Assessment of the efficacy of alkaline water in conjunction with conventional medication for the treatment of chronic gouty arthritis: A randomized controlled study

BACKGROUND

Chronic gouty arthritis, a prevalent metabolic disorder, has prompted interest in the role of diet and lifestyle in its management. This study examines alkaline water as a non-pharmacological adjunct to traditional medicine, hypothesizing its positive effects on uric acid levels and gout symptoms.

METHODS

In this research, 400 chronic arthritis patients from Guangdong Hydropower Hospital (September 2021-September 2023) were randomly assigned to groups receiving varying concentrations of alkaline water alongside conventional Western medicine, or Western medicine alone. A 1-year follow-up involved assessments using visual analogue scales, joint swelling scores, functional assessment scales, and biochemical markers (serum uric acid, creatinine, urea nitrogen) for comprehensive evaluation.

RESULTS

Pain relief: High-concentration alkaline water significantly reduced VAS pain scores posttreatment (P < .05). Joint swelling: Greatest improvement observed in high-concentration group (P < .001). Daily activity capability: Notable enhancements in daily activity scores in experimental groups (P < .05). Range of joint motion: All groups showed significant improvement posttreatment (P < .05). Inflammatory markers: Experimental groups experienced a notable decrease in C-reactive protein, especially in the low concentration group (P < .001). Erythrocyte sedimentation rate decreases were marginal and not statistically significant (P > .05). Interleukin-1β and tumor necrosis factor-α levels significantly decreased, particularly in the low concentration group. Serum uric acid levels: Significant reduction in serum uric acid observed in all alkaline water groups (P < .05), contrasting with the control group.

CONCLUSION

Alkaline water, particularly at high concentrations, effectively alleviated pain, reduced joint swelling, enhanced daily activities, and improved joint motion in chronic gouty arthritis treatment. It significantly reduced key inflammatory markers (C-reactive protein, interleukin-1β, tumor necrosis factor-α) and serum uric acid levels, suggesting its potential as a valuable adjunct in gout management. The limited impact on erythrocyte sedimentation rate warrants further investigation.

Prednisolone Versus Colchicine for Acute Gout in Primary Care: statistical analysis plan for the pragmatic, multicenter, randomized, and double-blinded COPAGO non-inferiority trial

BACKGROUND

To date, colchicine and prednisolone are two effective therapies for the treatment of acute gout but have never been compared directly in a randomized clinical trial. In addition, in previous trials of treating acute gout patients with concomitant comorbidities were often excluded due to contraindications to naproxen.

STUDY DESIGN

This pragmatic, prospective, double-blind, double-dummy, parallel-group, randomized, non-inferiority trial compares prednisolone with colchicine in terms of non-inferiority in patients with acute gout. Patients presenting to their general practitioner with acute gout can be included if the gout attack has occurred within the last 2 days. A total of 60 practices in the vicinity of three university medical centers (Greifswald, Göttingen, and Würzburg) participate in the study. The intervention group receives 30 mg prednisolone for 5 days, while the group of standard care receives low-dose colchicine (day 1: 1.5 mg; days 2-5: 1 mg). The first dose of treatment is provided at day 0 when patients present to the general practitioner due to an acute gout attack. From day 0 to day 6, patients will be asked to complete a study diary on daily basis regarding pain quantification. For safety reasons, potential side effects and the course of systolic blood pressure are also assessed.

STATISTICAL ANALYSIS PLAN

N = 314 patients have to be recruited to compensate for 10% of dropout and to allow for showing non-inferiority of prednisolone compared to colchicine with a power of 90%. We use permuted block randomization with block sizes of 2, 4, and 6 to avoid imbalanced treatment arms in this multi-center study; patients are randomized in a 1:1 ratio. The absolute level of pain on day 3 (in the last 24 h) is the primary outcome and measured on a numerical rating scale (NRS: 0-10). Using a multiple linear regression model adjusted for age, sex, and pain at baseline, prednisolone is considered non-inferior if the effect estimate including the confidence intervals is lower than a margin of 1 unit on the NRS. Average response to treatment, joint swelling and tenderness, physical function of the joint, and patients' global assessment of treatment success are secondary outcomes.

DISCUSSION

The trial will provide evidence from a direct comparison of colchicine and prednisolone regarding their efficacy of pain reduction in acute gout patients of primary care and to indicate possible safety signals.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05698680 first posted on January 26, 2023 (retrospectively registered).

Effect and mechanism of aqueous extract of Chinese herbal prescription (TFK) in treating gout arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

With the rapid development of China's economic level, great changes have taken place in people's diet structure, gout has become a common disease that puzzles people's health, seriously affects the realization of China's "Healthy China" strategic goal. Gouty arthritis (GA) is a common joint disease caused by chronic purine metabolism disorder. Currently, drugs used to treat GA are allopurinol and colchicine. However, these drugs can only temporarily relieve the clinical symptoms of GA with significant side effects. More and more basic and clinical studies have confirmed that Traditional Chinese medicine has definite curative effect on GA.

AIM OF THE STUDY

To elucidate the potential molecular mechanism of Tongfengkang (TFK) in the treatment of GA, and to provide experimental basis for the search and development of efficient and low-toxicity Chinese medicine for GA treatment.

MATERIALS AND METHODS

Aqueous extract of TFK (AETFK) were determined by liquid phase high resolution mass spectrometry and the possible effective constituents were screened out. Acute GA model rats were established to detect the anti-inflammatory and detumification effects of AETFK on GA and explore the potential mechanism. The effect of AETFK on serum uric acid and urinary uric acid levels in acute GA rats was determined by automatic biochemical analyzer, and the effect of AETFK on the expression of acute GA-related immunoinflammatory factors were determined by protein thermal fluorescence chip. The effect of AETFK on the concentration of neutrophils in the joint fluid of acute GA rats were determined by Reichs-Giemsa staining. The effect of AETFK on macrophage activation was detected by ELISA. In order to further investigate the mechanism of AETFK in the treatment of GA, a rat model of hyperuricemia was established to detect the effect of AETFK on the level of uric acid in hyperuricemia model rats. Biochemical indexes of liver and kidney and hematoxylin-eosin staining (HE) were used to evaluate the effects of AETFK on the organs, and to preliminatively evaluate the safety of ventilation confufang.

RESULTS

Compared with the model group, the joint swelling degree of GA rats in AETFK treatment group were significantly reduced, and the levels of blood uric acid and urine uric acid were also significantly decreased. Protein thermal fluorescence microarray results showed that the levels of gout - related inflammatory factors in GA rats in AETFK treatment group were significantly lower than those in control group. Reichsen-giemsa staining and ELISA showed that AETFK could reduce the activation of macrophages and the accumulation of neutrophils in the joint fluid. The results of liver and kidney biochemical indexes and HE staining showed that no obvious tissue damage was observed in the organs of rats treated with AETFK.

CONCLUSIONS

AETFK not only has significant anti-inflammatory effects on GA, but also can significantly reduce the level of blood uric acid in GA rats, without obvious toxic and side effects. These effects may be related to AETFK's inhibition of neutrophil enrichment and macrophage activation during early inflammation.

Tetrandrine alleviates inflammation and promotes macrophage M2 polarization in gouty arthritis by NF-κB-mediated Lcp1

Gouty arthritis (GA) is an inflammatory disease caused by the deposition of monosodium urate (MSU) crystals into joints. Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid extracted from the root of Stephania tetrandra and can exert an anti-inflammatory function in different diseases. Nevertheless, the specific function of TET in GA remains unclear. We established the GA mouse model by MSU injection into joints of mice. Paw volume and gait score were detected for measuring the degree of joint swelling and the situation of joint dysfunction. Western blot were utilized to test the alterations of M1-related factors (IL-6, IL-1β, TNF-α, IL-12, and iNOS) and M2-related factors (Mgl1, Mgl2, Pgc1-β, Arg-1, and IL-10). The activity of NF-κB p65 in tissues was determined. The interaction of NF-κB p65 and Lcp1 was measured by ChIP and luciferase reporter assay. Lcp1 KO mice were utilized to detect the effect of Lcp1 depletion on GA process. TET treatment markedly suppressed MSU-induced joint swelling, joint dysfunction, and joint injury in GA mice. TET can also reduce inflammatory reactions in MUS-induced mice. Furthermore, we proved that TET facilitated M2 macrophage polarization and inhibited M1 macrophage polarization in GA mice. In addition, TET was found to inhibit NF-κB activity and NF-κB-mediated Lcp1 expression. Lcp1 knockdown can improve joint injury and promote M2 macrophage polarization in GA mice, while this effect was further enhanced by TET. TET alleviates inflammation and facilitates macrophage M2 polarization in GA by NF-κB-mediated Lcp1.

Exploring effect of herbal monomers in treating gouty arthritis based on nuclear factor-kappa B signaling: A review

Gouty arthritis (GA) is an inflammatory disease caused by disorders of the purine metabolism. Although increasing number of drugs have been used to treat GA with the deepening of relevant research, GA still cannot be cured by simple drug therapy. The nuclear factor-kappa B (NF-κB) signaling pathway plays a key role in the pathogenesis of GA. A considerable number of Chinese herbal medicines have emerged as new drugs for the treatment of GA. This article collected relevant research on traditional Chinese medicine monomers in the treatment of GA using NF-κB, GA, etc. as keywords; and conducted a systematic search of relevant published articles using the PubMed database. In this study, we analyzed the therapeutic effects of traditional Chinese medicine monomers on GA in the existing literature through in vivo and in vitro experiments using animal and cell models. Based on this review, we believe that traditional Chinese medicine monomers that can treat GA through the NF-κB signaling pathway are potential new drug development targets. This study provides research ideas for the development and application of new drugs for GA.

