Ethanol Extract of Cudrania tricuspidata Leaf Ameliorates Hyperuricemia in Mice via Inhibition of Hepatic and Serum Xanthine Oxidase Activity

Therapeutic potential and pharmacological mechanisms of Traditional Chinese Medicine in gout treatment

Gout is a systemic metabolic disorder caused by elevated uric acid (UA) levels, affecting over 1% of the population. The most common complication of gout is gouty arthritis (GA), characterized by swelling, pain or tenderness in peripheral joints or bursae, which can lead to the formation of tophi. At present, western medicines like colchicine, febuxostat and allopurinol are the primary treatment strategy to alleviate pain and prevent flare-ups in patients with GA, but they have significant side effects and increased mortality risks. Traditional Chinese medicine (TCM) has been utilized for thousands of years for the prevention and treatment of GA, demonstrating effective control over serum UA (SUA) levels with fewer side effects. Herein we summarized a total of 541 studies published from 2000 to 2023 in sources including PubMed, Web of Science, the Cochrane Library and Embase, highlighting the therapeutic potential of TCM in treating gout and GA, particularly in combination with modern medical strategies. This review focuses on TCM formulas, Chinese herbal extracts, and active compounds derived from TCM, providing an overview of recent clinical application and the pharmacological research based on animal models and cellular systems. Particularly, the current review categorized the clinical and experimental evidence into the strategies for improving hyperuricemia, decreasing the sudden onset of acute GA and retarding chronic GA progression, supplied further coherent reference and enlightenment for clinicians, investigators of natural product chemistry, researchers in TCM and pharmacology. We hope this article will inspire the development of novel formulas and molecular entities for the treatment of gout and GA.

Study on the Possibility of Developing Functional Source Through Extraction Optimization of Schinus terebinthifolia Bark and Evaluation of Anti-Oxidant, Elastase Inhibitory and Xanthine Oxidase Inhibitory Effect

Introduction: Schinus terebinthifolia (ST) is a plant belonging to the cashew family Anacardiaceae, native to subtropical and tropical South America. ST is commonly called Brazil pepper and aroeira. Several reports have been made on the biological activities of ST, but studies on leaf extracts, especially lectins, have mainly been reported. Objectives: Our study analyzed the active compounds, antioxidant activities, xanthine oxidase inhibitory, elastase inhibitory, and tyrosinase inhibitory activities of S. terebinthifolia (ST) bark extract. Results: Hot water extracts showed the strongest electron donating ability (84.46%) and tyrosinase inhibitory activity (67.1%). Eighty percent ethanol extract showed the highest reducing power, total phenolic, xanthine oxidase (91.7%) and elastase inhibitory ability (85.44%). Catechin, α–amyrin, β–amyrone and 11-Oxo-.α-amyrin were identified through HPLC and GCMS analysis, while eighty percent extract contained the highest amount of catechin. Catechin, α–amyrin, and β–amyrone are considered to be the main xanthine oxidase inhibitors, while β–amyrone is considered to be the main inhibitor of xanthine oxidase and elastase. Conclusion: Through this study, we reported the basic information that S. terebinthifolia bark extract was used in folk medicine as an anti-inflammatory, anti-gout, and skin disease improvement material. S. terebinthifolia bark extract could be used as an anti-gout natural drug or cosmetic material.

Quercetin as the primary xanthine oxidase inhibitor compound in Maclura tricuspidata leaf

Maclura tricuspidata (MT) leaf demonstrated various health benefits, notably the inhibition of xanthine oxidase (XOD) activity, which is crucial in the management of hyperuricaemia and many diseases related to oxidative stress. This study aimed to identify the primary compound responsible for this inhibitory effect. Through a systematic investigation, MT leaf extracts were subjected to solvent-solvent partitioning using ethyl acetate, n-hexane, n-butanol, and dichloromethane. Further purification involved adsorption and desorption using Amberlite XAD-2 resin, followed by column chromatography on Silica Gel and Sephadex LH-20. The purified compounds were analysed using UPLC-QTOF-MS coupled with NMR spectroscopy. Our findings identified quercetin, a phenolic compound, as the most significant inhibitor of XOD activity in MT leaf, with an IC50 value of 212.92 μg/ml. This is the first report of purifying and identifying a single compound responsible for XOD inhibition in MT.

