New and improved strategies for the treatment of gout

Electroacupuncture improves low-grade duodenal inflammation in FD rats by reshaping intestinal flora through the NF-κB p65/NLRP3 pyroptosis pathway

Electroacupuncture (EA) is an effective alternative for the treatment of functional dyspepsia (FD). It reduces low-grade duodenal inflammation and improves the symptoms of FD by downregulating the expression of NF-κB p65 and NLRP3, but its mechanism needs to be elucidated. To examine the regulatory effect of electroacupuncture (EA) on intestinal flora and NF-κB p65/NLRP3 pyroptosis pathway in FD rats. The FD rat model was established via multi-factor stress intervention for two weeks. The rats were randomly divided into the NC group, model group, NF-kB inhibitor group (NF-κB inhibitor BAY 11-7082 was administered), EA group, and EA + NF-kB inhibitor group. After 14 days of treatment, the rats were sacrificed, and the protein and mRNA levels of NF-κB p65, IκB, and NLRP3 in the duodenum were evaluated by Western blotting assays and real-time fluorescent quantitative PCR. The Illumina MiSeq sequencing platform was used to analyze the V4 region of the 16S rRNA gene of intestinal flora and predict functional genes. The concentration of short-chain fatty acids (SCFAs) in feces was assessed by metabolomics. EA can decrease low-grade duodenal inflammation and promote gastrointestinal motility in FD rats. This effect is mediated by inhibition of the NF-κB p65/NLRP3 pyroptosis pathway, an increase in the alpha and beta diversity of gut microbiota in the duodenum, an increase in the abundance of beneficial bacteria at the phylum and genus levels, and an increase in the content of SCFAs. The protective effect of EA against FD might involve multiple hierarchy and pathways. EA may remodel intestinal flora by inhibiting the NF-κB p65/NLRP3 pyroptosis pathway, thereby improving low-grade duodenal inflammation in FD rats.

Comparative efficacy and safety of uricosuric agents in the treatment of gout or hyperuricemia: a systematic review and network meta-analysis

OBJECTIVES

The current world witnesses a greatly increased prevalence and incidence of hyperuricemia and gout with unfortunately the comparative efficacy and safety of present available uricosuric agents remaining uncertain. We herein aimed to investigate the most appropriate uricosuric agent for gout or hyperuricemia patients.

METHOD

PubMed, Embase, Cochrane Library databases, and ClinicalTrials.gov from inception to 2 July 2022 were searched to retrieve eligible studies assessing efficacy and safety of uricosuric drugs in hyperuricemia or gout patients. Network meta-analysis was carried out using the Stata 16.0 software.

RESULTS

Twelve randomized controlled trials comprising 1851 patients were eventually included. Network meta-analysis showed that dotinurad 4 mg once daily, verinurad, dotinurad 2 mg once daily, dotinurad 1 mg once daily, and benzbromarone were the top 5 effective treatments to achieve target serum uric acid. Furthermore, dotinurad 4 mg once daily was more effective at achieving urate-lowering targets (RR of dotinurad 4 mg once daily vs. probenecid: 1.68, 95% CI [1.13; 2.50]) and safer (RR of probenecid vs. dotinurad 4 mg once daily: 1.77, 95% CI [0.69; 4.56]) than probenecid.

CONCLUSIONS

This network meta-analysis demonstrated an important absolute benefit of dotinurad 4 mg once daily to achieve target serum uric acid and low risk of adverse events for drug treatment of gout or hyperuricemia patients. Additionally, verinurad might be used as an alternative uricosuric therapeutic option to dotinurad. These findings provided further comprehensive insight into the treatment value of current uricosuric agents for gout or hyperuricemia. Key Points 1. This is the first systematic review and network meta-analysis examining the efficacy and safety of currently available uricosuric agents in gout or hyperuricemia patients. 2. Recommended doses of dotinurad 4mg once daily used for the treatment of gout or hyperuricemia patients can significantly decrease serum uric acid levels. 3. The present findings will provide further comprehensive insight into the treatment value of certain uricosuric agents for gout or hyperuricemia.

Soy consumption and serum uric acid levels: A systematic review and meta-analysis

Background

Soy consumption has health benefits, but the relationship between soy and uric acid remains uncertain. This meta-analysis and systematic review evaluated the effects of soy intake on plasma uric acid.

