Ameliorative action of "daitongxiao" against hyperuricemia includes the "uric acid transporter group".

This study aimed to investigate the potential mechanisms involved in the therapeutic effects of daitongxiao (DTX) on hyperuricemia (HUA). DTX was administered to two animal models of HUA via gavage feeding: HUA quail model (a uricotelic animal with urate oxidase deficiency), treated continuously for 35 days post-HUA induction, and HUA rats (an animal with active urate oxidase), treated continuously for 28 days post-HUA induction. HUA was induced in quail by administering a solution of sterile dry yeast powder via gavage feeding, while in rats, it was induced by intragastric gavage feeding of a solution of adenine and ethambutol hydrochloride. DTX improved overall health; increased bodyweight; reduced renal index, serum urate levels, serum xanthine oxidase activity, blood urea nitrogen, and creatinine; and enhanced urinary and fecal uric acid (UA) excretion in these two animal models. The results of hematoxylin and eosin and hexamine silver staining of kidney sections revealed that DTX significantly mitigated HUA-induced renal structural damage and inflammatory response. The results of quantitative real-time polymerase chain reaction, Western blotting, and immunofluorescence analyses revealed that DTX downregulated the renal expression levels of glucose transporter 9 (GLUT9) and upregulated the renal expression levels of organic anion transporters (OAT1 and OAT3) in both HUA models. Thus, the findings of this study suggest that DTX suppresses the progression of HUA by modulating the expression of the UA transporter group members.

Limosilactobacillus reuteri HCS02-001 Attenuates Hyperuricemia through Gut Microbiota-Dependent Regulation of Uric Acid Biosynthesis and Excretion.

Hyperuricemia is a prevalent metabolic disorder that arises from abnormal purine metabolism and reduced excretion of uric acid (UA). The gut microbiota plays a significant role in the biosynthesis and excretion of UA. Probiotics capable of purine degradation possess the potential to prevent hyperuricemia. Our study aimed to screen probiotics in areas with abundant dairy products and longevity populations in China, which could attenuate the level of UA and explore the underlying mechanism. In this study, twenty-three lactic acid bacteria isolated from healthy Chinese infant feces and traditional fermented foods such as hurood and lump milk were evaluated for the ability to tolerance acid, bile, artificial gastric juice, and artificial intestinal juice to determine the potential of the candidate strains as probiotics. Eight strains were identified as possessing superior tolerance to simulated intestinal conditions and were further analyzed by high-performance liquid chromatography (HPLC), revealing that Limosilactobacillus reuteri HCS02-001 (Lact-1) and Lacticaseibacillus paracasei HCS17-040 (Lact-2) possess the most potent ability to degrade purine nucleosides. The effect of Lact-1 and Lact-2 on hyperuricemia was evaluated by intervening with them in the potassium oxonate and adenine-induced hyperuricemia Balb/c mice model in vivo. Our results showed that the level of serum UA in hyperuricemic mice can be efficiently reduced via the oral administration of Lact-1 (p < 0.05). It significantly inhibited the levels of liver inflammatory cytokines and hepatic xanthine oxidase through a TLR4/MyD88/NF-κB pathway across the gut-liver axis. Furthermore, UA transporters ABCG2 and SLC2A9 were substantially upregulated by the intervention of this probiotic. Fecal ATP levels were significantly induced, while fecal xanthine dehydrogenase and allantoinase levels were increased following probiotics. RNA sequencing of HT-29 cells line treated with Lact-1 and its metabolites demonstrated significant regulation of pathways related to hyperuricemia. In summary, these findings demonstrate that Limosilactobacillus reuteri HCS02-001 possesses a capacity to ameliorate hyperuricemia by inhibiting UA biosynthesis via enhancing gastrointestinal barrier functions and promoting UA removal through the upregulation of urate transporters, thereby providing a basis for the probiotic formulation by targeting the gut microbiota.

Design, synthesis, and biological evaluation of 3-phenyl substituted pyridine derivatives as potential dual inhibitors of XOR and URAT1.

Xanthine oxidoreductase (XOR) and uric acid transporter 1 (URAT1) are two most widely studied targets involved in production and reabsorption of uric acid, respectively. Marketed drugs almost target XOR or URAT1, but sometimes, single agents might not achieve aim of lowering uric acid to ideal value in clinic. Thus, therapeutic strategies of combining XOR inhibitors with uricosuric drugs were proposed and implemented. Based on our initial work of virtual screening, A and B were potential hits for dual-targeted inhibitors on XOR/URAT1. By docking A/B with XOR/URAT1 respectively, compounds I1-7 were designed to get different degree of inhibition effect on XOR and URAT1, and I7 showed the best inhibitory effect on XOR (IC50 = 0.037 ± 0.001 µM) and URAT1 (IC50 = 546.70 ± 32.60 µM). Further docking research on I7 with XOR/URAT1 led to the design of compounds II with the significantly improved inhibitory activity on XOR and URAT1, such as II11 and II15. Especially, for II15, the IC50 of XOR is 0.006 ± 0.000 µM, superior to that of febuxostat (IC50 = 0.008 ± 0.000 µM), IC50 of URAT1 is 12.90 ± 2.30 µM, superior to that of benzbromarone (IC50 = 27.04 ± 2.55 µM). In acute hyperuricemia mouse model, II15 showed significant uric acid lowering effect. The results suggest that II15 had good inhibitory effect on XOR/URAT1, with the possibility for further investigation in in-vivo models of hyperuricemia.