Korean Red Ginseng Ameliorates the Level of Serum Uric Acid via Downregulating URAT1 and Upregulating OAT1 and OAT3

Hyperuricemia is caused by an imbalance of uric acid and is associated with many diseases. Although gout which is one of hyperuricemia-related diseases is curable with anti-hyperuricemic drugs some medications have side effects, such as hypersensitivity in patients with circulatory system disorders, flare reoccurrences, and increased cardiac risk. This study consisted of test tube (xanthine oxidase's inhibition) and animal study. Animal study using with ICR mice was composed of control, potassium oxonate-induced hyperuricemia, allopurinol, and 3 Korean red ginseng water extract (KRGWE) treatment groups (62.5; 125, and 500 mg/kg). We orally administered KRGWE once a day for 7 d to induce hyperuricemia and injected PO 2 h before the final KRGWE administration. We measured serum uric acid, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), blood urea nitrogen, and creatinine and analyzed the genes such as organic anion transport (OAT)-1, OAT-3, and urate transport (URAT)-1. KRGWE dose-dependently controlled xanthine oxidase activity in the serum and completely inhibited serum uric acid. KRGWE affected both uric acid excretion-related and uric acid reabsorption-related gene expression. KRGWE stimulated uric acid excretion-related gene expressions, such as OAT-1 and OAT-3, but inhibited uric acid reabsorption-related gene expression, such as URAT-1. KRGWE improved liver and kidney functioning. KRGWE improved liver/kidney functioning and is promising anti-hyperuricemic agent which can control serum uric acid via downregulating URAT1 and upregulating OAT1 and OAT3.

A Review of Medicinal Plants and Phytochemicals for the Management of Gout

Gout, characterized by elevated uric acid levels, is a common inflammatory joint disease associated with pain, joint swelling, and bone erosion. Existing treatments for gout often result in undesirable side effects, highlighting the need for new, safe, and cost-effective anti-gout drugs. Natural products, including medicinal plants and phytochemicals, have gained attention as potential sources of anti-gout compounds. In this review, we examined articles from 2000 to 2020 using PubMed and Google Scholar, focusing on the effectiveness of medicinal plants and phyto-chemicals in managing gout. Our findings identified 14 plants and nine phytochemicals with anti-gout properties. Notably, Teucrium polium, Prunus avium, Smilax riparia, Rhus coriaria, Foenic-ulum vulgare, Allium cepa, Camellia japonica, and Helianthus annuus exhibited the highest xa-thine oxidase inhibitory activity, attributed to their unique natural bioactive compounds such as phenolics, tannins, coumarins, terpenoids, and alkaloids. Herbal plants and their phytochemicals have demonstrated promising effects in reducing serum urate and inhibiting xanthine. This review aims to report recent studies on plants/phytochemicals derived from herbs beneficial in gout and their different mechanisms.

Dispelling Dampness, Relieving Turbidity and Dredging Collaterals Decoction, Attenuates Potassium Oxonate-Induced Hyperuricemia in Rat Models

Purpose

Dispelling dampness, relieving turbidity and dredging collaterals decoction (DED), is a traditional Chinese medicine used in the treatment of hyperuricemia. We aimed to explore the effect and mechanism of DED in the treatment of hyperuricemia.

Methods

The effects of DED (9.48, 4.74, and 2.37 g/kg/d) on potassium oxonate (750 mg/kg/d)-induced hyperuricemia in rats were evaluated by serum uric acid (UA), creatinine (CRE), blood urea nitrogen (BUN), and renal pathological changes. Network pharmacology was used to identify the effective components and targets of DED, and the key targets and signaling pathways for its effects on hyperuricemia were screened. Molecular docking was used to predict the action of DED. H&E, immunohistochemistry, WB, and PCR were used to validate the network pharmacology results.