Effects of evodiamine on ROS/TXNIP/NLRP3 pathway against gouty arthritis

Evodiamine (EVO) was tested on acute gouty arthritis rats to investigate its anti-inflammatory effect. Seventy-two male Sprague-Dawley (SD) rats were randomly assigned into the control, model, high, medium, and low dose of EVO groups and colchicine group. The ankle swelling degrees were measured at 2 h, 6 h, and 24 h following sodium urate injection into ankle joint. Histopathological examination was performed 24 h after injection. Reactive oxygen species (ROS) content in the ankle joint was detected using chemical fluorescence. Serum interleukin-1β (IL-1β), interleukin-18 (IL-18), and tumor necrosis factor-α (TNF-α) content were determined by ELISA. Serum xanthine oxidase (XOD), superoxide dismutase (SOD), and malondialdehyde (MDA) were determined by spectrophotometry. The expressions of thioredoxin-interacting protein (TXNIP), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), pro-caspase-1, caspase-1, and apoptosis-related spot like protein (ASC) in synovium were detected by Western blot. Evodiamine alleviated the ankle swelling of the affected foot in gouty arthritis rats and reduced inflammatory cell infiltration in joint synovial tissue. Evodiamine also decreased the content of serum inflammatory factors including IL-1β, IL-18, and TNF-α, and increased serum SOD activity, while it decreased serum XOD, MDA activity, and ROS level. Moreover, evodiamine downregulated the protein expression levels of TXNIP, NLRP3, pro-caspase-1, cleaved caspae-1, and ASC. The mechanism of EVO in treating gouty arthritis is associated with the inhibition of NLRP3 inflammasome by regulating the ROS/TXNIP/NLRP3 signaling pathway.

Mechanism of DaiTongXiao in the treatment of gouty arthritis through the NLRP3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

DaiTongXiao (DTX) is a traditional Chinese Dai folk formulation utilized for gouty arthritis treatment, with substantial evidence supporting its anti-inflammatory properties. The NLRP3 inflammasome disorder is tightly linked to the development of many inflammatory diseases.

AIM OF THE STUDY

To elucidate the therapeutic efficacy of DTX in gouty arthritis and reveal its potential underlying mechanism.

MATERIALS AND METHODS

The primary active constituents in DTX were determined through ultraviolet spectrophotometry and gas chromatography. Rats underwent induction with monosodium urate (MSU), followed by treatment of J774A.1 cells with adenosine triphosphate (ATP) activation and lipopolysaccharide (LPS) induction and the subsequent culture in Dulbecco's modified Eagle's medium. The degree of foot joint swelling in rats was assessed, and ankle joints were evaluated through H&E staining. Enzyme-linked immunosorbent assay was performed to measure the levels of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α in both serum and cells. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to determine the relative mRNA expression levels of NLRP3, ASC, Caspase-1, and NF-κB in J774A.1 macrophages. The expression of NLRP3, ASC, Caspase-1, and NF-κB was examined by western blotting.

RESULTS

DTX could alleviate MSU-induced joint swelling in rats, as evidenced by a reduction in joint inflammation. Moreover, DTX effectively enhanced the survival rate of J774A.1 cells following LPS induction and ATP activation. Furthermore, DTX significantly reduced IL-1β, IL-6, IL-8, and TNF-α levels in both cell culture medium and rat serum. RT-PCR results revealed that DTX notably downregulated the mRNA expression levels of NLRP3, ASC, Caspase-1, and NF-κB in J774A.1 cells. Additionally, DTX downregulated NLRP3, ASC, NF-κB, and Caspase-1 expression in the joint tissue.

CONCLUSIONS

DTX exerts a significant anti-gouty arthritis effect, with its mechanism being tightly linked to the NLRP3 inflammatory signaling pathway. This pathway may be modulated by inhibiting IL-1β differentiation and maturation by downregulating NLRP3, ASC, Caspase-1, and NF-κB protein expression. This, in turn, leads to a reduction in the release of IL-6, IL-8, and TNF-α, ultimately impeding gouty arthritis progression.

Relieving urinary tract obstructions may increase the risk of gouty arthritis in patients with hyperuricemia and postrenal obstructions

To evaluate the effect of relieving urinary tract obstructions (RUO) on the risk of gouty arthritis in patients with postrenal obstructions and hyperuricemia. We retrospectively analyzed the clinical data of 130 patients with urinary tract obstructions at Rongcheng People's Hospital from 2018 to 2021. Patients were divided into groups A (n = 62) and B (n = 68) according to the treatment method. Patients in group A underwent conservative treatments, such as drugs, extracorporeal shock wave lithotripsy (ESWL), and hemodialysis. Patients in Group B underwent catheterization, cystostomy, nephrostomy, or double J ureteral catheterization for rapid RUO. The ages of groups A and B were 58.40 ± 17.69 and 59.63 ± 16.12 years, respectively (P = .42). Before treatment, the serum uric acid values were 572.05 ± 106.93 and 567.79 ± 97.21 µmol/L, respectively (P = .94); serum creatinine values were 226.66 ± 269.67 and 280.15 ± 200.75 µmol/L, respectively (P = .88); and urine volumes were 913.23 ± 481.92 and 886.18 ± 552.72 mL/24 h, respectively (P = .08). No significant differences in the general data were identified between the two groups (P > .05). The effects of the two treatments on the incidence of gout in patients with hyperuricemia complicated by postrenal obstruction were compared based on changes in uric acid level, creatinine level, and urine volume within 1 week after treatment. Multivariate logistic regression analysis was used to analyze clinical factors that increased the incidence of gout after RUO. The gout incidence rates in group A before and after treatment were 8.1% (5/62) and 6.5% (4/62), respectively (P > .99). The gout incidence rates in group B before and after treatment were 4.4% (3/68) and 19.1% (10/68), respectively (P = .01). Group B had a statistically significant increase in the gout incidence rate after RUO (P < .05). Multivariate logistic regression analysis showed that having an age > 60 years, urine volume ≤400 mL/24 h, and creatinine level > 186 µmol/L before treatment were risk factors for gout in patients with hyperuricemia after RUO. Relieving urinary tract obstruction increases the risk of gouty arthritis in patients with hyperuricemia and acute postrenal obstruction. Age, urine volume, and creatinine levels before treatment are risk factors for gout in patients with hyperuricemia after RUO.

Modified Simiaowan prevents and treats gouty arthritis via the Nrf2/NLRP3 inflammasome signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Simiaowan (MSM) is a six-herb formula that has been shown to be effective in gouty arthritis (GA) has been proven, but its regulatory mechanism has not been fully elucidated.

AIM OF THE STUDY

To investigate the therapeutic effects and mechanism of MSM on gouty arthritis.

MATERIALS AND METHODS

Mouse J774A.1 macrophages were induced with Lipopolysaccharide (LPS) and then stimulated with Adenosine 5'-triphosphate (ATP) or Nigericin (Nig.) in presence or absence of MSM. Expression of key indicators of pro-inflammatory cytokines and the NLRP3 inflammasome signaling pathway were investigated by western blot, ELISA and qRT-PCR. Fluorescence staining and flow cytometry were performed to detect intracellular reactive oxygen species (ROS) production. Another study, the anti-inflammatory and antioxidant activities of MSM were evaluated in rats with monosodium urate (MSU) -induced gouty arthritis using ELISA, hematoxylin-eosin staining (HE) staining, immunohistochemistry, and oxidative stress kits to measure relevant inflammatory markers and oxidative stress-related biomarkers.

RESULTS

ELISA and qRT-PCR results demonstrated that MSM effectively reduced the secretion and the mRNA expression levels of pro-inflammatory cytokines. Western blot results indicated that MSM can suppress the expression of NLRP3, an inflamasomes-related protein. In addition, MSM regulated the transition from M1 to M2 macrophages and upregulated the protein expression of Nrf2 and HO-1. The flow cytometry results and the fluorescence staining result were consistent with hypothesis that a large amount of ROS could be effectively cleared by MSM. However, the anti-inflammatory effect of MSM was attenuated after the use of ML385. In vivo experiments demonstrated that joint swelling was significantly attenuated and knee neutrophil infiltration was alleviated in rats given MSM. SOD and GSH-px levels were elevated significantly, while COX-2 and MDA levels decreased. The immunohistochemical results suggested that MSM could effectively inhibit the activation of the NLRP3 inflammasome and the regulation of macrophage polarization in rat synovial tissue, and remarkably enhance the expression of Nrf2 and HO-1.

CONCLUSION

MSM has potent anti-inflammatory and antioxidant effects on MSU-induced gouty arthritis. MSM alleviates GA through Nrf2/HO-1/ROS/NLRP3 signaling pathway.

Treatment of gouty arthritis with traditional Chinese medicine decoction: Meta-analysis, network pharmacology analysis, and molecular docking

BACKGROUND

Previous studies have shown that traditional Chinese medicine decoction (TCMD) could ameliorate the clinical symptoms and laboratory indicators of gouty arthritis (GA) patients. However, few investigations have been conducted on the efficacy and safety of TCMD for GA, the underlying mechanism of TCMD for GA, and the relationship between the TCMD active ingredients and GA targets.

METHODS

Randomized controlled trials of TCMD for GA were retrieved from Chinese and English databases. Meta-analysis was conducted by Stata 17 software. Potential sources of heterogeneity were identified through subgroup analysis, meta-regression, and heterogeneity test. Publication bias was assessed by Egger's test and funnel plots. The ingredients and targets related to TCMD and GA were obtained from multiple databases, such as TCMSP and DrugBank. The protein-protein interaction network, GO and KEGG analysis was constructed using STRING and DAVID. Molecular docking and visualization of the results were completed by AutoDock and PyMOL software.

RESULTS

Eighty-four studies were included, involving 7151 patients and 10 outcome indicators. Meta-analysis showed that, compared to routine treatment, TCMD could better reduce the incidence of adverse events and the level of laboratory indicators including blood uric acid (BUA), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 1β (IL-1β), and tumor necrosis factor-α (TNF-α). In the section of network pharmacology, we retrieved 150 active ingredients and 303 target genes from the top 10 herbs in 84 studies, as well as 3082 disease targets and 195 cross targets of the herbs and GA. The top ranked ingredients, intersection targets, and signaling pathways included quercetin, kaempferol, and wogonin; AKT1, TNF, and TP53; as well as IL-17, HIF-1, and PI3K-AKT, etc. Among the 81 molecular docking results, we visualized 10 results with low binding energy, including IL1B and beta-sitosterol, MYC and beta-sitosterol, etc.

CONCLUSION

TCMD could be a satisfactory complementary and alternative therapy for GA. However, it should be verified by further studies. Future research could be conducted from the following active ingredients, targets, and signal pathways, such as wogonin, sitosterol, and sitosterol; AKT1, TNF, IL6, and TP53; and IL-17, HIF-1, and PI3K-AKT signaling pathway.

Efficacy of Qingpeng ointment (a Tibetan medicine) for acute gouty arthritis: a multi-center, randomized, double-blind, placebo-controlled trial

BACKGROUND

This study aims to assess the efficacy and safety of Qingpeng ointment (QPO), a Tibetan medicine for alleviating symptoms in individuals with acute gouty arthritis (AGA).