Design, synthesis, and evaluation of the in vitro activity of novel dual inhibitors of XOR and URAT1 containing a benzoic acid group.

Xanthine oxidoreductase (XOR) and uric acid transporter 1 (URAT1) are involved in the production and reabsorption of uric acid, respectively. However, the currently available individual XOR- or URAT1-targeted drugs have limited efficacy. Thus, strategies for combining XOR inhibitors with uricosuric drugs have been developed. Previous virtual screening identified Compounds 1-5 as hits for the potential dual inhibition of XOR/URAT1. Nevertheless, in vitro experiments yielded unsatisfactory results. The first round of optimization work on those hits was performed, and two series of compounds were designed and synthesized. Compounds of the A series exerted moderate inhibitory effects on URAT1, but extremely weak inhibitory effects on XOR. Compounds of the B series exerted strong inhibitory effects on both XOR and URAT1. B5 exhibited the greatest inhibitory activity, with similar inhibitory effects on XOR and URAT1. The half maximal inhibitory concentration (IC50 ) of XOR was 0.012 ± 0.001 µM, equivalent to that of febuxostat (IC50 = 0.010 ± 0.001 µM). The IC50 of URAT1 was 30.24 ± 3.46 µM, equivalent to that of benzbromarone (IC50 = 24.89 ± 7.53 µM). Through this optimization, the in vitro activity of most compounds of the A and B series against XOR and URAT1 was significantly improved versus that of the hits. Compound B5 should be further investigated.

Model Informed Development of SIM0295 in Patients with Gout and Hyperuricemia and Healthy Volunteers Using a Population Pharmacokinetics/ Pharmacodynamics Approach.

BACKGROUND: SIM0295, a novel inhibitor of human uric acid transporter 1 (hURAT1), is used to treat patients with gout and hyperuricemia. This study aimed to develop population pharmacokinetics and pharmacodynamics (popPK/PD) models of SIM0295 and explore potential covariates to inform clinical drug development. RESEARCH DESIGN AND METHODS: Data were obtained from four phase I studies conducted in healthy Korean and Chinese subjects and two phase II studies conducted in Korean patients with gout and hyperuricemia. The popPK/PD model of SIM0295 was developed using nonlinear mixed effects modeling. RESULTS: SIM0295 pharmacokinetics was described using a two-compartment model with the absorption of four transit compartments and first-order elimination. PK parameters were normalized to weight via allometric scaling. Food was identified as a factor significantly affecting the absorption rate, with no clinical relevance. The sigmoid Emax model with a semi-mechanism of inhibition of serum uric acid (sUA) reabsorption was used to describe the exposure-response relationship. Additionally, Monte Carlo simulations demonstrated that approimately 9 mg/day of SIM0295 for 7 days could achieve the maximum decrease in sUA. CONCLUSION: The established popPK/PD model characterized the dose-exposure-response relationship for SIM0295 in healthy subjects and patients with gout and hyperuricemia and could be used to inform the drug development.

NRBP1 modulates uric acid transporter ABCG2 expression by activating the Wnt/B-catenin pathway in HK-2 cells / NRBP1 regula la expresión del transportador de ácido úrico ABCG2 en las células HK-2 mediante la activación de la vía Wnt/B-catenina

Background: Nuclear receptor binding protein 1 (NRBP1) and ATP-binding cassette subfamily G member 2 (ABCG2) was the gout risk gene and high-capacity urate exporter respectively. However, the relationship between NRBP1 and ABCG2 and the underlying molecular mechanism contributing to these associations are unknown. Methods: Firstly, the efficiency of the overexpression and knockdown of NRBP1 was confirmed by western blot. Next, the effect of NRBP1 overexpression and knockdown on the expression of ABCG2, organic anion transporter 1 (OAT1), glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) was detected by qRT-PCR and western blot. At the same time, the cellular location of ABCG2 and its expression after NRBP1 overexpression and knockdown was tested by immunofluorescence (IF) staining. Then, the mechanism of NRBP1 modulates ABCG2 expression was evaluated by western blot with or without the β-catenin inhibitor (21H7). Results: The lentivirus system was used to generate stable NRBP1 overexpression, while the plasmids carrying a NRBP1 siRNA was generated to knockdown NRBP1 expression in HK-2 cells. Meanwhile, the overexpression of NRBP1 significantly decreased the mRNAs and proteins expression of GLUT9 and URAT1, while the knockdown of NRBP1 increased the mRNAs and proteins expression of ABCG2 significantly. In addition, the NRBP1 modulates the expression of ABCG2 was by ctivating the Wnt/β-catenin pathway in HK-2 cells according to the IF and western blot results. Conclusion: Taken together, our study demonstrated that NRBP1 inhibition played an essential role in attenuating hyperuricemia and gout by upregulation of ABCG2 via Wnt/β-catenin signaling pathway in HK-2 cells. (AU)

