Rat Model Of Arthritis Research Articles

Effects of Repeated Exposure to Ambient Cold on the Development of Inflammatory Pain in a Rat Model of Knee Arthritis

This study investigated the effects of ambient cold exposure on inflammatory pain development, synovial cytokine levels, and spinal cord glial cell activation. Male Sprague–Dawley rats (6 weeks old) were divided into Cold and RT groups. The Cold group was exposed to cold (4 ± 1 °C) for 6 h/day for 5 consecutive days, while the RT group remained at room temperature (22 ± 1 °C). On day 6, knee arthritis was induced via intra-articular carrageenan injection. Pain was assessed by weight-bearing forces (WBFs) of the affected limb. Synovial pro-inflammatory (IL-1 β, IL-6, and TNF-α) and anti-inflammatory (IL-10) cytokines were measured by ELISA, while spinal cord microglia and astrocytes activation were evaluated via immunohistochemistry. WBFs were maximally reduced 4 h post-carrageenan injection, gradually recovering afterward. Cold-exposed rats showed significantly decreased WBF on days 1 and 2 post-injection compared to the RT group. In the Cold group, synovial cytokines (IL-1β, IL-6, IL-10) were significantly elevated 4 h post-injection, with no change in TNF-α levels. Additionally, OX42-positive cells (microglia) significantly increased 1 h post-injection in the Cold group, while GFAP-positive cells (astrocyte) remained unchanged. Repeated ambient cold exposure enhances inflammatory pain development through the regulation of synovial cytokines and microglia activation in the spinal cord in carrageenan-induced knee arthritis.

A Core-Brush Nanoplatform with Enhanced Lubrication and Anti-Inflammatory Properties for Osteoarthritis Treatment.

Osteoarthritis (OA) is recognized as a highly friction-related joint disease primarily associated with increased joint friction and inflammation due to pro-inflammatory M1-type macrophage infiltration in the articular cavity. Therefore, strategies to simultaneously increase lubrication and relieve inflammation to remodel the damaged articular microenvironment are of great significance for enhancing its treatment. Herein, a multifunctional core-brush nanoplatform composed of a ROS-scavenging polydopamine-coated SiO2 core and lubrication-enhancing zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) brush and loaded with the anti-inflammatory drug curcumin by a reactive oxygen species (ROS)-liable conjugation (named as SiO2@PP-Cur) is rationally designed. Benefiting from the grafted zwitterionic PMPC brush, a tenacious hydration layer with enhanced lubricity for reducing joint abrasions is developed. More importantly, based on the mono-iodoacetic acid-induced arthritis (MIA) rat model, intra-articular injection of SiO2@PP-Cur nanoplatform can effectively alleviate articular inflammation via promoting macrophage polarization from the pro-inflammatory M1 to anti-inflammatory M2 state by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and attenuating the degradation of cartilage matrix, resulting in the remodeling of the damaged microenvironment into a pro-regenerative microenvironment. As a result, SiO2@PP-Cur can considerably inhibit OA progression. Therefore, the work may provide a novel strategy for the development of an advanced core-brush nanoplatform for enhanced OA therapy.

In Silico and In Vivo Evaluation of Anti-Arthritic Effects of Bakuchiol from Psoralea corylifolia Seeds in Experimental Rat Model.

Rheumatoid arthritis is an autoimmune disease mainly affecting the joints categorized by inflammation, swelling of the synovium and decrease in the joint movement. Bakuchiol, a meroterpene class of natural product present in Psoralea corylifolia known to possess anti-inflammatory effects by a variety of mechanisms. However, its effects in rheumatoid arthritis still remain unclear. In the present investigation, we studied the anti-arthritic effects of bakuchiol via in silico and in vivo experiments. It also showed antioxidant effects measured using DPPH assay where it showed free radical scavenging activity with IC50 value 468.26 μg/ml. Molecular Docking studies carried out on COX-1 (PDB ID: 3 N8Z), COX-2 (PDB ID: 4PH9) and TNF-α (PDB ID: 7JRA), proteins involved in inflammation in arthritis. Bakuchiol showed the maximum binding affinity for TNF-α with binding affinity score is -7.29 kcal/moland less affinity was observed for COX-1 and 2. In vivo antiarthritic effects were studied in arthritic female wistar rats model prepared by intradermal injection of freund's complete adjuvant. Bakuchiol was administered orally at dose of 10,20 and 40 mg/kg for 21 days. Our treatment showed that bakuchiol at 20 and 40 mg/kg exhibited significant anti-inflammatory effects (p<0.001) showed by significant decrease in paw volume, paw diameter, spleen and thymus weight and increase in pain threshold and body weight in arthritic rat model. A significant decrease in hematological parameters such as total leukocyte count (TLC), platelet count, CRP and rheumatoid arthritis factor (RF) and increase in red blood cells count, ESR and hemoglobin further demonstrated that bakuchiol treatment suppresses the progression of adjuvant induced arthritis (AIA) in arthritic rat model. Histological analysis further revealed that bakuchiol ameliorates the pathological manifestations of AIA and reverse the abnormality induced by AIA in rats shown by protection against bone necrosis involved with low influx of inflammatory cells. Therefore, in silico and in vivo results revealed that bakuchiol has the potential to be developed as potent antiarthritic agent.

