Berberrubine attenuates potassium oxonate- and hypoxanthine-induced hyperuricemia by regulating urate transporters and JAK2/STAT3 signaling pathway

Nanostructured biloalbuminosomes loaded with berberine and berberrubine for Alleviating heavy Metal-Induced male infertility in rats

Despite the remarkable biological effects of berberine (BBR), particularly on fertility, its bioavailability is low. This study aims to test the effectiveness of novel nanostructured biloalbuminosomes (BILS) of BBR and its metabolite berberrubine (M1) in treatment of testicular and prostatic lesions. M1 was semi-synthesized from BBR using microwave-assisted reaction. The solvent evaporation method was used to prepare BBR-BILS and M1-BILS by three different concentrations of sodium cholate (SC) or glycocholate (SG), along with the incorporation of bovine serum albumin (BSA). The prepared BILS were fully characterized. Male infertility was induced by cadmium (Cd) at 5 mg/kg and lead (Pb) at 20 mg/kg contaminated water for 90 days, followed by treatment with BBR, M1, and their BILS (BBR-BILS and M1-BILS) for 45 days. Blood male infertility markers, testicular and prostatic oxidative stress status, autophagy, inflammation, along with testicular and prostatic concentrations of Cd and Pb, and histopathology of both tested tissues were determined using standardized protocols. The optimal BBR-BILS and M1-BILS nano-preparations, containing 30 mg SC, were chosen based on the best characterization properties of the preparations. Both nano-preparations improved heavy metals-induced testicular and prostatic deformities, as they reduced Bax and elevated Bcl-2 expressions in both tissues. Moreover, they activated the mTOR/PI3K pathway with a marked reduction in AMPK and activated LC-3II protein levels. Consequently, testicular and prostatic architecture and functions were improved. This study is the first to report the preparation of BBR and M1 BILS nano-preparations and proved their superior efficacy compared to free drugs against testicular and prostatic deformities by attenuating oxidative stress-induced excessive autophagy, offering a new hope to manage male infertility.

Targeting purine metabolism-related enzymes for therapeutic intervention: A review from molecular mechanism to therapeutic breakthrough

Purines are ancient metabolites with established and emerging metabolic and non-metabolic signaling attributes. The expression of purine metabolism-related genes is frequently activated in human malignancies, correlating with increased cancer aggressiveness and chemoresistance. Importantly, under certain stimulating conditions, the purine biosynthetic enzymes can assemble into a metabolon called "purinosomes" to enhance purine flux. Current evidence suggests that purine flux is regulated by a complex circuit that encompasses transcriptional, post-translational, metabolic, and association-dependent regulatory mechanisms. Furthermore, purines within the tumor microenvironment modulate cancer immunity through signaling mediated by purinergic receptors. The deregulation of purine metabolism has significant metabolic consequences, particularly hyperuricemia. Herbal-based therapeutics have emerged as valuable pharmacological interventions for the treatment of hyperuricemia by inhibiting the activity of hepatic XOD, modulating the expression of renal urate transporters, and suppressing inflammatory responses. This review summarizes recent advancements in the understanding of purine metabolism in clinically relevant malignancies and metabolic disorders. Additionally, we discuss the role of herbal interventions and the interaction between the host and gut microbiota in the regulation of purine homeostasis. This information will fuel the innovation of therapeutic strategies that target the disease-associated rewiring of purine metabolism for therapeutic applications.

Advancements in the study of IL-6 and its receptors in the pathogenesis of gout

Gout is an autoinflammatory disease characterized by the deposition of monosodium urate crystals in or around the joints, primarily manifesting as inflammatory arthritis that recurs and resolves spontaneously. Interleukin-6 (IL-6) is a versatile cytokine with both anti-inflammatory and pro-inflammatory capabilities, linked to a variety of inflammatory diseases such as gouty arthritis, rheumatoid arthritis, inflammatory bowel disease, vasculitis, and several types of cancer. The rapid production of IL-6 during infections and tissue damage aids in host defense. However, excessive synthesis of IL-6 and dysregulation of its receptor signaling (IL-6R) might contribute to the pathology of diseases. Recent advancements in clinical and basic research, along with developments in animal models, have established the significant role of IL-6 and its receptors in the pathogenesis of gout, although the precise mechanisms remain to be fully elucidated. This review discusses the role of IL-6 and its receptors in gout progression and examines contemporary research on modulating IL-6 and its signaling pathways for treatment. It aims to provide insights into the pathogenesis of gout and to advance the development of targeted therapies for gout-related inflammation.

Unraveling the enigma: Molecular mechanisms of berberrubine-induced nephrotoxicity reversed by its parent form berberine

BACKGROUND

Berberine is an isoquinoline alkaloid that is extensively applied in the clinic due to its potential therapeutic effects on dysentery and infectious diarrhoea. Its main metabolite, berberrubine, a promising candidate for ameliorating hyperlipidaemia, has garnered more attention than berberine. However, our study revealed that berberrubine induces severe kidney damage, while berberine was proven to be safe.

PURPOSE

Herein, we explored the opposite biological effects of these two compounds on the kidney and elucidated their underlying mechanisms.

METHODS

First, integrated metabolomic and proteomic analyses were conducted to identify relevant signalling pathways. Second, a click chemistry method combined with a cellular thermal shiftassay, a drug affinity responsive target stability assay, and microscale thermophoresis were used to identify the direct target proteins. Moreover, a mutation experiment was performed to study the specific binding sites.

