Adjuvant-induced Arthritis In Rats Research Articles

Manual acupuncture ameliorates inflammatory pain by upregulating adenosine A3 receptor in complete Freund’s adjuvant-induced arthritis rats

BackgroundAdenosine A3 receptor (A3R) exerts analgesic, anti-inflammatory, and anti-nociceptive effects. In this study, we determined the analgesic mechanism of manual acupuncture (MA) in rats with complete Freund's adjuvant (CFA)-induced arthritis and explored whether MA ameliorates inflammation in these rats by upregulating A3R. MethodsSixty Sprague Dawley (SD) rats were randomly divided into the following groups: Control, CFA, CFA + MA, CFA + sham MA, CFA + MA + DMSO, CFA + MA + IB-MECA, and CFA + MA + Reversine groups. The arthritis rat model was induced by injecting CFA into the left ankle joints. Thereafter, the rats were subjected to MA (ST36 acupoint) for 3 days. The clinical indicators paw withdrawal latency (PWL), paw withdrawal threshold (PWT), and open field test (OFT) were used to determine the analgesic effect of MA. In addition, to explore the effect of A3R on inflammation after subjecting arthritis rats to MA, IB-MECA (A3R agonist) and Reversine (A3R antagonist) were injected into ST36 before MA. ResultsMA ameliorated the pathological symptoms of CFA-induced arthritis, including the pain indicators PWL and PWT, number of rearing, total ambulatory distance, and activity trajectory. Furthermore, after MA, the mRNA and protein expression of A3R was upregulated in CFA-induced arthritis rats. In contrast, the protein levels of TNF-α, IL-1β, Rap1, and p-p65 were downregulated after MA. Interestingly, the A3R agonist and antagonist further downregulated and upregulated inflammatory cytokine expression, respectively, after MA. Furthermore, the A3R antagonist increased the degree of ankle swelling after MA. ConclusionMA can alleviate inflammatory pain by inhibiting the NF-κB signaling pathway via upregulating A3R expression of the superficial fascia of the ST36 acupoint site in CFA-induced arthritis rats.

Acupuncture alleviates inflammatory pain by activating CXCL1/CXCR2 signaling in the primary somatosensory cortex in adjuvant induced arthritis rats.

To observe whether acupuncture up-regulates chemokine CXC ligand 1 (CXCL1) in the brain to play an analgesic role through CXCL1/chemokine CXC receptor 2 (CXCR2) signaling in adjuvant induced arthritis (AIA) rats, so as to reveal its neuro-immunological mechanism underlying improvement of AIA. BALB/c mice with relatively stable thermal pain reaction were subjected to planta injection of complete Freund adjuvant (CFA) for establishing AIA model, followed by dividing the AIA mice into simple AF750 (fluorochrome) and AF750+CXCL1 groups (n=2 in each group). AF750 labeled CXCL1 recombinant protein was then injected into the mouse's tail vein to induce elevation of CXCL1 level in blood for simulating the effect of acupuncture stimulation which has been demonstrated by our past study. In vivo small animal imaging technology was used to observe the AF750 and AF750+CXCL1-labelled target regions. After thermal pain screening, the Wistar rats with stable pain reaction were subjected to AIA modeling by injecting CFA into the rat's right planta, then were randomized into model and manual acupuncture groups (n=12 in each group). Other 12 rats that received planta injection of saline were used as the control group. Manual acupuncture (uniform reinforcing and reducing manipulations) was applied to bilateral "Zusanli" (ST36) for 4×2 min, with an interval of 5 min between every 2 min, once daily for 7 days. The thermal pain threshold was assessed by detecting the paw withdrawal latency (PWL) using a thermal pain detector. The contents of CXCL1 in the primary somatosensory cortex (S1), medial prefrontal cortex, nucleus accumbens, amygdala, periaqueductal gray and rostroventromedial medulla regions were assayed by using ELISA, and the expression levels of CXCL1, CXCR2 and mu-opioid receptor (MOR) mRNA in the S1 region were detected using real time-quantitative polymerase chain reaction. The immune-fluorescence positive cellular rate of CXCL1 and CXCR2 in S1 region was observed after immunofluorescence stain. The immunofluorescence double-stain of CXCR2 and astrocyte marker glial fibrillary acidic protein (GFAP) or neuron marker NeuN or MOR was used to determine whether there is a co-expression between them. In AIA mice, results of in vivo experiments showed no obvious enrichment signal of AF750 or AF750+CXCL1 in any organ of the body, while in vitro experiments showed that there was a stronger fluorescence signal of CXCL1 recombinant protein in the brain. In rats, compared with the control group, the PWL from day 0 to day 7 was significantly decreased (P<0.01) and the expression of CXCR2 mRNA in the S1 region significantly increased in the model group (P<0.05), while in comparison with the model group, the PWL from day 2 to day 7, CXCL1 content, CXCR2 mRNA expression and CXCR2 content, and MOR mRNA expression in the S1 region were significantly increased in the manual acupuncture group (P<0.05, P<0.01). Immunofluorescence stain showed that CXCR2 co-stained with NeuN and MOR in the S1 region, indicating that CXCR2 exists in neurons and MOR-positive neurons but not in GFAP positive astrocytes. Acupuncture can increase the content of CXCL1 in S1 region, up-regulate CXCR2 on neurons in the S1 region and improve MOR expression in S1 region of AIA rats, which may contribute to its effect in alleviating inflammatory pain.

