New insight into the management of renal excretion and hyperuricemia: Potential therapeutic strategies with natural bioactive compounds

Antihyperuricemia Bioactive Substances Derived from Marine Organisms

Hyperuricemia is a metabolic disorder attributed to dysregulated purine metabolism or insufficient uric acid excretion. With a high incidence rate and comorbidities burden, hyperuricemia brings enormous pressure to society and attracts much attention nowadays. Though several urate-lowering drugs (including xanthine oxidase inhibitors, uricosuric drugs, and recombinant uricase) are available in clinical practice, their use is often limited due to serious side effects or contraindications. The development of novel urate-lowering drugs and functional foods is in the spotlight. Regarded as an important source of bioactive substances, marine organisms, including seaweeds, animals, and microorganisms, have yielded a large number of bioactive substances with novel structures and unique pharmacological activities. Up to the present, numerous marine organisms-derived bioactive substances have shown potential in combating hyperuricemia. Thus, this review discusses the antihyperuricemia substances derived from marine organisms and summarizes their antihyperuricemia pharmacological properties, with the aim of providing new insights for the development of antihyperuricemia drugs or functional foods from marine organism resources.

Stachydrine from Natural Foods Alleviates Hyperuricemia by Modulating Renal Urate Transporters and Suppressing Mitochondrial Oxidative Stress

Hyperuricemia (HUA) is a metabolic disease caused by disrupted purine metabolism, characterized by abnormally elevated uric acid (UA) levels. Stachydrine, an alkaloid in natural foods, exhibits multiple biological activities. This study aimed to evaluate the effects of stachydrine on alleviating HUA. An HUA mouse model was established through high-nucleoside diet induction, and stachydrine's effects on UA levels and renal injury were investigated. Our findings revealed that stachydrine enhanced uric acid excretion by upregulating ATP-binding cassette subfamily G member 2 (ABCG2). Furthermore, stachydrine mitigated HUA-induced renal inflammation, mitochondrial oxidative stress and apoptosis. Mechanistically, stachydrine facilitated the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) by downregulating Kelch-like ECH-associated protein 1 (Keap1), subsequently activating the Keap1/Nrf2 signaling pathway and alleviating local oxidative stress. This study demonstrated the UA-lowering and renoprotective effects of stachydrine, suggesting its potential as a functional food ingredient for mitigating HUA.

Prediction and evaluation of purine-binding peptides using integrated molecular descriptors and docking analysis

Peptides and purines frequently coexist in food systems and can form specific molecular interactions, which may influence the physicochemical properties and bioavailability of purines. However, the structural basis and binding mechanisms of these peptide-purine interactions remain poorly understood. This study established a comprehensive screening approach combining molecular docking and descriptor analysis to evaluate peptide-purine binding interaction. The analysis revealed that strong-binding peptides were likely characterized by reduced cyclic structures and aromatic rings, with elevated electron-donor groups primarily composed of N and O atoms (p < 0.0001). These electron-rich functional groups appeared to enhance the formation of hydrogen bonds, which could play a crucial role in stabilizing peptide-purine complexes. Among various dietary purines, hypoxanthine emerged as the predominant species in processed meat products, warranting particular attention. Fluorescence spectroscopy experiments validated the computational predictions, confirming that the tetrapeptide WDQW (Peptide Purine Binding Score: -3.32) formed stable complexes with hypoxanthine exhibiting static quenching characteristics, primarily driven by hydrophobic interactions and hydrogen bonding. This investigation provides fundamental insights into peptide-purine binding mechanisms and establishes a screening platform for identifying peptide sequences with enhanced purine-binding properties, which might be valuable for modulating purine bioavailability in food systems.

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.

Identification of Therapeutic Targets for Hyperuricemia: Systematic Genome-Wide Mendelian Randomization and Colocalization Analysis

Background: At present, there are still limitations and challenges in the treatment of hyperuricemia (HUA). Mendelian randomization (MR) has been widely used to identify new therapeutic targets. Therefore, we conducted a systematic druggable genome-wide MR to explore potential therapeutic targets and drugs for HUA. Methods: We integrated druggable genome data; blood, kidney, and intestinal expression quantitative trait loci (eQTLs); and HUA-associated genome-wide association study (GWAS) data to analyze the potential causal relationships between drug target genes and HUA using the MR method. Summary-data-based MR (SMR) analysis and Bayesian colocalization were used to assess causality. In addition, we conducted phenome-wide association studies, protein network construction, and enrichment analysis of significant targets to evaluate their biological functions and potential side effects. Finally, we performed drug prediction and molecular docking to identify potential drugs targeting these genes for HUA treatment. Results: Overall, we identified 22 druggable genes significantly associated with HUA through MR, SMR, and colocalization analyses. Among them, two prior druggable genes (ADORA2B and NDUFC2) reached statistically significant levels in at least two tissues in the blood, kidney, and intestine. Further results from phenome-wide studies revealed that there were no potential side effects of ADORA2B or NDUFC2. Moreover, we screened 15 potential drugs targeting the 22 druggable genes that could serve as candidates for HUA drug development. Conclusions: This study provides genetic evidence supporting the potential benefits of targeting 22 druggable genes for HUA treatment, offering new insights into the development of targeted drugs for HUA.