Antecedentes: La proteína de unión al receptor nuclear 1 (NRBP1) y el miembro G de la subclase ATP binding Box 2 (ABCG2) son los genes de riesgo de gota y los genes de salida de urato de alto rendimiento, respectivamente. Sin embargo, se desconoce la relación entre NRBP1 y ABCG2, y los posibles mecanismos moleculares que conducen a estas asociaciones. Métodos: En primer lugar, la sobreexpresión y el knockout de NRBP1 fueron confirmados por Western-blot. Los efectos de la sobreexpresión y knockout de NRBP1 en la expresión de ABCG2, transportador de aniones orgánicos 1 (OAT1), transportador de glucosa 9 (GLUT9) y transportador de ácido úrico 1 (URAT1) fueron detectados por qRT-PCR y Western-blot. Mientras tanto, la localización y expresión de ABCG2 después de la sobreexpresión y knockout de NRBP1 fueron detectadas por inmunofluorescencia (IF). Luego, el efecto regulador de NRBP1 sobre la expresión de ABCG2 fue estudiado por Western-blot y comparado con el inhibidor de la β-catenina (21H7). Resultados: El sistema lentiviral indujo una sobreexpresión estable de NRBP1, mientras que el plásmido portador de SiRNA NRBP1 inhibió la expresión de NRBP1 en las células HK-2. Mientras tanto, la sobreexpresión de NRBP1 redujo significativamente la expresión de ARNm y proteínas de GLUT9 y URAT1, mientras que el knockout de NRBP1 aumentó significativamente la expresión de ARNm y proteínas de ABCG2. Además, de acuerdo con los resultados de IF y Western-blot, NRBP1 regula la expresión de ABCG2 activando la vía Wnt/β-catenina en las células HK-2. Conclusión: La inhibición del NRBP1 aumenta la regulación de ABCG2 a través de la vía de señalización Wnt/β-catenina, que desempeña un papel importante en la reducción de la hiperuricemia y la gota. (AU)

Characterization of Urate Metabolism and Complications of Patients with Renal Hypouricemia.

Objective Both renal hypouricemia (RHU) and gout are associated with renal dysfunction and urolithiasis. The difference in renal complications associated with RHU and gout, however, has not been studied. We characterized the urate metabolism and complications of patients with RHU and compared them with patients with gout. Methods Eighteen patients with RHU who had a serum uric acid (SUA) level <2 mg/dL (10 men and 8 women), 44 patients with gout (44 men) and 16 normouricemic patients (4 men and 12 women) were included. The blood and urinary biochemical data were evaluated. A genetic analysis of uric acid transporter 1 (URAT1) was also conducted in 15 cases with RHU. Results The SUA level of RHU was 0.9±0.5/mg/dL, and the Uur/Ucr and Cur/Ccr were 0.56±0.14% and 45.7±18.0%, respectively. A genetic analysis of URAT1 in 15 RHU patients showed that 13 harbored a URAT1 gene mutation, whereas 2 harbored the wild-type gene. The SUA level was significantly lower in RHU patients (n=11) than in either gout patients (n=44) or normouricemic patients (n=16). This reduction was accompanied by the elevation of Cua/Ccr. Urinary beta 2-microglobulin levels were higher in RHU patients than in gout or normouricemia patients. Cua/Ccr correlated with normalized urinary beta 2-microglobulin levels. The prevalence of urolithiasis was 18.2% in RHU cases and 6.8% in gout cases. A homozygous URAT1 mutation was associated with urolithiasis. Conclusion Besides urolithiasis, RHU can be associated with tubular dysfunction, such as elevated urinary beta 2-microglobulin levels.

NRBP1 modulates uric acid transporter ABCG2 expression by activating the Wnt/ß-catenin pathway in HK-2 cells.

BACKGROUND: Nuclear receptor binding protein 1 (NRBP1) and ATP-binding cassette subfamily G member 2 (ABCG2) was the gout risk gene and high-capacity urate exporter respectively. However, the relationship between NRBP1 and ABCG2 and the underlying molecular mechanism contributing to these associations are unknown. METHODS: Firstly, the efficiency of the overexpression and knockdown of NRBP1 was confirmed by western blot. Next, the effect of NRBP1 overexpression and knockdown on the expression of ABCG2, organic anion transporter 1 (OAT1), glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) was detected by qRT-PCR and western blot. At the same time, the cellular location of ABCG2 and its expression after NRBP1 overexpression and knockdown was tested by immunofluorescence (IF) staining. Then, the mechanism of NRBP1 modulates ABCG2 expression was evaluated by western blot with or without the ß-catenin inhibitor (21H7). RESULTS: The lentivirus system was used to generate stable NRBP1 overexpression, while the plasmids carrying a NRBP1 siRNA was generated to knockdown NRBP1 expression in HK-2 cells. Meanwhile, the overexpression of NRBP1 significantly decreased the mRNAs and proteins expression of GLUT9 and URAT1, while the knockdown of NRBP1 increased the mRNAs and proteins expression of ABCG2 significantly. In addition, the NRBP1 modulates the expression of ABCG2 was by ctivating the Wnt/ß-catenin pathway in HK-2 cells according to the IF and western blot results. CONCLUSION: Taken together, our study demonstrated that NRBP1 inhibition played an essential role in attenuating hyperuricemia and gout by upregulation of ABCG2 via Wnt/ß-catenin signaling pathway in HK-2 cells.