RESULTS

Animal studies showed that berberrubine, but not berberine, induced severe chronic, subchronic, and acute nephrotoxicity. More importantly, berberine reversed the berberrubine-reduced nephrotoxicity. The results indicated that the cPLA2 signalling pathway was highly involved in the nephrotoxicity induced by berberrubine. We further confirmed that the direct target of berberrubine is the BASP1 protein (an upstream factor of cPLA2 signalling). Moreover, berberine alleviated nephrotoxicity by binding cPLA2 and inhibiting cPLA2 activation.

CONCLUSION

This study is the first to revel the opposite biological effects of berberine and its metabolite berberrubine in inducing kidney injury. Berberrubine, but not berberine, shows strong nephrotoxicity. The cPLA2 signalling pathway can be activated by berberrubine through targeting of BASP1, while berberine inhibits this pathway by directly binding with cPLA2. Our study paves the way for studies on the exact molecular targets of herbal ingredients. We also demonstrated that natural small molecules and their active metabolites can have opposite regulatory roles in vivo through the same signalling pathway.

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.

A System for Discovering Novel Uricosurics Targeting Urate Transporter 1 Based on In Vitro and In Vivo Modeling

Hyperuricemia has become a global burden with the increasing prevalence and risk of associated metabolic disorders and cardiovascular diseases. Uricosurics act as a vital urate-lowering therapy by promoting uric acid excretion via the kidneys. However, potent and safe uricosurics are still in urgent demand for use in the clinic. In this study, we aimed to establish in vitro and in vivo models to aid the discovery of novel uricosurics, and to search for potent active compounds, especially targeting urate transporter 1 (URAT1), the major urate transporter in the kidney handling uric acid homeostasis. As a result, for preliminary screening, the in vitro URAT1 transport activity was assessed using a non-isotopic uric acid uptake assay in hURAT1-stably expressed HEK293 cells. The in vivo therapeutic effect was evaluated in a subacute hyperuricemic mouse model (sub-HUA) and further confirmed in a chronic hyperuricemic mouse model (Ch-HUA). By utilizing these models, compound CC18002 was obtained as a potent URAT1 inhibitor, with an IC50 value of 1.69 μM, and favorable uric acid-lowering effect in both sub-HUA and Ch-HUA mice, which was comparable to that of benzbromarone at the same dosage. Moreover, the activity of xanthine oxidoreductase, the key enzyme catalyzing uric acid synthesis, was not altered by CC18002 treatment. Taken together, we have developed a novel screening system, including a cell model targeting URAT1 and two kinds of mouse models, for the discovery of novel uricosurics. Utilizing this system, compound CC18002 was investigated as a candidate URAT1 inhibitor to treat hyperuricemia.

Food-derived peptides as novel therapeutic strategies for NLRP3 inflammasome-related diseases: a systematic review

NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3), a member of the nucleotide-binding domain (NOD) and leucine-rich repeat sequence (LRR) protein (NLR) family, plays an essential role in the inflammation initiation and inflammatory mediator secretion, and thus is also associated with many disease progressions. Food-derived bioactive peptides (FDBP) exhibit excellent anti-inflammatory activity in both in vivo and in vitro models. They are encrypted in plant, meat, and milk proteins and can be released under enzymatic hydrolysis or fermentation conditions, thereby hindering the progression of hyperuricemia, inflammatory bowel disease, chronic liver disease, neurological disorders, lung injury and periodontitis by inactivating the NLRP3. However, there is a lack of systematic review around FDBP, NLRP3, and NLRP3-related diseases. Therefore, this review summarized FDBP that exert inhibiting effects on NLRP3 inflammasome from different protein sources and detailed their preparation and purification methods. Additionally, this paper also compiled the possible inhibitory mechanisms of FDBP on NLRP3 inflammasomes and its regulatory role in NLRP3 inflammasome-related diseases. Finally, the progress of cutting-edge technologies, including nanoparticle, computer-aided screening strategy and recombinant DNA technology, in the acquisition or encapsulation of NLRP3 inhibitory FDBP was discussed. This review provides a scientific basis for understanding the anti-inflammatory mechanism of FDBP through the regulation of the NLRP3 inflammasome and also provides guidance for the development of therapeutic adjuvants or functional foods enriched with these FDBP.

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.

Berberrubine is a novel and selective IMPDH2 inhibitor that impairs the growth of colorectal cancer

Inosine monophosphate dehydrogenase (IMPDH) catalyzes the rate-limiting reaction in the de novo synthesis pathway of guanine nucleotides that is highly required for cancer cell outgrowth. Herein, we found that IMPDH isoform 2 (IMPDH2) is highly expressed in colorectal cancer (CRC) and is correlated with poor patient prognosis. Via structure-based virtual screening, we identified berberrubine, a critical ingredient of the medical plant Coptis chinensis, as a novel, selective, and competitive inhibitor of IMPDH2, which demonstrated over 15-fold selectivity to IMPDH2 than IMPDH1. Besides, we also confirmed the interaction between berberrubine and IMPDH2. Of note, berberrubine treatment significantly impairs the growth of human CRC cells in a dose-dependent manner, which can be rescued by supplementing with guanosine. Furthermore, oral administration of berberrubine remarkably reduced tumor volume and weight in a human cell line-derived xenograft model. Importantly, the anti-cancer activity of berberrubine was also confirmed by using the azoxymethane (AOM) / dextran sulfate sodium (DSS)-induced spontaneous CRC mouse model. Taken together, our study highlights that berberrubine acts as a novel IMPDH2 inhibitor, suppressing the growth of CRC in vitro and in vivo, providing a fresh perspective for its potential application in the treatment of CRC.