White adipose tissue, a novel antirheumatic target: Clues from its secretory capability and adipectomy-based therapy.

White adipose tissue (WAT) is involved in rheumatoid arthritis (RA). This study explored its potential as an antirheumatic target. WAT status of healthy and adjuvant-induced arthritis (AIA) rats were compared. The contribution of WAT to RA pathology was evaluated by pre-adipocyte transplant experiments and by dissecting perirenal fat pads of AIA rats. The impact of RA on WAT was investigated by culturing pre-adipocytes. Proteins differentially expressed in WAT of healthy and AIA rats were identified by the UPLC/MS2 method. These together with PPARγ siRNA and agonist were used to treat pre-adipocytes in vitro. The medium was used for THP-1 monocyte culture. Compared with healthy controls, AIA WAT was smaller but secreted more leptin, eNAMPT, MCP-1, TNF-α, and IL-6. AIA rat pre-adipocytes increased the levels of these adipokines in healthy recipients. RA patients' serum induced a similar secretion change and impaired differentiation of pre-adipocytes. Adipectomy eased AIA-related immune abnormalities and arthritic manifestations. Hepatokines PON1, IGFBP4, and GPIHBP1 were among the differential proteins in high levels in RA blood, and induced inflammatory secretions by pre-adipocytes. GPIHBP1 inhibited PPARγ expression and caused differentiation impairment and inflammatory secretion by pre-adipocytes, a similar outcome to PPARγ-silencing. This endowed the cells with an ability to activate monocytes, which can be abrogated by rosiglitazone. Certain hepatokines potentiate inflammatory secretions by pre-adipocytes and expedite RA progression by inhibiting PPARγ. Targeting this signalling or abnormal WAT secretion by various approaches may reduce RA severity.

Supramolecular Hydrogel Dexamethasone-Diclofenac for the Treatment of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) severely affects patients' quality of life and is commonly treated with glucocorticosteroids injections, like dexamethasone, which may have side effects. This study aimed to create a novel low dose of twin-drug hydrogel containing dexamethasone and diclofenac and explore its potential as a drug delivery system for an enhanced anti-inflammatory effect. Its characterization involved rheology, transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Furthermore, the hydrogel demonstrated thixotropic properties. The hydrogel exhibited no cytotoxicity against RAW 264.7 macrophages. Furthermore, the hydrogel demonstrated a significant anti-inflammatory efficacy by effectively downregulating the levels of NO, TNF-α, and IL-6 in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. The co-delivery approach, when intra-articularly injected in adjuvant-induced arthritis (AIA) rats, significantly alleviated chronic inflammation leading to reduced synovitis, delayed bone erosion onset, and the downregulation of inflammatory cytokines. The biocompatibility and adverse effect evaluation indicated good biological safety. Furthermore, the hydrogel demonstrated efficacy in reducing NF-κB nuclear translocation in LPS-induced RAW 264.7 macrophages and inhibited p-NF-kB, COX-2, and iNOS expression both in RAW 264.7 macrophages and the joints of AIA rats. In conclusion, the findings indicate that the hydrogel possesses potent anti-inflammatory activity, which effectively addresses the limitations associated with free forms. It presents a promising therapeutic strategy for the management of RA.