hTERT and SV40LgT Renal Cell Lines Adjust Their Transcriptional Responses After Copy Number Changes from the Parent Proximal Tubule Cells

Primary mouse renal proximal tubule epithelial cells (moRPTECs) were immortalized by lentivirus transduction to create hTERT or SV40LgT (LgT) cell lines. Prior work showed a more pronounced injury and repair response in LgT versus hTERT cells after chemical challenge. We hypothesized that unique genomic changes occurred after immortalization, altering critical genes and pathways. RNA-seq profiling and whole-genome sequencing (WGS) of parent, hTERT, and LgT cells showed that 92.5% of the annotated transcripts were shared, suggesting a conserved proximal tubule expression pattern. However, the cell lines exhibited unique transcriptomic and genomic profiles different from the parent cells. Three transcript classes were quite relevant for chemical challenge response-Cyps, ion channels, and metabolic transporters-each important for renal function. A pathway analysis of the hTERT cells suggested alterations in intermediary and energy metabolism. LgT cells exhibited pathway activation in cell cycle and DNA repair that was consistent with replication stress. Genomic karyotyping by combining WGS and RNA-seq data showed increased gene copy numbers in chromosome 5 for LgT cells, while hTERT cells displayed gene copy losses in chromosomes 4 and 9. These data suggest that the exaggerated transcriptional responses of LgT cells versus hTERT cells result from differences in gene copy numbers, replication stress, and the unique selection processes underlying LgT or hTERT immortalization.

The association between serum uric acid and depression among U.S. National Health and Nutrition Examination Survey

Background

Previous studies have suggested that serum uric acid (UA) may influence depression through oxidative stress pathways, but with inconclusive results. This study aimed to investigate the association between serum UA levels and depression, as well as potential variations across demographic subgroups in the U.S. adult population.

Methods

A cross-sectional analysis of 23,059 participants from NHANES (2013-2018) was conducted. Serum UA levels were classified into quartiles, and depression was measured using the Patient Health Questionnaire-9 (PHQ-9), with a score ≥ 10 indicating depression. Weighted logistic regression models were used to analyze the association between UA levels and depression, adjusting for demographic and clinical covariates. Subgroup analyses were performed to assess variations by sex, age, race/ethnicity, and other health-related factors.

Results

Participants in the highest UA quartile had a lower prevalence of depression compared to those in the lowest quartile (13.9% vs. 16.2%, p = 0.004). After adjusting for covariates, higher UA levels were significantly associated with a reduced risk of depression (OR = 0.76, 95% CI: 0.67, 0.86, p < 0.001 for quartile 4). Subgroup analyses indicated significant interactions by age (p for interaction = 0.051), race/ethnicity (p for interaction = 0.027), and history of cardiovascular disease (p for interaction = 0.005), with more pronounced inverse associations observed among older adults, other races and participants with cardiovascular disease.

Conclusion

Higher serum UA levels were inversely associated with depression among U.S. adults, especially among races, participants with cardiovascular disease and older age. Further research is needed to confirm these findings and investigate potential underlying mechanisms.

The associations between serum carotenoids and hyperuricemia among U.S. National Health and Nutrition Examination Survey

BACKGROUND

Hyperuricemia is a risk factor for various metabolic disorders. We aimed to investigate the association between serum carotenoid levels and hyperuricemia using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

We conducted a cross-sectional analysis utilizing data from three specific NHANES cycles (2003-2004, 2005-2006, 2017-2018), containing the most complete serum carotenoid data from 12,253 participants aged 20 years and older. Serum carotenoids were quantified using high-performance liquid chromatography, while hyperuricemia was defined as serum uric acid levels ≥ 416 μmol/L (7.0 mg/dL) in men and ≥ 357 μmol/L (6.0 mg/dL) in women. Multivariable logistic regression models were employed to assess the relationship between carotenoids and hyperuricemia.