Whey protein peptides PEW and LLW synergistically ameliorate hyperuricemia and modulate gut microbiota in potassium oxonate and hypoxanthine-induced hyperuricemic rats

Pro-Glu-Trp (PEW) and Leu-Leu-Trp (LLW) are peptides derived from whey protein digestive products; both peptides exhibit xanthine oxidase inhibitory activity in vitro. However, it remains unclear whether these peptides can alleviate hyperuricemia (HUA) in vivo. In this study, we investigated the roles of PEW and LLW, both individually and in combination, in alleviating HUA induced by potassium oxonate and hypoxanthine. Together, PEW and LLW exhibited synergistic effects in reducing the serum levels of uric acid (UA), creatinine, and blood urea nitrogen, as well as increasing the fractional excretion of UA. The combined treatment with PEW and LLW inhibited UA synthesis, promoted UA excretion, and restored renal oxidative stress and mitochondrial damage. Moreover, the combined treatment alleviated dysbiosis of the gut microbiota, characterized by increased helpful microbial abundance, decreased harmful bacterial abundance, and increased production of short-chain fatty acids. Taken together, these results indicate that the combination of PEW and LLW mitigate HUA and kidney injury by rebalancing UA synthesis and excretion, modulating gut microbiota composition, and improving oxidative stress.

Berberine attenuates uric acid-induced cell injury by inhibiting NLRP3 signaling pathway in HK-2 cells

Hyperuricemia (HUA) is a common chronic metabolic disease that can cause renal failure and even death in severe cases. Berberine (BBR) is an isoquinoline alkaloid derived from Phellodendri Cortex with strong antioxidant, anti-inflammatory, and anti-apoptotic properties. The purpose of this study was to investigate the protective effects of berberine (BBR) against uric acid (UA)-induced HK-2 cells and unravel their regulatory potential mechanisms. The CCK8 assay was carried out to detect cell viability. The expression levels of inflammatory factors interleukin-1β (IL-1β) and interleukin-18 (IL-18) and Lactate dehydrogenase (LDH) were measured using Enzyme-linked immunosorbent assays (ELISA). The expression of the apoptosis-related protein (cleaved-Caspase3, cleaved-Caspase9, BAX, BCL-2) was detected by western blot. The effects of BBR on the activities of the NOD-like receptor family pyrin domain containing 3 (NLRP3) and the expression of the downstream genes were determined by RT-PCR and western blot in HK-2 cells. From the data, BBR significantly reversed the up-regulation of inflammatory factors (IL-1β, IL-18) and LDH. Furthermore, BBR down-regulated protein expression of pro-apoptotic proteins BAX, cleaved caspase3 (cl-Caspase3), cleaved caspase9 (cl-Caspase9), and enhanced the expression of antiapoptotic protein BCL-2. Simultaneously, BBR inhibited the activated NLPR3 and reduced the mRNA levels of NLRP3, Caspase1, IL-18, and IL-1β. Also, BBR attenuated the expression of NLRP3 pathway-related proteins (NLRP3, ASC, Caspase1, cleaved-Caspase1, IL-18, IL-1β, and GSDMD). Furthermore, specific NLRP3-siRNA efficiently blocked UA-induced the level of inflammatory factors (IL-1β, IL-18) and LDH and further inhibited activated NLRP3 pathway. Collectively, our results suggested that BBR can alleviate cell injury induced by UA. The underlying unctionary mechanism may be through the NLRP3 signaling pathway.

Simiao San alleviates hyperuricemia and kidney inflammation by inhibiting NLRP3 inflammasome and JAK2/STAT3 signaling in hyperuricemia mice

ETHNOPHARMACOLOGICAL RELEVANCE

Simiao San (SmS), a famous traditional Chinese formula, is clinically used to treat patients with hyperuricemia (HUA). However, its mechanism of action on lowering uric acid (UA) and inhibiting inflammation still deserves further investigation.

AIM OF THE STUDY

To examine the effect and its possible underlying mechanism of SmS on UA metabolism and kidney injury in HUA mouse.

MATERIALS AND METHODS

The HUA mouse model was constructed with the combined administration of both potassium oxalate and hypoxanthine. The effects of SmS on UA, xanthine oxidase (XOD), creatinine (CRE), blood urea nitrogen (BUN), interleukin-10 (IL-10), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were determined by ELISA or biochemical assays. Hematoxylin and eosin (H&E) was used to observe pathological alterations in the kidneys of HUA mice. The expression levels of organic anion transporter 1 (OAT1), recombinant urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), nucleotide binding domain and leucine rich repeat pyrin domain containing 3 (NLRP3), Cleaved-Caspase 1, apoptosis-associated speck like protein (ASC), nuclear factor kappa-B (NF-κB), IL-6, janus kinase 2 (JAK2), phosphor (P)-JAK2, signal transducers and activators of transcription 3 (STAT3), P-STAT3, suppressor of cytokine signaling 3 (SOCS3) were examined by Western blot and/or immunohistochemical (IHC) staining. The major ingredients in SmS were identified by a HPLC-MS assay.

RESULTS

HUA mouse exhibited an elevation in serum levels of UA, BUN, CRE, XOD, and the ratio of urinary albumin to creatinine (UACR), and a decline in urine levels of UA and CRE. In addition, HUA induces pro-inflammatory microenvironment in mouse, including an increase in serum levels of IL-1β, IL-6, and TNF-α, and renal expressions of URAT1, GULT9, NLRP3, ASC, Cleaved-Caspase1, P-JAK2/JAK2, P-STAT3/STAT3, and SOCS3, and a decrease in serum IL-10 level and renal OAT1 expression as well as a disorganization of kidney pathological microstructure. In contrast, SmS intervention reversed these alterations in HUA mouse.

