Search Results (22)

Background/Objective: Sinomenine hydrochloride (SH), a natural anti–rheumatic drug derived from the Chinese medicinal plant Sinomenium acutum, demonstrates disease–modifying properties but lacks comprehensive safety and toxicokinetic (TK) comparisons between physiological and pathological states. This study evaluated SH’s safety profile, TK parameters, and intestinal absorption differences in adjuvant–induced arthritis (AIA) and normal rats. Methods: Safety assessments determined median lethal doses (LD₅₀) in female Sprague Dawley rats. TK parameters were analyzed via a validated ultrahigh performance liquid chromatography-tandem mass spectrometry approach after single oral administration of 600 mg/kg SH. Plasma protein binding (PPB) were measured using equilibrium dialysis. Intestinal absorption was evaluated through everted gut sac experiments, with P–glycoprotein (P–gp) inhibition tested via verapamil co–administration. Results: LD₅₀ values revealed AIA rats tolerated SH better than normal rats (1179 vs. 805 mg/kg). TK analysis showed that C_max, AUC_(0-t), and AUC_(0-∞) of SIN in normal rats were 2.01, 1.94, and 2.14 times higher than in AIA rats, respectively, while CL/F and V/F in AIA rats were 2.24 times greater. In addition, the PPB of SIN in normal rats was 2 times greater than that in AIA rats. AIA rats exhibited significantly lower SH absorption in the jejunum and ileum compared to normal rats. Notably, verapamil co–administration markedly increased SH absorption across most intestinal segments. Conclusions: Pathological states significantly alter SH’s safety and TK profiles. Enhanced tolerance in AIA rats correlates with reduced intestinal absorption via altered P–gp activity and decreased PPB. These findings emphasize the necessity of disease–specific evaluations for optimizing SH’s therapeutic safety in pathological contexts. Full article

Background/Objectives: Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease characterized by a protracted course, high rates of morbidity, and disability yet lacks effective therapeutic modalities. Levamisole (LVM), an immunomodulatory drug, has been clinically reported for its potential in RA treatment, while its therapeutic mechanism toward RA remains to be elucidated. Hence, this study provides theoretical support for the application of LVM in the treatment of RA. Methods: This study employed male Sprague–Dawley (SD) rats to construct the adjuvant-induced arthritis (AIA) model, administering LVM orally (5 mg/kg, 15 mg/kg, and 45 mg/kg) for 25 days. An evaluation of LVM’s therapeutic effects on RA was conducted through arthritis index scores, paw pad thickness, paw volume, hematoxylin and eosin (H&E) staining, 3D microcomputed tomography (micro-CT) scans, serum levels of pro-/anti-inflammatory cytokines, and serum biochemical indicators. Western blotting and immunohistochemistry staining were utilized to measure the expression levels of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) proteins in synovial and ankle joint tissues. Results: Treatment with the median dose of LVM (15 mg/kg, M-LVM) significantly reduced the arthritis index (p < 0.01), paw pad thickness (p < 0.001), and paw volume (p < 0.01) without affecting body weight. Additionally, M-LVM alleviated inflammatory lesions in the synovium and ankle joints and also normalized serum levels of interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and transforming growth factor-beta (TGF-β). The Model group exhibited significant increases in serum levels of alkaline phosphatase (ALP) (p < 0.01), creatine kinase (CK) (p < 0.05), and glucose (GLU) (p < 0.001) compared with the Control group; however, M-LVM effectively regulated these parameters to normal levels. Western blotting and immunohistochemistry staining revealed that PI3K-/Akt-related proteins were highly expressed in the synovial and ankle joint tissues of rats in the Model group, while treatment with M-LVM significantly reduced the expression of these proteins. Furthermore, histological examination of major organs (heart, liver, lungs, kidneys, and thymus) showed no significant pathological changes, with the exception of the spleen, where M-LVM ameliorated splenic lesions. Conclusions: We demonstrate that LVM at an optimal dose substantially relieves synovitis and bone erosion in AIA rats by inhibiting the PI3K/Akt signaling pathway. Full article