TRPM7 facilitates fibroblast-like synoviocyte proliferation, metastasis and inflammation through increasing IL-6 stability via the PKCα-HuR axis in rheumatoid arthritis

Transient receptor potential melastatin 7 (TRPM7) is a cation channel that plays a role in the progression of rheumatoid arthritis (RA), yet its involvement in synovial hyperplasia and inflammation has not been determined. We previously reported that TRPM7 affects the destruction of articular cartilage in RA. Herein, we further confirmed the involvement of TRPM7 in fibroblast-like synoviocyte (FLS) proliferation, metastasis and inflammation. We observed increased TRPM7 expression in FLSs derived from human RA patients. Pharmacological inhibition of TRPM7 protected primary RA-FLSs from proliferation, metastasis and inflammation. Furthermore, we found that TRPM7 contributes to RA-FLS proliferation, metastasis and inflammation by increasing the intracellular Ca2+ concentration. Mechanistically, the PKCα-HuR axis was demonstrated to respond to Ca2+ influx, leading to TRPM7-mediated RA-FLS proliferation, metastasis and inflammation. Moreover, HuR was shown to bind to IL-6 mRNA after nuclear translocation, which could be weakened by TRPM7 channel inhibition. Additionally, adeno-associated virus 9-mediated TRPM7 silencing is highly effective at alleviating synovial hyperplasia and inflammation in adjuvant-induced arthritis rats. In conclusion, our findings unveil a novel regulatory mechanism involved in the pathogenesis of RA and suggest that targeting TRPM7 might be a potential strategy for the prevention and treatment of RA.

Dual-targeted halofuginone hydrobromide nanocomplexes for promotion of macrophage repolarization and apoptosis of rheumatoid arthritis fibroblast-like synoviocytes in adjuvant-induced arthritis in rats

Rheumatoid arthritis (RA) is a prevalent autoimmune disease characterized by chronic inflammation and excessive proliferation of the synovium. Currently, treatment options focus on either reducing inflammation or inhibiting synovial hyperplasia. However, these modalities are unsatisfactory in achieving the desired therapeutic outcomes. Halofuginone hydrobromide (HF), an herbal active ingredient, has demonstrated pharmacological effects of both anti-inflammation and inhibition of synovial hyperplasia proliferation. However, HF’s medical efficacy is limited due to its poor water solubility, short half-life, and non-target toxicity. In the current study, by using the advantages of nanotechnology, we presented a novel dual-targeted nanocomplex, termed HA-M@P@HF NPs, which consisted of a hyaluronic acid (HA)-modified hybrid membrane (M)-camouflaged poly lactic-co-glycolic acid (PLGA) nanosystem for HF delivery. These nanocomplexes not only overcame the limitations of HF but also achieved simultaneous targeting of inflammatory macrophages and human fibroblast-like synoviocytes-rheumatoid arthritis (HFLS-RA). In vivo experiments demonstrated that these nanocomplexes effectively suppressed immune-mediated inflammation and synovial hyperplasia, safeguarding against bone destruction in rats with adjuvant-induced arthritis (AIA). Remarkable anti-arthritic effects of these nanocomplexes were accomplished through promoting repolarization of M1-to-M2 macrophages and apoptosis of HFLS-RA, thereby offering a promising therapeutic strategy for RA.

Silibinin's Effects against Methotrexate-Induced Hepatotoxicity in Adjuvant-Induced Arthritis Rat Model.

Methotrexate (MTX) is the first drug of choice to treat several diseases, including rheumatoid arthritis. However, its administration is accompanied by severe side effects, most commonly hepatotoxicity. Hence, alternative therapies with a lower toxicity and fewer side effects are needed. This study aimed to investigate the antioxidant and hepatoprotective effects of silibinin (SIL, natural agent) against MTX-induced hepatotoxicity in an adjuvant-induced arthritis (AIA) rat model. Arthritic rats were treated with SIL (100 mg/kg) and/or methotrexate (2 mg/kg). Non-arthritic rats, arthritic untreated rats, and arthritic rats who received the vehicle were followed in parallel. SIL alleviated the systemic consequences of arthritis by restoring lost weight, decreasing the erythrocyte sedimentation rate, and ameliorating joint damage, which was evident both micro- and macroscopically. Additionally, SIL prevented the histopathological alterations in the liver and significantly reduced the liver damage caused by MTX and AIA, as shown by a decrease in the markers of liver damage (ALT and AST). Furthermore, SIL relieved the oxidative stress induced by AIA and MTX in liver tissue by decreasing the lipid peroxidation (MDA) levels and enhancing the antioxidant defense system (GSH levels; catalase and superoxide dismutase (SOD) activities). In conclusion, our results suggest that SIL is a potent antioxidant and hepatoprotective agent in arthritic rats. It markedly attenuated the progression and severity of the arthritic disease and eased the oxidative stress in liver tissue by improving the pro-oxidant/antioxidant balance.