RESULTS

The mean age of participants was 50.1 ± 18.7 years, with a hyperuricemia prevalence of 20.5%. Higher serum carotenoids were associated with a lower prevalence of hyperuricemia, with each 1-unit increase in total carotenoids being inversely associated with hyperuricemia (odds ratio [OR] = 0.77, 95% confidence interval [CI]: 0.72-0.82) in multivariable analyses. Compared to participants with the lowest quartile, reduced ORs for hyperuricemia odds were observed for those with the highest quartile for total carotenoids (0.55 [0.47-0.64]), α-carotene (0.60 [0.52-0.71]), β-carotene (0.56 [0.48-0.65]), β-cryptoxanthin (0.58 [0.49-0.67]), trans-lycopene (0.75 [0.65-0.87]), cis-lycopene (0.83 [0.65-1.06]), total-lycopene (0.75 [0.64-0.87]), and lutein + zeaxanthin (0.66 [0.57-0.77]). Subgroup analyses indicated stronger associations among younger individuals, women, and those without any history of diabetes or cardiovascular disease.

CONCLUSIONS

Higher serum carotenoid levels are associated with reduced odds of hyperuricemia. These results underscore the potential role of carotenoids in managing hyperuricemia and its related health complications.

Sodium-Glucose Transporter-2 Inhibitors (SGLT2i) and Myocardial Ischemia: Another Compelling Reason to Consider These Agents Regardless of Diabetes

In recent years, the introduction of sodium-glucose transporter-2 inhibitors (SGLT2is) marked a significant advancement in the treatment of cardiovascular disease (CVD). Beyond their known effects on glycemic control and lipid profile, SGLT2is demonstrate notable benefits for cardiovascular morbidity and mortality, regardless of diabetic status. These agents are currently recommended as first-line therapies in patients with heart failure, both with reduced and preserved ejection fraction, as they improve symptoms and reduce the risk of hospitalization. While several studies have demonstrated that SGLT2is can reduce the incidence of major adverse cardiovascular events (MACEs), the true impact of these agents on atherosclerosis progression and myocardial ischemia remains to be fully understood. A global beneficial effect related to improved glycemic and lipid control could be hypothesized, even though substantial evidence shows a direct impact on molecular pathways that enhance endothelial function, exhibit anti-inflammatory properties, and provide myocardial protection. In this context, this narrative review summarizes the current knowledge regarding these novel anti-diabetic drugs in preventing and treating myocardial ischemia, aiming to define an additional area of application beyond glycemic control and heart failure.

Mulberry (Fructus mori) extract alleviates hyperuricemia by regulating urate transporters and modulating the gut microbiota

Mulberry (Fructus mori) is a traditional Chinese fruit that has beneficial effects due to its numerous biological activities. This study aimed to investigate the anti-hyperuricemic activity and underlying mechanism of laboratory-prepared mulberry water extract in mice with hyperuricemia (HUA). Additionally, the effect of mulberry extract (ME) on the microbiota was investigated. The results demonstrated that ME reduced the levels of HUA-related biochemical indices [uric acid (UA), creatinine (Cr), and blood urea nitrogen (BUN)] and pro-inflammatory factors (TNF-α, IL-6, IL-8, and IL-1β) in the serum of HUA model mice. ME suppressed xanthine oxidase (XOD) and adenosine deaminase (ADA) activity while modulating the expression of the urate transporters ATP-binding cassette transporter G2 (ABCG2) and recombinant urate transporter 1 (URAT1) in the kidney. Furthermore, high-dose ME modulated the microbiota, including Ligilactobacillus, Prevotellaceae, Bacteroides and Desulfovibrio. Overall, these results demonstrate the efficacy of ME in alleviating HUA by inhibiting XOD and ADA activity, as well as modulating transport proteins to decrease urate synthesis. Additionally, ME regulates the microbiota associated with host UA metabolism. These findings confirm the UA-lowering effects of ME, highlighting its potential as a therapeutic agent for HUA.

9-Hydroxy-8-oxypalmatine, a novel liver-mediated oxymetabolite of palmatine, alleviates hyperuricemia and kidney inflammation in hyperuricemic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Palmatine is a main bioactive alkaloid of Cortex Phellodendri, which has been commonly prescribed for the treatment of hyperuricemia (HUA) in China. The metabolites of palmatine were crucial to its prominent biological activity. 9-Hydroxy-8-oxypalmatine (9-OPAL) is a novel liver-mediated secondary oxymetabolite of palmatine.

AIM OF THE STUDY

The current study was to assess the efficacy of 9-OPAL, a novel liver-mediated secondary oxymetabolite of palmatine derived from Cortex Phellodendri, in experimental HUA mouse model and further explore its underlying mechanism.