Effect of Alcohol Extract of Oroxylum indicum on Reducing Uric Acid and Protecting Kidney in Hyperuricemia Mice / 中国实验方剂学杂志

ObjectiveTo investigate the effect of alcohol extract of Oroxylum indicum （MHD-80） on reducing uric acid （UA） and protecting the kidney in the hyperuricemia （HUA） model in vivo. MethodPotassium oxazine （350 mg·kg-1） and adenine （80 mg·kg-1） were used to construct an HUA model of mice in vivo to evaluate the mechanism related to UA reduction and the protective effect of renal function of MHD-80. Seventy male ICR mice were randomly divided into seven groups， including the normal group， model group， allopurinol group （5 mg·kg-1）， febusotan group （5 mg·kg-1）， and MHD-80 low-， medium-， and high-dose groups （3， 6， 12 mg·kg-1）， with 10 in each group. Except for the normal group， the other groups were given intragastric administration of potassium oxazine and adenine for 14 consecutive days to establish the HUA model. On the 8th to 14th day after modeling， each group was given corresponding drugs by intragastric administration， once a day. 1 h after the last administration， blood was collected from the eyeballs， and kidney and liver tissues of mice were collected. Serum levels of UA， urea nitrogen （BUN）， and creatinine （Cr） and liver activity of xanthine oxidase （XOD） were determined by enzyme colorimetry. Serum contents of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） were determined by enzyme-linked immunosorbent assay （ELISA）. Hematoxilin-eosin （HE） staining was used to observe the pathological changes in kidney tissues. The protein expression levels of ATP-binding box transporter G2 （ABCG2） and glucose-facilitating transporter 9 （GLUT9） in kidney tissues were detected by Western blot. ResultIn vivo experiment shows that compared with the normal group， the serum levels of UA， Cr， BUN， inflammatory factors TNF-α， IL-1β， and liver XOD activity in the serum of mice in the model group were significantly increased （P<0.05， P<0.01）， and the expression of GLUT9 in kidney tissues was significantly up-regulated （P<0.05）. ABCG2 protein expression was significantly down-regulated （P<0.05）， and renal injury was obvious. Compared with the model group， the levels of UA， BUN， Cr， TNF-α， IL-1β， and liver XOD activity in the serum of mice in the high-dose group of MHD-80 were decreased to different degrees （P<0.05， P<0.01）， GLUT9 protein expression was significantly down-regulated （P<0.01）， ABCG2 protein expression was significantly up-regulated （P<0.05） in the high-dose group of MHD-80， and the degree of renal injury was reduced. ConclusionMHD-80 has certain uric acid reduction， anti-inflammatory， and anti-renal injury effects， which are related to inhibiting XOD activity and regulating the expression of ABCG2 and GLUT9 uric acid transporter.

Therapeutic effects and mechanisms of N-(9,10-anthraquinone-2-ylcarbonyl) xanthine oxidase inhibitors on hyperuricemia.

Objective: To observe the antioxidative effects of N-(9,10-anthraquinone-2-ylcarbonyl) xanthine oxidase inhibitors (NAY) in vitro and in vivo models of hyperuricemia and explore the mechanism. Methods: A classical experimental method of acute toxicity and a chronic toxicity test were used to compare the toxic effects of different doses of NAY in mice. The hyperuricemia mouse model was established by gavage of potassium oxonate in vivo. After treatment with different doses of NAY (low dose: 10 mg/kg, medium dose: 20 mg/kg, and high dose: 40 mg/kg) and allopurinol (positive drug, 10 mg/kg), observe the levels of uric acid (UA), creatinine (CRE), and urea nitrogen (BUN) in urine and serum, respectively, and detect the activities of xanthine oxidase in the liver. The hyperuricemia cell model was induced by adenosine and xanthine oxidase in vitro. The cells were given different doses of NAY (50, 100, and 200 µmol/L) and allopurinol (100 µmol/L). Then the culture supernatant UA level of the medium was measured. The next step was to detect the xanthine oxidase activity in the liver and AML12 cells, and the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammatory factors in the kidney and serum of mice. Western blot was used to detect xanthine oxidase protein expression in mouse liver tissue and AML12 cells, ASC, Caspase-1, NLRP3, GLUT9, OAT1, and OAT3 protein expression in mouse kidney tissue and HK-2 cells. Hematoxylin-eosin staining was used to stain the liver and kidney tissues of mice and observe the tissue lesions. Results: NAY had little effect on blood routine and biochemical indexes of mice, but significantly reduced the serum UA level. NAY significantly reduced the level of UA in hyperuricemia mice and cells by inhibiting xanthine oxidase activity and reduced the levels of TNF-α, IL-6, and other inflammatory factors in serum and kidney of mice. NAY can inhibit inflammation by inhibiting the NLRP3 pathway. In addition, NAY can downregulate GLUT9 protein expression and upregulate OAT1 and OAT3 protein expression to reduce the UA level by promoting UA excretion and inhibiting UA reabsorption. Conclusion: These findings suggested that NAY produced dual hypouricemic actions. On the one hand, it can inhibit the formation of UA by inhibiting xanthine oxidase inhibitors activity, and on the other hand, it can promote the excretion of UA by regulating the UA transporter. It provides new ideas for the development of hyperuricemia drugs in the future.