METHODS

This study was a randomized, double-blind, placebo-controlled trial that involved individuals with AGA whose joint pain, as measured on a visual analog scale (VAS) from 0 to 10, was equal to or greater than 3. The participants were randomly assigned to either the QPO or the placebo group and received their respective treatments twice daily for seven consecutive days. In case of intolerable pain, the participants were allowed to use diclofenac sodium sustained-release tablets as a rescue medicine. The primary outcomes measured were joint pain and swelling, while the secondary outcomes included joint mobility, redness, serum uric acid levels, C-reactive protein levels, and the amount of remaining rescue medicine. Any adverse events that occurred during the trial were also recorded.

RESULTS

A total of 203 cases were divided into two groups, with balanced baselines: 102 in the QPO group and 101 in the placebo group. For joint pain, differences between the groups were notable in the VAS scores [1.75 (0, 3.00) versus 2.00 (1.00, 3.50); P = 0.038], changes in VAS [5.00 (3.00, 6.00) versus 4.00 (2.00, 6.00); P = 0.036], and disappearance rate [26.47% compared to 15.84%; P = 0.046] after treatment. Concerning joint swelling, significant between-group differences were observed in the VAS scores [1.00 (0, 2.30) versus 2.00 (0.70, 3.00); P = 0.032] and disappearance rate [33.33% compared to 21.78%; P = 0.046] at treatment completion. The QPO group exhibited a statistically significant mobility improvement compared to the placebo group (P = 0.004). No significant differences were found in other secondary outcomes. Five patients, four from the QPO group and one from the other, encountered mild adverse events, primarily skin irritation. All of these cases were resolved after dosage reduction or discontinuation of the medication.

CONCLUSIONS

Compared to the placebo, QPO exhibits positive effects on AGA by alleviating pain, reducing swelling, and enhancing joint mobility, without causing significant adverse effects.

TRIAL REGISTRATION

ISRCTN34355813. Registered on 25/01/2021.

[Mechanism of acteoside in prevention and treatment of gouty arthritis based on liver metabolomics]

This study aims to reveal the effect of acteoside on gouty arthritis(GA) in rats based on liver metabolomics. The ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was employed to search for the potential biomarkers and metabolic pathways. SD rats were randomly assigned into blank, model, colchicine(0.3 mg·kg~(-1)), and high-, medium-, low-dose(200, 100, and 50 mg·kg~(-1), respectively) acteoside groups(n=7). The rats were administrated once a day for 7 continuous days. Monosodium urate(MSU) was used to induce GA model in rats during administration. The degree of joint swelling and pathological changes of synovial tissue in rats were observed, and the levels of interleukin(IL)-1β, IL-18 and tumor necrosis factor(TNF)-α in the synovial tissue of rats were measured. UPLC-Q-TOF-MS was employed to collect rat liver data, and Progenesis QI and EZ info were used for data analysis. Human Metabolomics Database(HMDB) and Kyoto Encyclopedia of Genes and Genomes(KEGG) were employed to predict the potential biomarkers and metabolic pathways. The results showed that acteoside alleviated joint swelling, reduced synovial tissue damage, and lowered the levels of inflammatory cytokines in GA rats. A total of 19 common biomarkers were identified, 17 of which can be regulated by acteoside. Seven metabolic pathways were enriched, such as glycerophospholipid metabolism, linoleic acid metabolism, and taurine and hypotaurine metabolism, among which glycerophospholipid metabolism was strongly disturbed. The metabolomics analysis suggested that acteoside may down-regulate the expression of inflammatory cytokines and alleviate the symptoms of GA rats by regulating glycerophospholipid metabolism, linoleic acid metabolism, and taurine and hypotaurine metabolism. The findings provide a reference for future research and development of acteoside.

Novel Leflunomide Analog, UTLOH-4e, Ameliorates Gouty Arthritis Induced by Monosodium Urate Via NF-κB/NLRP3 Signaling Pathway

BACKGROUND

Gouty arthritis (GA) is a common form of inflammatory arthritis caused by intra-articular deposition of monosodium urate (MSU) crystals; however, there is a tremendous lack of safe and effective therapy in the clinic.

OBJECTIVE

The goal of this work was to investigate a novel leflunomide analogue, N-(2,4- dihydroxyphenyl)-5-methyl-1,2-oxazole-3-carboxamide (UTLOH-4e), for its potential to prevent/ treat gouty arthritis.

METHODS

In this study, the anti-inflammatory activity of UTLOH-4e was evaluated by MSUinduced GA model in vivo and in vitro, and the molecular docking test was applied to estimate the affinity of UTLOH-4e/UTL-5g/b for MAPKs, NF-κB, and NLRP3.

RESULTS

In vitro, UTLOH-4e (1~100 μM) treatment inhibited the inflammatory reaction with no obvious cytotoxicity in PMA-induced THP-1 macrophages exposed to MSU crystals for 24 h, involving the prominent decreased production and gene expression of IL-1β, TNF-α, and IL-6. Western blot analyses demonstrated that UTLOH-4e (1~100 μM) significantly suppressed the activation of NLRP3 inflammasomes, NF-κB, and MAPK pathways. Furthermore, the data from the experiment on gouty rats induced by intra-articular injection of MSU crystal confirmed that UTLOH-4e markedly ameliorated rat paw swelling, articular synovium inflammation and reduced the concentration of IL-1β and TNF-α in serum through down-regulating NLRP3 protein expression.

CONCLUSION

These results manifested that UTLOH-4e ameliorates GA induced by MSU crystals, which contributes to the modulation of NF-κB/ NLRP3 signaling pathway, suggesting that UTLOH- 4e is a promising and potent drug candidate for the prevention and treatment of gouty arthritis.

Activation of Nrf2 antioxidant signaling alleviates gout arthritis pain and inflammation

Excessive deposition of monosodium urate (MSU) crystal in the joint results in gout arthritis, which triggers severe pain and affects life quality. Oxidative stress is a pivotal mechanism that contributes to etiology of gout pain and inflammation. Here we investigated whether activating Nrf2, which plays important roles in regulating endogenous antioxidant response, would attenuate gout arthritis via promoting antioxidant signaling in joint tissues. Gout arthritis model was established by intra-articular injection of MSU (500 μg/ankle) into the right ankle joint of mouse. Pharmacologically activating Nrf2 by activator oltipraz (50, 100 or 150 mg/kg, intraperitoneal) at 1 h before and 5, 23, 47 h after model establishment dose-dependently inhibited joint inflammation, mechanical and heat hypersensitivities in model mice. Oltipraz (100 mg/kg) reversed gait impairments without altering locomotor activity and reduced neutrophil infiltrations in ankle joints. In vitro studies revealed oltipraz (25 μM) inhibited MSU-induced ROS production in mouse macrophages and improved mitochondrial bioenergetics impairments caused by MSU. In vivo ROS imaging combined with biochemical assays confirmed the antioxidant effects of oltipraz on model mice. Nrf2 activation inhibited pro-inflammatory cytokine overproduction in ankle joint and attenuated the overexpression and enhancement in TRPV1 channel in DRG neurons innervating hind limb. Therapeutic effects of oltipraz were abolished by inhibiting Nrf2 or in Nrf2 knockout mice. These results suggest pharmacologically activating Nrf2 alleviates gout pain, gait impairments, inflammation and peripheral sensitization via Nrf2-dependent antioxidant mechanism. Targeting Nrf2 may represent a novel treatment option for gout arthritis.

Manganese-doped albumin-gelatin composite nanogel loaded with berberine applied to the treatment of gouty arthritis in rats via a SPARC-dependent mechanism

In this study, manganese-doped albumin-gelatin composite nanogels (MAGN) were prepared and used to load berberine (Ber) for the treatment of gouty arthritis (GA). The nanodrug delivery system (Ber-MAGN) can target inflammatory joints due to the intrinsic high affinity of albumin for SPARC, which is overexpressed at the inflammatory site of GA. Characterization of the pharmaceutical properties in vitro showed that Ber-MAGN had good dispersion, and the particle size was 121 ± 10.7 nm. The sustained release effect significantly improved the bioavailability of berberine. In vitro and in vivo experimental results showed that Ber-MAGN has better therapeutic effects in relieving oxidative stress and suppressing inflammation. Therefore, Ber-MAGN, as a potential pharmaceutical preparation for GA, provides a new reference for the clinical treatment plan of GA.

Network pharmacology identification and in vivo validation of key pharmacological pathways of Qin Jiao for gout and arthritis

Context: Gout is a chronic disease that imposes a huge financial and health burden on patients, which might diminish quality of life. Qin Jiao, a perennial herb found in northwestern China and Japan, is commonly used for treating various ailments.Objective: This study investigates the effects of Qin Jiao on gout and joint inflammation and elucidates its potential mechanism for gouty arthritis.Materials and methods: Study 1, a literature review was conducted using PubMed, Web of Science, and CNKI to assess the applications of Qin Jiao in arthritis treatment. Study 2 was performed to discover the component targets and gouty disease targets via TCMSP, OMIM, GeneCards and DRUGBANK, and network pharmacology analysis. Study 3, male Sprague-Dawley (SD) rats were divided into normal, model, colchicine, Qin Jiao low-dose (QJL), and Qin Jiao high-dose group (QJH), oral gavage for 40 d. Serum, synovial fluid, and synovial membrane tissue were collected to measure the expression levels of IL-1β, IL-6, and STAT3.Results: The research also identified potential targets and pharmacological pathways of Qin Jiao for gout treatment. In vivo study demonstrated Qin Jiao can reduce IL-1β levels in serum and ankle flushing fluid. ELISA analysis confirmed that Qin Jiao significantly reduces the protein expression of IL-6 and STAT3.Discussion and conclusion: Qin Jiao exerts anti-inflammatory effects on gouty arthritis by modulating the IL-6/STAT3 pathway. This study provides a biological basis for the use of Qin Jiao in treating arthritis-related diseases and offers experimental evidence for potential future drug development.

Non-loading versus loading low-dose colchicine in acute crystal-associated arthritis: A double-blinded randomized controlled study

INTRODUCTION

This study aimed to compare the efficacy of non-loading versus loading low-dose colchicine in patients with acute crystal-associated arthritis.

MATERIALS AND METHODS

All in-patients who were admitted to Chiang Mai University Hospital with non-arthritis disease and developed acute crystal-associated arthritis during admission (within 48 h after arthritis onset) were invited to join this study. The patients were randomized into two groups. Patients in Group I (non-loading group) and Group II (loading group) received colchicine at 1.2 and 2.4 mg in the first 24 h, respectively. The primary outcome was the patients' pain response at 24 h after treatment.