MATERIALS AND METHODS

An in vitro metabolic experiment with oxypalmatine was carried out using liver samples. We separated and identified a novel liver metabolite, and investigated its anti-HUA effect in mice. HUA mice were induced by potassium oxonate and hypoxanthine daily for one week. After 1 h of modeling, mice were orally administered with different doses of 9-OPAL (5, 10 and 20 mg/kg). The pathological changes of the kidneys were evaluated using hematoxylin-eosin staining (H&E). The acute toxicity of 9-OPAL was assessed. The effects of 9-OPAL on serum levels of uric acid (UA), adenosine deaminase (ADA), xanthine oxidase (XOD), creatinine (CRE), blood urea nitrogen (BUN) and inflammatory cytokines were measured by enzyme-linked immunosorbent assay (ELISA) or biochemical method. Furthermore, Western blot, quantitative real-time PCR (qRT-PCR) and molecular docking were used to investigate the effect of 9-OPAL on the expression of renal urate transporters and NLRP3 signaling pathway in HUA mice.

RESULTS

9-OPAL had been discovered to be a novel liver-mediated oxymetabolite of palmatine for the first time. Treatment with 9-OPAL significantly reduced the UA, CRE as well as BUN levels, and also effectively attenuated abnormal renal histopathological deterioration with favorable safety profile. Besides, 9-OPAL significantly decreased the serum and hepatic activities of XOD and ADA, dramatically inhibited the up-regulation of UA transporter protein 1 (URAT1) and glucose transporter protein 9 (GLUT9), and reversed the down-regulation of organic anion transporter protein 1 (OAT1). Additionally, 9-OPAL effectively mitigated the renal inflammatory markers (TNF-α, IL-1β, IL-6 and IL-18), and downregulated the transcriptional and translational expressions of renal Nod-like receptor family pyrin domain containing 3 (NLRP3), caspase-1, apoptosis-associated speck-like (ASC) and IL-1β in HUA mice. Molecular docking results revealed 9-OPAL bound firmly with XOD, OAT1, GLUT9, URAT1, NLRP3, caspase-1, ASC and IL-1β.

CONCLUSIONS

9-OPAL was found to be a novel liver-mediated secondary metabolite of palmatine with favorable safety profile. 9-OPAL had eminent anti-hyperuricemic and renal-protective effects, and the mechanisms might be intimately associated with repressing XOD activities, modulating renal urate transporter expression and suppressing the NLRP3 inflammasome activation. Our investigation might also provide further experimental evidence for the traditional application of Cortex Phellodendri in the treatment of HUA.

Cardiovascular-kidney-metabolic syndrome - An integrative review

The American Heart Association recently defined the complex interactions among the cardiovascular, renal, and metabolic systems as CKM syndrome. To promote better patient outcomes, having a more profound understanding of CKM pathophysiology and pursuing holistic preventative and therapy strategies is critical. Despite many gaps in understanding CKM syndrome, this study attempts to elucidate two of these gaps: the new emerging biomarkers for screening and the role of inflammation in its pathophysiology. For this review, an extensive search for specific terms was conducted in the following databases: PubMed, Scopus, Web of Science, and Google Scholar. Studies were first assessed by title, abstract, keywords, and selected for portfolio according to eligibility criteria, which led to 38 studies. They provided background information about CKM syndrome; data suggested that serum uric acid, leptin, aldosterone, bilirubin, soluble neprilysin, lipocalin-type-prostaglandin-D-synthase, and endocan could be valuable biomarkers for CKM screening; and finally, the inflammation role in CKM.

Hyperuricemia and epiretinal pathologies: a review of pathophysiological links and clinical implications

Hyperuricemia (HUA), defined by elevated serum uric acid levels, is well-established in its association with systemic conditions like gout and cardiovascular diseases. Recently, however, emerging research has revealed a potential connection between HUA and ocular disorders, particularly epiretinal pathologies. This review investigates the pathophysiological mechanisms linking HUA to epiretinal conditions, including epiretinal membrane formation, macular edema, and retinal vascular diseases. By thoroughly analyzing current literature, this review seeks to deepen the understanding of the relationship between HUA and epiretinal disorders, with the aim of informing new therapeutic strategies and enhancing patient outcomes.

Study on risk factor analysis and model prediction of hyperuricemia in different populations

Objectives

The purpose of the present study was to explore the influencing factors of hyperuricemia (HUA) in different populations in Shandong Province based on clinical biochemical indicators. A prediction model for HUA was constructed to aid in the early prevention and screening of HUA.

