Antihyperuricemia and antigouty arthritis effects of Persicaria capitata herba in mice

Traditional herbal medicine: Therapeutic potential in acute gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Acute gouty arthritis (AGA) is characterized by a rapid inflammatory reaction caused by the build-up of monosodium urate (MSU) crystals in the tissues surrounding the joints. This condition often associated with hyperuricemia (HUA), is distinguished by its symptoms of intense pain, active inflammation, and swelling of the joints. Traditional approaches in AGA management often fall short of desired outcomes in clinical settings. However, recent ethnopharmacological investigations have been focusing on the potential of Traditional Herbal Medicine (THM) in various forms, exploring their therapeutic impact and targets in AGA treatment.

AIM OF THE REVIEW

This review briefly summarizes the current potential pharmacological mechanisms of THMs - including active ingredients, extracts, and prescriptions -in the treatment of AGA, and discusses the relevant potential mechanisms and molecular targets in depth. The objective of this study is to offer extensive information and a reference point for the exploration of targeted AGA treatment using THMs.

MATERIALS AND METHODS

This review obtained scientific publications focused on in vitro and in vivo studies of anti-AGA THMs conducted between 2013 and 2023. The literature was collected from various journals and electronic databases, including PubMed, Elsevier, ScienceDirect, Web of Science, and Google Scholar. The retrieval and analysis of relevant articles were guided by keywords such as "acute gouty arthritis and Chinese herbal medicine," "acute gouty arthritis herbal prescription," "acute gouty arthritis and immune cells," "acute gouty arthritis and inflammation," "acute gouty arthritis and NOD-like receptor thermoprotein domain associated protein 3 (NLRP3)," "acute gouty arthritis and miRNA," and "acute gouty arthritis and oxidative stress."

RESULTS

We found that AGA has a large number of therapeutic targets, highlighting the effectiveness the potential of THMs in AGA treatment through in vitro and in vivo studies. THMs and their active ingredients can mitigate AGA symptoms through a variety of therapeutic targets, such as influencing macrophage polarization, neutrophils, T cells, natural killer (NK) cells, and addressing factors like inflammation, NLRP3 inflammasome, signaling pathways, oxidative stress, and miRNA multi-target interactions. The anti-AGA properties of THMs, including their active components and prescriptions, were systematically summarized and categorized based on their respective therapeutic targets.

CONCLUSION

phenolic, flavonoid, terpenoid and alkaloid compounds in THMs are considered the key ingredients to improve AGA. THMs and their active ingredients achieve enhanced efficacy through interactions with multiple targets, of which NLRP3 is a main therapeutic target. Nonetheless, given the intricate composition of traditional Chinese medicine (TCM), additional research is required to unravel the underlying mechanisms and molecular targets through which THMs alleviate AGA.

Xanthoceras sorbifolium leaves alleviate hyperuricemic nephropathy by inhibiting the PI3K/AKT signaling pathway to regulate uric acid transport

ETHNOPHARMACOLOGICAL RELEVANCE

In China, Xanthoceras sorbifolium Bunge was first documented as "Wen Guan Hua" in the "Jiu Huang Ben Cao" in 1406 A.D. According to the "National Compilation of Chinese Herbal Medicine," X. sorbifolium leaves are sweet and flat in nature and can dispel wind and dampness, suggesting that their extract can be used to treat rheumatoid arthritis. X. sorbifolium Bunge has also been used to treat arteriosclerosis, hyperlipidemia, hypertension, chronic hepatitis, and rheumatism, complications associated with hyperuricemic nephropathy (HN), a condition characterized by kidney damage resulting from high levels of uric acid (UA) in the blood.

AIM OF THE STUDY

The purpose of this study was to investigate the effects and underlying mechanisms of a 70% ethanol extract from X. sorbifolium leaves (EX) in alleviating HN.