Metabolic effects of quercetin on inflammatory and autoimmune responses in rheumatoid arthritis are mediated through the inhibition of JAK1/STAT3/HIF-1α signaling

BackgroundRheumatoid arthritis, a chronic autoimmune disease, is characterized by synovial hyperplasia and cartilage erosion. Here, we investigated the potential mechanism of action of quercetin, the main component of flavonoids, in treating rheumatoid arthritis.ObjectTo examine the anti-arthritic effects of quercetin and elucidate the specific mechanisms that differentiate its metabolic effects on autoimmune and inflammatory responses at the synovial cell level.MethodsWe created a collagen-induced arthritis (CIA) model in Wistar rats, which were administered quercetin (50 or 100 mg/kg) continuously for four weeks via stomach perfusion. The arthritis score, histopathological staining, radiological assessment, and serum biochemical parameters were used to study the impact of quercetin on disease improvement. Additionally, immunofluorescence was employed to detect JAK1/STAT3/HIF-1α expression in rat joints. Moreover, the effects of quercetin (20, 40, and 80 µmol/L) on the properties and behavior of synovial fibroblasts were evaluated in an in vitro MH7A cell model using flow cytometry, CCK8, and transwell assays. Further, the mRNA expression levels of inflammatory cytokines IL1β, IL6, IL17, and TNFα were assessed by quantitative real-time PCR. Glucose, lactate, lactate dehydrogenase, pyruvate, pyruvate dehydrogenase, and adenosine triphosphate assay kits were employed to measure the metabolic effects of quercetin on synovial fibroblasts. Finally, immunoblotting was used to examine the impact of quercetin on the JAK1/STAT3/HIF-1α signaling pathway in synovial fibroblasts.ResultsIn vivo experiments confirmed the favorable effects of quercetin in CIA rats, including an improved arthritis score and reduced ankle bone destruction, in addition to a decrease in the pro-inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α in serum. Immunofluorescence verified that quercetin may ameliorate joint injury in rats with CIA by inhibiting JAK1/STAT3/HIF-1α signaling. Various in vitro experiments demonstrated that quercetin effectively inhibits IL-6-induced proliferation of MH7A cells and reduces their migratory and invasive behavior, while inducing apoptosis and reducing the expression of the pro-inflammatory cytokines IL1β, IL6, IL17, and TNFα at the mRNA level. Quercetin caused inhibition of glucose, lactate, lactate dehydrogenase, pyruvate, and adenosine triphosphate and increased pyruvate dehydrogenase expression in MH7A cells. It was further confirmed that quercetin may inhibit energy metabolism and inflammatory factor secretion in MH7A cells through JAK1/STAT3/HIF-1α signaling.ConclusionsQuercetin’s action on multiple target molecules and pathways makes it a promising treatment for cartilage injury in rheumatoid arthritis. By reducing joint inflammation, improving joint metabolic homeostasis, and decreasing immune system activation energy, quercetin inhibits the JAK1/STAT3/HIF-1α signaling pathway to improve disease status.

