Adjuvant-induced Arthritis In Rats Research Articles

Changes within Liver Accounts for Fatty Acids Decrease in the Blood of Rats with Adjuvant‐Induced Arthritis

AbstractThis study characterizes rheumatoid arthritis‐related free fatty acids (FFAs) changes using adjuvant‐induced arthritis (AIA) model. Blood FFAs of healthy and AIA rats are periodically determined. During acute inflammation, FFAs levels are analyzed under both fasting and non‐fasting conditions. Oral intake capacities are compared by everted intestinal sac experiment. Tissue distribution of FFAs in the rats fed with/without linolenic acid is also investigated. AIA decreases FFAs in rats. Saturated FFAs are gradually recovered, but unsaturated FFAs are further reduced till the secondary inflammation. FFAs level gap remains unchanged regardless of feeding/fasting, and intestinal intake capacities of the rats are similar. FFAs levels in liver fluctuate in accordance with blood levels. Increased carnitine palmitoyltransferase 1 (CPT‐1) reveals the accelerated FFAs utilization in AIA rats, resulting in the accumulation of acetoacetic acid and 2‐hydroxybutyrate. Hepatocytes incubated with AIA serum take in more FFAs than normal controls when supply is sufficient. To the opposite, intracellular FFAs are reduced after AIA serum stimulus without additional supply. Besides, AIA serum‐challenged cells produce more CPT‐1. Hence, the reduced circulating FFAs in AIA rats should be attributed to the accelerated utilization in liver.Practical Applications: This study provides additional possible therapeutic approaches for the treatment of RA by focusing on the changes of blood FFAs. Obtained clues demonstrate that liver will be a key in the elucidation of RA‐related lipid paradox, and diet supplement of the unsaturated FFAs will be beneficial in treating RA.

Effect of Different Nuts Oil Consumption on Morphological Features and Some Biomarkers of Inflammation in Adjuvant-Induced Arthritis (AIA) Rat Model

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.

Majoon chobchini reinstates PDL-1 expression and blocks dendritic cell -T helper 17 pathogenic axis in rheumatoid arthritis animal model.

Dendritic cells (DCs) are the critical players in the puzzle of rheumatoid arthritis (RA) disease pathogenesis. Blockade of DC activation has been shown to curtail Th17 cell differentiation and its aberrant function in RA. Recent studies have pointed to the role of the PI3K/AKT signaling axis in the maturation and activation of DCs. However, it is yet to be established how PI3K/AKT inhibition would lead to the abolishment of DC activation and Th17 cell plasticity in RA. Herein, our study decoded whether and how majoon chobchini, an unani compound, abated dendritic cell maturation and regulated the Th17/Treg paradigm in RA. Given our results, majoon chobchini conspicuously restrained MHC II, CD86 expression and, subsequently elevated PDL-1 levels in DCs in-vivo. Of note, inhibition of DC maturation by majoon chobchini, in turn, favoured suppression of the Th17 cell population while driving Treg cell development in adjuvant induced arthritic (AA) rats. Concurrently, majoon chobchini decreased the catabolic effects of IL-17 (Th17 associated cytokine) via a reciprocal increase in IL-10 (Treg associated cytokine) levels in AA rats. Mechanistically, majoon chobchini sustained FoxO1 nuclear localization signaled through dampened PI3K/AKT phosphorylation in-vitro. In concert, PDL-1 expression was heightened in majoon chobchini treated activated DCs that provides a framework for ablation of the DC-Th17 cell pathogenic axis in RA. Notwithstanding, the PI3K inhibitor LY294002 exhibited similar inhibitory effects. In essence, majoon chobchini enhanced PDL-1 expression that abolished DC maturation via regulation of the PI3K/AKT/FoxO1 axis, thereby hindering Th17 differentiation in an animal model of RA. This further warrants a clinical investigation that could validate majoon chobchini as a prospective therapeutic drug in the treatment of RA.