RESULTS

Of 80 patients, 49 were acute gouty arthritis, and 31 acute calcium pyrophosphate (CPP) arthritis. The mean [95% CI] pain score was no different between Groups I and II at the baseline level (6.46[5.72-7.19] vs. 6.654[5.85-7.44], p = .867) and at 24 h (3.13[2.43-3.82] vs. 3.18[2.42-3.93], p = .907). The proportion of patients with ≥50% pain reduction was not different (57.50% vs. 55.00%, p = .822). Sensitivity analysis among patients with a baseline pain score of ≥4 showed the same pattern of response. Mild diarrhea was common and comparable in both groups. Subgroup analysis according to renal function (eGFR < 60 vs. ≥60 mL/min/1.73 m2 ) or type of crystals (acute gouty arthritis vs. acute CPP arthritis) also showed the same pattern of response.

CONCLUSION

Non-loading low-dose colchicine was as effective as loading low-dose colchicine in patients with acute crystal-associated arthritis, regardless of renal function or type of crystals.

Chinese herbal compound Huangqin Qingrechubi capsule reduces lipid metabolism disorder and inflammatory response in gouty arthritis via the LncRNA H19/APN/PI3K/AKT cascade

CONTEXT

Gouty arthritis (GA) is a characteristically inflammatory disease often associated with lipid metabolism disorder. Huangqin Qingrechubi capsule (HQC) has been used for the treatment of GA.

OBJECTIVE

To explore the mechanism of HQC in the treatment of GA.

MATERIALS AND METHODS

A total of 30 GA patients (GA group) and 30 healthy subjects [normal control (NC) group] were recruited. The GA group was treated with HQC (3.6 g/d) for 10 days. Lipid metabolism and inflammation indexes were detected. Five herbal names of HQC, or 'gouty arthritis', 'hyperlipidemia' and 'inflammation' were used as key words to search related databases for network pharmacological analysis. Subsequently, GA-fibroblast-like synoviocytes (FLSs) were stimulated with GA-peripheral blood mononuclear cells (PBMCs) (3:1) and treated with HQC drug-containing serum (20%). RT-qPCR, Western blot, and ELISA were conducted to further explore the mechanism of HQC in improving GA.

RESULTS

In clinical observation, HQC decreased the expression of lncRNA H19 and IL-1β, and increased the expression of adiponectin (APN) and IL-4 in the GA group (about half). Through network pharmacology, the PI3K/AKT signaling pathway was identified. Cell experiments showed that HQC treatment reduced the viability of GA-FLSs (49.61%), up-regulated the expression of IL-4 (155.18%), IL-10 (165.13%), and APN (31.24%), and down-regulated the expression of lncRNA H19 (33.70%), IL-1β (64.70%), TNF-α (78.32%), p-PI3K (48.80%), and p-AKT (53.48%).

DISCUSSION AND CONCLUSIONS

HQC improved lipid metabolism disorder and inflammatory response of GA by regulating the lncRNA H19/APN/PI3K/AKT. Maintaining the stability of lipid metabolism may be an effective way to alleviate GA.

Clinical efficacy evaluation and potential mechanism prediction on Guizhi-Shaoyao-Zhimu decoction in the treatment of gouty arthritis based on meta-analysis, network pharmacology analysis, and molecular docking

BACKGROUND

Guizhi-Shaoyao-Zhimu decoction (GSZD) is a Chinese herb formula. Previous studies have reported that the clinical symptoms and laboratory indicators of gouty arthritis patients could be improved by GSZD. However, no previous study has evaluated and analyzed its efficacy, safety, underlying mechanisms, and the relationship between related ingredients of herbs and targets of gouty arthritis.

METHODS

Randomized controlled trials of GSZD for gouty arthritis were retrieved from various databases. Meta-analysis was performed by Stata 17 software. Galbraith plot was used to find studies with possible heterogeneity. Publication bias was assessed by Egger test and funnel plot. The related ingredients of herbs and the targets of herbs and gouty arthritis were obtained from several databases, such as TCMSP, HERB, and DrugBank. The protein-protein interaction network was conducted by the STRING platform. DAVID database was used to perform GO and KEGG analysis. Molecular docking and visualization of docking results were carried out by AutoDock and PyMOL software.

RESULTS

Twenty studies with 1633 patients were included. Meta-analysis indicated that GSZD could better improve the clinical efficiency and visual analogue scale score, and reduce the level of blood uric acid and inflammatory biomarkers (including C-reactive protein, erythrocyte sedimentation rate, interleukin 6, interleukin 8, and tumor necrosis factor-α) than conventional treatment. In addition, we retrieved 157 active compounds, 517 herb target genes, 3082 disease targets, and 295 intersection targets of herb and disease. The results of network pharmacology analysis showed that the core related ingredients included quercetin, kaempferol, sitosterol, luteolin, catechin, etc. The core intersection targets contained AKT1, TNF-α, TP53, IL6, etc. And the critical signaling pathways included IL-17, HIF-1, TNF, PI3K-Akt, etc. Among the 56 molecular docking results, only 8 results had binding energy values greater than -5.0 kcal/mol.

CONCLUSION

GSZD could be a satisfactory complementary and alternative therapy for treating gouty arthritis. However, it should be verified by further studies. Future research on gouty arthritis could be conducted from the active components including beta-sitosterol and sitosterol, the targets including TNF-1, IL1B, and ESR1, and the signaling pathways including IL-17 and HIF-1.

The dysregulation of immune cells induced by uric acid: mechanisms of inflammation associated with hyperuricemia and its complications

Changes in lifestyle induce an increase in patients with hyperuricemia (HUA), leading to gout, gouty arthritis, renal damage, and cardiovascular injury. There is a strong inflammatory response in the process of HUA, while dysregulation of immune cells, including monocytes, macrophages, and T cells, plays a crucial role in the inflammatory response. Recent studies have indicated that urate has a direct impact on immune cell populations, changes in cytokine expression, modifications in chemotaxis and differentiation, and the provocation of immune cells by intrinsic cells to cause the aforementioned conditions. Here we conducted a detailed review of the relationship among uric acid, immune response, and inflammatory status in hyperuricemia and its complications, providing new therapeutic targets and strategies.

[Unusual case of pseudotumoral hip injury due to gout: case report]

Background

Gout is known as arthropathy due to the deposit of monosodium urate crystals; This pathology comprises a set of clinical and radiographic tests in the context of the intra-articular presence of said crystals. It is a chronic disease associated with other comorbidities such as arterial hypertension, osteoarthritis, diabetes mellitus, etc. The case of a patient with gouty arthritis with consequent hip lesion with a pseudotumoral appearance difficult to diagnose is presented, in order to highlight the importance of this, as well as the appropriate follow-up and treatment for this chronic pathology.

Clinical case

A 51-year-old male patient, with a history of hip osteoarthritis and gout. The symptoms and signs were pain in the right hip with an 8/10 on an analogue pain scale, associated with functional limitation characterized by reduced range of motion and impossibility of standing. Imaging studies are carried out which are suggestive of a tumor lesion at the proximal femur with malignant characteristics, for which a biopsy and subsequent histopathological diagnosis of gouty tophi is performed.

Conclusions

Gout is a prevalent disease in the adult population, however, its infrequent joint location can result in a difficult diagnosis, so it is necessary not to rule out this entity and to carry out specific studies for its identification.

New animal model of chronic gout reproduces pathological features of the disease in humans

OBJECTIVES

Gout, as the most prevalent form of inflammatory arthritis, necessitates the use of animal models to investigate the molecular mechanisms involved in its development. Therefore, our objective was to develop a novel chronic mouse model of gout that more closely mimics the progression of gout in humans.

METHODS

A novel chronic mouse model of gout was established by a simple method, which does not require high technical proficiency, predominantly involves daily intraperitoneal injections of potassium oxonate for approximately 4 months, combined with a high fat-diet and injections of acetic acid into the hind paws to facilitate the formation of monosodium urate (MSU). Arthritis scores and paw oedema were assessed, behavioural tests were conducted, and histopathological and imaging evaluations of the arthritic paw joints were performed.

RESULTS

After 4 months of induction, mice in the model group exhibited noticeable increases in arthritis severity, joint and cartilage damage, as well as bone erosion. Gomori's methenamine silver stain revealed the presence of MSU crystal deposition or tophi in the paw joints or ankle joints of up to 37.9% of the model mice (11 out of 29 mice). Moreover, treatment with benzbromarone effectively prevented the further development of gout or tophi formation in model mice.

CONCLUSIONS

Our model more accurately replicates the pathological features of gouty arthritis compared with gout induced by MSU crystal injections. Therefore, it is particularly suitable for further investigations into the pathogenesis of gout and also serves as a valuable platform for screening potential antigout agents.

Total Saponin Fraction of Dioscorea Nipponica Makino Improves Gouty Arthritis Symptoms in Rats via M1/M2 Polarization of Monocytes and Macrophages Mediated by Arachidonic Acid Signaling

OBJECTIVE

To explore the mechanism of effects of total saponin fraction from Dioscorea Nipponica Makino (TSDN) on M1/M2 polarization of monocytes/macrophages and arachidonic acid (AA) pathway in rats with gouty arthritis (GA).

METHODS

Seventy-two Sprague Dawley rats were randomly divided into 4 groups (n=18 in each): normal, model, TSDN at 160 mg/kg, and celecoxib at 43.3 mg/kg. Monosodium urate crystal (MSU) was injected into the rats' ankle joints to induce an experimental GA model. Blood and tissue samples were collected on the 3rd, 5th, and 8th days of drug administration. Histopathological changes in the synovium of joints were observed via hematoxylin and eosin (HE) staining. The expression levels of arachidonic acid (AA) signaling pathway were assessed via real-time polymerase chain reaction (qPCR) and Western blot. Flow cytometry was used to determine the proportion of M1 and M2 macrophages in the peripheral blood. An enzyme-linked immunosorbent assay (ELISA) was used to detect interleukine (IL)-1 β, tumor necrosis factor-alpha (TNF-α), IL-4, IL-10, prostaglandin E2 (PGE2), and leukotriene B4 (LTB4).