Glutamate functions as the major excitatory neurotransmitter for primary sensory neurons and has a crucial role in sensitizing peripheral nociceptor terminals producing sensitization. Glutaminase (GLS) is the synthetic enzyme that converts glutamine to glutamate. GLS-immunoreactivity (-ir) and enzyme activity are elevated in dorsal root ganglion (DRG) neuronal cell bodies during chronic peripheral inflammation, but the mechanism for this GLS elevation is yet to be fully characterized. It has been well established that, after nerve growth factor (NGF) binds to its high-affinity receptor tropomyosin receptor kinase A (TrkA), a retrograde signaling endosome is formed. This endosome contains the late endosomal marker Rab7GTPase and is retrogradely transported via axons to the cell soma located in the DRG. This complex is responsible for regulating the transcription of several critical nociceptive genes. Here, we show that this retrograde NGF signaling mediates the expression of GLS in DRG neurons during the process of peripheral inflammation. We disrupted the normal NGF/TrkA signaling in adjuvant-induced arthritic (AIA) Sprague Dawley rats by the pharmacological inhibition of TrkA or blockade of Rab7GTPase, which significantly attenuated the expression of GLS in DRG cell bodies. The results indicate that NGF/TrkA signaling is crucial for the production of glutamate and has a vital role in the development of neurogenic inflammation. In addition, our pain behavioral data suggest that Rab7GTPase can be a potential target for attenuating peripheral inflammatory pain. Full article

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. Full article

Chronic inflammatory diseases are considered the most significant cause of death worldwide. Current treatments for inflammatory diseases are limited due to the lack of understanding of the biological factors involved in early-stage disease progression. Nerve growth factor (NGF) is a neurotrophic factor directly associated with inflammatory and autoimmune diseases like osteoarthritis, multiple sclerosis, and rheumatoid arthritis. It has been shown that NGF levels are significantly upregulated at the site of inflammation and play a crucial role in developing a robust inflammatory response. However, little is known about NGF’s temporal expression profile during the initial progressive phase of inflammation. This study aimed to determine the temporal expression patterns of NGF in rat skin (epidermis) during adjuvant-induced arthritis (AIA). Sprague Dawley rats were randomly divided into control and complete Freund’s adjuvant (CFA)-treated groups. Levels of NGF were evaluated following unilateral AIA at different time points, and it was found that peripheral inflammation due to AIA significantly upregulated the expression of NGF mRNA and protein in a biphasic pattern. These results suggest that NGF signaling is crucial for initiating and maintaining peripheral neurogenic inflammation in rats during AIA. Full article

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. Full article

Leflunomide is an isoxazole immunomodulating drug used to treat rheumatoid arthritis (RA). It is adopted as a metal-containing molecule to proceed with saturated salts of essential and detected metals; it amends the pharmacokinetic and pharmacodynamics activity of leflunomide to provide [M(Lef)₄]X₂-type complexes. Earlier it has been reported that after forming complexes with metals, leflunomide anti-arthritic activity was significantly altered in an acute arthritic model. In the present study, we evaluated the possible modification in anti-arthritic activities of leflunomide–metal complexes (Mg⁺², Ca⁺², Fe⁺², Zn⁺²) with and without an anti-depressant drug, i.e., fluoxetine (10 mg/kg) in a chronic AIA model. Rats (n = 5) were administered with 0.1 mL of CFA into the right hind paw while treated groups received leflunomide and its metal complexes orally (3.2 mg/kg) for 24 days. On the final day of experiment, rats were sacrificed; a specific rat immunoassay ELISA kit was used to assess TNF-α in serum samples and read at 450 nm; a tissue sample of a paw was homogenized in a phosphate buffer using DCFH-DA dye for binding to assess ROS. A rat’s brain sample was homogenized and evaluated for tryptophan, serotonin (5-HT), and HIAA by RP-HPLC with EC detector. The overall TNF production was altered in treated rats. In addition, a decreased ROS was observed in all categories, except lef+Mg⁺² group. Moreover, depletion in the brain indolamine levels were found in treated groups; an upraised level of these indolamines was observed when fluoxetine was added. It is concluded that metals affect leflunomide activity on complexation and simultaneous administration of fluoxetine cope up with the depression in arthritic-induced rats. Full article