Formulation of a dual drug-loaded nanoparticulate co-delivery hydrogel system and its validation in rheumatoid arthritis animal model

Rheumatoid arthritis (RA), a systemic autoimmune disease that dramatically affects patients’ quality of life. Given the intricacy of RA’s pathophysiology, no single treatment can completely halt the disease progression. Here, we attempted to treat RA holistically and synergistically by co-delivering methotrexate (MTX), a standard slow-acting anti-rheumatic drug, and phenethyl isothiocyanate (PEITC), a bioactive phytochemical, using a sodium alginate (SA)-pluronic F127 (PF-127) in situ hydrogel formulation. Therefore, in the current study, the co-delivery of MTX and PEITC in the nanoparticulate form could help enhance stability and solubility and facilitate greater penetration in the target arthritic tissues. The fabricated MTX NP and PEITC NE were found to have a minimum particle size, PDI, and good zeta potential. Results from in vitro release studies showed that MTX and PEITC were simultaneously released from the DD NP HG matrix over 6–7 days through diffusion and erosion mechanisms. An intra-articular (IA) injection of DD NP HG dramatically reduced chronic inflammation in adjuvant-induced arthritis (AIA) rats, delayed the onset of bone erosion, significantly reduced synovitis, and down-regulated the inflammatory cytokine expression. Most notably, the co-delivery strategy almost entirely restored the morphological features of the ankle joints of RA rats. The hepatic and renal function tests indicated good biological safety for DD NP HG in RA conditions. Taken together, these findings indicated that DD NP HG could achieve good anti-inflammatory activity and reverse cartilage disruption through a synergistic effect between two nanoparticulate forms of MTX and PEITC, which can effectively improve the drawbacks of their free forms.

The Underling Mechanisms Exploration of Rubia cordifolia L. Extract Against Rheumatoid Arthritis by Integrating Network Pharmacology and Metabolomics.

Rubia cordifolia L. (RC) is a classic herbal medicine for the treatment of rheumatoid arthritis (RA) and has been used since ancient times. The ethanol extract of Rubia cordifolia L. (RCE) showed obvious anti-RA effects in our previous study. However, further potential mechanisms require more exploration. We aimed to investigate the mechanism of RCE for the treatment of RA by integrating metabolomics and network pharmacology in this study. An adjuvant-induced arthritis (AIA) rat model was established, and we evaluated the therapeutic effects of RCE. Metabolomics of serum and urine was used to identify the differential metabolites. Network pharmacology was applied to determine the key metabolites and potential targets. Finally, the potential targets and compounds of RCE were verified by molecular docking. The results indicated that RCE suppressed foot swelling and alleviated joint damage and also had anti-inflammatory properties by inhibiting the expressions of tumor necrosis factor (TNF)-α, Interleukin (IL)-1β, prostaglandin E2 (PGE2), and P65. Ten and seven differential metabolites were found in the serum and urine, respectively, of rats. Six key targets, ie, phospholipase A2 group IIA (PLA2G2A), phospholipase A2 group X (PLA2G10), cytidine deaminase (CDA), uridine-cytidine kinase 2 (UCK2), charcot-leyden crystal galectin (CLC), and 5',3'-nucleotidase, mitochondrial (NT5M), were discovered by network pharmacology and metabolite analysis and were found to be related to glycerophospholipid metabolism and pyrimidine metabolism. Molecular docking confirmed that the favorable compounds showed affinities with the key targets, including alizarin, 6-hydroxyrubiadin, ruberythric acid, and munjistin. This study revealed the underlying mechanisms of RCE and provided evidence that will allow researchers to further investigate the functions and components of RCE against RA.

(+)/(-)-Yanhusamides A-C, three pairs of unprecedented benzylisoquinoline-pyrrole hetero-dimeric alkaloid enantiomers from Corydalis yanhusuo.

A chemical investigation on the aqueous extract of Corydalis yanhusuo tubers led to the isolation and structural elucidation of three pairs of trace enantiomeric hetero-dimeric alkaloids, (+)/(-)-yanhusamides A-C (1-3), featuring an unprecedented 3,8-diazatricylco[5.2.2.02,6]undecane-8,10-diene bridged system. Their structures were exhaustively characterized by X-ray diffraction, comprehensive spectroscopic data analysis, and computational methods. Guided by the hypothetical biosynthetic pathway for 1-3, a gram-scale biomimetic synthesis of (±)-1 was achieved in 3 steps using photoenolization/Diels-Alder (PEDA) [4+2] cycloaddition. Compounds 1‒3 exhibited potent inhibition of NO production induced by LPS in RAW264.7 macrophages. The invivo assay showed that oral administration of 30mg/kg of (±)-1 attenuated the severity of rat adjuvant-induced arthritis (AIA). Additionally, (±)-1 induced a dose-dependent antinociceptive effect in the acetic acid-induced mice writhing assay.