Methods

In total, 705 cases were collected from five hospitals, and the risk factors were analyzed by Pearson correlation analysis, binary logistic regression, and receiver operating characteristic (ROC) curve in the gender and age groups. All data were divided into a training set and test set (7:3). The training set included age, gender, total protein (TP), low-density lipoprotein cholesterol (LDL-C), and 15 other indicators. The random forest (RF) and support vector machine (SVM) methods were used to build the HUA model, and model performances were evaluated through 10-fold cross-validation to select the optimal method. Finally, features were extracted, and the ROC curve of the test set was generated.

Results

TP, LDL-C, and glucose (GLU) were risk factors for HUA, and the area under the curve (AUC) value of the SVM validation set was 0.875.

Conclusion

The SVM model based on clinical biochemical indicators has good predictive ability for HUA, thus providing a reference for the diagnosis of HUA and the development of an HUA prediction model.

Gut microecology: effective targets for natural products to modulate uric acid metabolism

Gut microecology,the complex community consisting of microorganisms and their microenvironments in the gastrointestinal tract, plays a vital role in maintaining overall health and regulating various physiological and pathological processes. Recent studies have highlighted the significant impact of gut microecology on the regulation of uric acid metabolism. Natural products, including monomers, extracts, and traditional Chinese medicine formulations derived from natural sources such as plants, animals, and microorganisms, have also been investigated for their potential role in modulating uric acid metabolism. According to research, The stability of gut microecology is a crucial link for natural products to maintain healthy uric acid metabolism and reduce hyperuricemia-related diseases. Herein, we review the recent advanced evidence revealing the bidirectional regulation between gut microecology and uric acid metabolism. And separately summarize the key evidence of natural extracts and herbal formulations in regulating both aspects. In addition,we elucidated the important mechanisms of natural products in regulating uric acid metabolism and secondary diseases through gut microecology, especially by modulating the composition of gut microbiota, gut mucosal barrier, inflammatory response, purine catalyzation, and associated transporters. This review may offer a novel insight into uric acid and its associated disorders management and highlight a perspective for exploring its potential therapeutic drugs from natural products.

Uric acid-lowering effect of harpagoside and its protective effect against hyperuricemia-induced renal injury in mice

Hyperuricemia (HUA) is caused by increased synthesis and/or insufficient excretion of uric acid (UA). Long-lasting HUA may lead to a number of diseases including gout and kidney injury. Harpagoside (Harp) is a bioactive compound with potent anti-inflammatory activity from the roots of Scrophularia ningpoensis. Nevertheless, its potential effect on HUA was not reported. The anti-HUA and nephroprotective effects of Harp on HUA mice were assessed by biochemical and histological analysis. The proteins responsible for UA production and transportation were investigated to figure out its anti-HUA mechanism, while proteins related to NF-κB/NLRP3 pathway were evaluated to reveal its nephroprotective mechanism. The safety was evaluated by testing its effect on body weight and organ coefficients. The results showed that Harp significantly reduced the SUA level and protected the kidney against HUA-induced injury but had no negative effect on safety. Mechanistically, Harp significantly reduced UA production by acting as inhibitors of xanthine oxidase (XOD) and adenosine deaminase (ADA) and decreased UA excretion by acting as activators of ABCG2, OAT1 and inhibitors of GLUT9 and URAT1. Moreover, Harp markedly reduced infiltration of inflammatory cells and down-regulated expressions of TNF-α, NF-κB, NLRP3 and IL-1β in the kidney. Harp was a promising anti-HUA agent.

Metabolomics of human umbilical vein endothelial cell-based analysis of the relationship between hyperuricemia and dyslipidemia

BACKGROUND AND AIMS

Hyperuricemia frequently accompanies dyslipidemia, yet the precise mechanism remains elusive. Leveraging cellular metabolomics analyses, this research probes the potential mechanisms wherein hyperuricemia provokes endothelial cell abnormalities, inducing disordered bile metabolism and resultant lipid anomalies.

METHODS AND RESULTS

We aimed to identify the differential metabolite associated with lipid metabolism through adopting metabolomics approach, and thereafter adequately validating its protective function on HUVECs by using diverse assays to measure cellular viability, reactive oxygen species, migration potential, apoptosis and gene and protein levels of inflammatory factors. Taurochenodeoxycholic acid (TCDCA) (the differential metabolite of HUVECs) and the TCDCA-involved primary bile acid synthesis pathway were found to be negatively correlated with high UA levels based on the results of metabolomics analysis. It was noted that compared to the outcomes observed in UA-treated HUVECs, TCDCA could protect against UA-induced cellular damage and oxidative stress, increase proliferation as well as migration, and decreases apoptosis. In addition, it was observed that TCDCA might protect HUVECs by inhibiting UA-induced p38 mitogen-activated protein kinase/nuclear factor kappa-B p65 (p38MAPK/NF-κB p65) pathway gene and protein levels, as well as the levels of downstream inflammatory factors.