CPD-002, a novel VEGFR2 inhibitor, relieves rheumatoid arthritis by reducing angiogenesis through the suppression of the VEGFR2/PI3K/AKT signaling pathway

Synovial angiogenesis is a key player in the development of rheumatoid arthritis (RA), and anti-angiogenic therapy is considered a promising approach for treating RA. CPD-002 has demonstrated efficacy in suppressing tumor angiogenesis as a VEGFR2 inhibitor, but its specific impacts on RA synovial angiogenesis and possible anti-RA effects need further study. We examined the influences of CPD-002 on the migration and invasion of human umbilical vein endothelial cells (HUVECs) and its impacts on HUVECs' tube formation and vessel sprouting ex vivo. The therapeutic potential of CPD-002 in adjuvant-induced arthritis (AIA) rats and its suppression of synovial angiogenesis were examined. The involvement of the VEGFR2/PI3K/AKT pathway was assessed both in HUVECs and AIA rat synovium. Here, CPD-002 inhibited the migration and invasion of VEGF-stimulated HUVECs, decreased their chemotactic response to RA fibroblast-like synoviocyte-released chemoattractants, and exhibited anti-angiogenic effects in vitro and ex vivo. CPD-002′s targeting of VEGFR2 was confirmed with molecular docking and cellular thermal shift assays, supported by the abolishment of CPD-002′s effects upon using VEGFR2 siRNA. CPD-002 relieved paw swelling, arthritis index, joint damage, and synovial angiogenesis, indicating its anti-arthritic and anti-angiogenic effects in AIA rats. Moreover, the anti-inflammatory effects in vivo and in vitro of CPD-002 contributed to its anti-angiogenic effects. Mechanistically, CPD-002 hindered the activation of VEGFR2/PI3K/AKT pathway in VEGF-induced HUVECs and AIA rat synovium, as evidenced by reduced p-VEGFR2, p-PI3K, and p-AKT protein levels alongside elevated PTEN protein levels. Totally, CPD-002 showed anti-rheumatoid effects via attenuating angiogenesis through the inhibition of the VEGFR2/PI3K/AKT pathway.

Nyctanthes Arbor-tristis: Biological Activites

Rheumatism and inflammatory illnesses have long been treated with NAT. Using Freund's adjuvant-induced arthritic rat model, current study assesses antiarthritic potential of NAT. For a total of twenty days in a row, treatments with methanolic, ethyl acetate, and n-hexane extracts were administered. The assessment of arthritic development was done using water displacement plethysmometry and macroscopic arthritic grading. The study examined hematological and biochemical data and processed ankle joints for histological assessment. The ingredients were identified by GC-MS analysis and qualitative phytochemical examination. The infiltration of inflammatory cells, bone degradation, paw edema, pannus development, and arthritic scoring were all inhibited by NAT extracts. The plant extracts restored hemoglobin (Hb) content and red blood cell (RBC) counts to almost normal levels while also improving total leukocyte and platelet counts. As assessed by levels of alanine aminotransferase (ALT), creatinine, urea, aspartate aminotransferase (AST). Hepatotoxicity and nephrotoxicity, the extracts were deemed safe. Ethyl acetate extract caused best prevention of paw edema, according to comparative analysis of data. Terpenes, terpenoids, iridoid glycosides and fatty acids are three main classes into which contents of ethyl acetate extract can be divided. According to the current investigation, ethyl acetate extract had highest inhibitory action and NAT improved experimental rheumatoid arthritis.

Shikonin suppresses rheumatoid arthritis by inducing apoptosis and autophagy via modulation of the AMPK/mTOR/ULK-1 signaling pathway