RESULTS

HE staining showed that TSDN improved the synovial tissue. qPCR and Western blot showed that on the 3rd, 5th and 8th days of drug administration, TSDN reduced the mRNA and protein expressions of cyclooxygenase (COX)2, microsomal prostaglandin E synthase-1 derived eicosanoids (mPGES-1), 5-lipoxygenase (5-LOX), recombinant human mothers against decapentaplegic homolog 3 (Smad3), nucleotide-binding oligomerization domain-like receptor protein 3 (NALP3), and inducible nitric oxide synthase (iNOS) in rats' ankle synovial tissues (P<0.01). TSDN decreased COX1 mRNA and protein expression on 3rd and 5th day of drug administration and raised it on the 8th day (both P<0.01). It lowered CD68 protein expression on days 3 (P<0.01), as well as mRNA and protein expression on days 5 and 8 (P<0.01). On the 3rd, 5th, and 8th days of drug administration, TSDN elevated the mRNA and protein expression of Arg1 and CD163 (P<0.01). Flow cytometry results showed that TSDN decreased the percentage of M1 macrophages while increasing the percentage of M2 in peripheral blood (P<0.05 or P<0.01). ELISA results showed that on the 3rd, 5th, and 8th days of drug administration, TSDN decreased serum levels of IL-1 β, TNF-α, and LTB4 (P<0.01), as well as PGE2 levels on days 3rd and 8th days (P<0.05 or P<0.01); on day 8 of administration, TSDN increased IL-4 serum levels and enhanced IL-10 contents on days 5 and 8 (P<0.05 or P<0.01).

CONCLUSION

The anti-inflammatory effect of TSDN on rats with GA may be achieved by influencing M1/M2 polarization through AA signaling pathway.

Prednisolone Versus Colchicine for Acute Gout in Primary Care (COPAGO): protocol for a two-arm multicentre, pragmatic, prospective, randomized, double-blind, controlled clinical trial of prednisolone and colchicine for non-inferiority with a parallel group design

BACKGROUND

Gout is the most common form of rheumatic disease in which monosodium urate crystals are deposited in the joints followed by acute inflammatory reactions. There are various approved drugs that can be prescribed for pain relief during an acute gout attack. However, to date, no direct comparison of efficacy of colchicine and prednisolone for the treatment of acute gout attacks has been investigated. Furthermore, the majority of previous research studies were not only conducted in tertiary centres but also excluded patients with common comorbidities due to contraindications to naproxen.

METHODS

This pragmatic, prospective, double-blind, double-dummy, parallel-group, randomized, non-inferiority trial investigates whether prednisolone (intervention) is non-inferior to treatment with colchicine (active control) in patients with acute gout. Adult patients presenting with acute gout to their general practitioners in 60 practices across 3 university sites (Greifswald, Göttingen, and Würzburg) are eligible to participate in the study. Participants in the intervention group receive 30 mg prednisolone for 5 days. Those in the control group receive low-dose colchicine (day 1: 1.5 mg; days 2-5: 1 mg). The primary outcome is the absolute level of the most severe pain on day 3 (in the last 24 h) measured with an 11-item numerical rating scale. Day 0 is the day patients take their study medication for the first time. They are then asked to fill out a study diary the same time each day for pain quantification. Pain scores are used for comparison between the two medications. Secondary outcomes are average response to treatment, swelling, tenderness and physical function of the joint, patients' global assessment of treatment success, use of additional pain medication and non-pharmacological pain therapies. For safety reasons, potential side effects and course of systolic blood pressure are assessed.

DISCUSSION

This trial will provide evidence on the effectiveness of pain reduction and side effects of colchicine and prednisolone in acute gout in primary care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05698680 first posted on January 26, 2023 (retrospectively registered). URL of trial registry record: https://clinicaltrials.gov/study/NCT05698680.

Kaempferol Attenuates Gouty Arthritis by Regulating the Balance of Th17/Treg Cells and Secretion of IL-17

Kaempferol is a common flavonoid aglycone widely found in plants. It exhibits beneficial therapeutic effects in the treatment of arthritis. However, the effects of kaempferol on gouty arthritis (GA) have not been verified. This study aimed to explore the potential mechanisms by which kaempferol regulates GA by network pharmacology and experimental validation. Potential drug targets for GA were identified with a protein-protein interaction network. Then, we performed a KEGG pathway analysis to elucidate the major pathway involved in the kaempferol-mediated treatment of GA. In addition, the molecular docking was performed. A rat model of GA was constructed to verify the results of network pharmacology analysis and investigate the mechanism of kaempferol against GA. The network pharmacology study indicated that there were 275 common targets of kaempferol and GA treatment. Kaempferol exerted therapeutic effects on GA, in part, by regulating the IL-17, AGE-RAGE, p53, TNF, and FoxO signaling pathways. Molecular docking results showed that kaempferol stably docked with the core MMP9, ALB, CASP3, TNF, VEGFA, CCL2, CXCL8, AKT1, JUN, and INS. Experimental validation suggested that kaempferol eased MSU-induced mechanical allodynia, ankle edema, and inflammation. It significantly suppressed the expression of IL-1β, IL-6, TNF-α, and TGF-β1 and restored Th17/Treg imbalance in MSU-induced rats and IL-6-induced PBMCs. Kaempferol also affected RORγt and Foxp3 through IL-17 pathway. The present study clarifies the mechanism of kaempferol against GA and provides evidence to support its clinical use.

Autophagy induced by PP121 alleviates MSU crystal-induced acute gouty arthritis via inhibition of the NLRP3 inflammasome

Acute gouty arthritis (AGA) is a frequent self-limiting inflammatory condition produced by the deposition of monosodium urate (MSU) crystals in the joints and periarticular tissues of patients with hyperuricemia. However, no effective interventional measures currently exist for AGA. Pyroptosis, a kind of pro-inflammatory programmed cell death, plays a crucial role in MSU crystal-induced inflammation and represents a potential treatment target for AGA. Therefore, we determined the therapeutic benefits and mechanism of PP121, a pyroptosis-related compound, on AGA. First, we injected an MSU crystal solution intra-articularly into the left foot pad of C57BL/6 mice to create an AGA mouse model. Subsequent treatment with PP121 substantially decreased tissue damage, pro-inflammatory cytokine release, and inflammatory cell infiltration caused by MSU crystals in the ankle joint. Consistent with these observations, the beneficial effects of PP121 on AGA were cancelled in Beclin1+/-(Becn1+/-) mice. Furthermore, after PP121 treatment, super-resolution microscopy revealed a strong relationship between lysosome-connected membrane protein/light chain 3 positive vesicles and the nucleotide-binding domain of leucine-rich family pyrin domain-containing 3 (NLPR3), demonstrating that PP121 promotes phagocytosis of the NLPR3 inflammasome. In summary, PP121-mediated autophagy can improve degradation of the NLRR3 inflammasome in AGA, which suggests the therapeutic potential of PP121 in AGA.

Neutrophil autophagy induced by monosodium urate crystals facilitates neutrophil extracellular traps formation and inflammation remission in gouty arthritis

Neutrophil extracellular traps (NETs) are composed of chromatin filaments coated with granular and cytosolic proteins, which contribute to the pathogenesis and progression of immune-related diseases. NETs are frequently observed in gouty arthritis, but the related mechanisms remain poorly understood. The aim of our study was to systematically elucidate the molecular mechanisms of self-remitting effects in gouty arthritis, and the causative relationship between neutrophil autophagy and NETs. The air pouch and paw edema model were used to simulate gouty arthritis in mice. Neutrophil infiltration and the formation of NETs were found in gouty arthritis. Interestingly, monosodium urate (MSU) crystals could induce the formation of NETs, degrade inflammatory factors, and alleviate the inflammatory response in gouty arthritis. In addition, MSU crystals resulted in profound molecular alterations in neutrophils using RNA-seq analysis, including autophagy activation. MSU crystals could activate neutrophil autophagy in vitro, and autophagy activators and inhibitors could regulate the formation of NETs. Furthermore, we explored the mechanism of autophagy-induced NETs. Autophagy related protein 7 (ATG7) produced by neutrophils stimulated with MSU crystals worked synergistically with p53 to enter the nucleus, promoting peptidyl arginine deiminase 4 (PAD4) expression, and inducing the formation of NETs. Finally, we substantiated that neutrophil autophagy regulates the severity of gouty arthritis via the formation of NETs in PAD4 -/- mice. Our results indicated that the autophagy of neutrophils regulates the formation of NETs and degrades inflammatory factors. Regulating autophagy and interfering with the formation of NETs represents a potential therapeutic approach against gouty arthritis during clinical practice.

Discovery and Characterization of Moracin C as an Anti-Gouty Arthritis/Hyperuricemia Candidate by Docking-Based Virtual Screening and Pharmacological Evaluation

In the present study, a natural product database of compounds associated with herbs traditionally verified to treat gout/hyperuricemia/arthritis was constructed. 3D-shape and docking-based virtual screening was conducted. To identify potential xanthine oxidase (XOD) inhibitors in the database, eight compounds with commercial availability were identified as high 3D-shape similarity with febuxostat (1), a known XOD inhibitor. Docking was used to further predict the possible interactions between XOD and these compounds. Moracin C (2), moracin D (3), and isoformononetin (8) exhibited higher docking scores and binding energies than other compounds. In vitro, 2 inhibited XOD with an IC50 value of 0.25 ± 0.14 μM, which is similar to that of 1 (0.16 ± 0.08 μM). In a hyperuricemic mouse model, 5-20 mg/kg 2 exhibited satisfying urate-lowering and XOD inhibitory effects. Compound 2 also exhibited antiarthritis activities. In RAW264.7 cells, 2 at 1-10 μM inhibited the expression of IL-1β and TNF-α induced by MSU. In an acute gouty arthritis model in SD rats, 5-20 mg/kg 2 significantly alleviated the toe swelling, inflammatory response, and dysfunction disorder caused by monosodium urate (MSU). Compound 2 inhibited serum IL-1β and TNF-α cytokines as well as reduced the expression of the NLRP3/ASC/caspase-1 inflammasome in joints. In summary, 2 was an effective compound for the treatment of hyperuricemia/gouty arthritis.

Acute severe gouty arthritis secondary to isotretinoin toxicity in a young male: a case report

Acute gouty arthritis is a recognized complication of hyperuricemia and one of the most common forms of inflammatory arthritis in adults. Drug-induced hyperuricemia is increasingly prevalent in clinical practice. Diuretics, antitubercular medications, and immunosuppressants are the common drugs associated with hyperuricemia. Oral isotretinoin is the drug of choice for different forms of severe acne and is rarely associated with hyperuricemia. We present the case of a 30-year-old male with severe acne vulgaris who was prescribed isotretinoin and later presented with acute gout. The patient developed hyperuricemia and swelling of the right first metatarsophalangeal joint within two months of isotretinoin commencement. There was a second episode of similar joint swelling three months later, parallel to the isotretinoin rechallenge. The dose of isotretinoin was reduced with the addition of febuxostat. The patient did not develop further episodes and remained symptom-free without urate-lowering therapy.