Nanoemulsion is a new multi-component drug delivery system; the selection of different oil phases can give it special physiological activity, and play the role of “medicine and pharmaceutical excipients all-in-one”. In this paper, we used glycyrrhizic acid as the natural surfactant, and Blumea balsamifera oil (BB) and tea tree oil (TTO) as the mixed oil phase, to obtain a new green functional composite nanoemulsion. Using the average particle size and polydispersion index (PDI) as the evaluation criteria, the effects of the oil ratio, oil content, glycyrrhizic acid concentration, and ultrasonic time on the nanoemulsion were systematically investigated. The stability and physicochemical properties and biological activities of BB-TTO NEs prepared via the optimum formulation were characterized. The optimal prescription was BB: TTO = 1:1, 5% oil phase, 0.7% glycyrrhizic acid, and 5 min ultrasonication time. The mean particle size, PDI, and zeta potential were 160.01 nm, 0.125, and −50.94 mV, respectively. The nanoemulsion showed non-significant changes in stability after centrifugation, dilution, and 120 days storage. These nanoemulsions were found to exhibit potential antibacterial and anti-inflammatory activities. The minimal inhibitory concentration (MIC) of BB-TTO NEs against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa is 2975 μg/mL, 2975 μg/mL, and 5950 μg/mL, respectively. A lower level of inflammatory cell infiltration and proportion of fibrosis were found in the synovial tissue of AIA rats treated with BB-TTO NEs. These findings demonstrate that the BB-TTO NEs produced in this study have significant potential for usage in antibacterial and anti-inflammatory areas. Full article

This study evaluated the protective effect of different dietary ω-6/ω-3 ratios in oils obtained from various nuts (walnut, peanut, cashew, and hazelnut) against morphological features and markers of inflammation on an adjuvant-induced arthritis rat model. Rheumatoid arthritis (RA) was induced via intradermal injection of heat-killed Mycobacterium tuberculosis. Five groups of rats with RA (n = 5) were randomly categorized as follows: control positive, walnut oil group, peanut oil group, cashew nut oil group, and hazelnut oil group. Another five healthy rats served as a normal non-arthritic (control) group. We assessed the therapeutic effects by measuring arthritis scores during the experiment and serum inflammatory markers at the end of the study. The serum levels of the rheumatoid factor, TNF-α, IL-6, IL-1β, and PGE2, were significantly (p ≤ 0.05) reduced in all treatment groups. The daily consumption of nut oils ameliorates clinical and morphological abnormalities by inhibiting the inflammatory cells that produce inflammatory interleukins and eicosanoids. Full article

Rheumatoid arthritis (RA) is a chronic, systemic immune disease that causes joint affection and even disability. Activated macrophages play an important role in the pathogenesis and progression of RA by producing pro-inflammatory factors. The use of dexamethasone (DXM) is effective in relieving the intractable pain and inflammatory progression of RA. However, long-term use of DXM is strongly associated with increased rates of diabetes, osteoporosis, bone fractures, and mortality, which hinders its clinical use. In this study, the dextran sulfate-cisaconitic anhydride-dexamethasone (DXM@DS-cad-DXM) micelles were prepared to treat RA by selectively recognizing scavenger receptor (SR) on the activated macrophages. The potent targeting property of DXM@DS-cad-DXM micelles to SR was by fluorescence microscope. Additionally, the effective accumulation and powerful anti-inflammatory activity of DXM@DS-cad-DXM micelles were observed in the inflamed joints of adjuvant-induced arthritis (AIA) rats after intravenous administration. Overall, DXM@DS-cad-DXM micelles are a potentially effective nanomedicine for targeted therapy of RA. Full article