CONCLUSION

The pathogenesis of hyperuricemia accompanying dyslipidemia may involve high uric acid levels eliciting inflammatory reactions and cellular damage in human umbilical vein endothelial cells (HUVECs), mediated through the p38MAPK/NF-κB signaling pathway, subsequently impinging on cellular bile acid synthesis and reducing bile acid production.

Priestia megaterium ASC-1 Isolated from Pickled Cabbage Ameliorates Hyperuricemia by Degrading Uric Acid in Rats

Pickled cabbage, a traditional fermented food rich in functional microorganisms, can effectively control hyperuricemia and gout. In this study, a Priestia megaterium ASC-1 strain with strong uric acid (UA) degradation ability was isolated from pickled cabbage. After oral administration for 15 days, ASC-1 was stably colonized in the rats in this study. ASC-1 significantly reduced UA levels (67.24%) in hyperuricemic rats. Additionally, ASC-1 alleviated hyperuricemia-related inflammatory response, oxidative stress, and blood urea nitrogen. Intestinal microbial diversity results showed that ASC-1 restored intestinal injury and gut flora dysbiosis caused by hyperuricemia. These findings suggest that P. megaterium ASC-1 may be used as a therapeutic adjuvant for the treatment of hyperuricemia.

Data mining-guided alleviation of hyperuricemia by Paeonia veitchii Lynch through inhibition of xanthine oxidase and regulation of renal urate transporters

BACKGROUND

Hyperuricemia (HUA) is a metabolic disease characterized by a high level of uric acid (UA). The extensive historical application of traditional Chinese medicine (TCM) offers a range of herbs and prescriptions used for the treatment of HUA-related disorders. However, the core herbs in the prescriptions and their mechanisms have not been sufficiently explained.

PURPOSE

Our current investigation aimed to estimate the anti-HUA effect and mechanisms of Paeonia veitchii Lynch, an herb with high use frequency identified from data mining of TCM prescriptions.

METHODS

Prescriptions for HUA/gout treatment were statistically analyzed through a data mining approach to determine the common nature and use frequency of their composition herbs. The chemical constituents of Paeonia veitchii extract (PVE) were analyzed by UPLC-QTOF-MS/MS, while its UA-lowering effect was further evaluated in adenosine-induced liver cells and potassium oxonate (PO) and hypoxanthine (HX)-induced HUA mice.

RESULTS

A total of 225 prescriptions involving 246 herbs were sorted out. The properties, flavors and meridians of the appearing herbs were mainly cold, bitter and liver, respectively, while their efficacy was primarily concentrated on clearing heat and dispelling wind. Further usage frequency analysis yielded the top 20 most commonly used herbs, in which PVE presented significant inhibitory activity (IC50 = 131.33 µg/ml) against xanthine oxidase (XOD), and its constituents showed strong binding with XOD in a molecular docking study and further were experimentally validated through XOD enzymatic inhibition and surface plasmon resonance (SPR). PVE (50 to 200 μg/ml) dose-dependently decreased UA levels by inhibiting XOD expression and activity in BRL 3A liver cells. In HUA mice, oral administration of PVE exhibited a significant UA-lowering effect, which was attributed to the reduction of UA production by inhibiting XOD activity and expression, as well as the enhancement of UA excretion by regulating renal urate transporters (URAT1, GLUT9, OAT1 and ABCG2). Noticeably, all doses of PVE treatment did not cause any liver injury, and displayed a renal protective effect.

CONCLUSIONS

Our results first comprehensively clarified the therapeutic effect and mechanisms of PVE against HUA through suppressing UA production and promoting UA excretion with hepatic and renal protection, suggesting that PVE could be a promising UA-lowering candidate with a desirable safety profile for the treatment of HUA and prevention of gout.

Fuling-Zexie formula attenuates hyperuricemia-induced nephropathy and inhibits JAK2/STAT3 signaling and NLRP3 inflammasome activation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Fuling-Zexie (FZ) formula, a traditional Chinese herbal prescription composed of Poria cocos (Schwan.) Wolf. (Poria), Pueraria lobate (Willd.) Howe. (Puerariae Lobatae Radix), Alisma orientale (Sam.) Julep. (Alismatis Rhizoma), and Atractylodes lancea (Thunb.) Dc. (Atractylodis Rhizoma), has been clinically used to ameliorate hyperuricemia (HUA) and its associated renal injury.

AIM OF STUDY

This study aims to explore the action and mechanism of FZ on renal inflammation and dysfunction caused by HUA.