Results

DED can effectively alleviate hyperuricemia, inhibit UA, CRE, BUN, and xanthine oxidase (XOD) activity, and reduce renal inflammatory cell infiltration and glomerular atrophy. The experiment identified 27 potential targets of DED for hyperuricemia, involving 9 components: wogonin, stigmasterol 3-O-beta-D-glucopyranoside, 3β-acetoxyatractylone, beta-sitosterol, stigmasterol, diosgenin, naringenin, astilbin, and quercetin. DED can relieve hyperuricemia mainly by inhibiting RAGE, HMGB1, IL17R, and phospho-TAK1, and by regulating the AGE-RAGE and IL-17 signaling pathways.

Conclusion

DED can alleviate hyperuricemia by inhibiting XOD activity and suppressing renal cell apoptosis and inflammation via the AGE-RAGE signaling pathway and IL-17 signaling pathway. This study provides a theoretical basis for the clinical application of DED.

Strong inhibition of xanthine oxidase and elastase of Baccharis trimera (Less.) DC stem extract and analysis of biologically active constituents

Introduction: In the present study, strong xanthine oxidase and elastase activities of Baccharis trimera (Less) DC stem (BT) were evaluated and active ingredients were identified to determine the possibility of using BT extract as an anti-hyperuricemia (gout) and cosmetic functional material. Methods: Hot water, 20, 40, 60, 80, and 100% ethanolic extracts of BT were prepared. The hot water extract had the highest extraction yield whereas the 100% ethanolic extract had the lowest yield. Results and discussion: Antioxidant effects were investigated based on DPPH radical scavenging activity, reducing power, and total phenolic contents. The 80% ethanolic extract showed the highest antioxidant activity. However, the 100% ethanol BT extract showed strong xanthine oxidase and elastase inhibitory activities. Functional substances were thought to be caffeic acid and luteolin. Minor active substances such as o-coumaric acid, palmitic acid, naringenin, protocatechoic acid, and linoleic acid were identified. Through this study, we firstly reported evidence that BT stem extract could be used as functional materials with anti-hyperuricemia and skin disease improving effects. BT stem extract could be used as an anti-hyperuricemia (gout) natural drug or cosmetic material. For further study, practical studies such as optimizing BT extraction and functional experiments for hyperuricemia (gout) and skin wrinkle improvement are considered necessary.

In-vitro antigout potential of Alstonia scholaris flower, characterization and prospective ligand-receptor interaction of bioactive lead compound

Gout is an arthropathic and inflammatory disease. The prevalence and incidence of such disease has risen in last decades. It is associated with life style thus it could be recognize as life style diseases. In the present study, the flower extract of Alstonia scholaris Linn R.Br., Flower was initially subjected to extraction, isolation which leads to purification of pure eight compounds. All these compounds were identified using various spectroscopic techniques. In-vitro Xanthine oxidase inhibition activity was performed to determine the antigout potential of lead compounds. Compound 8 showed significant activity among all i.e. 14.7 ± 0.43 as compare to standard allopurinol 6.77 ± 0.26. Accordingly, in-silico studies using Autodock vina 4 showed the ligand-protein interaction of luteolin with 3AX7. The docking simulations showed significant binding pocket sites of respective proteins 3AX7 with the least binding energy -10.2 kcal/mol. Consequently, molecular docking simulations for 100ns indicated robust evidence with their conformational structural interaction which serve as active sites for Lead compound. Principal Component Analysis indicated first three PCs capture 23.8%, 39%, and 49% of structural variance in protein. Therefore compound 8 could be consider for potential drug design and development in gout therapy.

Research Progress of Natural Active Substances with Uric-Acid-Reducing Activity

Hyperuricemia is a metabolic disease caused by the accumulation of uric acid in the body. Allopurinol, benzbromarone, and febuxostat, which are available in the market, have reduced the circulating urate levels; however, they exhibit serious side effects. Therefore, it is reasonable to develop a new active antihyperuricemia drug with few side effects. With the deepening of research, numerous kinds of literature have shown that natural active substances are effective in the treatment of hyperuricemia with a variety of sources and few side effects, which have become the focus of research in recent years. This review focuses on natural active substances with uric-acid-reducing activity and discusses their pharmacological effects. More specifically, the bioactive compounds of natural active substances are divided into five categories: natural extracts, monomer compounds extracted from plants, natural protease hydrolysates, peptides, and probiotic bacteria. In addition, the mechanisms by which these bioactive compounds exhibit hypouricemic effects can be divided into four classes: inhibition of key enzyme activities, promotion of uric acid excretion and inhibition of reabsorption in the kidney, promotion of decomposing uric acid precursors, and promotion of decomposing uric acid. Overall, this current and comprehensive review examines the role of natural active substances in the treatment of hyperuricemia.