Therapeutic effects of kefir peptides on adjuvant-induced arthritis in rats through anti-inflammation and downregulation of matrix metalloproteinases

AimsRheumatoid arthritis (RA) is a chronic autoimmune disease. Its pathological features are synovial inflammation, bone erosion, and joint structural damages. Our previous studies have shown that kefir peptides (KPs) can reduce cardiovascular disease, osteoporosis and renal inflammation. In this study, we further evaluate the efficacy of KPs on adjuvant-induced arthritis (AIA) in a rat model. Main methodsAfter the 14th day of adjuvant induction, rats were subsequently orally administered KPs (83 or 166 mg/day/kg) or tofacitinib (6.2 mg/day/kg) for 14 days. On the 28th day, the rats were anesthetized with isoflurane for ultrasonic, in vivo imaging system (IVIS), and radiographic imaging and then sacrificed for ankle tissues collection and analysis. In vitro, IL-1β-treated human synovial cells (SW982) were subjected to anti-arthritis mechanism study in the presence of KPs. Key findingsThe results of ultrasonography, radiograph, histology, the expression of matrix metalloproteinases (MMPs), inflammatory cytokines and RANKL/OPG ratio demonstrated decreasing severity of synovitis and bone erosion in the ankle joints after KPs treatment. Activation of the NF-κB and MAPK pathways was significantly reduced in KPs treated AIA group. Furthermore, KPs attenuated IL-1β-induced inflammatory cytokine production and the expression of MMPs in a human synovial cell line SW982. These results demonstrated that KPs alleviated adjuvant-induced arthritis in rats by inhibiting IL-1β-related inflammation and MMPs production. SignificanceWe concluded that KPs can exhibit anti-inflammatory effects by reducing the levels of macrophage-related inflammatory cytokines and MMPs, thus alleviating bone erosion in the ankle joint and constituting a potential therapeutic strategy for rheumatoid arthritis.

Anti-Inflammatory Activity of Phenylethanoids from Acanthus ilicifolius var. xiamenensis.

Acanthus ilicifolius var. xiamenensis is a traditional herbal medicine in China. In this study, the anti-inflammatory activities of active ingredients of A. ilicifolius var. xiamenensis were investigated in RAW 264.7 cells and Freund's complete adjuvant-induced arthritic rats. Results showed that n-butanol extract exerted antiarthritic potential by reducing paw edema, arthritis score, and altered hematological and biochemical parameters in experimental rats. Phytochemical studies on n-butanol extract resulted in the isolation of five alkaloids (1-5) and five phenylethanoids (6-10). The anti-inflammatory assay of compounds 1-10 on lipopolysaccharide (LPS)-treated RAW 264.7 cells indicated that phenylethanoids 9 and 10 exhibited notable inhibitory activities. The result indicated that compounds 9 and 10 attenuated inflammation by decreasing the production of nuclear factor kappa-B (NF-κB) p65, inhibitory subunit of NF kappa B alpha, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), and inducible nitric oxide synthase in LPS-mediated RAW 264.7 macrophages. Phenylethanoids 9 and 10 increased the expression of interleukin-10 and endothelial nitric oxide synthase. Therefore, compounds 9 and 10 showed anti-inflammatory activity by regulation of NF-κB and JAK/STAT signaling pathways.

Macrophage-Targeted Dextran Sulfate-Dexamethasone Conjugate Micelles for Effective Treatment of Rheumatoid Arthritis.

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.

Core Constituents of Caragana sinica Root for Rheumatoid Arthritis Treatment and the Potential Mechanism.

