. A TLR4-dependent role was also observed for Tenascin-C and cFb immune complexes in osteoclast differentiation in vitro. Taken together, our data suggests that the pathogenic contribution of TLR4 in promoting joint inflammation and bone erosion during CIA occurs via various TLR4 ligands arising at different stages of disease. The data also suggests that Blockade of TLR4 with monoclonal antibodies is a promising strategy in RA treatment.