Hypouricemic effect of 2,4-dihydroxybenzoic acid methyl ester in hyperuricemic mice through inhibiting XOD and down-regulating URAT1.

In this paper, we reported the hypouricemic effect of 2,4-dihydroxybenzoic acid methyl ester (DAE), a component of Ganoderma applanatum, in hyperuricemic mice through inhibiting XOD and down-regulating URAT1. Computationally, DAE showed a high similarity to allopurinol and depicted a high affinity in docking to XOD. In vitro, DAE exhibited an inhibitory effect against XOD. Importantly, DAE demonstrated a remarkable hypouricemic effect, decreasing serum uric acids (SUAs) of hyperuricemic mice (407 ± 31 µmol/L) to 195 ± 23, 145 ± 33 and 134 ± 16 µmol/L (P < 0.01) at the doses of 20, 40, and 80 mg/kg with a dose-dependent manner and showing efficacies at 54-68 %, which were close to the efficacies of allopurinol (61 %) and benzbromarone (57 %). DAE depicted higher and negatively dose-independent urinary uric acids in comparison with that of the hyperuricemic control, implying DAE exerted an uricosuric effect and also a reduction effect on uric acid production. Unlike toxic allopurinol and benzbromarone, no general toxicity on body weights and no negative influence on liver, kidney, spleen and thymus were observed for DAE. Mechanistically, DAE inhibited XOD activities in vivo. Moreover, DAE up-regulated OAT1 and down-regulated GLUT9, URAT1 and CNT2. Overall, DAE may present a hypouricemic effect through inhibiting XOD and up-regulating OAT1 and down-regulating GLUT9, URAT1 and CNT2. This work provided novel insights into the hypouricemic effect of DAE and G. applanatum.

Eurycomanol alleviates hyperuricemia by promoting uric acid excretion and reducing purine synthesis.

BACKGROUND: An elevated level of blood uric acid (UA) leads to serious damages to human health. In clinic, xanthine oxidase inhibitor is commonly used to reduce uric acid production. However, UA excretion promotion drug is rare. Our previous study demonstrated that the 70% ethanolic extract of stem of Eurycoma longifolia could effectively increase UA excretion and decrease blood level of UA in hyperuricemia animal model. In this paper, we tried to find active substance on UA regulation from E. longifolia. METHODS: The constituents of stem from E. longifolia were isolated and analyzed by chemical and spectral methods. Ultra Performance Liquid Chromatography was applied to measure the concentrations of UA in serum and urine. H&E staining was used to characterize renal histopathological changes. The protein and mRNA expressions of UA transporters were measured by western blot and quantitative real-time PCR analysis. RESULTS: Ten kinds of quassinoids were isolated from stem of E. longifolia, and the structures were identified. Pharmacological research revealed the major component, eurycomanol (5-20 mg/kg, p.o.) significantly decreased serum UA level and increased 24 h clearance of uric acid in potassium oxonate and adenine induced hyperuricemic mice. Eurycomanol ameliorated UA induced kidney histological injury, inhibited hepatic purine synthesis through decreasing phosphoribosyl pyrophosphate synthetase, promoted UA excretion by modulation of renal and intestinal urate transporters, such as GLUT9, ABCG2, OAT1, and NPT1. CONCLUSION: The results showed eurycomanol from E. longifolia can promote UA excretion through kidney and intestine, decrease hepatic purine synthesis and further keep UA homeostasis, suggesting that eurycomanol has the potential to be developed into a novel drug for the treatment of under-excretion type hyperuricemia.

Effects of water extract and ethanol extract from the root of Caragana sinica on hyperuricemia in mice / 中国药房