Herbal medicine for external use in acute gouty arthritis: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Acute gouty arthritis is accompanied by severe pain during an acute attack. This systematic review aimed to evaluate the efficacy and safety of herbal medicines acting directly on the affected area of acute gouty arthritis for external use.

METHODS

An envelope search was performed using 4 electronic databases (CNKI, PubMed, EMBASE, Cochrane), resulting in 27 clinical studies from inception to February 2023. Randomized controlled trials on external use herbal medicines for acute gouty arthritis were considered. The assessed outcomes were total effective rate, uric acid level, pain score, and inflammatory factor levels such as erythrocyte sedimentation rate and C-reactive protein. Quality assessment and meta-analysis of the included randomized controlled trials were also performed.

RESULTS

Twenty-seven randomized controlled trials with a total of 1951 participants were included in the meta-analysis. All assessed outcomes including pain, inflammation, and uric acid levels, indicated that the treatment effects in the external use herbal medicine group were significantly better than those of the western medicine control group. Of the 10 studies mentioning side effects, no side effects were reported in 4, and in the remaining 6, the incidence of complications in the intervention group was much lower than that in the control group.

CONCLUSIONS

This systematic review and meta-analysis suggests that external use herbal medicines may be a safe and effective alternative for treatment of pain and symptoms of acute gouty arthritis. However, owing to the heterogeneity of interventions, outcomes, and regional bias, further high-quality clinical trials on this topic are needed to confirm the level of evidence.

Targeted treatment of gouty arthritis by biomineralized metallic nanozyme-mediated oxidative stress-mitigating nanotherapy

Gouty arthritis is characterized by chronic deposition of monosodium urate (MSU) crystals in the joints and other tissues, resulting in the production of excess reactive oxygen species (ROS) and proinflammatory cytokines that intensify synovial inflammation. This condition is mainly associated with inflammatory M1 macrophage activation and oxidative stress production. Hence, gout symptoms can often be resolved by eliminating M1 macrophage activation and scavenging oxidative stress in the inflamed areas. Herein, we developed M1-macrophage-targeting biomineralized metallic nanozymes (FALNZs) that deplete oxidative stress and reduce the M1 macrophage levels to mitigate gouty arthritis. Intra-articular injection of the FALNZs targets inflammatory macrophages and suppresses ROS levels in joints with MSU-crystal-induced arthritis. In addition, the FALNZs alleviate joint swelling, inflammatory cytokine production, and pathological features of the joints. Overall, the proposed therapeutic approach is biocompatible and is an effective ROS scavenger for the treatment of gouty pathogenesis.

Tophaceous spinal gout in a young man with complete spinal cord injury

Gout is a common inflammatory arthritis, caused by monosodium urate crystal deposition in the joints. Gout typically affects peripheral joints but less commonly it affects the spine. We report a case of a man in his 30s with chronic gout who presented acutely with thoracic back pain and flaccid paralysis of his lower limbs. CT showed abnormal facet joints at T8/9 with lucency suggestive of septic arthritis and MRI showed signal changes suggestive of epidural collection. The patient underwent emergency spinal surgery to evacuate the collection, followed by broad-spectrum antibiotic treatment. Cultures were negative; however, histopathology was suggestive of gout tophi. The patient was subsequently treated for spinal gout with prednisolone, allopurinol and colchicine and saw significant improvement in symptoms though he sustained a complete spinal cord injury. This case demonstrates that spinal gout is an important differential to consider in patients with chronic gout, presenting with acute back pain.

Resveratrol alleviates MSU-induced gouty arthritis in rats through inhibition of HIF-1α- and NLRP3-derived IL-1β secretion in macrophages

Gouty arthritis is an acute and chronic joint inflammatory joint disease characterized by the deposition of monosodium urate (MSU) crystals in joints and periarticular tissues. Resveratrol (3, 5, 4-trihydroxy-trans-stilbene, RV), a natural polyphenolic compound, has anti-inflammatory and antioxidant properties. The purpose of this study was to investigate the effect of resveratrol on rats with gouty arthritis and its molecular mechanism. THP-1-derived macrophages were induced by lipopolysaccharide (LPS) and MSU to create an in vitro gout cell inflammation model, and rats were injected with MSU crystals into the right ankle joint for an in vivo acute gouty arthritis model. We investigated the anti-inflammatory properties of resveratrol using these in vitro and in vitro models. Our findings suggested that resveratrol effectively reduced ankle swelling and synovial inflammation in a dose-dependent manner in rats with acute gouty arthritis, with almost the same effect as colchicine treatment. In MSU-treated THP-1-derived macrophages, resveratrol inhibited NLRP3 inflammasome activation and IL-1β secretion. Furthermore, resveratrol and the HIF-1α inhibitor PX478 both inhibited the expression of the NLRP3 inflammasome, IL-1β, and HIF-1α. This study demonstrated that resveratrol significantly improved the symptoms of acute gouty arthritis and its potential mechanism may be IL-1β reduction via HIF-1α modulation and inhibition of NLRP3 inflammasome activation. Our study might offer a novel sight for the treatment of gouty arthritis.

Exploring the inhibition mechanism of interleukin-1-beta in gouty arthritis by polygonum cuspidatum using network pharmacology and molecular docking: A review

Polygonum cuspidatum (Huzhang, HZ) is one of the commonly used traditional Chinese medicines for treating gouty arthritis (GA), but the specific mechanism is not clear. This study employed network pharmacology and molecular docking techniques to examine the molecular mechanisms underlying the therapeutic effects of HZ on GA. The network pharmacology approach, including active ingredient and target screening, drug-compound-target-disease network construction, protein-protein interaction (PPI) networks, enrichment analysis, and molecular docking, was used to explore the mechanism of HZ against GA. Ten active ingredients of HZ were predicted to interact with 191 targets, 14 of which interact with GA targets. Network pharmacology showed that quercetin, physovenine, luteolin, and beta-sitosterol are the core components of HZ, and IL (interleukin)-1β, IL-6, and tumor necrosis factor (TNF) are the core therapeutic targets. The mechanism of HZ in GA treatment was shown to be related to the IL-17 signaling pathway, NOD-like receptor signaling pathway, and Toll-like receptor signaling pathway, and is involved in the inflammatory response, positive regulation of gene expression, cellular response to lipopolysaccharide, and other biological processes. Molecular docking showed that all four core compounds had good binding properties to IL-1β, with luteolin and beta-sitosterol showing better docking results than anakinra, suggesting that they could be used as natural IL-1β inhibitors in further experimental studies. The mechanism of action of HZ against GA has multi-target and multi-pathway characteristics, which provides an important theoretical basis for the study of the active ingredients of HZ as natural IL-1β inhibitors.

MSC therapy ameliorates experimental gouty arthritis hinting an early COX-2 induction

Objective

The specific effect of Adipose-Derived Mesenchymal Stem Cells (Ad-MSC) on acute joint inflammation, where the response mostly depends on innate immunity activation, remains elusive. The pathogenesis of gouty arthritis, characterized by the deposition of monosodium urate (MSU) crystals in the joints, associated to acute flares, has been associated to NLRP3 inflammasome activation and subsequent amplification of the inflammatory response. Our aim was to study the effect of human Ad-MSC administration in the clinical inflammatory response of rabbits after MSU injection, and the molecular mechanisms involved.

Methods

Ad-MSC were administered by intraarterial route shortly after intraarticular MSU crystal injections. Joint and systemic inflammation was sequentially studied, and the mechanisms involved in NLRP3 inflammasome activation, and the synthesis of inflammatory mediators were assessed in the synovial membranes 72h after insult. Ad-MSC and THP-1-derived macrophages stimulated with MSU were co-cultured in transwell system.

Results

A single systemic dose of Ad-MSC accelerated the resolution of local and systemic inflammatory response. In the synovial membrane, Ad-MSC promoted alternatively M2 macrophage presence, inhibiting NLRP3 inflammasome and inducing the production of anti-inflammatory cytokines, such as IL-10 or TGF-β, and decreasing nuclear factor-κB activity. Ad-MSC induced a net anti-inflammatory balance in MSU-stimulated THP-1 cells, with a higher increase in IL-10 and IDO expression than that observed for IL-1β and TNF.

Conclusion

Our in vivo and in vitro results showed that a single systemic dose of Ad-MSC decrease the intensity and duration of the inflammatory response by an early local COX-2 upregulation and PGE2 release. Ad-MSCs suppressed NF-kB activity, NLRP3 inflammasome, and promoted the presence of M2 alternative macrophages in the synovium. Therefore, this therapeutic approach could be considered as a pharmacological alternative in patients with comorbidities that preclude conventional treatment.

Component identification of modified sanmiao pills by UPLC-Xevo G2-XS QTOF and its anti-gouty arthritis mechanism based on network pharmacology and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Modified sanmiao pills (MSMP), a traditional Chinese medicine (TCM) formula, is consisted of rhizome of Smilax glabra Roxb., Cortexes of Phellodendron chinensis Schneid., rhizome of Atractylodes chinensis (DC.) Koidz., and roots of Cyathula officinalis Kuan. in a ratio of 3:3:2:1. This formula has been broadly applied to treat gouty arthritis (GA) in China.

AIMS OF THE STUDY

To elaborate the pharmacodynamic material basis and pharmacological mechanism of MSMP against GA.

MATERIALS AND METHODS

UPLC-Xevo G2-XS QTOF combined with UNIFI platform was applied to qualitatively assess the chemical compounds of MSMP. Network pharmacology and molecular docking were used to identify the active compounds, core targets and key pathways of MSMP against GA. The GA mice model was established by MSU suspension injecting into ankle joint. The swelling index of ankle joint, expressions of inflammatory cytokines, and histopathological changes in mice ankle joints were determined to validate the therapeutic effect of MSMP against GA. The protein expressions of TLRs/MyD88/NF-κB signaling pathway and NLRP3 inflammasome in vivo was detected by Western blotting.