MATERIALS AND METHODS

A mouse model of hyperuricemia was established to initially evaluate the hypouricemic effects and determine the effective dose of EX. Phytochemical analyses were conducted using ultra high-performance liquid chromatography and liquid chromatography-mass spectroscopy. The potential key pathways of EX in the alleviation of HN were inferred using network pharmacology and bioinformatics. An HN rat model was then established, and experiments including biomarker detection, western blotting, reverse transcription quantitative polymerase chain reaction, immunohistochemical and Masson's trichrome staining, and transmission electron microscopy were conducted to evaluate the effect of EX on UA transporter expression in vitro.

RESULTS

Network pharmacology and bioinformatics analyses revealed that the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway was the key pathway for the alleviation of HN progression by EX. EX treatment reduced serum biomarkers in HN rats, downregulated the expression of p-PI3K, p-AKT, glucose transporter 9 (GLUT9), urate transporter 1 (URAT1), Collagen I, matrix metalloproteinase (MMP)-2, and MMP-9, and upregulated the expression of ATP binding cassette subfamily G member 2 (ABCG2) to improve renal interstitial fibrosis in HN rats. A high content of both quercitrin and cynaroside were identified in EX; their administration inhibited the increased expression of GLUT9 and URAT1 in damaged HK-2 cells.

CONCLUSION

Our study provides evidence that EX alleviates HN. The potential mechanism underlying this effect may be the regulation of UA transporters, such as GLUT9 and URAT1, by limiting the activation of the PI3K/AKT signaling pathway to improve renal injury.

Sanmiao wan alleviates inflammation and exhibits hypouricemic effect in an acute gouty arthritis rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Sanmiao wan (SMW), a classical traditional Chinese medicine (TCM) formula, has been employed to treat gouty diseases in clinic as early as Yuan dynasty. It shows remarkably therapeutic effects in acute gouty arthritis (GA). However, the potential mechanisms of SMW are still not fully revealed.

AIM OF THE STUDY

The objective of this project is to evaluate the pharmacological effects and possible mechanisms of SMW in a rat model of acute GA.

MATERIALS AND METHODS

Monosodium urate (MSU) suspension was injected into the ankle joint of rats to establish acute GA model. The inflammation was evaluated by measuring the posterior ankle diameter. The pathological status of synovial tissue was assessed by hematoxylin eosin (HE), Masson, and picrosirius red staining. The level of IL-6 was measured using ELISA kit. The levels of blood urea nitrogen (BUN), creatinine (CR), UA (uric acid), and xanthine oxidase (XOD) in the serum were measured using standard diagnostic kits. The percentage of Th17 cells in blood samples was performed using flow cytometry. Moreover, RT-qPCR was performed to examine the mRNA level of RANK, RORγt, RANKL, and STAT3 in the synovial tissue. Furthermore, immunofluorescence was carried out to assess the expression of STAT3 in the synovial tissue.

RESULTS

SMW effectively alleviated the inflammation and improved the pathological status of the ankle joint in rats with acute GA. It significantly suppressed the release of proinflammatory cytokine (IL-6). Meanwhile, the levels of UA, BUN, and CR were markedly reduced after SMW treatment. A remarkable reduction of XOD activity was observed in the study. Importantly, SMW treatment significantly reduced the frequency of Th17 cells, decreased the mRNA levels of RANK, RORγt, RANKL, and STAT3 in the synovial tissue. Furthermore, the suppression of STAT3 was also demonstrated using immunofluorescence in SMW-treated group.

CONCLUSION

SMW showed significant anti-inflammatory and hypouricemic effects in a rat model of GA. It is an effective TCM formula for GA therapy.

Herb-drug interactions: Quantitative analysis of levofloxacin absorption and transporter expression in the rat intestine following combined treatment with Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross

Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross, a traditional Chinese medicinal plant, is often used to treat various urologic disorders in China. P. capitata extracts (PCE) have been used in combination with levofloxacin (LVFX) to treat urinary tract infections (UTIs) for a long time. However, little is known about the absorption of LVFX and transporter expression in the intestine after combined treatment with PCE, restricting the development and utilization of PCE. In view of this, a UPLC-MS/MS method was established for the determination of LVFX in intestinal sac fluid samples and in situ intestinal circulation perfusate samples to explore the effect of PCE on the intestinal absorption characteristics of LVFX ex vivo and in vivo. To further evaluate the interaction between LVFX and PCE, western blotting, immunohistochemistry, and RT-qPCR were utilized to determine the expression levels of drug transporters (OATP1A2, P-gp, BCRP, and MRP2) involved in the intestinal absorption of LVFX after combined treatment with PCE. Using the everted intestinal sac model, the absorption rate constant (Ka) and cumulative drug absorption (Q) of LVFX in each intestinal segment were significantly lower in groups treated with PCE than in the control group. Ka at 2 h decreased most in the colon segment (from 0.088 to 0.016 µg/h·cm2), and Q at 2 h decreased most in the duodenum (from 213.29 to 33.92 µg). Using the intestinal circulation perfusion model, the Ka value and percentage absorption rate (A) of LVFX in the small intestine decreased significantly when PCE and LVFX were used in combination. These results showed that PCE had a strong inhibitory effect on the absorption of LVFX in the rat small intestine (ex vivo and in vivo intestinal segments). In addition, PCE increased the protein and mRNA expression levels of efflux transporters (P-gp, BCRP, and MRP2) and decreased the expression of the uptake transporter OATP1A2 significantly. The effects increased as the PCE concentration increased. These findings indicated that PCE changed the absorption characteristics of levofloxacin, possibly by affecting the expression of transporters in the small intestine. In addition to revealing a herb-drug interaction (HDI) between PCE and LVFX, these results provide a basis for further studies of their clinical efficacy and mechanism of action.

Gut-immunity-joint axis: a new therapeutic target for gouty arthritis

Gouty arthritis (GA) is an inflammatory disease characterized by pain. The primary goal of current treatment strategies during GA flares remains the reduction of inflammation and pain. Research suggests that the gut microbiota and microbial metabolites contribute to the modulation of the inflammatory mechanism associated with GA, particularly through their effect on macrophage polarization. The increasing understanding of the gut-joint axis emphasizes the importance of this interaction. The primary objective of this review is to summarize existing research on the gut-immune-joint axis in GA, aiming to enhance understanding of the intricate processes and pathogenic pathways associated with pain and inflammation in GA, as documented in the published literature. The refined comprehension of the gut-joint axis may potentially contribute to the future development of analgesic drugs targeting gut microbes for GA.

Pathology, target discovery, and the evolution of XO inhibitors from the first discovery to recent advances (2020-2023)

Hyperuricemia, a disease characterized by elevation of serum uric acid level beyond 6 mg/dL. This elevation led to appearance of symptoms from joint pain to gout and from gout to difficulty in mobility of the patient. So, in this review, we have summarized the pathology of hyperuricemia, discovery of target and discovery of first XO inhibitor. At last, this review provides in-sights about the recently discovered as natural XO inhibitors, followed by design, structure activity relationship and biological activity of synthetic compounds as XO inhibitors discovered between 2020 and 2023 years. At last, the pharmacophores generated in this study will guide new researchers to design and modify the structure of novel XO inhibitors.

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.

Overview of the pharmacokinetics and pharmacodynamics of URAT1 inhibitors for the treatment of hyperuricemia and gout

INTRODUCTION

Hyperuricemia is a common metabolic disease, which is a risk factor for gouty arthritis and ureteral stones and may also lead to cardiovascular and chronic kidney disease (CDK). Therefore, hyperuricemia should be treated early. Xanthine oxidase inhibitors (XOIs) and uricosuric agents (UAs), which target uric acid, are two types of medications that are used to treat gout and hyperuricemia. XOIs stop the body from producing excessive uric acid, while UAs eliminate it rapidly via the kidneys. Urate transporter 1 (URAT1) belongs to the organic anion transporter family (OAT) and is specifically localized to the apical membrane of the epithelial cells of proximal tubules. Unlike other organic anion transporter family members, URAT1 identifies and transports organic anions that are primarily responsible for urate transport.

AREAS COVERED

This article reviews the pharmacokinetics and pharmacodynamics of the existing URAT1 inhibitors to serve as a reference for subsequent drug studies.

EXPERT OPINION

The URAT1 inhibitors that are currently used as clinical drugs mainly include dotinurad, benzbromarone, and probenecid. Results indicate that RDEA3170 may be the most promising inhibitor, in addition to SHR4640, URC-102, and MBX-102, which are in the early stages of development.