OBJECTIVE To investigat e the effects of water extract （WCS）and ethanol extract （ECS）from the root of Caragana sinica on hyperuricemia （HUA）in mice. METHODS Kunming mice were randomly divided into normal control group ， model group ，allopurinol group （positive control ，5 mg/kg），benzbromarone group （positive control ，7.8 mg/kg），WCS low-dose ， medium-dose and high-dose groups （38，75，150 mg/kg），ECS low-dose ，medium-dose and high-dose groups （50，100，200 mg/kg）， with 10 mice in each group. Except for the normal control group ，the other mice were given potassium oxazinate intraperitoneally and hypoxanthine intragastrically for consecutive 7 d to establish HUA model. On the third day of modeling ，mice in each administration group were given corresponding drugs intragastrically ，and normal control group and model group were given equal volume of normal saline once a day for 5 consecutive days.The body weight of mice were weighted during administration ；one hour after the last administration ，the organ indexes of liver ，kidney and spleen were calculated ；the contents of serum uric acid （SUA）， blood urea nitrogen （BUN）and serum creatinine （SCR）；the activity of xanthine oxidase （XOD）in serum and liver tissue were determined. Relative mRNA and protein expressions of XOD in liver tissue ，relative expre ssions of GLUT9，URAT1 and OAT 1 in renal tissue were all detected ；and the pathological changes of renal tissue were observed. RESULTS There were no significant differences in liver index and spleen index in each group （P＞0.05）. Compared with normal control group ， except for allopurinol group ， there were no significant differences in the body weight and the contents of BUN and SCR in mice of other administration groups （P＞0.05）；the renal index and SUA content of mice in the m odel group and allopurinol group were significantly increased （P＜0.05）；in the model group ，the XOD activity in serum and liver tissue ，the relative mRNA and protein expression of XOD in liver tissue ，the relative expressions of GLUT 9 and URAT 1 protein in renal tissue were significantly increased （P＜0.05），and the relative expression of OAT 1 protein in renal tissue was significantly decreased （P＜ 0.05）. Compared with model group ，renal indexes of mice were decreased significantly in WCS and ECS groups （P＜0.05），and the pathological damage of renal tissue was significantly improved ；SUA content ，XOD activity in serum and liver tissue ，the relative mRNA and protein expression of XOD in liver tissue ，and the relative expression of URAT 1 protein in renal tissue were decreased significantly in administration groups （P＜0.05）. The relative expression of GLUT 9 protein in renal tissue of mice in benzbromarone group and ECS high-dose group decreased significantly （P＜0.05）；relative expression of OAT 1 protein in renal tissue of mice in benzbromarone group ，WCS low-dose and high-dose groups ，ECS low-dose group were increased significantly （P＜0.05）. CONCLUSIONS WCS and ECS can significantly decrease the contents of SUA in HUA model mice ，and improve pathological state of renal tissue ，the mechanism of which may be associated with inhibiting XOD activity and uric acid reabsorption，and down-regulating protein and mRNA expression of XOD.

Effect of Total Flavonoids in Flower of Paeonia suffruticosa on Uric Acid in Rats with Hyperuricemia / 中国实验方剂学杂志

ObjectiveTo explore the pharmacodynamic effects of total flavonoids of Paeonia suffruticosa flower （TFPFs） on rats with hyperuricemia and provide scientific data support for the research and development of therapeutic drugs for hyperuricemia. MethodThe hyperuricemia model was induced by adenine combined with ethambutol in rats. The rats were randomly divided into a blank control group， a model group， two positive control groups （allopurinol at 42 mg·kg-1 and Tongfengshu tablets at 600 mg·kg-1）， and high-， medium-， and low-dose TFPFs groups （260， 130， and 65 mg·kg-1）. The general conditions of rats were observed and recorded， and the body weight was recorded once every 5 days. The 24-hour urine volume， water intake， uric acid （UA）， and urinary protein of rats were determined after the last administration. The kidney index was calculated. The pathological changes in thymus and spleen tissues of rats were observed by hematoxylin-eosin （HE） staining. The serum activities of UA， creatinine （Cr）， blood urea nitrogen （BUN）， malondialdehyde （MDA）， superoxide dismutase （SOD）， and total antioxidant capacity （T-AOC） of rats were determined. The xanthine oxidase （XOD） and adenosine deaminase （ADA） activities in the liver were detected. The content of uric acid transporter 1 （URAT1）， organic anion transporter 1 （OAT1）， and glucose transporter 9 （GLUT9） in the kidney was detected by enzyme-linked immunosorbent assay （ELISA）. ResultCompared with the results in the model group， TFPFs could improve the mental state of rats， increase the body weight（P<0.01）， promote UA excretion（P<0.01）， reduce the content of urinary protein（P<0.05）， relieve renal glomerular atrophy， renal tubular epithelial cell status， and urate crystal deposition in renal tubules， dwindle 24-hour urine volume， water intake， kidney index（P<0.05）， serum levels of UA， Cr， BUN， and MDA（P<0.05，P<0.01）， inhibit the activities of XOD（P<0.05） and ADA（P<0.05，P<0.01）in the liver， diminish the expression of GLUT9 in the renal homogenate（P<0.05）， and increase serum SOD and T-AOC activities as well as OAT1 expression（P<0.01） in the kidney. The pathological changes of thymus and spleen were improved. ConclusionTFPFs possess a protective effect on the kidney of rats with hyperuricemia， which is achieved by promoting uric acid excretion， inhibiting oxidation and the activity of key enzymes in uric acid synthesis， and regulating the expression of uric acid transporters.