As a traditional herb product, the root of Caragana sinica (Buc'hoz) Rehder (Chinese name: Jin Quegen [JQG]) has been widely used in folk medicines for rheumatoid arthritis (RA) treatment. However, which herbal constituents exert a core pharmacological role in RA treatment remains a great challenge due to the multiple phytochemical constituents, targets, and pathways. In this work, we aimed to use a new strategy to explore the core herbal constituents and potential mechanisms of JQG against RA for the first time. A successively partitioned extract of JQG, bioactive partition screening in vitro and in vivo, qualitative analysis, bioinformatic analysis, molecular docking, and mechanism validation were used in this study. The partitioned extract was used to obtain the bioactive partition, while in vitro anti-inflammatory effects and in vivo anti-arthritis effects in adjuvant-induced arthritis (AIA) rats were applied to screen the bioactive partition with the best efficacy. Qualitative analysis was used to identify bioactive constituents. Bioinformatic analysis was used to explore the potential mechanism for RA treatment. Molecular docking and immunofluorescence were used to validate the underlying mechanism. After successively partitioning extract and bioactive partition screening, ethyl acetate extract (EAE) yielded the best anti-inflammatory effects in vitro and in vivo among JQG extracts. By ultra-performance liquid chromatography (UPLC) coupled with Orbitrap mass spectrometry, a total of 58 constituents were identified in EAE, and 17 constituents were regarded as the core constituents based on their oral bioavailability and drug-like properties. The nuclear factor kappa B (NF-κB) signal pathway was screened as the core pathway of core constituents for RA treatment based on bioinformatic analysis, and the core constituents showed good ligand-receptor binding activity to NF-κB P65. In vitro study demonstrated that EAE could significantly reduce NF-κB P65 transfer from the cytoplasm to the nucleus. Our study suggested that the therapeutic efficacy of JQG for RA treatment could be derived from negative regulation of the NF-κB pathway, and EAE of JQG could represent a promising herb product for RA treatment that deserves further development.

Comparison of the effects of peficitinib and tofacitinib in the adjuvant-induced arthritis rat model

We investigated and compared the pharmacologic properties of two Janus kinase (JAK) inhibitors, peficitinib and tofacitinib, in an adjuvant-induced arthritis rat model. Repeated administration of peficitinib (3 − 30 mg/kg) or tofacitinib (1 − 10 mg/kg) exhibited a dose-related and significant attenuation of arthritis score, paw swelling, pain threshold, grip strength and histopathologic injuries in the model; peficitinib 10 mg/kg and tofacitinib 3 mg/kg demonstrated comparable efficacy. Equivalent Cmax and AUC0–12h values were observed with peficitinib 10 mg/kg and tofacitinib 3 mg/kg, suggesting that the two drugs may demonstrate comparable efficacy on arthritis-associated symptoms at comparable plasma concentration levels. However, peficitinib 10 mg/kg had greater efficacy than tofacitinib 3 mg/kg on some inflammation- and bone destruction-associated parameters in the paw fluid, including the production of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), receptor activator of nuclear factor kappa-B ligand, and matrix metalloproteinase-3, which are associated with arthritis exacerbation. Peficitinib 10 mg/kg also showed significantly greater inhibitory effects than tofacitinib 3 mg/kg on loss of bone mineral density and synovial thickening score, which might be a result of the VEGF and PDGF receptor kinase inhibitory effects of peficitinib, in addition to JAK inhibition. In conclusion, both tofacitinib and peficitinib potently improved arthritis and associated symptoms in adjuvant-induced arthritis rats; moreover, owing to possible differences in the mechanism of action of the two drugs, peficitinib may have exerted its effects through JAK inhibition and additional unique off-target properties.

The Effective Treatment of Purpurin on Inflammation and Adjuvant-Induced Arthritis.

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.

Green chemistry and anti-inflammatory activity of silver nanoparticles using an aqueous curcumin extract

Rat models are sensitive to the induction of arthritis with adjuvants. Therefore, they are beneficial for studying this pathogenesis through the induction of adjuvant arthritis by injection of Complete Freund's Adjuvant (CFA). An eco-friendly green chemistry approach was utilized to synthesize silver nanoparticles (AgNPs) using an aqueous extract of curcumin root as a capping and reducing agent. AgNPs formation was evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–vis spectroscopy analyses. The study aims to assess in vivo inhibitory effect of AgNPs on complete Freund’s adjuvant-induced arthritis in rats. Therefore, male albino rats were divided into four groups: Normal control; arthritic rats untreated; arthritis rats received standard drug (dexamethasone) as a positive control for 14 days; and arthritis rats received 100 mg/kg AgNPs for 14 days. The results showed that the AgNPs exhibit anti‑inflammatory effects in rats arthritis model by reducing the edema and levels of interleukin‑6 (IL-6) and high-sensitive C‑reactive protein (hs-CRP) in the paw tissues compared to the arthritic rats untreated. Overall, these findings evidence that the AgNPs have a potential promising anti‑inflammatory effect against arthritis disease.