Amelioration effects of α-viniferin on hyperuricemia and hyperuricemia-induced kidney injury in mice

BACKGROUND

α-Viniferin, the major constituent of the roots of Caragana sinica (Buc'hoz) Rehder with a trimeric resveratrol oligostilbenoid skeleton, was demonstrated to possess a strong inhibitory effect on xanthine oxidase in vitro, suggesting it to be a potential anti-hyperuricemia agent. However, the in vivo anti-hyperuricemia effect and its underlying mechanism were still unknown.

PURPOSE

The current study aimed to evaluate the anti-hyperuricemia effect of α-viniferin in a mouse model and to assess its safety profile with emphasis on its protective effect on hyperuricemia-induced renal injury.

METHODS

The effects were assessed in a potassium oxonate (PO)- and hypoxanthine (HX)-induced hyperuricemia mice model by analyzing the levels of serum uric acid (SUA), urine uric acid (UUA), serum creatinine (SCRE), serum urea nitrogen (SBUN), and histological changes. Western blotting and transcriptomic analysis were used to identify the genes, proteins, and signaling pathways involved.

RESULTS

α-Viniferin treatment significantly reduced SUA levels and markedly mitigated hyperuricemia-induced kidney injury in the hyperuricemia mice. Besides, α-viniferin did not show any obvious toxicity in mice. Research into the mechanism of action of α-viniferin revealed that it not only inhibited uric acid formation by acting as an XOD inhibitor, but also reduced uric acid absorption by acting as a GLUT9 and URAT1 dual inhibitor as well as promoted uric acid excretion by acting as a ABCG2 and OAT1 dual activator. Then, 54 differentially expressed (log₂ FPKM ≥ 1.5, p ≤ 0.01) genes (DEGs) repressed by the treatment of α-viniferin in the hyperuricemia mice were identified in the kidney. Finally, gene annotation results revealed that downregulation of S100A9 in the IL-17 pathway, of CCR5 and PIK3R5 in the chemokine signaling pathway, and of TLR2, ITGA4, and PIK3R5 in the PI3K-AKT signaling pathway were involved in the protective effect of α-viniferin on the hyperuricemia-induced renal injury.

CONCLUSIONS

α-Viniferin inhibited the production of uric acid through down-regulation of XOD in hyperuricemia mice. Besides, it also down-regulated the expressions of URAT1 and GLUT9 and up-regulated the expressions of ABCG2 and OAT1 to promote the excretion of uric acid. α-Viniferin could prevent hyperuricemia mice from renal damage by regulating the IL-17, chemokine, and PI3K-AKT signaling pathways. Collectively, α-viniferin was a promising antihyperuricemia agent with desirable safety profile. This is the first report of α-viniferin as an antihyperuricemia agent.

Improved effect of fresh ginseng paste (radix ginseng-ziziphus jujube) on hyperuricemia based on network pharmacology and molecular docking

Background: Hyperuricemia (HUA) is a metabolic disease caused by reduced excretion or increased production of uric acid. This research aims to study the practical components, active targets, and potential mechanism of the “Radix ginseng (RG)-Ziziphus jujube (ZJ)” herb pair through molecular docking, network pharmacology, and animal experiments.

Methods: The potential targets of “Radix ginseng (RG)-Ziziphus jujube (ZJ)” herb pair were obtained from the TCMSP database. The therapeutic targets of HUA were acquired from the GendCards, OMIM, PharmGkb, and TTD databases. Protein-protein interaction network (PPI) was constructed in the STRING 11.0 database. The David database was used for enrichment analysis. Molecular Docking was finished by the AutoDock Vina. And we employed Radix ginseng and Ziziphus jujube as raw materials, which would develop a new functional food fresh ginseng paste (FGP) after boiling. In addition, benzbromarone (Ben) (7.8 mg/kg) and allopurinol (All) (5 mg/kg) were used as positive drugs to evaluate the hyperuricemia induced by FGP (400 and 800 mg/kg) potassium oxazine (PO) (100 mg/kg) and hypoxanthine (HX) (500 mg/kg) on mice.