CONCLUSION

SmS could alleviate hyperuricemia and renal inflammation in HUA mouse. The action mechanisms behind these alterations may be associated with a limitation of the NLRP3 inflammasome and JAK2/STAT3 signaling pathways.

Self-Assembled nanoparticles Combining Berberine and Sodium Taurocholate for Enhanced Anti-Hyperuricemia Effect

Propose

Berberine (BBR) is extensively studied as an outstanding anti-hyperuricemia drug. However, the clinical application of BBR was limited due to its poor absorption and low bioavailability. Therefore, there is an urgent necessity to find a novel drug formulation to address the issues of BBR in clinical application.

Methods

Herein, we conducted the solubility, characterization experiments to verify whether BBR and sodium taurocholate (STC) self-assembled nanoparticles (STC@BBR-SANPs) could form. Furthermore, we proceeded the release experiment in vitro and in vivo to investigate the drug release effect. Finally, we explored the therapeutic effect of STC@BBR-SANPs on hyperuricemia (HUA) through morphological observation of organs and measurement of related indicators.

Results

The solubility, particle size, scanning electron microscopy (SEM), and stability studies showed that the stable STC@BBR-SANPs could be formed in the BBR-STC system at ratio of 1:4. Meanwhile, the tissue distribution experiments revealed that the STC@BBR-SANPs could accelerate the absorption and distribution of BBR. In addition, the pharmacology study demonstrated that both BBR and STC@BBR-SANPs exhibited favorable anti-HUA effects and nephroprotective effects, while STC@BBR-SANPs showed better therapeutic action than that of BBR.

Conclusion

This work indicated that STC@BBR-SANPs can be self-assembly formed, and exerts excellent uric acid-lowering effect. STC@BBR-SANPs can help to solve the problems of poor solubility and low absorption rate of BBR in clinical use, and provide a new perspective for the future development of BBR.

FTZ polysaccharides ameliorate kidney injury in diabetic mice by regulating gut-kidney axis

BACKGROUND

The Fufang-zhenzhu-tiaozhi formula (FTZ), a traditional Chinese medicine (TCM) commonly used to treat metabolic diseases, potentially impacts the microbial ecosystem. Increasing evidence suggests that polysaccharides, bioactive components of TCMs, have great potential on kinds of diseases such as DKD by regulating intestinal flora.

PURPOSE

This study aimed to investigate whether the polysaccharide components in FTZ (FTZPs) have beneficial effects in DKD mice via the gut-kidney axis.

STUDY DESIGN AND METHODS

The DKD model in mice was established by streptozotocin combined with a high-fat diet (STZ/HFD). Losartan was used as a positive control, and FTZPs were administered at doses of 100 and 300 mg/kg daily. Renal histological changes were measured by H&E and Masson staining. Western blotting, quantitative real-time polymerase chain reaction (q-PCR) and immunohistochemistry were performed to analyze the effects of FTZPs on renal inflammation and fibrosis, which were further confirmed using RNA sequencing. Immunofluorescence was used to analyze the effects of FTZPs on colonic barrier function in DKD mice. Faecal microbiota transplantation (FMT) was used to evaluate the contribution of intestinal flora. 16S rRNA sequencing was utilized to analyze the composition of intestinal bacteria, and UPLC-QTOF-MS-based untargeted metabolomics was used to identify the metabolite profiles.

RESULTS

Treatment with FTZPs attenuated kidney injury, as indicated by the decreased urinary albumin/creatinine ratio and improved renal architecture. FTZPs downregulated the expression of renal genes associated with inflammation, fibrosis, and systematically blunted related pathways. FTZPs also restored the colonic mucosal barrier and increased the expression of tight junction proteins (E-cadherin). The FMT experiment confirmed the substantial contribution of the FTZPs-reshaped microbiota to relieving DKD symptoms. Moreover, FTZPs elevated the content of short-chain fatty acids (propionic acid and butanoic acid) and increased the level of the SCFAs transporter Slc22a19. Intestinal flora disorders caused by diabetes, including the growth of the genera Weissella, Enterococcus and Akkermansia, were inhibited by FTZPs treatment. Spearman's analysis revealed that these bacteria were positively correlated with indicators of renal damage.

CONCLUSION

These results show that oral administration of FTZPs, by altering SCFAs levels and the gut microbiome, is a therapeutic strategy for the treatment of DKD.

Research progress on the prevention and treatment of hyperuricemia by medicinal and edible plants and its bioactive components

Hyperuricemia is another common metabolic disease, which is considered to be closely related to the development of many chronic diseases, in addition to the "three highs." Currently, although drugs show positive therapeutic effects, they have been shown to produce side effects that can damage the body. There is growing evidence that medicinal and edible plants and their bioactive components have a significant effect on hyperuricemia. In this paper, we review common medicinal and edible plants with uric acid-lowering effects and summarize the uric acid-lowering mechanisms of different bioactive components. Specifically, the bioactive components are divided into five categories: flavonoids, phenolic acids, alkaloids, polysaccharides, and saponins. These active substances exhibit positive uric acid-lowering effects by inhibiting uric acid production, promoting uric acid excretion, and improving inflammation. Overall, this review examines the potential role of medicinal and edible plants and their bioactive components as a means of combating hyperuricemia, with the hope of providing some reference value for the treatment of hyperuricemia.