BackgroundThe overproliferation of fibroblast-like synoviocytes (FLS) contributes to synovial hyperplasia, a pivotal pathological feature of rheumatoid arthritis (RA). Shikonin (SKN), the active compound from Lithospermum erythrorhizon, exerts anti-RA effects by diverse means. However, further research is needed to confirm SKN's in vitro and in vivo anti-proliferative functions and reveal the underlying specific molecular mechanisms. PurposeThis study revealed SKN's anti-proliferative effects by inducing both apoptosis and autophagic cell death in RA FLS and adjuvant-induced arthritis (AIA) rat synovium, with involvement of regulating the AMPK/mTOR/ULK-1 pathway. MethodsSKN's influences on RA FLS were assessed for proliferation, apoptosis, and autophagy with immunofluorescence staining (Ki67, LC3B, P62), EdU incorporation assay, staining assays of Hoechst, Annexin V-FITC/PI, and JC-1, transmission electron microscopy, mCherry-GFP-LC3B puncta assay, and western blot. In AIA rats, SKN's anti-arthritic effects were assessed, and its impacts on synovial proliferation, apoptosis, and autophagy were studied using Ki67 immunohistochemistry, TUNEL, and western blot. The involvement of AMPK/mTOR/ULK-1 pathway was examined via western blot. ResultsSKN suppressed RA FLS proliferation with reduced cell viability and decreased Ki67-positive and EdU-positive cells. SKN promoted RA FLS apoptosis, as evidenced by apoptotic nuclear fragmentation, increased Annexin V-FITC/PI-stained cells, reduced mitochondrial potential, elevated Bax/Bcl-2 ratio, and increased cleaved-caspase 3 and cleaved-PARP protein levels. SKN also enhanced RA FLS autophagy, featuring increased LC3B, reduced P62, autophagosome formation, and activated autophagic flux. Autophagy inhibition by 3-MA attenuated SKN's anti-proliferative roles, implying that SKN-induced autophagy contributes to cell death. In vivo, SKN mitigated the severity of rat AIA while also reducing Ki67 expression, inducing apoptosis, and enhancing autophagy within AIA rat synovium. Mechanistically, SKN modulated the AMPK/mTOR/ULK-1 pathway in RA FLS and AIA rat synovium, as shown by elevated P-AMPK and P-ULK-1 expression and decreased P-mTOR expression. This regulation was supported by the reversal of SKN's in vitro and in vivo effects upon co-administration with the AMPK inhibitor compound C. ConclusionSKN exerted in vitro and in vivo anti-proliferative properties by inducing apoptosis and autophagic cell death via modulating the AMPK/mTOR/ULK-1 pathway. Our study revealed novel molecular mechanisms underlying SKN's anti-RA effects.

Antiarthritic potential of ethanolic extract of Ixora coccinea leaves on complete Freund's adjuvant-induced arthritis in animal model.

Ixora coccinea leaves possess antioxidant, anti-inflammatory, antinociceptive, antimutagenic, and gastroprotective properties. On this background, its antiarthritic potential was evaluated. The objective is to evaluate the effect of Ethanolic extract of Ixora coccinea leaves (EEICL) on complete Freund's adjuvant-induced arthritis in rats. PG research laboratory, Pharmacology Department, MKCG Medical College, Berhampur, Odisha. Thirty-six Wistar albino rats were randomly distributed into sixgroups (n = 6) as follows: Gr 1 (normal control)-DW p.o, Gr-2 (disease control [DC] - Tween 80 p.o), Gr-3 (piroxicam 0.9 mg/kg p.o), Gr-4 (EEICL-1 g/kg, p.o, Gr 4-EEICL-1.5 g/kg p.o, Gr 5-ED50 (0.82 g/kg) + piroxicam (0.45 mg/kg) p.o. After induction of arthritis, drugs, and vehicles were administered daily from 5th to 25th day. On 0, 5th, 10th, 15th, and 25th day, parameters like body weight, rotarod fall time, paw volume displacement, and arthritis index were measured. On the last day, Erythrocyte sedimentation rate (ESR), tissue malondialdehyde (MDA), and histopathological analysis were done. Analysis of parametric data was done by one-way ANOVA and nonparametric data by Kruskal-Wallis test using graph pad prism 7.0. P < 0.05 was considered statistically significant. EEICL (1.5 mg/kg) showed anti-arthritic effect compared with DC. Rotarod fall-off time 137.5 ± 2.5 sec and body weight (139 ± 12.74 g) were increased significantly. The percentage inhibition of paw volume was increased(52%) whereas arthritic score(0.33), ESR(3.51mm/hr), synovial tissue MDA level (0.62±0.13µmol/gm) and Mankin score(2) were reduced significantly as compared to disease control. EEICL has anti-arthritic potential in rat model.

Schisandrin B ameliorates adjuvant-induced arthritis in rats via modulation of inflammatory mediators, oxidative stress, and HIF-1α/VEGF pathway.