Wutou decoction attenuates rheumatoid arthritis in rats through SIRT1-mediated deacetylation of the HMGB1/NF-κB pathway

Ethnopharmacological relevanceIn traditional Chinese medicine (TCM), Wutou Decoction (WTD) has long been used to alleviate arthritis. Emerging studies have reported that WTD could improve the symptoms of rheumatoid arthritis (RA). However, the mechanism by which WTD is involved in the treatment of RA remains elusive, posing a challenge to the worldwide acceptance of WTD as an efficient RA therapy. Aim of the studyThis study investigated the antiarthritic efficacy of WTD in a collagen-induced arthritis (CIA) rat model and explored silent information regulator 1 (SIRT1)-mediated deacetylation of the high mobility group box 1 (HMGB1)/NF-κB pathway. Materials and methodsA rat CIA model was used to evaluate the antiarthritic activity of WTD. Clinical arthritis score assessment, left ankle thickness assessment, micro-CT, histopathological staining, immunofluorescence staining, and ELISA were conducted to elucidate the anti-inflammatory effects of WTD. The M1 macrophage polarization state, cell viability, and invasion were also determined to assess the effects of WTD on macrophage proliferation and invasion in vitro. Additionally, in vivo and in vitro HMGB1 nuclear translocation and NF-κB activation were analysed. Finally, deacetylase activity was assessed by Western blot, NAD+/NADH analysis, and co-immunoprecipitaion. ResultsWTD significantly alleviated arthritis in CIA rats and inhibited pathological changes in joint lesions while concurrently suppressing TNF-α, IL-6, and IL-1β release. Mechanistically, WTD suppressed M1 infiltration in ankle tissues and their invasion in vitro. Furthermore, WTD downregulated HMGB1/p65 nuclear translocation and acetylation, which may be associated with SIRT1 upregulation. ConclusionsOverall, WTD potentially alleviates RA through SIRT1-mediated downregulation of HMGB1 and NF-κB acetylation.

Macrophage targeted nanocarriers containing methotrexate against arthritis

The present study aimed to develop macrophage-targeted nanocarriers containing methotrexate (MTX) against arthritis. To achieve this goal, mannosylated thiolated chitosan (MTCS) was synthesized and conjugation was confirmed by FTIR analysis. The synthesized MTCS was then used to develop nanocarriers by ionic gelation method utilizing chondroitin sulfate (ChS) as an oppositely charged polymer. The prepared nanocarriers were characterized in terms of size, zeta potential, SEM, and FTIR analysis. In vitro drug release, permeation enhancement, and macrophage targeting potential were investigated along with in-vivo efficacy studies in the arthritic rat model. The size of the macrophage targeted formulation chondroitin sulfate-methotrexate-mannosylated thiolated chitosan nanoparticles (ChS-MTX-MTCS-NPs) was found to be 379 ± 97.74 nm, with a zeta potential of 13 ± 8.76 mV. ChS-MTX-MTCS-NPs exhibited the entrapment efficacy of 78.60 ± 2.3 % with a cumulative drug release of 52 % after 60 h at pH 7.4. Florescent microscopy studies indicated the enhanced potential of ChS-MTX-MTCS-NPs to accumulate inside macrophages compared to non-targeted nanoformulations ChS-MTX-CS-NPs and ChS-MTX-TCS-NPs. Ex vivo intestinal permeation values for ChS- ChS-MTX-MTCS-NPs were measured to be 1.8 × 10-6 cm2/s. In vivo, studies in the arthritic rat model showed that the ChS-MTX-MTCS-NPs nanocarriers significantly reduced the diameter of the arthritic paw (P < 0.05), compared with MTX, ChS-MTX-CS-NPs and disease control. The results suggest that macrophage-targeted MTX-loaded nanocarriers based on MTCS are a promising approach for the treatment of arthritis.

Strychni Semen Combined with Atractylodes Macrocephala Koidz Attenuates Rheumatoid Arthritis by Regulating Apoptosis.

Rheumatoid Arthritis (RA) is a chronic autoimmune disease that can lead to joint pain and disability, and seriously impact patients' quality of life. Strychni Semen combined with Atractylodes Macrocephala koidz (SA) have pronounced curative effect on RA, and there is no poisoning of Strychni Semen (SS). However, its pharmacological mechanisms are still unclear. In this study, we aimed to investigate the pharmacological mechanisms of Strychni Semen combined with Atractylodes Macrocephala Koidz (SA) for the treatment of RA. We used network pharmacology to screen the active components of SA and predict the targets and pathways involved. Results originating from network pharmacology were then verified by animal experiments. Network pharmacology identified 81 active ingredients and 141 targets of SA; 2640 disease- related genes were also identified. The core targets of SA for the treatment of RA included ALB, IL-6, TNF and IL-1β. A total of 354 gene ontology terms were identified by Gene ontology (GO) enrichment analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis results showed that SA was closely associated with TNF signaling pathways in the treatment of RA. Furthermore, according to the predicted results of network pharmacology, we established a rat model of Adjuvant Arthritis (AA) for in vivo experiments. Analysis showed that each treatment group led to an improvement in paw swelling, immune organ coefficient and synovial tissue morphology in AA rats to different degrees, inhibit the expression levels of IL-1β, TNF-α and IL-6, upregulated the levels of Fas, Bax and Caspase 3, down-regulated the expression levels of Fas-L, Bcl-2 and p53. SA has an anti-RA effect, the mechanism underlying the therapeutic action of SA in AA rats was related to the regulation of apoptosis signaling pathways.