Inflammatory Response and Oxidative Stress as Mechanism of Reducing Hyperuricemia of Gardenia jasminoides-Poria cocos with Network Pharmacology

Hyperuricemia (HUA) is a metabolic disease, closely related to oxidative stress and inflammatory responses, caused by reduced excretion or increased production of uric acid. However, the existing therapeutic drugs have many side effects. It is imperative to find a drug or an alternative medicine to effectively control HUA. It was reported that Gardenia jasminoides and Poria cocos could reduce the level of uric acid in hyperuricemic rats through the inhibition of xanthine oxidase (XOD) activity. But there were few studies on its mechanism. Therefore, the effective ingredients in G. jasminoides and P. cocoa extracts (GPE), the active target sites, and the further potential mechanisms were studied by LC-/MS/MS, molecular docking, and network pharmacology, combined with the validation of animal experiments. These results proved that GPE could significantly improve HUA induced by potassium oxazine with the characteristics of multicomponent, multitarget, and multichannel overall regulation. In general, GPE could reduce the level of uric acid and alleviate liver and kidney injury caused by inflammatory response and oxidative stress. The mechanism might be related to the TNF-α and IL-7 signaling pathway.

The effect of chayote leaves (Sechium edule)’s flavonoid fraction on the reduction of the serum uric acid levels through the inhibition of xanthine oxidase activity

Uric acid is the final product of purine metabolism and is categorized as hyperuricemia when it reaches >6.0 mg.dL-1 for women and >7.0 mg.dL-1 for men. The chayote leaves (Sechium edule) contain a high amount of flavonoid and might be used as an alternative to reduce hyperuricemia. The purpose of this study is to analyze the effect of chayote leaves (Sechium edule)’s flavonoid fraction on the level of uric acid and the activity of xanthine oxidase (XO) in Sprague Dawley Rats. The flavonoid fraction (FF) was obtained by extracting the chayote leaves, fractionating with n-hexane, hydrolyzing with HCl, and finally re-fractionating with ethyl acetate. Thirty male Sprague Dawley rats were induced for hyperuricemia by potassium oxonate and broth block for 21 days, and the interventions were given orally for 14 days. The rats were divided randomly into five groups: normal control (K-), hyperuricemia control (K+), hyperuricemia with FF dose 50 mg.200g-1 body weight (P1), hyperuricemia with FF dose 100 mg.200g-1 body weight (P2) and hyperuricemia with allopurinol 1.8 mg.200g-1 body weight. Xanthine oxidase activity was measured by CheKineTM Xanthine Oxidase Assay Kit, with simple colorimetry methods. The statistical analysis for XO activity was done using Kruskal-Wallis followed by Mann Whitney. The results showed that chayote leaves (Sechium edule)’s flavonoid fraction contains apigenin, apigenin o-glucoside, and luteolin. It also has antioxidant activity with 98.45% inhibition.  There was a significant reduction in xanthine oxidase activity in groups treated with FF (p <0.005). The best dose of FF affecting XO activity was 100 mg.200g-1 body weight. The combination of FF and allopurinol can be more effective in decreasing uric acid levels by inhibiting XO activity.

The Efficacy and Mechanism of Chinese Herbal Medicines in Lowering Serum Uric Acid Levels: A Systematic Review