Effect of Total Flavonoids in Flower of Paeonia suffruticosa on Uric Acid in Rats with Hyperuricemia / 中国实验方剂学杂志

ObjectiveTo explore the pharmacodynamic effects of total flavonoids of Paeonia suffruticosa flower （TFPFs） on rats with hyperuricemia and provide scientific data support for the research and development of therapeutic drugs for hyperuricemia. MethodThe hyperuricemia model was induced by adenine combined with ethambutol in rats. The rats were randomly divided into a blank control group， a model group， two positive control groups （allopurinol at 42 mg·kg-1 and Tongfengshu tablets at 600 mg·kg-1）， and high-， medium-， and low-dose TFPFs groups （260， 130， and 65 mg·kg-1）. The general conditions of rats were observed and recorded， and the body weight was recorded once every 5 days. The 24-hour urine volume， water intake， uric acid （UA）， and urinary protein of rats were determined after the last administration. The kidney index was calculated. The pathological changes in thymus and spleen tissues of rats were observed by hematoxylin-eosin （HE） staining. The serum activities of UA， creatinine （Cr）， blood urea nitrogen （BUN）， malondialdehyde （MDA）， superoxide dismutase （SOD）， and total antioxidant capacity （T-AOC） of rats were determined. The xanthine oxidase （XOD） and adenosine deaminase （ADA） activities in the liver were detected. The content of uric acid transporter 1 （URAT1）， organic anion transporter 1 （OAT1）， and glucose transporter 9 （GLUT9） in the kidney was detected by enzyme-linked immunosorbent assay （ELISA）. ResultCompared with the results in the model group， TFPFs could improve the mental state of rats， increase the body weight（P<0.01）， promote UA excretion（P<0.01）， reduce the content of urinary protein（P<0.05）， relieve renal glomerular atrophy， renal tubular epithelial cell status， and urate crystal deposition in renal tubules， dwindle 24-hour urine volume， water intake， kidney index（P<0.05）， serum levels of UA， Cr， BUN， and MDA（P<0.05，P<0.01）， inhibit the activities of XOD（P<0.05） and ADA（P<0.05，P<0.01）in the liver， diminish the expression of GLUT9 in the renal homogenate（P<0.05）， and increase serum SOD and T-AOC activities as well as OAT1 expression（P<0.01） in the kidney. The pathological changes of thymus and spleen were improved. ConclusionTFPFs possess a protective effect on the kidney of rats with hyperuricemia， which is achieved by promoting uric acid excretion， inhibiting oxidation and the activity of key enzymes in uric acid synthesis， and regulating the expression of uric acid transporters.

Active components from Lagotis brachystachya maintain uric acid homeostasis by inhibiting renal TLR4-NLRP3 signaling in hyperuricemic mice.

Lagotis brachystachya Maxim is a herb widely used in traditional Tibetan medicine. Our previous study indicated that total extracts from Lagotis brachystachya could lower uric acid levels. This study aimed to further elucidate the active components (luteolin, luteoloside and apigenin) isolated from Lagotis brachystachya and the underlying mechanism in vitro and in vivo. The results showed that treatment with luteolin and luteoloside reversed the reduction of organic anion transporter 1 (OAT1) levels, while apigenin attenuated the elevation of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) levels in uric acid-treated HK-2 cells, which was consistent with the finding in the kidneys of potassium oxonate (PO)-induced mice. On the other hand, hepatic xanthine oxidase activity was inhibited by the components. In addition, all of these active components improved the morphology of the kidney in hyperuricemic mice. Moreover, molecular docking showed that luteolin, luteoloside and apigenin could bind Toll-like receptor 4 (TLR4) and NLR family pyrin domain containing 3 (NLRP3). Congruently, western blot analysis showed that the components inhibited TLR4/myeloid differentiation primary response 88 (MyD88)/NLRP3 signaling. In conclusion, these results indicated that luteolin, luteoloside and apigenin could attenuate hyperuricemia by decreasing the production and increasing the excretion of uric acid, which were mediated by inhibiting inflammatory signaling pathways.

Uric Acid as a Risk Factor for Chronic Kidney Disease and Cardiovascular Disease　- Japanese Guideline on the Management of Asymptomatic Hyperuricemia.

Serum uric acid (UA) is taken up by endothelial cells and reduces the level of nitric oxide (NO) by inhibiting its production and accelerating its degradation. Cytosolic and plasma xanthine oxidase (XO) generates superoxide and also decreases the NO level. Thus, hyperuricemia is associated with impaired endothelial function. Hyperuricemia is often associated with vascular diseases such as chronic kidney disease (CKD) and cardiovascular disease (CVD). It has long been debated whether hyperuricemia is causally related to the development of these diseases. The 2020 American College of Rheumatology Guideline for the Management of Gout (ACR2020) does not recommend pharmacological treatment of hyperuricemia in patients with CKD/CVD. In contrast, the Japanese Guideline on Management of Hyperuricemia and Gout (JGMHG), 3rdedition, recommends pharmacological treatment of hyperuricemia in patients with CKD. In a FREED study on Japanese hyperuricemic patients with CVD, an XO inhibitor, febuxostat, improved the primary composite endpoint of cerebro-cardio-renovascular events, providing a rationale for the use of urate-lowering agents (ULAs). Since a CARES study on American gout patients with CVD treated with febuxostat revealed increased mortality, ACR2020 recommends switching to different ULAs. However, there was no difference in the mortality of Japanese patients between the febuxostat-treated group and the placebo or allopurinol-treated groups in either the FEATHER or FREED studies.