Rubia cordifolia L. (Rubiaceae), one of the traditional anti-rheumatic herbal medicines in China, has been used to treat rheumatoid arthritis (RA) since ancient times. Purpurin, an active compound of Rubia cordifolia L., has been identified in previous studies and exerts antibacterial, antigenotoxic, anticancer, and antioxidant effects. However, the efficacy and the underlying mechanism of purpurin to alleviate RA are unclear. In this study, the effect of purpurin on inflammation was investigated using macrophage RAW264.7 inflammatory cells, induced by lipopolysaccharide (LPS), and adjuvant-induced arthritis (AIA) rat was established to explore the effect of purpurin on joint damage and immune disorders; the network pharmacology and molecular docking were integrated to dig out the prospective target. Purpurin showed significantly anti-inflammatory effect by reducing the content of IL-6, TNF-α, and IL-1β and increasing IL-10. Besides, purpurin obviously improved joint injury and hypotoxicity in the liver and spleen and regulated the level of FOXP3 and CD4+/CD8+. Furthermore, purpurin reduced the MMP3 content of AIA rats. Network pharmacology and molecular docking also suggested that MMP3 may be the key target of purpurin against RA. The results of this study strongly indicated that purpurin has a potential effect on anti-RA. Full article

Rheumatoid arthritis (RA) is a major global public health challenge, and novel therapies are required to combat it. Silver nanoparticles (AgNPs) have been employed as delivery vehicles of anti-inflammatory drugs for RA therapy, and it has been recently realized that AgNPs have anti-inflammatory action on their own. However, their conventional synthesis processes might result in cytotoxicity and environmental hazards. Instead, the use of natural products as a reducing and stabilizing agent in the biosynthesis of silver nanoparticles has arisen as an option to decrease the cytotoxic and environmental concerns associated with chemical synthesis of AgNPs. In this study, we challenged the efficacy of Commiphora mukul (guggul) aqueous extract as a reducing and/or capping agent for the biosynthesis of AgNPs. Guggul-mediated biosynthesized silver nanoparticles (G-AgNPs) were characterized via UV-vis spectroscopy, dynamic light scattering, and scanning electron microscopy. In addition, their anti-arthritic potential was evaluated in an adjuvant-induced arthritis (AIA) model. The fabricated NPs showed an absorption peak at 412 nm, corresponding to the typical surface plasmon resonance band of AgNPs. The synthesized G-AgNPs were nearly spherical, with a particle size of 337.6 ± 12.1 nm and a negative surface charge (−18.9 ± 1.8 mV). In AIA rat model, synthesized G-AgNPs exerted a potent anti-inflammatory action, as manifested by a remarkable reduction in paw volume (>40%) along with elicitation of a minimal arthritic score, compared to control rats. In addition, when compared to arthritic rats, treatment with G-AgNPs efficiently restored the activity of antioxidant enzyme, superoxide dismutase, and catalase, indicating the efficiency of synthesized G-AgNPs in alleviating the oxidative stress associated with RA. Finally, histological examination revealed comparatively lower inflammatory cells infiltration in ankle joint tissue upon treatment with G-AgNPs. Collectively, biosynthesized G-AgNPs might represent a plausible therapeutic option for the management of RA. Full article