MATERIALS AND METHODS

FZ was orally administered to rapid HUA mouse induced by potassium oxonate (PO) and hypoxanthine (HX) for 7 days. Serum levels of uric acid (UA), creatinine (CRE), blood urea nitrogen (BUN), xanthine oxidase (XOD), adenosine deaminase (ADA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urine levels of UA, CRE and urinary albumin were determined by biochemical assays. Serum levels of interleukin (IL)-1β and IL-6 were tested by ELISA. Hematoxylin-eosin and Masson staining were used to examine kidney and liver histopathological alterations. The expressions of renal glucose transporter 9 (GLUT9), ATP-binding cassette subfamily G member 2 (ABCG2), organic anion transporter 1 (OAT1), phospho-janus kinase 2 (p-JAK2), p-signal transducer and activator of transcription 3 (p-STAT3), suppression of cytokine signaling 3 (SOCS3), NLR family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein (ASC), and cleaved-cysteinyl aspartate specific proteinase-1 (cleaved-Cas-1) were detected by western blots. The potential protein targets and pathways of FZ intervention on HUA were predicted by network pharmacology. The constituents in FZ aqueous extract were analyzed by UPLC-MS.

RESULTS

FZ reduced serum UA, CRE, BUN, and urinary albumin and increased urine UA, CRE levels in HUA mice. In addition, the treatment with FZ to HUA mice inhibited the elevated serum levels of XOD and ADA, and regulated renal urate transports including OAT1, GLUT9 and ABCG2. FZ also attenuated kidney inflammation and fibrosis and downregulated the expressions of IL-1β, p-JAK2, p-STAT3, SOCS3, IL-6, NLRP3, ASC, and cleaved-Cas-1. Thirteen compounds were identified in the FG, including L-phenylalanine, D-tryptophan, 3'-hydroxypuerarin, Puerarin, 3'-Methoxy Puerarin, Daidzin, Pueroside A, formononetin-8-C- [xylosyl (1→6)]-glucoside, Ononin, Alisol I 23-acetate, 16-oxo-alisol A, Alisol C and Alisol A.

CONCLUSION

FZ inhibits serum UA generation and promotes urine UA excretion as well as attenuates kidney inflammation and fibrosis in HUA mouse with nephropathy. The underlying mechanism of its action may be associated with suppression of the JAK2/STAT3 signaling pathway and NLRP3 inflammasome activation. This formula may offer a novel source for developing anti-HUA drugs.

Anti-Hyperuricemia Activity and Potential Mechanisms of Medicinal Mushroom Activity: A Review of Preclinical Studies

Hyperuricemia (HUA) is characterized by abnormally elevated levels of serum uric acid, the product of purine metabolism. The primary symptom of HUA is gout; however, asymptomatic HUA is associated with complications such as hypertension, kidney disease, cardiovascular disease, and metabolic syndrome. The activation of xanthine oxidase (XO), a pivotal enzyme in uric acid biosynthesis, is coupled with extensive reactive oxygen species generation, leading to inflammatory responses, and triggers the development of HUA and its complications. In clinical practice, XO inhibitors are primarily used to treat HUA; however, their prolonged use is accompanied by serious adverse effects. Mushrooms and their bioactive constituents have shown promising anti-HUA activities in both in vitro and in vivo studies, including inhibition of urate production, modulation of renal urate transporters, enhancement of intestinal uric acid excretion, and antioxidant, anti-inflammatory, and antimetabolic syndrome properties. Clinical trials are necessary to validate the beneficial effects and safety of mushrooms in preventing or alleviating HUA and attenuating the associated complications. This review presents contemporary insights into the pathogenesis of HUA, the bioactive components of mushrooms, their therapeutic potential, and the underlying mechanisms involved in ameliorating HUA.

Emerging Urate-Lowering Drugs and Pharmacologic Treatment Strategies for Gout: A Narrative Review