Surface-decorated nanoliposomal leonurine targets activated fibroblast-like synoviocytes for efficient rheumatoid arthritis therapy.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes progressive joint destruction, leading to impaired life quality, disability, and even premature mortality. However, current medications suffer from limited clinical outcomes and severe side effects due to low bioavailability and non-specific distribution after administration. Herein, a targeting nanosystem (HAP-Lipo@Leo) was constructed for efficient RA treatment, which can precisely deliver a natural anti-arthritic drug leonurine (Leo) to the inflamed joint by HAP-1 peptide-mediated recognition of activated fibroblast-like synoviocytes (FLS). More specifically, HAP-Lipo@Leo was prepared by a combination of thin film hydration and high-pressure microfluidization and surface-decorated with HAP-1 peptide and PEG before encapsulating Leo by the ammonium sulfate gradient method. The as-obtained HAP-Lipo@Leo can be selectively internalized by activated FLS and impairs the lamellipodia formation and overexpression of inflammatory cytokines, both of which play detrimental roles in joint damage. Furthermore, HAP-Lipo@Leo demonstrated arthritic joint-specific distribution, significant inhibition of synovial inflammation, and reversal of cartilage and bone destruction in adjuvant-induced arthritis rats as evidenced by comprehensive investigations including ELISA tests, histopathology examinations, and micro-CT analysis. In addition, HAP-Lipo@Leo exhibited good biocompatibility and safety both in vitro and in vivo. Taken together, HAP-Lipo@Leo holds great potential for clinical RA management by integrating activated FLS targeting, long circulation, multifaceted therapeutic effects, and excellent biocompatibility.

IgD enhances the release of neutrophil extracellular traps (NETs) via FcδR in rheumatoid arthritis patients.

Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disorder affecting primarily the joints. Neutrophils and the release of neutrophil extracellular traps (NETs) contribute to the pathogenesis of RA. However, IgD, which was abnormally higher in RA, has not been studied for its pathological role in neutrophil activation and NETs formation. To investigate the effects of IgD on neutrophil activation and NETs formation via IgD receptor (FcδR), we collect peripheral blood of RA patients and established adjuvant-induced arthritis (AA) rat model. We found that the expression of FcδR on neutrophils was significantly higher in RA patients compared with healthy controls. As a specific marker of NETs, the level of citrullinated histone H3 was positively correlated with sIgD and FcδR in RA patients. IgD enhances the release of NETs and promotes the proliferation of fibroblast-like synoviocytes (FLS) from RA patients by activating neutrophils. As a competitive FcδR blocker, IgD-Fc-Ig fusion protein could significantly reduce NETs formation and FcδR expression on neutrophils in vitro. In vivo, IgD-Fc-Ig could restrain IgD-induced neutrophil activation and NETs formation, thus inhibited FLS proliferation in AA rats. Data presented here demonstrate that neutrophils could be triggered by IgD to release NETs and take part in FLS proliferation in RA patients with excessive IgD. Blocking IgD-FcδR could inhibit neutrophil activation and NETs formation, and represent an additional attractive novel therapeutic strategy for the treatment of RA.

Thermosensitive smart hydrogel of PEITC ameliorates the therapeutic efficacy in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune condition that accompanies chronic inflammation of joints with limited therapeutic options. Phenethyl isothiocyanate (PEITC), a bioactive phytochemical, exerts its chemopreventive, anti-oxidant, and anti-inflammatory activity via the Nrf-2 pathway. However, limited water solubility, short half-life, and instability are reasons for the low bioavailability of PEITC that hampers clinical application. From studies in healthy rats, the performance of PEITC-loaded chitosan/pluronic F-127 smart hydrogel (PH) as a thermosensitive injectable demonstrated adequate thermosensitivity (gel formation), injectability (ease of administration), biocompatibility (with prolonged contact), pharmacokinetics (sustained drug release), and biosafety (nontoxic to major organs). In the adjuvant-induced arthritis (AIA) rat model, PEITC-hydrogel (PH50) injected into the knee joint lowered RA-related symptoms significantly (paw edema and arthritis score). Further, a marked reduction in bone erosion and inflammation-specific biomarkers was observed. Finally, this study demonstrates a smart injectable hydrogel optimally loaded with PEITC which is safe, biocompatible and exhibits significant therapeutic efficacy in RA conditions.