Schisandrin B (Sch B) has been shown to possess anti-inflammatory and antioxidant properties, however, its antirheumatoid arthritis properties and potential mechanism remain unexplored. This study evaluated the potential of Sch B in adjuvant-induced arthritic (AIA) rats. AIA was induced by injecting 0.1ml of CFA into the paw of rats and the animals were administered with Sch B (50mg/kg) for 28 days. The effects of Sch B were evaluated using arthritis severity, serum levels of oxido-inflammatory, and metabolic index parameters. Sch B eased arthritic symptoms by significantly reducing paw swelling and arthritic score and increased body weight gain. Moreover, Sch B alleviated the levels of oxido-inflammatory markers including interleukin-1 beta, interleukin-6, tumor necrosis factor alpha, nuclear factor kappa B, transforming growth factor β1, inducible nitric oxide synthase and malonaldehyde, as well as increased the levels of superoxide dismutase, glutathione, and Nrf2. Sch B also remarkably restored the altered levels of triglyceride, aspartate aminotransferase, lactic acid, pyruvate, phosphoenolpyruvate carboxylase, glucose, hypoxia inducible factor-1 alpha, and vascular endothelial growth factor. In addition, Sch B markedly alleviated p65 expression in the treated AIA rats. This study suggests that Sch B alleviated AIA by reducing oxidative stress, inflammation, and angiogenesis.

The discovery of a novel IκB kinase β inhibitor based on pharmacophore modeling, virtual screening and biological evaluation.

Background: IκB kinase β (IKKβ) plays a pivotal role in the NF-κB signaling pathway and is considered a promising therapeutic target for various diseases. Materials & methods: The authors developed and validated a 3D pharmacophore model of IKKβ inhibitors via the HypoGen algorithm in Discovery Studio 2019, then performed virtual screening, molecular docking and kinase assays to identify hit compounds from the ChemDiv database. The compound with the highest inhibitory activity was further evaluated in adjuvant-induced arthritis rat models. Results: Among the four hit compounds, Hit 4 had the highest IKKβ inhibitory activity (IC50=30.4±3.8), and it could significantly ameliorate joint inflammation and damage in vivo. Conclusion: The identified compound, Hit 4, can be optimized as a therapeutic agent for inflammatory diseases.

Statement of Retraction: Dehydroevodiamine suppresses inflammatory responses in adjuvant-induced arthritis rats and human fibroblast-like synoviocytes

Statement of Retraction: Dehydroevodiamine suppresses inflammatory responses in adjuvant-induced arthritis rats and human fibroblast-like synoviocytes

Integration of serum pharmacochemistry and metabolomics to reveal the underlying mechanism of shaoyao-gancao-fuzi decoction to ameliorate rheumatoid arthritis

Ethnopharmacological relevanceFor centuries, Shaoyao-Gancao-Fuzi decoction (SGFD) has been a reliable traditional Chinese medicine for treating rheumatoid arthritis (RA). Despite its long history of use, the specific active components and underlying mechanisms of its therapeutic effects have yet to be fully understood. Aim of the studyThe aim of this study was to investigate the active ingredients and therapeutic effects of SGFD on RA, and to further understand its underlying mechanism. Materials and methodsThe chemical constituents in SGFD extract and in rat serum after oral administration of SGFD were identified and evaluated using ultra-performance liquid chromatography quadrupole-time-flight mass spectrometry (UPLC-Q-TOF/MS) together with various data-processing methods, respectively. The efficacy of SGFD was assessed by using an adjuvant-induced arthritis (AIA) rat model and lipopolysaccharide-stimulated RAW 264.7 cell. Subsequently, cell metabolomic was conducted to clarify the potential biomarkers and pathways. ELISA, RT-qPCR, and WB were used to verify the anti-arthritis mechanism of SGFD. ResultsA total of 65 chemical constituents were identified in SGFD. 17 active components were distinguished in rat serum samples, of which 13 may be the main active ingredients for SGFD treatment of RA. The remarkable efficacy of SGFD in reducing the symptoms of RA is evident through its ability to alleviate the redness and swelling of the affected paws, as well as reduce the infiltration of inflammatory cells. Cell experiments revealed that rat serum of SGFD reduced IL-1β, IL-6, and TNF-α secretion in RAW 264.7 cells. 27 potential biomarkers were identified through cell metabolomics analysis. The arachidonic acid (AA) metabolism signaling pathway was activated in RA, which could be reversed by rat serum of SGFD. SGFD effectively inhibited the expression and transformation of AA by downregulating the expression of key enzymes, including phospholipase A and cyclooxygenase. ConclusionSGFD may ameliorate RA symptoms by regulating the AA-PGH2-PGE2/PGF2α pathway. The main active components include songorine, fuziline, neoline, albiflorin, paeoniflorin, liquiritin, benzoylmesaconine, isoformononetin, liquiritigenin, isoliquiritigenin, formononetin, glycyrrhizic acid, and glycyrrhetinic acid.