Methods

PubMed, Embase, CNKI, and the Cochrane Library were searched for studies evaluating the effects of soy, soy products, soy protein, and soy isoflavones on uric acid levels. The primary outcome was serum or plasma uric acid concentration. Study quality was evaluated by the Cochrane Collaboration and SYRCLE risk-of-bias tools.

Results

A total of 17 studies were included. Qualitative analysis of three human clinical studies of acute effects revealed that soy consumption increased serum uric acid concentration; however, soy-derived products, including tofu, bean curd cake, and dried bean curd sticks, had no significant effect on serum uric acid. A meta-analysis of five long-term human studies (10 data sets) revealed that soy protein and soy isoflavones had no significant effects on uric acid levels [weighted mean difference (WMD) = -2.11; 95% confidence interval (CI): -8.78, 4.55; p = 0.53]. However, most epidemiological data revealed that soy intake is inversely associated with uric acid levels. Meta-analysis of nine animal trials (29 data sets) revealed that soy protein and soy isoflavones significantly reduced serum uric acid concentrations (vs. controls; MD = -38.02; 95% CI: -50.60, -25.44; p < 0.001).

Conclusion

Soy and its products have different effects on serum uric acid. Soy products like tofu, bean curd cake, and dried bean curd sticks could be high-quality protein sources for individuals with hyperuricemia or gout. It can be beneficial to nutritionists and healthcare decision-makers reconsider their conceptions about the relationship between soy and uric acid levels according to the latest and further scientific study results.

Systematic review registration

[www.crd.york.ac.uk/PROSPERO], identifier [CRD42022331855].

A fly GWAS for purine metabolites identifies human FAM214 homolog medusa, which acts in a conserved manner to enhance hyperuricemia-driven pathologies by modulating purine metabolism and the inflammatory response

Elevated serum urate (hyperuricemia) promotes crystalline monosodium urate tissue deposits and gout, with associated inflammation and increased mortality. To identify modifiers of uric acid pathologies, we performed a fly Genome-Wide Association Study (GWAS) on purine metabolites using the Drosophila Genetic Reference Panel strains. We tested the candidate genes using the Drosophila melanogaster model of hyperuricemia and uric acid crystallization ("concretion formation") in the kidney-like Malpighian tubule. Medusa (mda) activity increased urate levels and inflammatory response programming. Conversely, whole-body mda knockdown decreased purine synthesis precursor phosphoribosyl pyrophosphate, uric acid, and guanosine levels; limited formation of aggregated uric acid concretions; and was sufficient to rescue lifespan reduction in the fly hyperuricemia and gout model. Levels of mda homolog FAM214A were elevated in inflammatory M1- and reduced in anti-inflammatory M2-differentiated mouse bone marrow macrophages, and influenced intracellular uric acid levels in human HepG2 transformed hepatocytes. In conclusion, mda/FAM214A acts in a conserved manner to regulate purine metabolism, promotes disease driven by hyperuricemia and associated tissue inflammation, and provides a potential novel target for uric acid-driven pathologies.

Effect of Lactobacillus acidophilus fermentation on the composition of chlorogenic acids and anti-hyperuricemia activity of Artemisia selengensis Turcz

FASTE can relieve hyperuricemia by inhibiting the production of uric acid, alleviating oxidative stress damage and inflammation, promoting uric acid excretion and improving the abundance of intestinal flora.

Quercetin: A Potential Candidate For The Treatment Of Arthritis

Diet plays a significant role in ensuring healthy life and the bioactive compounds present in food and medicinal plants may be developed as drugs that combat various illnesses. A bioactive flavanoid, quercetin which is a dietary component possesses numerous health-promoting effects. In preclinical models of rheumatoid arthritis, gouty arthritis and osteoarthritis, quercetin has shown significant joint protective effects. Taking into account the significance of this compound, the present review discusses its anti-arthritic properties, demonstrating its mechanism of action for the treatment of arthritis with its therapeutic potential.

Medicinal Plants as a Drug Alternative Source for the Antigout Therapy in Morocco

BACKGROUND

The gout is a metabolic disease that is associated with a high level of uric acid in the blood. This disease is treated with some medications that aim to reduce serum urate levels. However, the use of various medicines leads to the appearance of some side effects, hence the importance of using other treatments based on natural resources.

OBJECTIVE

This study presents some medical treatments, their side effects, and some plants that are used for gout management in Morocco in the aim to valorize them.