Bioactive Compounds from Plant-Based Functional Foods: A Promising Choice for the Prevention and Management of Hyperuricemia.

Hyperuricemia is a common metabolic disease that is caused by high serum uric acid levels. It is considered to be closely associated with the development of many chronic diseases, such as obesity, hypertension, hyperlipemia, diabetes, and cardiovascular disorders. While pharmaceutical drugs have been shown to exhibit serious side effects, and bioactive compounds from plant-based functional foods have been demonstrated to be active in the treatment of hyperuricemia with only minimal side effects. Indeed, previous reports have revealed the significant impact of bioactive compounds from plant-based functional foods on hyperuricemia. This review focuses on plant-based functional foods that exhibit a hypouricemic function and discusses the different bioactive compounds and their pharmacological effects. More specifically, the bioactive compounds of plant-based functional foods are divided into six categories, namely flavonoids, phenolic acids, alkaloids, saponins, polysaccharides, and others. In addition, the mechanism by which these bioactive compounds exhibit a hypouricemic effect is summarized into three classes, namely the inhibition of uric acid production, improved renal uric acid elimination, and improved intestinal uric acid secretion. Overall, this current and comprehensive review examines the use of bioactive compounds from plant-based functional foods as natural remedies for the management of hyperuricemia.

Coexistence of autosomal dominant polycystic kidney disease type 1 and hereditary renal hypouricemia type 2: A model of early-onset and fast cyst progression.

Autosomal dominant polycystic kidney disease (ADPKD) is a heterogeneous inherited disease characterized by renal and extrarenal manifestations with progressive fluid-filled cyst development leading to end-stage renal disease. The rate of disease progression in ADPKD exhibits high inter- and intrafamilial variability suggesting involvement of modifier genes and/or environmental factors. Renal hypouricemia (RHUC) is an inherited disorder characterized by impaired tubular uric acid transport with severe complications, such as acute kidney injury and chronic kidney disease (CKD). However, the two disorders have distinct and well-delineated genetic, biochemical, and clinical findings. Only a few cases of coexistence of ADPKD and RHUC (type 1) in a single individual have been reported. We report a family with two members: an ADPKD 24-year-old female which presented bilateral renal cysts in utero and hypouricemia since age 5, and her mother with isolated hypouricemia. Next-generation sequencing identified two mutations in two genes PKD1 and SLC2A9 in this patient and one isolated SLC2A9 mutation in her mother, showing RHUC type 2, associated to CKD. The coexistence of these two disorders provides evidence of SLC2A9 variant could act as a modifier change, with synergistic actions, that could promote cystogenesis and rapid ADPKD progression. This is the first case of coexistence of PKD1 and SLC2A9 mutations treated with tolvaptan.

Research Progress of Pathology of Gout and Clinical Treatment with Traditional Chinese and Western Medicine / 中国实验方剂学杂志

With the improvement of people's living standard and the change of dietary structure, the prevalence of gout has increased gradually with the increased intake of protein, sugar and fat. There has been a positive correlation between gout and age, and the age of onset decreased gradually. The inflammation induced by sodium urate crystal is the pathological basis of gout, which activates innate immunity, releases many kinds of inflammatory mediators, such as interleukin(IL)-1β, IL-6 and tumor necrosis factor(TNF)-α, and then causes inflammatory cascade reaction and acute attacks, such as joint redness, swelling and heat pain. There is a spontaneous remission mechanism in gout. For one thing, macrophages reduce the stimulation of monosodium urate(MSU) through phagocytosis of MSU crystals as foreign bodies, for another, differentiated and mature macrophages secrete anti-inflammatory factor transforming growth factor(TGF)-β1, inhibit the expression of inflammatory factors and promote spontaneous relief of acute gout attack. In addition to the activation mechanism of intracellular signaling molecules associated with inflammatory response, the inflammatory mechanism of gout also involves complement activation, cell activation and other pathways. The complications caused by gout, such as cardiovascular system damage and joint destruction, are seriously harmful to human health. At present, western drugs, such as allopurinol and febuxostat, exert an effect in inhibiting xanthine oxidase. Benzimarone has effect in reducing renal absorption of uric acid and promoting uric acid excretion by inhibiting uric acid transporter 1(URAT1) and glucose transporter 9(GLUT9). Even Lesinurad and other medicines in current studies are based on the inhibition of uric acid re-absorption, but with adverse reactions that limit the clinical application. The treatment of gout with traditional Chinese medicine(TCM) has multi-target characteristics, with advantages in reducing uric acid, resisting inflammation and improving joint function and a high safety. It has been gradually popularized and applied in clinical treatment of gout. Therefore, it is a promising research direction to treat gout with TCM and western medicine based on the pathomechanism of gout.