Results: The results showed that 25 targets in the “RG-ZJ” herb pair interacted with hyperuricemia. Then protein-protein interaction (PPI) analysis showed that TNF, IL-1β, and VEGFA were core genes. KEGG enrichment analysis showed that the Toll-like receptor signaling pathway and IL-17 signaling pathway were mainly involved. Meantime, animal experiments showed that FGP could improve the HUA status of mice by reducing serum UA BUN, XO, and liver XO levels (p < 0.05, p < 0.01). Furthermore, we analyzed the main ingredients of FGP by HPLC. We found that the main ingredients of FGP had solid binding activity to the core target of HUA by molecular docking.

Conclusion: This study explored the active ingredients and targets of the “RG-ZJ” herb pair on HUA through network pharmacology, molecular docking, and animal experiments. It revealed the improvement of FGP in mice with HUA.

Lactate metabolism in rheumatoid arthritis: Pathogenic mechanisms and therapeutic intervention with natural compounds

BACKGROUND

Rheumatoid arthritis (RA) is a common chronic and systemic autoimmune disease characterized by persistent inflammation and hyperplasia of the synovial membrane, the degradation of cartilage, and the erosion of bones in diarthrodial joints. The inflamed joints of patients with RA have been recognized to be a site of hypoxic microenvironment which results in an imbalance of lactate metabolism and the accumulation of lactate. Lactate is no longer considered solely a metabolic waste product of glycolysis, but also a combustion aid in the progression of RA from the early stages of inflammation to the late stages of bone destruction.

PURPOSE

To review the pathogenic mechanisms of lactate metabolism in RA and investigate the potential of natural compounds for treating RA linked to the regulation of imbalance in lactate metabolism.

METHODS

Research advances in our understanding of lactate metabolism in the pathogenesis of RA and novel pharmacological approaches of natural compounds by targeting lactate metabolic signaling were comprehensively reviewed and deeply discussed.

RESULTS

Lactate produced by RA synovial fibroblasts (RASFs) acts on targeted cells such as T cells, macrophages, dendritic cells and osteoclasts, and affects their differentiation, activation and function to accelerate the development of RA. Many natural compounds show therapeutic potential for RA by regulating glycolytic rate-limiting enzymes to limit lactate production, and affecting monocarboxylate transporter and acetyl-CoA carboxylase to inhibit lactate transport and conversion.

CONCLUSION

Regulation of imbalance in lactate metabolism offers novel therapeutic approaches for RA, and natural compounds capable of targeting lactate metabolic signaling constitute potential candidates for development of drugs RA.

Systematically Exploring the Chemical Ingredients and Absorbed Constituents of Polygonum capitatum in Hyperuricemia Rat Plasma Using UHPLC-Q-Orbitrap HRMS

Polygonum capitatum as an ethnic medicine has been used to treat urinary tract infections, pyelonephritis and urinary calculi. In our previous study, P. capitatum was found to have anti-hyperuricemia effects. Nevertheless, the active constituents of P. capitatum for treating hyperuricemia were still unclear. In this study, an ultra-high-performance liquid chromatography coupled to quadrupole/orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) was used to comprehensively detect the chemical ingredients of P. capitatum and its absorbed constituents in the plasma of hyperuricemia rats for the first time. Xcalibur 3.0 and Compound Discoverer 2.0 software coupled to mzCloud and ChemSpider databases were utilized for qualitative analysis. A total of 114 chemical components including phenolics, flavonoids, tannins, phenylpropanoids, amino acids, amides and others were identified or tentatively characterized based on the exact mass, retention time and structural information. Compared to the previous P. capitatum study, an additional 66 different components were detected. Moreover, 68 related xenobiotics including 16 prototype components and 52 metabolites were found in the plasma of hyperuricemia rats. The metabolic pathways included ring fission, hydrolysis, decarboxylation, dehydroxylation, methylation, glucuronidation and sulfation. This work may provide important information for further investigation on the active constituents of P. capitatum and their action mechanisms for anti-hyperuricemia effects.