METHODS

We have been consulting various English publications in PubMed, Web of Science, and ScienceDirect published between 1991 and 2019 using the following keywords "drugs," "gout," "Morocco," "medicinal plants," "in vitro," and "in vivo" terms. Then, we have classified the medicines, according to their action mechanisms, and we have cited some species that were reported in Moroccan pharmacopeia as antigout.

RESULTS

Three methods of the gout medical management were cited in this work: xanthine oxidase inhibitors, uric acid excretion enhancer, and uricase recombinant. However, it was found that these treatments had various side effects. We have described 23 species, and some of them showed experimentally an antigout effect by blocking the "xanthine oxidase" enzyme. These plants belong to 11 families. Lamiaceae represents the most dominant family with six species followed by Asteraceae with two species. Colchicine isolated from Colchicum autumnale is the most known compound for its efficiency towards gout.

CONCLUSION

This work summarized different treatments particularly medicinal plants that are used in Morocco to treat gout disease by blocking uric acid secretion. However, several studies are needed to valorize these antigout natural sources.

Antioxidant Activity, Enzyme Inhibition Potentials, and Phytochemical Profiling of Premna serratifolia L. Leaf Extracts

Premna serratifolia, commonly known as Arogo in Tentena-Sulawesi, is a popular vegetable. As a promising herbal tea and food ingredient, further investigation is required to find the best knowledge for medicinal use of P. serratifolia leaves. This research investigated the antioxidant activity of the ethanol (EEPS) and water (WEPS) extracts of P. serratifolia leaves, based on their scavenging activities on DPPH radicals and their reducing capacities (CuPRAC, total antioxidant/phosphomolybdenum, and ferric thiocyanate reducing power assays). The DNA-protecting effect by EEPS was tested using pBR322 plasmid DNA against •OH radical-induced damage. The inhibition potentials of both extracts against several enzymes related to metabolic diseases (α-glucosidase, α-amylase, xanthine oxidase, and protease) were evaluated. The phytochemical analysis was conducted by an LC-QTOF-MS/MS technique. EEPS proved to be a better antioxidant and had higher phenolic content compared to WEPS. EEPS demonstrated a protective effect on DNA with recovery percentage linearly correlated with EEPS concentrations. Strong inhibition on α-glucosidase and α-amylase was observed for EEPS; however, EEPS and WEPS showed weak inhibitions on xanthine oxidase and protease. LC-QTOF-MS/MS analysis identified seven main components in EEPS, namely scroside E, forsythoside A and forsythoside B, lavandulifolioside, diosmin, nobilin D, campneoside I, and isoacteoside. These components may be responsible for the observed enzymes inhibitions and antioxidant properties. Premna serratifolia leaves can be an appropriate choice for the development of nutraceutical and drug preparations.

Is there a role for cherries in the management of gout?

Despite the availability of effective urate-lowering therapy (ULT) and anti-inflammatory drugs for the treatment of gout, there is considerable interest in novel treatment approaches. Patients with gout often have a multitude of comorbidities, leading to concern over drug–drug interactions and medication adverse events. The cherry is a small nutrient-rich fruit that has garnered a great deal of attention in recent years as a nonpharmacologic option for the treatment of a multitude of disease manifestations. Perhaps a quarter of patients with gout try cherries or cherry products to treat their gout, which have antioxidant and anti-inflammatory (IL-6, TNF-α, IL-1β, IL-8, COX-I and -II) properties, hypouricemic effects, and the ability to downregulate NFkB-mediated osteoclastogenesis. Based on these properties, cherries may reduce both the acute and chronic inflammation associated with recurrent gout flares and its chronic destructive arthropathy. In this review, we explore the potential benefits of cherries and cherry products as a nonpharmacologic option for the treatment of gout.