Qinling liquid ameliorates renal immune inflammatory damage via activating autophagy through AMPK/Stat3 pathway in uric acid nephropathy

BACKGROUND

Excessive deposition of uric acid (UA) is one of the risk factors for kidney damage. Qinling liquid (QL) has a certain therapeutic effect on uric acid nephropathy (UAN), but its regulation mechanism is still unclear.

METHODS

UAN rat models and UA induced rat renal tubular epithelial cells (NRK-52E) were constructed to evaluate the functional roles of QL. We firstly evaluated the kidney function and the degree of kidney damage in rats after QL treatment. Then, effects of QL on autophagy and NLRP3 inflammasome activation were assessed. Moreover, the regulation of QL in AMPK and Stat3 phosphorylation levels and the relationship among autophagy, AMPK/Stat3 pathway and NLRP3 inflammasomes were determined.

RESULTS

QL could alleviate the inflammatory damage in UAN rats and promote the activation of autophagy. In addition, QL suppressed UA-induced activation of NLRP3 inflammasomes in rat renal tubular epithelial cells, which was partially reversed by autophagy inhibitor. Further, AMPK/Stat3 axis-mediated autophagy participated in the regulation of UA-induced NLRP3 inflammasome activation in NRK-52E cells. Finally, we confirmed that inhibiting AMPK/Stat3 pathway partly deteriorated the ameliorating effect of QL on renal immune inflammatory injury in UAN rats.

CONCLUSION

Through in vivo and in vitro experiments, we found that QL promotes autophagy by activating the AMPK/Stat3 pathway, thereby improving renal immune inflammatory injury in UAN.

A Network Pharmacology Method Combined with Molecular Docking Verification to Explore the Therapeutic Mechanisms Underlying Simiao Pill Herbal Medicine against Hyperuricemia

Objective

Hyperuricemia (HUA) is a common metabolic disease caused by disordered purine metabolism. We aim to reveal the mechanisms underlying the anti-HUA function of Simiao pill and provide therapeutic targets.

Methods

Simiao pill-related targets were obtained using Herbal Ingredients' Targets (HIT), Traditional Chinese Medicine Systems Pharmacology (TCMSP), and Traditional Chinese Medicine Integrated Database (TCMID). HUA-associated targets were retrieved from GeneCards, DisGeNET, and Therapeutic Targets Database (TTD). Protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, ggraph and igraph R packages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed using ClusterProfiler. The top 10 core targets were identified through cytoHubba. Molecular docking was conducted using PyMOL and AutoDock high-performance liquid chromatograph (HPLC) analysis was performed to identify effective compounds of Simiao pill.

Results

Simiao pill-HUA target network contained 80 targets. The key targets were mainly involved in inflammatory responses. Insulin (INS), tumor necrosis factor (TNF), interleukin-6 (IL6), interleukin 1 beta (IL1B), vascular endothelial growth factor A (VEGFA), leptin (LEP), signal transducer and activator of transcription 3 (STAT3), C-C motif chemokine ligand 2 (CCL2), interleukin-10 (IL10), and toll like receptor 4 (TLR4) were the top 10 targets in the PPI network. GO analysis demonstrated the main implication of the targets in molecular responses, production, and metabolism. KEGG analysis revealed that Simiao pill might mitigate HUA through advanced glycation end-product- (AGE-) receptor for AGE- (RAGE-) and hypoxia-inducible factor-1- (HIF-1-) associated pathways. IL1B, IL6, IL10, TLR4, and TNF were finally determined as the promising targets of Simiao pill treating HUA. Through molecular docking and HPLC analysis, luteolin, quercetin, rutaecarpine, baicalin, and atractylenolide I were the main active compounds.

Conclusions

Simiao pill can mitigate HUA by restraining inflammation, mediating AGE-RAGE- and HIF-1-related pathways, and targeting IL1B, IL6, IL10, TLR4, and TNF.

Hypouricemic and nephroprotective effects of palmatine from Cortex Phellodendri Amurensis: A uric acid modulator targeting Keap1-Nrf2/NLRP3 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Palmatine (Pal) is a major bioactive alkaloid originated from ancient Chinese herbal medicine Cortex Phellodendri Amurensis (CPA), which has long been applied to treat hyperuricemia (HUA)-related diseases. Pal possesses potent anti-inflammatory and anti-oxidant effects against metabolic diseases. However, its potential beneficial effect against PO (potassium oxonate)/HX (hypoxanthine)-induced HUA remains elusive.

AIM OF THE STUDY

This study aimed to investigate the potential pharmacological effect and mechanism of Pal on PO/HX-induced HUA in mice.

MATERIAL AND METHODS

A mouse model of HUA was established by co-administration of PO/HX once daily for 7 consecutive days. The HUA mice were orally given three doses (25, 50 and 100 mg/kg) of Pal daily for a week. Febuxostat (Feb, 5 mg/kg) was given as a positive control. At the scheduled termination of the experiment, the whole blood, liver and kidney were collected for subsequent analyses. The concentrations of uric acid (UA), creatinine (CRE) and blood urea nitrogen (BUN), and activities of adenosine deaminase (ADA) and xanthine oxidase (XOD) were evaluated. Histopathological alterations of the kidney were detected by H&E staining. The inflammatory and oxidative stress status was detected by assay kits. Additionally, key proteins involved in the urate transporter, Keap1-Nrf2 and TXNIP/NLRP3 signaling pathways were evaluated by immunohistochemistry and Western blotting. Finally, molecular docking was employed to probe the binding characteristics of Pal and target proteins Keap1, NLRP3, URAT1 and HO-1.