Strategic development of aceclofenac loaded organosomes for topical application: An explorative ex-vivo and in-vivo investigation for arthritis

Present study intends to develop aceclofenac-encapsulated organosomes (OS), which consist of phospholipids coupled with a combination of organic solvents, for the management of arthritis. The formulation was characterized and tested for efficacy using formalin-induced hyperalgesia, air pouch, and CFA-induced arthritic rat models. OS system exhibited spherical dimension, nanometric size with low PDI (278.3 ± 12.21 nm; 0.145), zeta potential (−24.56 ± 7.53 mV), drug entrapment (85.62 ± 7.2 %) and vesicles count (4.2x104 mm3). The gelled OS formulation demonstrated increased drug permeability and accumulation rate (51.77 ± 7.1 % and 396.19 ± 59.21 µg/cm2) compared to the MKT product (102.93 ± 13.78 µg/cm2 and 16.14 ± 4.3 %). Dermatokinetic assessments exhibited significantly higher drug levels in dermal layers compared to MKT product (p < 0.001), and CLSM studies further supported the OS system’s deeper penetration. The results of arthritic index significantly better (9 times) in the OS-treated group than the MKT product. OS system treatment significantly reduced biochemicals and cytokines levels, such as CRP, ESR, TLC, lymphocytes, TNF-α, IL-6, and IL-1β to levels of the control group (p < 0.001). Pseudoplastic behaviour of the developed product was indicated by the rheological results, and it also demonstrated biocompatibility through skin compliance studies. Based on the current findings, it appears that OS may be a better choice for managing arthritis and related inflammations.

Discovery and In Vivo Exploration of 1,3,4-Oxadiazole and α-Fluoroacrylate Containing IL-17 Inhibitors.

IL-17, a pro-inflammatory cytokine produced mainly by Th17 cells, is involved in the immune response to fungal and bacterial infections, whereas its aberrant production is associated with autoimmune and inflammatory diseases. IL-17 blocking antibodies like secukinumab (Cosentyx) have been developed and are used to treat conditions like psoriasis, psoriatic arthritis, and ankylosing spondylitis. Recently, the low molecular weight IL-17 inhibitor LY3509754 entered the clinic but was discontinued in Phase 1 due to adverse effects. In this study, we explored the replacements of furazan moiety posing a potential toxicology risk in LY3509754. By exploring replacements such as heterocycles as amide-isosteres as well as α-F-acrylamides, two compounds (18 and 26) were identified. Both compounds effectively reduced knee swelling in a rat arthritis model. However, early rat and dog toxicity studies revealed adverse findings, preventing their further development and indicating that furazan might not be responsible for the adverse effects of LY3509754.

Therapeutic Potential of Olax subscorpioidea Root Extracts in Managing Inflammatory Conditions: A Preclinical Study

Olax subscorpioidea, a plant species endemic to tropical Africa, has long been utilized in traditional medicine for its purported anti-inflammatory and analgesic properties. This preclinical study evaluates the therapeutic potential of Olax subscorpioidea root extracts in managing inflammatory conditions, specifically in a Freund’s adjuvant (CFA)-collagen type II induced arthritis model in albino rats. Both aqueous and ethanol extracts were prepared and assessed for their effects on inflammatory parameters, including cytokine levels, paw edema, joint swelling, and histopathological changes. The study found that both extracts significantly reduced inflammation and clinical signs of arthritis, with the ethanol extract demonstrating a broader range of bioactive compounds and potentially greater efficacy. Mechanistic insights suggest that the extracts exert their effects through inhibition of pro-inflammatory enzymes, modulation of cytokine production, and enhancement of antioxidant activity. Safety and toxicity assessments confirmed the non-toxic nature of the extracts at tested doses. These findings validate the traditional use of Olax subscorpioidea for inflammatory conditions and support its potential integration into modern therapeutic regimens. Future research should focus on dosage optimization, long-term effects, and clinical trials to further establish the efficacy and safety of Olax subscorpioidea root extracts in human subjects. Keywords: Olax subscorpioidea, Root Extracts, Inflammatory Conditions, Preclinical Study.