The Antioxidant and Xanthine Oxidase Inhibitory Activity of Plumeria rubra Flowers

Plumeria rubra Linn of the family Apocynaceae is locally known in Malaysia as “Kemboja”. It has been used by local traditional medicine practitioners for the treatment of arthritis-related disease. The LCMS/MS analysis of the methanol extract of flowers (PR-ME) showed that it contains 3-O-caffeyolquinic acid, 5-caffeoquinic acid, 1,3-dicaffeoquinic acid, chlorogenic acid, citric acid, 3,3-di-O-methylellagic acid, kaempferol-3-O-glucoside, kaempferol-3-rutinoside, kaempferol, quercetin 3-O-α-l-arabinopyranoside, quercetin, quinic acid and rutin. The flower PR-ME contained high amounts of phenol and flavonoid at 184.632 mg GAE/g and 203.2.2 mg QE/g, respectively. It also exhibited the highest DPPH, FRAP, metal chelating, hydrogen peroxide, nitric oxide superoxide radical scavenging activity. Similarly, the XO inhibitory activity in vitro assay possesses the highest inhibition effects at an IC₅₀ = 23.91 μg/mL. There was no mortality or signs of toxicity in rats at a dose of 4 g/kg body weight. The administration of the flower PR-ME at doses of 400 mg/kg to the rats significantly reduced serum uric acid 43.77%. Similarly, the XO activity in the liver was significantly inhibited by flower PR-ME at doses of 400 mg/kg. These results confirm that the flower PR-ME of P. rubra contains active phytochemical compounds as detected in LCMS/MS that contribute to the inhibition of XO activity in vitro and in vivo in reducing acid uric level in serum and simultaneously scavenging the free radical to reduce the oxidative stress.

Beneficial Properties of Phytochemicals on NLRP3 Inflammasome-Mediated Gout and Complication

Gouty arthritis is characterized by the precipitation of monosodium urate (MSU) crystals in the joint. Pro-inflammatory cytokine IL-1β is a critical manifestation in response to MSU crystals attack. IL-1β secretion is dependent on the nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Abnormal activation of the NLRP inflammasome is related to cellular oxidative stress. However, recent studies have illustrated that phytochemicals with potent antioxidant activity exert inhibitory effects on NLRP3 inflammasome-mediated diseases. This review focuses on the current findings of studies on the NLRP3 inflammasome and the proposed mechanisms that MSU crystals trigger inflammation via activation of the NLRP3 inflammasome. We also summarized the potential use of phytochemicals on NLRP3 inflammasome-mediated diseases, suggesting that phytochemicals can further prevent acute gout attack.

Systematic Structure-Activity Relationship (SAR) Exploration of Diarylmethane Backbone and Discovery of A Highly Potent Novel Uric Acid Transporter 1 (URAT1) Inhibitor

In order to systematically explore and better understand the structure-activity relationship (SAR) of a diarylmethane backbone in the design of potent uric acid transporter 1 (URAT1) inhibitors, 33 compounds (1a-1x and 1ha-1hi) were designed and synthesized, and their in vitro URAT1 inhibitory activities (IC₅₀) were determined. The three-round systematic SAR exploration led to the discovery of a highly potent novel URAT1 inhibitor, 1h, which was 200- and 8-fold more potent than parent lesinurad and benzbromarone, respectively (IC₅₀ = 0.035 μM against human URAT1 for 1h vs. 7.18 μM and 0.28 μM for lesinurad and benzbromarone, respectively). Compound 1h is the most potent URAT1 inhibitor discovered in our laboratories so far and also comparable to the most potent ones currently under development in clinical trials. The present study demonstrates that the diarylmethane backbone represents a very promising molecular scaffold for the design of potent URAT1 inhibitors.

The development of an effective synthetic route of lesinurad (RDEA594)

Background

Lesinurad is a novel selective uric acid salt transport protein 1 (URAT1) inhibitor which is approved in the USA for the treatment of gout. However, there are some shortcomings among the reported synthetic routes, such as expensive materials, environmental pollution and poor yield.

Results

In this study, an efficient, practical and environmentally-friendly synthetic route of lesinurad is reported. The main advantages of this route include inexpensive starting materials, mild conditions and acceptable overall yield (38.8%).

Conclusion

Generally, this procedure is reasonable, reliable and suitable for industrial production.Graphical abstract

Pharmacological Basis for Use of Selaginella moellendorffii in Gouty Arthritis: Antihyperuricemic, Anti-Inflammatory, and Xanthine Oxidase Inhibition