Quercetin-loaded chitosan nanoparticles ameliorate adjuvant-induced arthritis in rats by regulating anti-oxidant enzymes and downregulating pro- and inflammatory cytokines.

Rheumatoid arthritis (RA) is an inflammatory condition and associated with the symmetrical synovitis of the joints and cause joint pain. The use of anti-rheumatic drugs is associated with many adverse effects. Quercetin, an important polyphenolic flavonoid, possess anti-inflammatory and anti-rheumatic effects. Quercetin use is limited due to poor absorption and bioavailability. Nanomedicines are used for the targeted drug delivery, hence it reduces the adverse effects of the drug. Based upon these factors, quercetin-loaded chitosan nanoparticles (Q-NPs) were prepared by solvent evaporation method, characterized and their better anti-rheumatic effect with mechanistic insights was validated in Freund's complete adjuvant (FCA)-induced arthritic rats along with safety studies. The animals were divided into five groups, each containing 5 animals. Group I was normal control, group II was arthritic control, while groups III, IV and V were administered with quercetin (15mg/Kg) and Q-NPs (10 and 20mg/Kg), respectively. The reduction in ankle diameter, serum oxidative stress markers as well as pro- and inflammatory cytokines, e.g., tumor necrosis factor (TNFα), interleukin (IL-6) were determined. The prepared Q-NPs showed hydrodynamic size of 83.9nm, polydispersity index of 0.687, entrapment efficiency 90.5% as well as no interaction between quercetin and chitosan in Fourier transform infrared spectroscopy (FTIR). A significant reduction (p < 0.001) in ankle diameter was observed after administration of high-dose Q-NPs (4.32 ± 0.14cm to 5.13 ± 0.62cm). There was also reduction (p < 0.001) in levels of TNFα and IL-6 following high-dose Q-NPs (72.56 ± 2.30 and 308.19 ± 11.5pg). The effect on biochemical tests, hematological parameters and oxidative stress parameters was also found to be significant. Histopathological changes of kidney, liver and ankle also confirmed the anti-rheumatic effect of high-dose Q-NPs. The study concludes that administration of Q-NPs (20mg/Kg) may be used for the treatment of FCA-induced RA in rats.

Novel tryptanthrin derivatives with benzenesulfonamide substituents: Design, synthesis, and anti-inflammatory evaluation

Herein, two series of tryptanthrin derivatives with benzenesulfonamide substituents were designed and synthesized to discover novel anti-inflammatory agents. The anti-inflammatory activities of all derivatives were screened by evaluating their inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells. Among them, compound 8j exhibited the best NO inhibitory activity (IC50 = 1.25 ± 0.21 μM), with no obvious toxicity. Further evaluation showed that 8j could also significantly reduce the levels of pro-inflammatory cytokines interleukin-1β (IL-1β, IC50 = 8.48 ± 0.23 μM) and tumor necrosis factor-α (TNF-α, IC50 = 11.53 ± 0.35 μM) and downregulate the LPS-induced expression of iNOS and COX-2. Reverse docking of 8j suggested p38α as the molecular target, which is a well-known crucial player in the p38 MAPK signaling pathway that controls the transcription of pro-inflammatory mediators. Cellular thermal shift assay showed that 8j efficiently stabilized p38α in LPS-treated RAW264.7 cells. Western blot showed that inflammatory response was inhibited by 8j through inhibiting the phosphorylation of p38α and MK2 in the p38 MAPK signaling pathway. Finally, In vivo studies showed that 8j could significantly ameliorate the degree of foot swelling and knee joint pathology in adjuvant-induced arthritis (AIA) rats and reduce levels of TNF-α and IL-1β in serum, achieving the effect of protecting synovial tissue and ameliorating arthritis. These findings suggested that 8j may be a promising compound for further development of anti-inflammatory agents.