Transformable peptide blocks NF-κB/IκBα pathway through targeted coating IκBα against rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by destructive effects. Although current therapies utilizing antibodies against inflammatory cytokines have shown some success, the inhibition of a single inflammatory molecule may not suffice to impede the progression of RA due to the intricate pathogenesis involving multiple molecules. In this study, we have developed an intelligent transformable peptide, namely BP-FFVLK-DSGLDSM (BFD). BFD has the ability to self-assemble into spherical nanoparticles in water or in the blood circulation to facilitate their delivery and distribution. When endocytosed into immune cells, BFD can identify and attach to phosphorylation sites on IκBα and in situ transform into a nanofibrous network coating NF-κB/IκBα complexes, blocking the phosphorylation and degradation of IκBα. As a result, BFD enables decreasing expression of proinflammatory mediators. In the present study, we demonstrate that BFD exhibits notable efficacy in alleviating arthritis-related manifestations, such as joints and tissues swelling, as well as bone and cartilage destruction on the collagen-induced arthritis (CIA) rat model. The investigation of intracellular biodistribution, phosphorylation of IκBα, and cytokine detection in culture medium supernatant, joint tissue, and serum exhibits strong associations with therapeutic outcomes. The utilization of transformable peptide presents a novel approach for the management of inflammatory diseases.

Formulation, optimization and evaluation of ibuprofen loaded menthosomes for transdermal delivery

The study aimed to improve the transdermal permeation of IBU utilizing menthosomes as a vesicular carrier. IBU-loaded menthosomes were formulated by thin film hydration & optimized using 23 factorial designs (Design Expert® version 13 software). In vitro &ex vivo skin permeation analysis of IBU-encapsulated menthosomes was studied across the rat skin sample. In vivo pharmacodynamic activity was studied in an arthritis rat model. The optimized IBU-loaded menthosomes exhibited an optimum vesicle size of 214.2 ± 2.96 nm, Zeta potential of −21.1 ± 2.72 mV, (PDI) Polydispersity Index of 0.267 ± 0.018 with Entrapment efficiency (EE%) of 78.7 ± 2.73 %. The in vitro &ex vivo skin penetration study displayed enhanced release of drug of 77.02 ± 1.0 % and 40.91 ± 0.81 % respectively, compared to conventional liposomes. In vivo pharmacodynamic study on carrageenan-induced paw edema in Wistar albino rats demonstrated superior anti-inflammatory activity of the optimized IBU-encapsulated menthosomes (**p < 0.01) and effective inhibition of paw edema (34.04 ± 0.155 %). The formalin test indicated a significant analgesic effect of optimized formulation during the chronic phase of analgesia (*p < 0.05) compared to the control group. Thus, the developed and optimized drug-loaded menthosomes could serve as a suitable vesicular delivery carrier in enhancing the transdermal delivery of other NSAID drugs.

A novel inhibitor of class IIa histone deacetylases attenuates collagen-induced arthritis.

Most inhibitors of histone deacetylases (HDACs) are not selective and are cytotoxic. Some have anti-inflammatory activity in disease models, but cytotoxicity prevents long-term uses in non-fatal diseases. Inhibitors selective for class IIa HDACs are much less cytotoxic and may have applications in management of chronic inflammatory diseases. LL87 is a novel HDAC inhibitor examined here for HDAC enzyme selectivity. It was also investigated in macrophages for cytotoxicity and for inhibition of lipopolysaccharide (LPS)-stimulated cytokine secretion. In a rat model of collagen-induced arthritis, LL87 was investigated for effects on joint inflammation in Dark Agouti rats. Histological, immunohistochemical, micro-computed tomography and molecular analyses characterise developing arthritis and anti-inflammatory efficacy. LL87 was significantly more inhibitory against class IIa than class I or IIb HDAC enzymes. In macrophages, LL87 was not cytotoxic and reduced both LPS-induced secretion of pro-inflammatory cytokines, and IL6-induced class IIa HDAC activity. In rats, LL87 attenuated paw swelling and clinical signs of arthritis, reducing collagen loss and histological damage in ankle joints. LL87 decreased immune cell infiltration, especially pro-inflammatory macrophages and osteoclasts, into synovial joints and significantly reduced expression of pro-inflammatory cytokines and tissue-degrading proteases. A novel inhibitor of class IIa HDACs has been shown to have an anti-inflammatory and anti-arthritic profile distinct from current therapies. It is efficacious in reducing macrophage infiltration and joint inflammation in a chronic model of rat arthritis.