Objective: The mechanism of action and potential targets of Paeoniae RadixAlba (Baishao, B) in the treatment of adjuvant-induced arthritis (AIA) rats are explained using metabolomics and network pharmacology techniques, and the research evidence for the development of anti-rheumatoid arthritis (RA) drugs is enriched. Methods: The rats were injected with Freund’s complete adjuvant (CFA) to induce arthritis. We then measured the general physical characteristics, examined their X-rays and histopathology to evaluate the pathological condition of the inflammation models, and conducted metabolomics studies on the change in urine metabolism caused by CFA. The lyophilized powder of B at a dose of 2.16 g/kg was orally administered to the rats continuously for 28 days, and the therapeutic effect was evaluated. Network pharmacology prediction shows that B contains the target action of the ingredient, and the simulation of the target molecular docking, in combination with the metabolomics analysis results, shows that B has a potential role in the treatment of AIA rats. Results: B can reduce the paw swelling and pathological changes in rats caused by CFA, reverse the levels of 12 urine biomarkers, and regulate histidine metabolism, phenylalanine metabolism, arginine, proline metabolism, pyrimidine metabolism, etc. The prediction of the active ingredient target in B indicates that it may act as an inflammatory signaling pathway in anti-RA, among them being paeoniflorin, palbinone, beta-sitosterol, kaempferol, and catechin, which are the significant active ingredients. Conclusion: The metabolomics results revealed the markers and metabolic mechanisms of urinary metabolic disorders in rats with AIA, demonstrated the efficacy of the therapeutic effect of B, and identified the key ingredients in B, providing theoretical support for the subsequent development and utilization of B. Full article

Rheumatoid arthritis (RA) is a chronic inflammatory condition of synovial joints that causes disability and systemic complications. Ang-(1-7), one of the main peptides in the renin-angiotensin (Ang) system (RAS), imposes its protective effects through Mas receptor (MasR) signaling. It has a short half-life, limiting its feasibility as a therapeutic agent. In this study, we evaluated the anti-inflammatory effects of Ang-(1-7)’s novel and stable conjugate (Ang. Conj.) by utilizing its affinity for bone through bisphosphonate (BP) moiety in an adjuvant-induced arthritis (AIA) rat model. The rats received subcutaneous injections of vehicle, plain Ang-(1-7), or an equivalent dose of Ang. Conj. The rats’ body weights, paws, and joints’ diameters were measured thrice weekly. After 14 days, the rats were euthanized, and the blood and tissue samples were harvested for further analysis of nitric oxide (NO) and RAS components’ gene and protein expression. The administration of Ang. Conj. reduced body weight loss, joint edema, and serum NO. Moreover, the Ang. Conj. treatment significantly reduced the classical arm components at peptide, enzyme, and receptor levels while augmenting them for the protective arm. The results of this study introduce a novel class of bone-targeting natural peptides for RA caused by an inflammation-induced imbalance in the activated RAS. Our results indicate that extending the half-life of Ang-(1-7) augments the RAS protective arm and exerts enhanced therapeutic effects in the AIA model in rats. Full article

Rheumatoid arthritis (RA) is characterized by systemic inflammation and synovial hyperplasia. Pristimerin, a natural triterpenoid isolated from plants belonging to the Celastraceae and Hippocrateaceae families, has been reported to exhibit anti-inflammation and anti-proliferation activities. Our study aims to reveal the antiarthritic effects of pristimerin and explore its potential mechanism using in vitro, in silico, and in vivo methods. In the present study, pristimerin treatment led to a dose-dependent decrease in cell viability and migration in TNF-α stimulated human rheumatoid arthritis fibroblast-like synoviocytes MH7A. Moreover, UPLC-LTQ-Orbitrap-based cell metabolomics analysis demonstrated that phospholipid biosynthesis, fatty acid biosynthesis, glutathione metabolism and amino acid metabolic pathways were involved in TNF-α induced MH7A cells after pristimerin treatment. In addition, the adjuvant–induced arthritis (AIA) rat model was employed, and the results exhibited that pristimerin could effectively relieve arthritis symptoms and histopathological damage as well as reduce serum levels of TNF-α, NO and synovial expressions of p-Akt and p-Erk in AIA rats. Furthermore, network pharmacology analysis was performed to visualize crucial protein targets of pristimerin for RA treatment, which showed that the effects were mediated through the MAPK/Erk1/2, PI3K/Akt pathways and directing binding with TNF-α. Taken together, our study not only offered new insights into the biochemical mechanism of natural compounds for RA treatment, but also provided a strategy that integrated in vitro, in silico and in vivo studies to facilitate screening of new anti-RA drugs. Full article