RESULTS

Administration of Pal substantially decreased the elevated kidney weight, lowered UA, CRE and BUN levels, and attenuated abnormal histopathological alterations. Meanwhile, treatment with Pal also dramatically lowered hepatic XOD and ADA activities. Besides, Pal treatment effectively mitigated the renal inflammatory and oxidative stress markers. Further mechanistic investigation indicated Pal distinctly downregulated the protein levels of GLUT9 and URAT1, while up-regulated the expression levels of OAT1 and ABCG2. Pal also restored Nrf2 activation, promoted subsequent expression of anti-oxidative enzymes, and downregulated the expressions of TXNIP, NLRP3, apoptosis-associated speck-like (ASC), caspase-1, IL-1β and IL-18. Molecular docking analysis also indicated Pal firmly bound with Keap1, NLRP3, URAT1 and HO-1.

CONCLUSIONS

These findings indicated that Pal exhibited favorable anti-HUA effect via modulating the expressions of transporter-related proteins and suppressing XOD activity. Furthermore, Pal also alleviated HUA-induced kidney injury, which was at least partially related to restoring Keap1-Nrf2 pathway and inhibiting TXNIP/NLRP3 inflammasome. Our investigation was envisaged to provide experimental support for the traditional application of CPA and CPA-containing classical herbal formulas in the management of HUA-related diseases and might provide novel dimension to the clinical application of Pal.

Oxyberberrubine, a novel liver microsomes-mediated secondary metabolite of berberine, alleviates hyperuricemic nephropathy in mice

BACKGROUND

Berberrubine (BRB), one of the major metabolites of berberine (BBR), exerts an anti-hyperuricemic effect even superior to BBR. Liver is an important location for drug transformation. Nevertheless, there are few studies on the bioactivities and metabolites of BRB.

PURPOSE

We investigated whether oxyberberrubine (OBR), a liver metabolite of BRB, exerted urate-lowering and reno-protective effects in hyperuricemic mice.

METHODS

Liver microsomes were used to incubate BRB for studying its biotransformation. We isolated and identified its new metabolite OBR, and investigated its anti-hyperuricemic and reno-protective effects. In this work, the hyperuricemic mice model was established by receiving potassium oxonate (PO) and hypoxanthine (HX) for 7 consecutive days. 1 h after modeling, different dosages of OBR (5, 10 and 20 mg/kg), BRB (20 mg/kg) or febuxostat (Fex, 5 mg/kg) were given mice by gavage.

RESULTS

Results showed that OBR possessed potent anti-hyperuricemic and reno-protective effects in hyperuricemic mice. Serum uric acid (UA) level was lowered, and the activities of xanthine oxidase (XOD) as well as adenosine deaminase (ADA) in the liver were suppressed after treatment with OBR. Hepatic expressions of XOD were remarkably decreased at mRNA and protein levels by OBR treatment. In addition, OBR prominently alleviated renal injury, embodied in markedly reduced serum creatinine and blood urea nitrogen (BUN) levels, decreased inflammatory mediators (TNF-α, IL-1β, IL-6 and IL-18) levels, mRNA expression of CYP27B1 and repairment of renal tissues damage. Besides, OBR down-regulated renal expression of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), and caspase-1 at mRNA and protein levels.

CONCLUSIONS

In short, our study indicated that OBR possessed superior anti-hyperuricemic and reno-protective effects, at least in part, through the inhibition of XOD, URAT1, GLUT9 and NLRP3 inflammasome signaling pathway in the kidney.

Berberine Depresses Inflammation and Adjusts Smooth Muscle to Ameliorate Ulcerative Colitis of Cats by Regulating Gut Microbiota

Intestinal microbiota dysbiosis is a well established characteristic of ulcerative colitis (UC). Regulating the gut microbiota is an effective UC treatment strategy. Berberine (BBR), an alkaloid extracted from several Chinese herbs, is a common traditional Chinese medicine. To establish the efficacy and mechanism of action of BBR, we constructed a UC model using healthy adult shorthair cats to conduct a systematic study of colonic tissue pathology, inflammatory factor expression, and gut microbiota structure. We investigated the therapeutic capacity of BBR for regulating the gut microbiota and thus work against UC in cats using 16S rRNA genes amplicon sequencing technology. Our results revealed that dextran sulfate sodium (DSS)-induced cat models of UC showed weight loss, diarrhea accompanied by mucous and blood, histological abnormalities, and shortening of the colon, all of which were significantly alleviated by supplementation with BBR. A 16S rRNA gene-based microbiota analysis demonstrated that BBR could significantly benefit gut microbiota. Western blot, quantitative PCR, and enzyme-linked immunosorbent assays (ELISAs) showed that in DSS-induced cat models, the expression of the inflammatory factors was increased, activating the JAK2/STAT3 signaling pathway, and treatment with BBR reversed this effect. The myosin light chain (MLC) phosphorylation in the smooth muscle of the intestines is associated with motility of inflammation-related diarrhea in cats. This study used gut flora analyses to demonstrate the anti-UC effects of BBR and its potential therapeutic mechanisms and offers novel insights into the prevention of inflammatory diseases using natural products. IMPORTANCE Ulcerative colitis (UC) is common in clinics. Intestinal microbiota disorder is correlated with ulcerative colitis. Although there are many studies on ulcerative colitis in rats, there are few studies on colitis in cats. Therefore, this study explored the possibility of the use of BBR as a safe and efficient treatment for colitis in cats. The results demonstrated the therapeutic effects of BBR on UC based on the state of the intestinal flora. The study found BBR supplementation to be effective against dextran sulfate sodium (DSS)-induced colitis, smooth muscle damage, and gut microbiota dysbiosis.