A CCL2/MCP-1 antagonist attenuates fibrosis of the infrapatellar fat pad in a rat model of arthritis

BackgroundFibrosis of the infrapatellar fat pad (IFP) is a feature of osteoarthritis and contributes substantially to the pain and dysfunction in patients’ joints. However, the underlying mechanisms remain unclear. C-C motif chemokine ligand-2 (CCL2) plays a central role in tissue fibrosis. Thus, we aimed to investigate the role of CCL2 in the development of IFP fibrosis in a rat model of arthritis, hypothesizing that a CCL2 antagonist could mitigate fibrotic progression.MethodsWe induced arthritis in male Wistar rats using intra-articular injections of carrageenan. Furthermore, to evaluate the effects of a CCL2 antagonist on protein expression and collagen deposition in the IFP of the rats, we transferred an N-terminal-truncated CCL2 gene into a rat model via electroporation-mediated intramuscular injection. Macrophage infiltration and collagen deposition in the IFP were analyzed in vivo. Groups were compared using the Mann–Whitney U test and Student’s t-test.ResultsWe identified infiltrating macrophages as well as increases in CCL2 and TGF-β levels as collagen deposition progressed. Gene transfer of the CCL2-antagonist before arthritis induction attenuated collagen deposition remarkably.ConclusionsWe provide initial evidence that anti-CCL2 gene therapy can effectively suppress the development of IFP fibrosis in a rat model. Thus, targeting CCL2 holds promise as a therapeutic strategy for managing tissue fibrosis in osteoarthritis patients.

Nuciferine inhibits TLR4/NF-κB/MAPK signaling axis and alleviates adjuvant-induced arthritis in rats

Rheumatoid arthritis is an inflammatory condition primarily affecting the joints. Nuciferine (NCF), a key bioactive aporphine alkaloid biosynthesized in lotus leaves, exhibits promising anti-inflammatory and antioxidant properties. In this study, we investigated whether NCF could alleviate inflammatory arthritis conditions in a complete Freund's adjuvant (CFA)-mediated arthritis model in rats. The arthritis model was established through intradermal injection of CFA (100 μL) in the sub-plantar region of the right hind paw. The arthritic animals were treated orally with NCF at 5 and 10 mg/kg and indomethacin (Indo) at 5 mg/kg body weight as reference control. NCF treatment remarkably alleviated inflammatory joint swelling and arthritic index. The radiological and histological analysis revealed evidence of the beneficial effects of NCF. NCF treatment decreased the content of pro-inflammatory cytokines (TNF-α and IL-1β) and myeloperoxidase (MPO) activity and restored the anti-inflammatory cytokine (IL-10) in the paw joints. The serum levels of pro-inflammatory cytokines were also markedly reduced in the NCF (10 mg/kg) treatment group. Moreover, the arthritis-induced inflammatory mediators, including cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) and the toll-like receptor (TLR)-4, mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB) signaling proteins were substantially decreased in the NCF treatment groups. NCF treatment also restored the antioxidant defense enzymes and abrogated lipid peroxidation in the paw tissue. Our findings strongly suggest that NCF is a promising therapeutic molecule for rheumatoid arthritis, inspiring further research, and development in this area.

WTAP promotes fibroblast-like synoviocyte pyroptosis in Rheumatoid arthritis by upregulating N6-methyladenosine modification of NLRP3.

Rheumatoid arthritis (RA) is a chronic condition characterized by inflammation and an abnormal immune response. N6-methyladenosine (m6A) methylation has altered nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing (NLRP) 3. This change is implicated in the regulation of cell pyroptosis and inflammation. WTAP has a crucial role in regulating NLRP3 m6A. In this work, we used a rat model of collagen-induced arthritis (CIA) to investigate the involvement of WTAP in the evolution of inflammation in RA. The purpose of silencing or overexpressing WTAP in RA-fibroblast-like synoviocytes (RA-FLSs) treated with TNF-α was to identify its impact on pyroptosis, NLRP3 inflammasome-related proteins, the secretion of pro-inflammatory cytokines and migration. Bioinformatics techniques were used to pinpoint the exact target controlled by WTAP. To assess WTAP and NLRP3's role in RA-FLSs, we used methylated RNA immunoprecipitation, LDH test, flow cytometry, RT-qPCR, Western blotting, and Transwell. Our results show that WTAP expression is upregulated in both RA rats and cell models. Cell pyroptosis, NLRP3-related pro-inflammatory cytokines, and migration were reduced in TNF-α-treated RA-FLSs when WTAP was knocked down, whereas overexpression of WTAP displayed the opposite effect in RA-FLSs. WTAP mediated m6A modification in the NLRP3 mRNA and enhanced its mRNA stability. These results suggested that WTAP promoted FLSs pyroptosis and related inflammatory response via NLRP3 and identified WTAP as a potential target for treating RA.