This study was aimed at evaluating the effects of Selaginella moellendorffii Hieron. (SM) on gouty arthritis and getting an insight of the possible mechanisms. HPLC method was developed for chemical analysis. The paw oedema, the neutrophil accumulation, inflammatory mediators, lipid peroxidation, and histopathological changes of the joints were analyzed in gouty arthritis rat model, and the kidney injury and serum urate were detected in hyperuricemic mice. Pharmacokinetic result demonstrated that the main apigenin glycosides might be quantitatively transformed into apigenin in the mammalian body. Among these compounds, the apigenin exhibited the strongest effect on xanthine oxidase (XOD). SM aqueous extract has proved to be active in reducing hyperuricemia in dose-dependent manner, and the levels of blood urea nitrogen (BUN) and creatinine (Cr) in high dose group were decreased significantly as compared with hyperuricemic control group (P < 0.01). The high dose of SM extract could significantly prevent the paw swelling, reduce gouty joint inflammatory features, reduce the release of IL-1β and TNF-α, lower malondialdehyde (MDA) and myeloperoxidase (MPO) levels, and increase superoxide dismutase (SOD) level (P < 0.01). For the first time, this study provides a rational basis for the traditional use of SM aqueous extract against gout in folk medicine.

Allopurinol, benzbromarone, or a combination in treating patients with gout: analysis of a series of outpatients

Objective. To profile a sample of gouty patients treated with allopurinol, benzbromarone, or a combination of these two drugs and to describe the impact of this therapy in reducing uric acid levels. Methods. An observational, transversal study was performed. We evaluated 48 patients diagnosed with gout who were seen at the Outpatient Rheumatology Clinic of the Federal University of Paraná between January 2009 and November 2010. Clinical data, creatinine serum levels, and basal and posttreatment levels of serum urates, transaminases, and bilirubins were recorded. Uric acid levels were measured in a 24-hour urine sample. Patients were divided into three groups: patients given only allopurinol (A), only benzbromarone (B), and both in combined therapy (A + B). Results. The average age of these patients was 56.6 ± 11.4 years, varying from 35 to 81 years. The entire patient group experienced a significant drop in serum urate levels, from 8.5 ± 1.8 mg/dL (0.472 ± 0.1 mmol/L) to 6.7 ± 2.1 mg/dL (0.372 ± 0.116 mmol/L) (P < 0.001), regardless of the prescribed medication. The number of patients taking both drugs whose serum uric acid values fell within normal range (men <7 mg/dL (0.38 mmol/L) and women <6 mg/dL (0.33 mmol/L)) was 85.7% (6/7) while this value for the group taking benzbromarone alone was 75% (3/4) and for the group taking allopurinol alone this number was 51.8% (14/27). Conclusions. The therapeutic combination of benzbromarone and allopurinol significantly decreased serum urate levels in patients with gout when compared to individual use of each of these agents. This finding is especially important in treating patients who cannot control hyperuricemia with monotherapy. Benzbromarone alone or in combination with allopurinol has an important clinical role in controlling hyperuricemia in patients with gout.

3,4-Dihydroxy-5-nitrobenzaldehyde (DHNB) is a potent inhibitor of xanthine oxidase: a potential therapeutic agent for treatment of hyperuricemia and gout

Hyperuricemia, excess of uric acid in the blood, is a clinical problem that causes gout and is also considered a risk factor for cardiovascular disease. The enzyme xanthine oxidase (XO) produces uric acid during the purine metabolism; therefore, discovering novel XO inhibitors is an important strategy to develop an effective therapy for hyperuricemia and gout. We found that 3,4-dihydroxy-5-nitrobenzaldehyde (DHNB), a derivative of the natural substance protocatechuic aldehyde, potently inhibited XO activity with an IC₅₀ value of 3 μM. DHNB inhibited XO activity in a time-dependent manner, which was similar to that of allopurinol, a clinical XO inhibitory drug. DHNB displayed potent mixed-type inhibition of the activity of XO, and showed an additive effect with allopurinol at the low concentration. Structure-activity relationship studies of DHNB indicated that the aldehyde moiety, the catechol moiety, and nitration at C-5 were required for XO inhibition. DHNB interacted with the molybdenum center of XO and was slowly converted to its carboxylic acid at a rate of 10⁻¹⁰ mol/L/s. In addition, DHNB directly scavenged free radical DPPH and ROS, including ONOO⁻ and HOCl. DHNB effectively reduced serum uric acid levels in allantoxanamide-induced hyperuricemic mice. Furthermore, mice orally given a large dose (500 mg/kg) of DHNB did not show any side effects, while 42% of allopurinol (500 mg/kg)-treated mice died and their offspring lost their fur. Thus, DHNB could be an outstanding candidate for a novel XO inhibitory drug that has potent activity and low toxicity, as well as antioxidant activity and a distinct chemical structure from allopurinol.