Background. Chinese herbal medicines are widely used to lower serum uric acid levels. However, no systemic review summarizes and evaluates their efficacies and the underlying mechanisms of action. Objectives. To evaluate the clinical and experimental evidences for the effectiveness and the potential mechanism of Chinese herbal medicines in lowering serum uric acid levels. Methods. Four electronic databases PubMed, Wed of Science, the Cochrane Library and Embase were used to search for Chinese herbal medicines for their effects in lowering serum uric acid levels, dated from 1 January 2009 to 19 August 2020. For clinical trials, randomized controlled trials (RCTs) were included; and for experimental studies, original articles were included. The methodological quality of RCTs was assessed according to the Cochrane criteria. For clinical trials, a meta-analysis of continuous variables was used to obtain pooled effects. For experimental studies, lists were used to summarize and integrate the mechanisms involved. Results. A total of 10 clinical trials and 184 experimental studies were included. Current data showed that Chinese herbal medicines have promising clinical efficacies in patients with elevated serum uric acid levels (SMD: −1.65, 95% CI: −3.09 to −0.22; p = 0.024). There was no significant difference in serum uric acid levels between Chinese herbal medicine treatments and Western medicine treatments (SMD: −0.13, 95% CI: −0.99 to 0.74; p = 0.772). Experimental studies revealed that the mechanistic signaling pathways involved in the serum uric acid lowering effects include uric acid synthesis, uric acid transport, inflammation, renal fibrosis and oxidative stress. Conclusions. The clinical studies indicate that Chinese herbal medicines lower serum uric acid levels. Further studies with sophisticated research design can further demonstrate the efficacy and safety of these Chinese herbal medicines in lowering serum uric acid levels and reveal a comprehensive picture of the underlying mechanisms of action.

Exploration of the mechanism of Zisheng Shenqi decoction against gout arthritis using network pharmacology

BACKGROUND

In this study, the network pharmacological methods were used to predict the target of effective components of compounds in Zisheng Shenqi Decoction (ZSD, or Nourishing Kidney Qi Decoction) in the treatment of gouty arthritis (GA).

METHOD

The main effective components and corresponding key targets of herbs in the ZSD were discerned through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis (TCMSP), Bioinformatics Analysis Tool for Molecular mechanism of Traditional Chinese Medicine (BATMAN-TCM) database. UniProt database and Swiss Target Prediction (STP) database was used to rectify and unify the target names and supply the target information. The targets related to GA were obtained by using GeneCards database. After we discovered the potential common targets between ZSD and GA, the interaction network diagram of "ZSD-component-GA-target" was constructed by Cytoscape software (Version 3.7.1). Subsequently, the Protein-protein interaction (PPI) network of ZSD effective components-targets and GA-related targets was constructed by Search Tool for the Retrieval of Interacting Genes Database (STRING). Bioconductor package "org.Hs.eg.db" and "cluster profiler" package were installed in R software (Version 3.6.0) which used for Gene Ontology analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis.

RESULTS

146 components and 613 targets of 11 herbal medicines in the ZSD were got from TCMSP database and BATMAN-TCM database. 987 targets of GA were obtained from GeneCards database. After intersected and removed duplications, 132 common targets between ZSD and GA were screened out by Cytoscape software (Version 3.7.1). These common targets derived from 81 effective components of 146 components, such as quercetin, stigmasterol and kaempferol. They were closely related to anti-inflammatory, analgesic and anti oxidative stress and the principal targets comprised of Purinergic receptor P2X, ligand-gated ion channel 7 (P2x7R), Nod-like receptor protein 3 (NLRP3) and IL-1β. GO enrichment analysis and KEGG pathway enrichment analysis by R software (Version 3.6.0) showed that the key target genes had close relationship with oxidative stress, reactive oxygen species (ROS) metabolic process and leukocyte migration in aspects of biological process, cell components and molecular function. It also indicated that ZSD could decrease inflammatory reaction, alleviate ROS accumulation and attenuate pain by regulating P2 × 7R and NOD like receptor signaling pathway of inflammatory reaction.

CONCLUSION

A total of 81 effective components and 132 common target genes between ZSD and GA were screened by network pharmacology. The PPI network, GO enrichment analysis and KEGG pathway enrichment analysis suggested that ZSD can exerte anti-inflammatory and analgesic effects on the treatment of GA by reducing decreasing inflammatory reaction, alleviating ROS accumulation, and attenuating pain. The possible molecular mechanism of it mainly involved multiple components, multiple targets and multiple signaling pathways, which provided a comprehensive understanding for further study. In general, the network pharmacological method applied in this study provides an alternative strategy for the mechanism of ZSD in the treatment of GA.