Evaluation of Anti-arthritic Activity of hydro-alcoholic Root Extract of Moringa concanensis in complete Freund’s Adjuvant-induced Arthritic Rats

Background: Arthritis, a debilitating inflammatory disorder, has been a target for numerous therapeutic interventions. Natural plant extracts, especially those rich in phytochemicals like terpenoids, have demonstrated potential as alternative remedies. In this context, Moringa concanensis, a traditionally known medicinal plant, needs further elucidation regarding its anti-arthritic efficacy. Objective: This study aimed to investigate the anti-arthritic potential of the hydro-alcoholic root extract of Moringa concanensis in a Complete Freund’s Adjuvant (CFA)-induced arthritis rat model. Methods: An initial phytochemical screening and GC-MS analysis were executed on the hydro-alcoholic root extract of Moringa concanensis. Arthritis was subsequently induced in rats using CFA. Comprehensive assessments were made on various parameters such as body weight, paw volume, joint diameter, serum rheumatoid factor, serum C-reactive protein, ALP, ALT, total protein, total cholesterol, and urea. Additionally, histopathological studies of the liver and ankle joints were carried out. For comparative efficacy, methotrexate was employed as a positive control. Results: Rats receiving the hydro-alcoholic extract at dosages of 200mg/kg (p.o) and 400mg/kg (p.o) exhibited a notable reduction in the physical and biochemical indicators of arthritis, in comparison to the untreated arthritic model. Histopathological observations further confirmed that the anti-arthritic effects of the hydro-alcoholic extract were on par with methotrexate. Conclusion: The hydro-alcoholic root extract of Moringa concanensis exhibited significant anti-arthritic activity, possibly attributed to its terpenoid content. The findings advocate for its potential application as a therapeutic agent in managing arthritis.

Uncovering the mechanisms of Zhubi decoction against rheumatoid arthritis through an integrated study of network pharmacology, metabolomics, and intestinal flora

Ethnopharmacological relevanceZhubi Decoction (ZBD) is a modified formulation derived from the classic traditional Chinese medicine prescription “Er-Xian Decoction” documented in the esteemed “Clinical Manual of Chinese Medical Prescription”. While the utilization of ZBD has exhibited promising clinical outcomes in treating rheumatoid arthritis (RA), the precise bioactive chemical constituents and the underlying mechanisms involved in its therapeutic efficacy remain to be comprehensively determined. Aim of the studyThis study aims to systematically examine ZBD's pharmacological effects and molecular mechanisms for RA alleviation. Materials and methodsUtilizing the collagen-induced arthritis (CIA) rat model, we comprehensively evaluated the anti-rheumatoid arthritis effects of ZBD in vivo through various indices, such as paw edema, arthritis index, ankle diameter, inflammatory cytokine levels, pathological conditions, and micro-CT analysis. The UPLC-MS/MS technique was utilized to analyze the compounds of ZBD. The potential therapeutic targets and signaling pathways of ZBD in the management of RA were predicted using network pharmacology. To analyze comprehensive metabolic profiles and identify underlying metabolic pathways, we conducted a serum-based widely targeted metabolomics analysis utilizing LC-MS technology. Key targets and predicted pathways were further validated using immunofluorescent staining, which integrated findings from serum metabolomics and network pharmacology analysis. Additionally, we analyzed the gut microbiota composition in rats employing 16 S rDNA sequencing and investigated the effects of ZBD on the microbiota of CIA rats through bioinformatics and statistical methods. ResultsZBD exhibited remarkable efficacy in alleviating RA symptoms in CIA rats without notable side effects. This included reduced paw redness and swelling, minimized joint damage, improved the histopathology of cartilage and synovium, mitigated the inflammatory state, and lowered serum concentrations of cytokines TNF-α, IL-1β and IL-6. Notably, the effectiveness of ZBD was comparable to MTX. Network pharmacology analysis revealed inflammation and immunity-related signaling pathways, such as PI3K/AKT, MAPK, IL-17, and TNF signaling pathways, as vital mediators in the effectual mechanisms of ZBD. Immunofluorescence analysis validated ZBD's ability to inhibit PI3K/AKT pathway proteins. Serum metabolomics studies revealed that ZBD modulates 170 differential metabolites, partially restored disrupted metabolic profiles in CIA rats. With a notable impact on amino acids and their metabolites, and lipids and lipid-like molecules. Integrated analysis of metabolomics and network pharmacology identified 6 pivotal metabolite pathways and 3 crucial targets: PTGS2, GSTP1, and ALDH2. Additionally, 16 S rDNA sequencing illuminated that ZBD mitigated gut microbiota dysbiosis in the CIA group, highlighting key genera such as Ligilactobacillus, Prevotella_9, unclassified_Bacilli, and unclassified_rumen_bacterium_JW32. Correlation analysis disclosed a significant link between 47 distinct metabolites and specific bacterial species. ConclusionZBD is a safe and efficacious TCM formulation, demonstrates efficacy in treating RA through its multi-component, multi-target, and multi-pathway mechanisms. The regulation of inflammation and immunity-related signaling pathways constitutes a crucial mechanism of ZBD's efficacy. Furthermore, ZBD modulates host metabolism and intestinal flora. The integrated analysis presents experimental evidence of ZBD for the management of RA.