Selective mPGES-1 Inhibitor Ameliorated Adjuvant-Induced Arthritis in the Rat Model

Endogenous prostaglandin E2 (PGE2) plays an important role in maintaining the homeostasis conditions. However, the overexpression of PGE2 in response to various inflammatory stimulations is an important target of anti-inflammatory drugs. Both inducible COX-2 (cyclooxygenase-2) and mPGES-1 (microsomal prostaglandin E2 synthase-1) enzymes are responsible for the inflammatory overexpressed PGE2 production. Among them, mPGES-1 is regarded as a more promising ideal target for anti-inflammatory drugs without the gastrointestinal and cardiovascular side effects. As our continuous research for the discovery of novel mPGES-1 inhibitors, we have characterized MPO-0144 as a selective mPGES-1 inhibitor with a selectivity index of &gt;270 over COX-1 and &gt;25 over COX-2, respectively. Herein, we evaluated the anti-inflammatory effect of MPO-0144 in an adjuvant-induced arthritis rat model. MPO-0144 attenuated the inflammatory responses without severe gastrointestinal side effects and organ toxicities. These overall data suggest a possibility that MPO-0144 downregulates PGE2 production by potent mPGES-1 and weak COX-2 inhibitory activities, thus attenuating the paw swelling in AIA (adjuvant-induced arthritis) rat models. MPO-0144 also exhibited favorable ADMET profiles. However, MPO-0144 did not show any inhibitory effects on human mPGES-1 enzyme at a high concentration. Therefore, MPO-0144 represents a valuable pharmacological tool for the study of regulation of inducible mPGES-1 in an inflammatory arthritis rat model.

Protective effects of piperlongumine against adjuvant-induced arthritis in rats through modulating OPG/RANKL/NF-κB signaling pathway

Abstract Objectives We examined the antirheumatoid effects of piperlongumine (PLM) on rat adjuvant-induced arthritis (AIA) and explored the underlying mechanisms involved. Methods PLM (2.5, 5, and 10 mg/kg) was administered intraperitoneally to AIA rats to assess its effectiveness. Blood, thymus, spleen, ankle joint, and synovial tissue samples were gathered for subsequent analyses, like enzyme-linked immunosorbent assay, thymus/spleen index measurement, ankle joint pathological examination, immunohistochemistry assay, polymerase chain reaction, and western blot assay. Moreover, the involvement of osteoprotegerin (OPG)/receptor activators of nuclear factor κB ligand (RANKL)/nuclear factor-κB (NF-κB) signaling was investigated. Key findings PLM effectively relieved inflammation and joint destruction in AIA rats, as indicated by reductions in hind paw swelling, arthritis index, thymus/spleen index, ankle joint pathological damage, production of TNF-α, IL-1β, and IL-6 in both serum and synovium, and osteoclast formation. Also, PLM treatment raised OPG production, reduced RANKL expression, and elevated the OPG/RANKL ratio in synovial tissues. Furthermore, PLM prevented IκBα degradation and phosphorylation, resulting in a reduced expression of the nuclear NF-κB p65 protein in AIA rat synovial tissues. Conclusions PLM demonstrated strong antiarthritic effects in rats with AIA by influencing the OPG/RANKL/NF-κB signaling pathway, highlighting its potential clinical relevance in treating rheumatoid arthritis.

Discovery of novel NSAID hybrids as cPLA2/COX-2 dual inhibitors alleviating rheumatoid arthritis via inhibiting p38 MAPK pathway