Validation of traditional claims of anti-arthritic efficacy of trans-Himalayan snow mountain garlic (Allium ampeloprasum L.) extract using adjuvant-induced arthritis rat model: A comparative evaluation with normal garlic (Allium sativum L.) and dexamethasone

Ethnopharmacological relevanceSnow Mountain Garlic (SMG) (Allium ampeloprasum L.) is a wild trans-Himalayan member of the genus Allium, valued for its anti-inflammatory and anti-arthritic properties in the mountain folk medicinal system (Sowa-Rigpa). Despite its age-old medicinal usage by traditional therapists and the native population for various ailments including rheumatism, there is no scientific validation of its phyto-pharmaceutical merits. Aim of the studyThe present pre-clinical study compared the in-vivo anti-arthritic effects of SMG with reported efficacy doses of normal garlic (Allium sativum L.) extract and dexamethasone in a complete Freund's adjuvant (CFA)-induced arthritis rat model. Materials and methodsThe female Wistar rats were immunized by the subplannter injection of CFA into the right hind footpad. Aqueous extracts of SMG and normal garlic were administered orally at a dose of 250 mg/kg and 500 mg/kg for 28 days. Dexamethasone was used as positive control drug. Behavioral parameters including paw markers, arthritis index, joint stiffness, body weight change, etc. were measured. Also, the changes in histopathological indices, hematological profile, inflammatory mediators, and serum cytokines level was determined. ResultsTreatment of rats with SMG extracts significantly (p < 0.001) prevented the reduction in body weight and hematological changes as well as ameliorated clinical symptoms such as arthritic index, joint stiffness, arthritis score, edema, hyperalgesia, and histopathological indices. This was associated with a significant reduction in the serum levels of RF, CRP, anti-CCP, and proinflammatory cytokines exhibiting strong anti-arthritic potential. SMG extracts could also significantly down regulate the NF-κB, COX-2, and iNOS expression in the ankle joint tissues. ConclusionsThe present study is the first attempt to validate the phyto-pharmaceutical efficacy of this folk garlic variety from the trans-Himalayan region. Overall, SMG extract showed remarkable preventive anti-inflammatory and anti-arthritic activities which were closely comparable to therapeutic effects of dexamethasone and at par or even better than normal garlic w.r.t. several study parameters.

Anti-arthritic potential of aqueous leaf extract of Combretum platypterum (Welw) Hutch &amp; Dalziel (Combretaceae) on rats

Combretum platypterum is used in the treatment of malaria, swellings, lumps, conjunctivitis, backache, fever, helminthiasis and diarrhea in ethnomedicine. This study evaluates the anti-arthritis activity of aqueous leaf extract of C.platypterum. C. platypterum leaf sample was pulverized and the powdered sample was extracted using cold maceration, which was freeze dried, and graded doses of 50, 100, 200 and 400 mg/kg of the extract were administered for the anti-arthritis property using an established formaldehyde and Complete Freund’s adjuvant induced arthritis models in rats. The result showed that the extract had a significant reduction in the diameter of formaldehyde induced inflammation at day 10 (0.97, 0.97, 0.67 and 0.8 mm) and Complete Freund’s adjuvant at day 28 (1.98, 1.79, 1.77, 1.43 mm) when compared with arthritis control for days 10 and 28 (2.95 and 4.06 mm) (p &lt; 0.05). Percentage inhibition of the leaf extract in formaldehyde at day 10 (67.12, 67.12, 77.29, and 71.86 %) and Complete Freund’s adjuvant induced arthritis at day 28 (51.23, 55.91, 56.40 and 64.78 %) showed a significant increase in the inhibitory effect of C. platypterum in dose dependent order. The ankle weight, erythrocyte sedimentary rate (ESR) and malondialdehyde level had a significant (p &lt; 0.05) decrease in graded doses on complete freund’s adjuvant induced arthritis rats when compared with arthritis control C. platypterum leaf extract elicited a significant (p &lt; 0.05) increase in endogenous superoxide dismutase on complete freund’s adjuvant induced arthritis when compared with arthritis control. This study led it credence to C. platypterum leaf extract scientifically validated for its anti-arthritis property