Sinapic acid-pullulan based inflammation responsive nanomicelles for the local treatment of experimental inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disorder of joints. It is one of the major causes of disability and morbidity worldwide. Administration of conventional drugs through the systemic route restricts the bioavailability of drugs, systemic toxicity, and reduced efficacy. We have introduced Rebamipide (Reb)-loaded Sinapic acid (SA)-Pullulan (PL) nanomicelles (Reb@SA-PL NMs), a nanotechnology based drug delivery system for the treatment of inflammatory arthritis. PL is a polysaccharide obtained from the fungus Aureobasidium pullulans, and SA is a bioactive polyphenol found in various plants. Both are classified by US-FDA Generally Recognised as Safe (GRAS) materials. Reb@SA-PL NMs found to be cytocompatible. Subsequently, intra-articular administration of Reb@SA-PL NMs enhances the anti-arthritic potential compared to free Reb drug in collagen-induced experimental inflammatory arthritis rat model. Reb@SA-PL NMs reduced the expression of RANKL receptor and Nf-κB. Reb@SA-PL NMs reverses the breakdown of type II collagen, MMP-13, and inhibits the pro-inflammatory markers. Reb@SA-PL NMs prevented bone erosion, cartilage degradation, joint oedema, and synovial inflammation. The results of the study demonstrated that Reb@SA-PL NMs, an enzyme-responsive drug delivery system, has excellent potential for alleviating inflammatory arthritis by blocking MMP-13 and RANKL.

Transdermal fluocinolone acetonide loaded decorated hyalurosomes cellulose acetate/polycaprolactone nanofibers mitigated Freund’s adjuvant-induced rheumatoid arthritis in rats

Abstract Purpose This study aimed to develop a transdermal delivery system for fluocinolone acetonide (FLA), a corticosteroid used in treating inflammatory conditions like rheumatoid arthritis (RA), to overcome the limitations of oral administration, such as poor solubility and bioavailability. Methods FLA-loaded PEG decorated hyalurosomes (FLA-PHs) were fabricated using ethanol injection, incorporating various Brij® surfactants and different amounts of hyaluronic acid (HA) based on a full factorial design. The impact of independent variables, HA amount (mg) (X1) and Brij type (X2) were inspected for entrapment efficiency (EE%), particle size (PS), and zeta potential (ZP). The optimum FLA-PHs were then incorporated into ε-polycaprolactone (PCL) and cellulose acetate (CA) nanofibers to enhance sustained transdermal delivery (FLA-NFs). Results The optimum FLA-PHs exhibited EE% of 83.58 ± 0.69%, PS of 169.00 ± 1.41 nm, and ZP of -22.90 ± 0.14 mV. Morphological assessment of FLA-NFs showed promising results in terms of surface roughness. In a Freund-induced rat model of adjuvant-induced arthritis, transdermal treatment with FLA-NFs significantly improved joint histopathological analyses. Furthermore, it suppressed inflammatory markers such as mTORC1, TNF-α, and NF-κB while upregulating TRIM24 and the anti-inflammatory IL-10. Conclusion FLA-NFs present a promising strategy for enhancing the transdermal delivery of FLA for managing RA, offering potential improvements in efficacy and reduced systemic side effects compared to conventional oral administration.