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

Hyperuricemia is the result of increased production and/or underexcretion of uric acid. Hyperuricemia has been epidemiologically associated with multiple comorbidities, including metabolic syndrome, gout with long-term systemic inflammation, chronic kidney disease, urolithiasis, cardiovascular disease, hypertension, rheumatoid arthritis, dyslipidemia, diabetes/insulin resistance and increased oxidative stress. Dysregulation of xanthine oxidoreductase (XOD), the enzyme that catalyzes uric acid biosynthesis primarily in the liver, and urate transporters that reabsorb urate in the renal proximal tubules (URAT1, GLUT9, OAT4 and OAT10) and secrete urate (ABCG2, OAT1, OAT3, NPT1, and NPT4) in the renal tubules and intestine, is a major cause of hyperuricemia, along with variations in the genes encoding these proteins. The first-line therapeutic drugs used to lower serum uric acid levels include XOD inhibitors that limit uric acid biosynthesis and uricosurics that decrease urate reabsorption in the renal proximal tubules and increase urate excretion into the urine and intestine via urate transporters. However, long-term use of high doses of these drugs induces acute kidney disease, chronic kidney disease and liver toxicity. Therefore, there is an urgent need for new nephroprotective drugs with improved safety profiles and tolerance. The current systematic review summarizes the characteristics of major urate transporters, the mechanisms underlying the pathogenesis of hyperuricemia, and the regulation of uric acid biosynthesis and transport. Most importantly, this review highlights the potential mechanisms of action of some naturally occurring bioactive compounds with antihyperuricemic and nephroprotective potential isolated from various medicinal plants.

Apigenin Ameliorates Hyperuricemia and Renal Injury through Regulation of Uric Acid Metabolism and JAK2/STAT3 Signaling Pathway

Hyperuricemia (HUA) is a kind of metabolic disease with high incidence that still needs new countermeasures. Apigenin has uric-lowering and kidney-protective activities, but how apigenin attenuates HUA and renal injury remains largely unexploited. To this end, an acute HUA mouse model was established by intraperitoneal injection of potassium oxazinate and oral administration with hypoxanthine for 7 consecutive days. Apigenin intervention decreased serum uric acid (UA), creatinine (CRE), blood urea nitrogen (BUN), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor (TNF-α), interleukin-18 (IL-18), liver xanthine oxidase (XOD), and urine protein levels, and increased serum interleukin-10 (IL-10) and urine UA and CRE levels in HUA mice. Moreover, administration of apigenin to HUA mice prevented renal injury, decreased renal glucose transporter 9 (GLUT9) and urate anion transporter 1 (URAT1) levels, and increased renal organic anion transporter 1 (OAT1). These alterations were associated with an inhibition of IL-6, phospho-janus kinase 2 (P-JAK2), phospho-signal transducer, and activator of transcription 3 (P-STAT3), and suppression of cytokine signaling 3 (SOCS3) expression in the kidneys. Additionally, the molecular docking results showed that apigenin had strong binding capacity with UA transporters and JAK2 proteins. In summary, apigenin could improve UA metabolism and attenuate renal injury through inhibiting UA production, promoting excretion, and suppressing the JAK2/STAT3 signaling pathway in HUA mice. The results suggest that apigenin may be a suitable drug candidate for management of HUA and its associated renal injury.

Integrating network pharmacology and pharmacological validation to explore the effect of Shi Wei Ru Xiang powder on suppressing hyperuricemia

ETHNOPHARMACOLOGICAL RELEVANCE

Shi Wei Ru Xiang powder (SWR) is a traditional Tibetan medicinal formula with the effect of dispelling dampness and dispersing cold. In clinical practice, SWR is generally used for the treatment of hyperuricemia (HUA). However, its exact pharmacological mechanism remains unclear.

AIMS OF THE STUDY

To preliminarily elucidate the regulatory effects and possible mechanisms of SWR on hyperuricemia using network pharmacology and experimental validation.

MATERIALS AND METHODS

A mouse model of hyperuricemia was used to evaluate the alleviating effect of SWR on hyperuricemia. The major components of SWR were acquired by UPLC-Q/TOF-MS. The potential molecular targets and associated signaling pathways were predicted through network pharmacology. The mechanism of action of SWR in ameliorating hyperuricemia was further investigated by pharmacological evaluation.

RESULTS

Mice with hyperuricemia and renal dysfunction were ameliorated by SWR. The 36 components of SWR included phenolic acids, terpenoids, alkaloids and flavonoids were identified. Network pharmacological analysis showed the involvement of the above compounds, and 115 targets were involved to treat hyperuricemia, involving multiple biological processes and different signaling pathways. Pharmacological experiments validated that SWR ameliorated hyperuricemic nephropathy in mice by modulating the mitogen-activated protein kinase (MAPK) signaling pathway, nuclear factor kappaB (NF-κB) signaling pathway and NOD-like receptor signaling pathway.

CONCLUSION

MAPK signaling pathway, NF-κB signaling pathway and NOD-like receptor signaling pathway play important roles in the therapeutic effects of SWR on hyperuricemia.