Hyperuricemia with consequent monosodium urate crystal deposition leads to gout, characterized by painful, incapacitating inflammatory arthritis flares that are also associated with increased cardiovascular event and related mortality risk. This narrative review focuses on emerging pharmacologic urate-lowering treatment (ULT) and management strategies in gout. Undertreated, gout can progress to palpable tophi and joint damage. In oral ULT clinical trials, target serum urate of < 6.0 mg/dL can be achieved in ~ 80-90% of subjects, with flare burden reduction by 1-2 years. However, real-world ULT results are far less successful, due to both singular patient nonadherence and prescriber undertreatment, particularly in primary care, where most patients are managed. Multiple dose titrations commonly needed to optimize first-line allopurinol ULT monotherapy, and substantial potential toxicities and other limitations of approved, marketed oral monotherapy ULT drugs, promote hyperuricemia undertreatment. Common gout comorbidities with associated increased mortality (e.g., moderate-severe chronic kidney disease [CKD], type 2 diabetes, hypertension, atherosclerosis, heart failure) heighten ULT treatment complexity and emphasize unmet needs for better and more rapid clinically significant outcomes, including attenuated gout flare burden. The gout drug armamentarium will be expanded by integrating sodium-glucose cotransporter-2 (SGLT2) inhibitors with uricosuric and anti-inflammatory properties as well as clinically indicated antidiabetic, nephroprotective, and/or cardioprotective effects. The broad ULT developmental pipeline is loaded with multiple uricosurics that selectively target uric acid transporter 1 (URAT1). Evolving ULT approaches include administering selected gut anaerobic purine degrading bacteria (PDB), modulating intestinal urate transport, and employing liver-targeted xanthine oxidoreductase mRNA knockdown. Last, emerging measures to decrease the immunogenicity of systemically administered recombinant uricases should simplify treatment regimens and further improve outcomes in managing the most severe gout phenotypes.

Recent Advances in Synthetic Drugs and Natural Actives Interacting with OAT3

Organic anion transporter 3 (OAT3) is predominantly expressed in the kidney and plays a vital role in drug clearance. Consequently, co-ingestion of two OAT3 substrates may alter the pharmacokinetics of the substrate. This review summarizes drug-drug interactions (DDIs) and herbal-drug interactions (HDIs) mediated by OAT3, and inhibitors of OAT3 in natural active compounds in the past decade. This provides a valuable reference for the combined use of substrate drugs/herbs for OAT3 in clinical practice in the future and for the screening of OAT3 inhibitors to avoid harmful interactions.

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.

Mechanistic insights of soluble uric acid-induced insulin resistance: Insulin signaling and beyond

Hyperuricemia is a metabolic disease caused by purine nucleotide metabolism disorder. The prevalence of hyperuricemia is increasing worldwide, with a growing trend in the younger populations. Although numerous studies have indicated that hyperuricemia may be an independent risk factor for insulin resistance, the causal relationship between the two is controversial. There are few reviews, however, focusing on the relationship between uric acid (UA) and insulin resistance from experimental studies. In this review, we summarized the experimental models related to soluble UA-induced insulin resistance in pancreas and peripheral tissues, including skeletal muscles, adipose tissue, liver, heart/cardiomyocytes, vascular endothelial cells and macrophages. In addition, we summarized the research advances about the key mechanism of UA-induced insulin resistance. Moreover, we attempt to identify novel targets for the treatment of hyperuricemia-related insulin resistance. Lastly, we hope that the present review will encourage further researches to solve the chicken-and-egg dilemma between UA and insulin resistance, and provide strategies for the pathogenesis and treatment of hyperuricemia related metabolic diseases.

Triglyceride-Glucose Index is Significantly Associated with the Risk of Hyperuricemia in Patients with Nonalcoholic Fatty Liver Disease

Purpose

The triglyceride-glucose (TyG) index is a new index of insulin resistance (IR), and its association with hyperuricemia (HUA) is unclear. The aim of this study was to investigate whether TyG is an independent risk factor for hyperuricemia (HUA) in patients with nonalcoholic fatty liver disease (NAFLD).

Patients and Methods

We retrospectively analyzed 461 patients with ultrasound-confirmed NAFLD and calculated the TyG index. Multivariate logistic regression was used to analyze the relationship between the TyG index and HUA in NAFLD patients. The correlation between the TyG index and HUA was further confirmed by a restricted cubic spline. Furthermore, the stability of the association between TyG index and HUA was examined using subgroup analysis. Receiver operating characteristic (ROC) curves were constructed to evaluate the predictive value of the TyG index on HUA. Multivariate linear regression was used to analyze the linear relationship between the TyG index and serum uric acid.

Results

A total of 166 HUA patients and 295 non-HUA patients were included in the study. The results of multivariate logistic regression analysis showed that after controlling the confounding risk factors, TyG was still an independent risk factor for HUA (OR = 2.00, 95% CI: 1.38 -2.91, p < 0.001). Restricted cubic splines showed that HUA risk increased linearly with TyG across the entire TyG range. The ROC curve showed that TyG index was better than triglyceride in predicting HUA in NAFLD patients, with AUC values of 0.62 and 0.59, respectively. Multiple linear regression analysis showed that TyG index was significantly positively correlated with blood uric acid (B = 1.37, 95% CI: 0.67-2.08, p < 0.001).

Conclusion

TyG index is an independent risk factor for HUA in patients with NAFLD. The increase of the TyG index level is closely related to the occurrence and development of HUA in patients with NAFLD.