A series of NSAIDs hybrid molecules were synthesized and characterized, and their ability to inhibit NO release in LPS-induced RAW264.7 macrophages was evaluated. Most of the compounds showed significant anti-inflammatory activity in vitro, of which (2E,6Z,9Z,12Z,15Z)-1,1,1-trifluorohenicosa-2,6,9,12,15-pentaen-2-yl 2-(4-benzoylphenyl) propanoate (VI-60) was the most optimal (IC50 = 3.85 ± 0.25 μΜ) and had no cytotoxicity. In addition, VI-60 notably reduced the production of PGE2 in LPS-stimulated RAW264.7 cells compared to ketoprofen. Futhur more, VI-60 significantly inhibited the expression of iNOS, cPLA2, and COX-2 and the phosphorylation of p38 MAPK in LPS-stimulated RAW264.7 cells. The binding of VI-60 to cPLA2 and COX-2 was directly verified by the CETSA technique. In vivo studies illustrated that VI-60 exerted an excellent therapeutic effect on adjuvant-induced arthritis in rats by regulating the balance between Th17 and Treg through inhibiting the p38 MAPK/cPLA2/COX-2/PGE2 pathway. Encouragingly, VI-60 showed a lower ulcerative potential in rats at a dose of 50 mg/kg compared to ketoprofen. In conclusion, the hybrid molecules of NSAIDs and trifluoromethyl enols are promising candidates worthy of further investigation for the treatment of inflammation, pain, and other symptoms in which cPLA2 and COX-2 play a role in their etiology.

Mechanistic evaluation of antiarthritic and anti-inflammatory effect of campesterol ester derivatives in complete Freund's adjuvant-induced arthritic rats.

Background: Current therapies for RA have limitations and side effects, leading to a growing need for safer treatment options. Natural compounds from plants are gaining attention for their therapeutic benefits and fewer side effects. One such compound is the campesterol derivative, a steroid derivative occurring in plants. Studies have shown that this derivative has anti-inflammatory properties and can impact the expression of pro-inflammatory factors. The primary objective of this study was to explore and assess the potential therapeutic effects of Campesterol Ester Derivatives (CED) utilizing a rat model of arthritis induced by Complete Freund's Adjuvant (CFA). Method: The rats were divided into specific experimental groups and treated with either CED or piroxicam (as a positive control) for a duration of 28days. We determined the effects of CED on various parameters including paw edema, thermal hyperalgesia, and mechanical allodynia at different time points. Furthermore, serum levels of inflammatory cytokines, oxidative stress markers and histological analyses were performed. Additionally, mRNA expression levels of inflammatory markers, both pro-inflammatory (such as TNF-α, NF-κB, IL-6, COX-1, COX-2, and IL-4) and anti-inflammatory were analyzed. Results: In the arthritic rat model, CED exhibited significant anti-inflammatory effects and resulted in a notable reduction in paw edema levels compared to the control group. Histopathological examination of the treated rats' paws confirmed a decrease in inflammation and tissue damage, including reduced pannus formation and bone erosion. Importantly, there were no observable signs of damage to the liver and kidneys following CED treatment, indicating its safety profile and potential for organ protection. At the molecular level, CED treatment downregulated mRNA expression levels of pro-inflammatory markers, indicating its ability to suppress inflammation. Conversely, certain anti-inflammatory markers were upregulated following CED treatment, suggesting a positive influence on the immune response. The positive effects of CED were not limited to joint inflammation; it also showed systemic benefits by positively influencing hematological and biochemical parameters. Conclusion: CED demonstrated promising therapeutic potential as an anti-inflammatory intervention for arthritis in the experimental rat model. Its ability to reduce inflammation, protect tissues, and improve organ function indicates its multifaceted benefits.

Regulation of polysaccharide in Wu‐tou decoction on intestinal microflora and pharmacokinetics of small molecular compounds in AIA rats

Wu-tou decoction (WTD), a traditional Chinese medicine prescription, is used to treat rheumatoid arthritis (RA). It works by controlling intestinal flora and its metabolites, which in turn modulates the inflammatory response and intestinal barrier function. Small molecular compounds (SM) and polysaccharides (PS) were the primary constituents of WTD extract. In this work, a model of adjuvant-induced arthritis (AIA) in rats was established and treated with WTD, SM, and PS, respectively. 16S rRNA gene sequencing was used to examine the regulatory impact of the various groups on the disturbance of the gut flora induced by RA. Further, since PS cannot be absorbed into the blood, the influence of PS on the absorption and metabolism of SM was studied by examining their pharmacokinetic (PK) parameters of 23 active components in SM by UPLC-MS/MS. WTD was found to be more effective than PS and SM in alleviating arthritis in AIA rats, which may be related to changes in gut flora. The PK properties of 13 active compounds were altered after PS intervene. Based on the findings, PS may be able to manage the disruption of intestinal microbiota, enhance the intestinal environment of model animals, and hence influence SM absorption and metabolism.