Fufang Zhenzhu Tiaozhi capsule ameliorates hyperuricemic nephropathy by inhibition of PI3K/AKT/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Excessive serum uric acid (SUA) causes hyperuricemic nephropathy (HN), characterized by inflammatory infiltration and tubulointerstitial fibrosis. Most recently, we demonstrated that Fufang Zhenzhu Tiaozhi (FTZ) capsule attenuated diabetic nephropathy through inhibition of renal inflammation and fibrosis. However, whether FTZ ameliorates HN is still unclear.

AIM OF THE STUDY

To determine the protective roles and mechanism of FTZ in mouse renal injury and fibrosis under hyperuricemic condition.

MATERIALS AND METHODS

HN mice, induced by potassium oxonate and hypoxanthine, were administrated with 600 and 1200 mg/kg FTZ (intragastrically) daily for three weeks. SUA levels, renal functions and histological changes were analyzed. Western blotting, quantitative real-time PCR (q-PCR) and RNA sequencing were used to identify the roles and underlying mechanism of FTZ in HN mice.

RESULTS

We demonstrated that FTZ treatment mitigated renal injury in mice, as evidenced by the decrease in SUA, serum creatinine (SCr) and cystatin C (Cys C) levels, as well as improved renal histology. FTZ markedly attenuates inflammasome activation, collagen deposition and the imbalance of uric acid transporters. RNA-sequencing revealed a key mechanism involved in the protective effects on HN mice was related to PI3K/AKT/NF-κB pathway. Western blot also confirmed that FTZ diminished the phosphorylation of AKT and p65 in HN mice.

CONCLUSIONS

FTZ prevents renal injury, inflammation and fibrosis in HN mice via promoting uric acid excretion and inhibiting PI3K/AKT/NF-κB signaling pathway.

Integrating network pharmacology and experimental validation to clarify the anti-hyperuricemia mechanism of cortex phellodendri in mice

Hyperuricemia (HUA), a common metabolic disease, is treated as the second-largest metabolic disease after diabetes in China. Cortex Phellodendri (CP) is one of the most frequently used herbal medicines for treating gout or HUA. However, the mechanism underlying the anti-HUA effect of CP is still unrevealed. Hence, this study aimed to explore the pharmacological mechanism of CP against HUA using network pharmacology coupled with in vivo experimental validation. Active compounds and potential targets of CP, as well as the potential targets related to HUA, were retrieved from multiple open-source databases. The drug-disease overlapping targets were obtained by Venn diagram analysis and used to construct the herb-component-target (HCT), protein-protein-interaction (PPI), and component-target-pathway (CTP) networks. The functional enrichment analysis was also performed for further study. Furthermore, a HUA mouse model was induced by a combination of intraperitoneal injection of potassium oxonate (PO, 300 mg/kg) and intragastric administration of hypoxanthine (HX, 300 mg/kg) daily for 10 days. Different dosages of CP (200, 400, and 800 mg/kg) were orally given to mice 1 h after modeling. The results showed that 12 bioactive compounds and 122 drug-disease overlapping targets were obtained by matching 415 CP-related targets and 679 HUA-related targets, and berberine was one of the most important compounds with the highest degree value. The core targets of CP for treating HUA were TP53, MAPK8, MAPK3, IL-6, c-Jun, AKT1, xanthine oxidase (XOD), and ATP-binding cassette subfamily G member 2 (ABCG2). The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results showed that the anti-HUA effect of CP mainly involved the pathways of inflammation and apoptosis, such as PI3K/Akt, TNF, MAPK, TLR, AMPK, NF-κB, and NLRP3 signaling pathways. In vivo animal experiment further confirmed the hypouricemic effect of CP in a HUA mouse model, as evidenced by significantly restored kidney histological deteriorations, and considerably decreased levels of serum uric acid (sUA), creatinine (Cre), blood urea nitrogen (BUN), and hepatic UA. Furthermore, the hypouricemic action of CP in vivo might be attributed to its suppression of XOD activity in the liver, rather than ABCG2 in the kidney. Real-time qPCR (RT-qPCR) and Western blot analysis also confirmed the key roles of the hub genes in CP against HUA. In conclusion, CP exhibited therapeutic effect against HUA via multi-compounds, multi-targets, and multi-pathways. It possessed anti-HUA and nephroprotective effects via suppressing XOD activity, and reversed the progression of renal injury by exerting anti-inflammatory and anti-apoptotic effects.

A Brief Review of Natural Products with Urate Transporter 1 Inhibition for the Treatment of Hyperuricemia

Hyperuricemia is a common disease caused by a high level of uric acid. Urate transporter 1 (URAT1) is an important protein and mediates approximately 90% of uric acid reabsorption. Therefore, the URAT1 inhibitor is a class of uricosuric medicines widely used in the clinic for the treatment of hyperuricemia. To find the new medicine with stronger URAT1 inhibition and lower toxicity, researchers have been exploring natural products. This study systematically summarizes the natural products with URAT1 inhibition. The results show that many natural products are potential URAT1 inhibitors, such as flavonoids, terpenoids, alkaloids, coumarins, stilbenes, and steroids, among which flavonoids are the most promising source of URAT1 inhibitors. It is worth noting that most studies have focused on finding natural products with inhibition of URAT1 and have not explored their activities and mechanisms toward URAT1. By reviewing the few existing studies of the structure-activity relationship and analyzing common features of natural products with URAT1 inhibition, we speculate that the rigid ring structure and negative charge may be the keys for natural products to produce URAT1 inhibition. In conclusion, natural products are potential URAT1 inhibitors, and exploring the mechanism of action and structure-activity relationship will be an important research direction in the future.