RESULTS

In total, 34 chemical compounds and 302 potential targets of MSMP were ascertained, of which 28 were overlapping targets pertaining to GA. 143 KEGG enrichment pathway were obtained, of which the NOD-like receptor signaling pathway, Toll-like receptor signaling pathway, and NF-κB signaling pathway were strongly associated with GA. In silico study indicated that the active compounds had excellent binding affinity to core targets. In vivo study confirmed that MSMP observably decreased swelling index and alleviated pathological damage to ankle joints in acute GA mice. Besides, MSMP significantly inhibited the secretion of inflammatory cytokines (IL-1β, IL-6, and TNF-α) induced by MSU, as well as the expression levels of key proteins involved in TLRs/MyD88/NF-κB signaling pathway and NLRP3 inflammasome.

CONCLUSION

MSMP possessed a pronounced therapeutic effect on acute GA. Results from network pharmacology and molecular docking showed that obaculactone, oxyberberine, and neoisoastilbin might treat gouty arthritis by down-regulating TLRs/MyD88/NF-κB signaling pathway and NLRP3 inflammasome.

Role of NLRP3 in the pathogenesis and treatment of gout arthritis

Gout arthritis (GA) is a common and curable type of inflammatory arthritis that has been attributed to a combination of genetic, environmental and metabolic factors. Chronic deposition of monosodium urate (MSU) crystals in articular and periarticular spaces as well as subsequent activation of innate immune system in the condition of persistent hyperuricemia are the core mechanisms of GA. As is well known, drugs for GA therapy primarily consists of rapidly acting anti-inflammatory agents and life-long uric acid lowering agents, and their therapeutic outcomes are far from satisfactory. Although MSU crystals in articular cartilage detected by arthrosonography or in synovial fluid found by polarization microscopy are conclusive proofs for GA, the exact molecular mechanism of NLRP3 inflammasome activation in the course of GA still remains mysterious, severely restricting the early diagnosis and therapy of GA. On the one hand, the activation of Nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome requires nuclear factor kappa B (NF-κB)-dependent transcriptional enhancement of NLRP3, precursor (pro)-caspase-1 and pro-IL-1β, as well as the assembly of NLRP3 inflammasome complex and sustained release of inflammatory mediators and cytokines such as IL-1β, IL-18 and caspase-1. On the other hand, NLRP3 inflammasome activated by MSU crystals is particularly relevant to the initiation and progression of GA, and thus may represent a prospective diagnostic biomarker and therapeutic target. As a result, pharmacological inhibition of the assembly and activation of NLRP3 inflammasome may also be a promising avenue for GA therapy. Herein, we first introduced the functional role of NLRP3 inflammasome activation and relevant biological mechanisms in GA based on currently available evidence. Then, we systematically reviewed therapeutic strategies for targeting NLRP3 by potentially effective agents such as natural products, novel compounds and noncoding RNAs (ncRNAs) in the treatment of MSU-induced GA mouse models. In conclusion, our present review may have significant implications for the pathogenesis, diagnosis and therapy of GA.

Qingre Huazhuo Jiangsuan Decoction promotes autophagy by inhibiting PI3K/AKT/mTOR signaling pathway to relieve acute gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Gout belongs to the category of "arthralgia syndrome" in traditional Chinese medicine. It is believed that gout is caused by stagnation of blood stasis, heat, and turbid toxin. Qingre Huazhuo Jiangsuan Decoction (QHJD) is a traditional Chinese medicine prescription developed from the classic Chinese medicine prescription Simiao powder to clear heat, remove turbidity, reduce acid, and reduce inflammation. Now Traditional Chinese Medicine (TCM) physicians often apply it to treat acute gouty arthritis (AGA). However, the mechanism of QHJD in relieving acute gouty arthritis is still unclear, and further research is needed.

AIM OF THE STUDY

Here, we aim to explore the potential mechanism of QHJD in relieving acute gouty arthritis.

MATERIALS AND METHODS

Acute gouty arthritis model was established by injecting monosodium urate (MSU) suspension into knee joint. The pathological state of synovial tissue in each group was evaluated by hematoxylin-eosin (HE) staining. The level of TNF-α, IL-6, and IL-1β were detected by enzyme-linked immunosorbent assay (ELISA). qRT-PCR was used to detect the mRNA expression of NLRP3, ATG5, ATG7, PI3K, AKT, and mTOR. The protein expression of LC3II/I, p62, ULK1, P-ULK1, Beclin-1, PI3K, AKT, mTOR, P-PI3K, P-AKT, and P-mTOR were detected by Western blot.

RESULTS

(1) The level of autophagy protein (mRNA) was significantly up-regulated in QHJD group and rapamycin, while the expression of autophagy protein (mRNA) was significantly downregulated in the 3-methyladenoenoic acid (3 MA) group; (2) QHJD and rapamycin significantly inhibited PI3K/AKT/mTOR pathway, while 3 MA group activated this pathway. (3) It was worth noting that after treatment with QHJD and rapamycin, the inflammatory pathological state of AGA synovial tissue was significantly reduced with the activation of the autophagy gene in knee synovial tissue, and the inhibition of PI3K/AKT/mTOR pathway.

CONCLUSIONS

This research revealed that QHJD activates autophagy by inhibiting PI3K/AKT/mTOR pathway, thereby relieving acute gouty arthritis.

Nanoreporter for Real-Time Monitoring of Inflammasome Activity and Targeted Therapy

Inflammasome activation is associated with a myriad of inflammatory diseases. However, existing methods provides a limited understanding of spatiotemporal kinetics of inflammasome activation, with restricted scope for early detection of associated treatment efficacy. This limitation offers an opportunity for the development of biocompatible in-vivo inflammasome monitoring tools with translational prospects. To achieve this, they report developing a pair of lipid-based nanoparticle systems, a reporter nanoparticle consisting of a caspase-1 activatable probe alone, and a theranostic nanoparticle combining the probe with an inflammasome-inhibiting drug. This biocompatible platform enhances the probe's residence time in circulation by preventing its opsonization and allowing its sustained release over time. Their results demonstrate the specificity of reporter nanoparticles towards caspase-1 activity and provides early-on monitoring of inflammasome activation both in-vitro as well as in-vivo. Additionally, the delivery of disulfiram, an inflammasome-inhibiting drug, along with reporter probe using theranostic nanoparticles enables real-time tracking of treatment efficacy in the gouty-arthritis inflammatory model. In summary, they report an unparalleled pair of the inflammasome-associated reporter and theranostic platforms suited not only for diagnostic applications but can also detect inflammasome-targeted treatment efficiency in real-time. These findings establish two novel, sensitive nanotools for non-invasive evaluation of inflammasome-targeted immunotherapy.

Biomineralized Nanoscavenger Abrogates Proinflammatory Macrophage Polarization and Induces Neutrophil Clearance through Reverse Migration during Gouty Arthritis

The deposition of monosodium urate (MSU) crystals induces the overexpression of reactive oxygen species (ROS) and proinflammatory cytokines in residential macrophages, further promoting the infiltration of inflammatory leukocytes in the joints of gouty arthritis. Herein, a peroxidase-mimicking nanoscavenger was developed by forming manganese dioxide over albumin nanoparticles loaded with an anti-inflammatory drug, indomethacin (BIM), to block the secretion of ROS and COX2-induced proinflammatory cytokines in the MSU-induced gouty arthritis model. In the MSU-induced arthritis mouse model, the BIM nanoparticles alleviated joint swelling, which is attributed to the abrogation of ROS and inflammatory cytokine secretions from proinflammatory macrophages that induces neutrophil infiltration and fluid building up in the inflammation site. Further, the BIM nanoparticle treatment reduced the influx of macrophages and neutrophils in the injured region by blocking migration and inducing reverse migration in the zebrafish larva tail amputation model as well as in MSU-induced peritonitis and air pouch mouse models. Overall, the current strategy of employing biomineralized nanoscavengers for arthritis demonstrates clinical significance in dual blocking of peroxides and COX2 to prevent influx of inflammatory cells into the sites of inflammation.

Changes of serum uric acid level during acute gout flare and related factors

OBJECTIVE

By studying the changes of serum uric acid (SUA) in acute stage and remission stage of gouty arthritis, we aimed to explore the relationship between the changes of SUA level and free glucocorticoids and inflammatory factors.

METHODS

A prospective, longitudinal study was conducted on 50 acute gout patients in the dedicated gout clinic of the Affiliated Hospital of Qingdao University. Blood and 24-hour urine samples were collected during the acute phase and two weeks after the initial visit. Patients with acute gouty arthritis were treated primarily with colchicine and nonsteroidal anti-inflammatory drugs.

RESULTS

A total of 32 patients completed the two-week follow-up trial. SUA levels were significantly downregulated during the acute flare than after the flare (464.14 ± 90.97 vs. 527.36 ± 86.90 μmol/L, p < 0.001). The 24-hour fractional excretion of uric acid (24 h FEur) (5.54 ± 2.82% vs. 4.68 ± 2.83%, p < 0.001) and 24-hour urinary uric acid excretion (24 h Uur) (663.08 ± 249.48 μmol/L vs. 540.87 ± 263.18 μmol/L, p = 0.001) increased significantly in patients during the acute phase. The percent change in SUA was associated with those in 24 h FEur and C-reactive protein. Meanwhile, the percent change in 24 h Uur was associated with those in 24-hour urinary free cortisol, percent change in interleukin 1β and interleukin 6.

CONCLUSION

Decreased SUA level during the acute gout flare was associated with increased excretion of urinary uric acid. Inflammatory factors and bioactive free glucocorticoids may play significant roles in this process.

Angiotensin type 2 receptor antagonism as a new target to manage gout

BACKGROUND

There is a growing search for therapeutic targets in the treatment of gout. The present study aimed to evaluate the analgesic and anti-inflammatory potential of angiotensin type 2 receptor (AT₂R) antagonism in an acute gout attack mouse model.

METHODS

Male wild-type (WT) C57BL/6 mice either with the AT₂R antagonist, PD123319 (10 pmol/joint), or with vehicle injections, or AT₂R KO mice, received intra-articular (IA) injection of monosodium urate (MSU) crystals (100 µg/joint), that induce the acute gout attack, and were tested for mechanical allodynia, thermal hyperalgesia, spontaneous nociception and ankle edema development at several times after the injections. To test an involvement of AT₂R in joint pain, mice received an IA administration of angiotensin II (0.05-5 nmol/joint) with or without PD123319, and were also evaluated for pain and edema development. Ankle joint tissue samples from mice undergoing the above treatments were assessed for myeloperoxidase activity, IL-1β release, mRNA expression analyses and nitrite/nitrate levels, 4 h after injections.

RESULTS

AT₂R antagonism has robust antinociceptive effects on mechanical allodynia (44% reduction) and spontaneous nociception (56%), as well as anti-inflammatory effects preventing edema formation (45%), reducing myeloperoxidase activity (54%) and IL-1β levels (32%). Additionally, Agtr2^tm1a mutant mice have largely reduced painful signs of gout. Angiotensin II administration causes pain and inflammation, which was prevented by AT₂R antagonism, as observed in mechanical allodynia 4 h (100%), spontaneous nociception (46%), cold nociceptive response (54%), edema formation (83%), myeloperoxidase activity (48%), and IL-1β levels (89%). PD123319 treatment also reduces NO concentrations (74%) and AT₂R mRNA levels in comparison with MSU untreated mice.

CONCLUSION

Our findings show that AT₂R activation contributes to acute pain in experimental mouse models of gout. Therefore, the antagonism of AT₂R may be a potential therapeutic option to manage gout arthritis.

Anethole ameliorates inflammation induced by monosodium urate in an acute gouty arthritis model via inhibiting TLRs/MyD88 pathway

OBJECTIVE

To assess the effects of anethole on monosodium urate (MSU)-induced inflammatory response, investigate its role in acute gouty arthritis (AGA), and verify its molecular mechanism.

METHODS

Hematoxylin and eosin staining assay and time-dependent detection of degree of ankle swelling were performed to assess the effects of anethole on joint injury in MSU-induced AGA mice. Enzyme-linked-immunosorbent serologic assay was performed to demonstrate the production levels of inflammatory factors (interleukin 1β [IL-1β], interleukin 6 [IL-6], interleukin 8 [IL-8], tumor necrosis factor α [TNF-α], and monocyte chemo-attractant protein-1 [MCP-1]) in MSU-induced AGA mice. Western blot assays were used to confirm the effects of anethole on oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activity and the activation of toll-like receptors (TLRs)-myeloid differentiation factor 88 (MyD88) pathway in MSU-induced AGA mice.

RESULTS

We observed that a significant joint injury occurred in MSU-induced AGA mice. Anethole could alleviate the pathological injury of the synovium in MSU-induced AGA mice and suppressed ankle swelling. In addition, we observed that anethole could inhibit MSU-induced inflammatory response and inflammasome activation in MSU-induced AGA mice. Moreover, we discovered that anethole enabled to inhibit the activation of TLRs/MyD88 pathway in MSU-induced AGA mice. Our findings further confirmed that anethole contributed to the inhibitory effects on progression in MSU-induced AGA mice.

CONCLUSION

It confirmed that anethole ameliorated the MSU-induced inflammatory response in AGA mice in vivo via inhibiting TLRs-MyD88 pathway.

Medicinal Plants and Nonsteroidal Anti-inflammatory Drugs (NSAIDs) in Treatment of Arthritis: A Literature Review

CONTEXT

Arthritis is an inflammatory disease of diarthrodial joints and is associated with swollen inflamed joints, disruption of joints, and loss of integrity of articular cartilage and synovial joints.

OBJECTIVE

The current review intended to examine the data on the epidemiology, causes, clinical diagnosis, and prevention and control of different types of arthritis and on the use of medicinal plants in gouty arthritis.

DESIGN

The research team performed a literature review, searching relevant literature databases, including bioRxiv, medRxiv, Google Scholar, Embase, PsychINFO, and PubMed. The search terms were arthritis, diarthodial joints, use of medicinal plants in gouty arthritis, and synovial joints.

SETTING

The study took place in the main library of the University of Sargodha in Sargodha, Pakistan.

RESULTS

The research team identified 135 studies, and eventually 92 unique academic publications were included in the analysis. Arthritis can develop and progress in any musculoskeletal joint, and most commonly occurs in knees, hips, shoulders, and hands. Major risk factors for arthritis include age, obesity, trauma, other diseases, and smoking. Arthritis is classified into various types, including rheumatoid arthritis (RA), osteoarthritis (OA), gouty arthritis, septic arthritis, and psoriatic arthritis (PsA). RA and OA are the most common types worldwide. RA is an autoimmune disease in which the body's immune cells attack the joints. OA develops due to damage of cartilage, tissues, and joints due to age, obesity, or stress on joints. Gouty arthritis develops due to hyperuricemia; deposits of monosodium urate crystals can lead to gouty arthritis. Septic arthritis occurs due to a microbial infection in synovial joints because in synovial joints the basement membrane is absent. PsA develops due to the psoriasis-skin disease.

CONCLUSIONS

The current review showed that different types of arthritis has different causes and pathogeneses. Pain in joints is a major and common symptom in all types of arthritis. Arthritis is managed pharmacologically and nonpharmacologically. Treatment is different for each class of arthritis according to its cause and symptoms.

[Mechanism of total flavonoids from Ampelopsis grossedentata against gouty arthritis based on multi-level interactive network and in vivo experimental validation]

The present study investigated the mechanism of total flavonoids from Ampelopsis grossedentata(AGTF) against gouty arthritis(GA) by network pharmacology and experimental validation. The main active ingredients and targets of AGTF, as well as disease targets, were screened out using relevant databases and literature data. The &quot;protein-protein interaction&quot;(PPI) network and &quot;drug-ingredient-target-pathway&quot; network were constructed, and the potential targets and mechanism of AGTF against GA were predicted. The hyperuricemia(HUA) combined with GA model was induced in rats. The gait behaviors of rats were scored, and ankle swelling degree was observed. The uric acid(UA) level and xanthine oxidase(XOD) activity in the rat serum were detected, and the levels of interleukin-1β(IL-1β), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α) were measured. The protein expression of toll-like receptor 4(TLR4), myeloid differentiation factor 88(MyD88), and nuclear factor-kappa B(NF-κB) in the synovial tissues of the rat ankle joint was determined by immunohistochemistry. Ten active ingredients of AGTF and 73 candidate targets of AGTF against GA were screened out by network pharmacology. Eighty-six signaling pathways were enriched, including TNF signaling pathway, NF-κB signaling pathway, TLR signaling pathway, Nod-like receptor signaling pathway, and purine metabolism signaling pathway, which were closely related to AGTF against GA. Animal experimental results showed that AGTF could effectively improve the abnormal gait behaviors of GA rats, relieve ankle inflammation, and reduce ankle joint swelling. In addition, AGTF could significantly reduce UA level, inhibit XOD activity, decrease TNF-α, IL-6, and IL-1β content, and down-regulate the expression of TLR4, MyD88, and NF-κB in ankle synovial tissues(P&lt;0.05, P&lt;0.01). The results of network pharmacology and experimental validation are consistent, indicating that AGTF exerts its therapeutic effect on GA by regulating UA metabolism, improving abnormal UA level, reducing the release of inflammatory factors, and regulating immunity and the TLR4/MyD88/NF-κB inflammatory pathway.

Study on the effect and mechanism of quercetin in treating gout arthritis

Quercetin is widely found in natural plants, especially Chinese herbal plants. It has been used to treat arthritis in China for thousands of years. However, the effects and mechanisms of quercetin in the treatment of gout arthritis (GA) remain unclear. We aimed to verify the treatment of GA with quercetin and investigate the underlying mechanism. A combination of network pharmacology and experiments was used to reveal the mechanism of quercetin in the treatment of GA. Potential targets of quercetin and gout were identified. Then, the protein-protein interaction network for the common targets between quercetin and gout was constructed and the core targets were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses for the common targets were performed to elucidate the pharmacological functions and mechanisms associated with quercetin treatment in GA. Finally, a monosodium urate-induced GA rat model was used to validate the predicted mechanisms in network pharmacology. Seventy-two common targets were identified. KEGG analysis revealed that treatment of GA with quercetin predominantly involved the interleukin (IL)-17, tumor necrosis factor (TNF), mitogen-activated protein kinase, and phosphoinositide 3-kinase-Akt signaling pathways. In an experimental validation, quercetin attenuated ankle joint inflammation-induced bone destruction and histological lesions. It also diminished the expression of IL-6, IL-17A, and IL-17F in the IL-17 pathway, and regulated the release of RAR-related orphan receptor gamma t,IL-17E, IL-1β, IL-6, TNF-α, Foxp3, and transforming growth factor-beta 1. The collective findings implicate quercetin as a valuable alternative drug for the treatment of GA.

Stephalagine, an aporphinic alkaloid with therapeutic effects in acute gout arthritis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Gout is an inflammatory disease characterized by the accumulation of monosodium urate crystals (MSU) in the joints, leading to severe pain and inflammation. Stephalagine is a Brazilian Savanna aporphine alkaloid isolated from Annona crassiflora Mart. Fruit peel, that has been popularly used to treat rheumatism and have been described with antinociceptive properties. However, no studies evaluated the possible therapeutic properties of stephalagine in arthritic pain.

AIM OF THE STUDY

To evaluate the possible antinociceptive and anti-inflammatory effects of stephalagine in an acute gout attack in mice.

MATERIALS AND METHODS

Adult male wild type C57BL/6/J/UFU mice (20-25 g) were used (process number 018/17). The treated group received stephalagine (1 mg/kg, by gavage) and the vehicle group received saline (10 mL/kg, by gavage), both 1 h before the MSU crystals (100 μg/ankle joint) administration. All groups were analyzed for mechanical allodynia, thermal hyperalgesia, overt pain-like behaviors, and edema development at 2, 4, 6 and 24 h after injections. Synovial fluid and the ankle articulation from the injected joint were collected 4 h after administrations for myeloperoxidase enzyme activity, IL-1β measurement, and histological analysis.

RESULTS

Stephalagine had a significant antinociceptive effect on mechanical allodynia, when compared to vehicle group at 2-24 h after intra-articular injection of MSU and 2 h for spontaneous and cold thermal sensitivity. Stephalagine was also able to significantly reduce the articular edema (45 ± 1%), the activity of the myeloperoxidase enzyme (37 ± 6%), and IL-1β levels (43 ± 3%). The histological analysis confirms that stephalagine dramatically reduced the number of infiltrating inflammatory cells (75 ± 6%) in MSU injected animals. Also, stephalagine treatment did not alter the uric acid levels, xanthine oxidase activity, AST and ALT activities, urea and creatinine levels, neither cause any macroscopic changes in the mice's weight, deformations, changes in the coat, or feces.

CONCLUSION

Stephalagine may be an alternative for the management of gout, once it was able to induce antinociceptive and anti-inflammatory effects without causing adverse effects on the evaluated parameters.