Konjac glucomannan improves hyperuricemia through regulating xanthine oxidase, adenosine deaminase and urate transporters in rats

Structure characterization of polysaccharide isolated from Ribes nigrum L. and it's bioactivity against gout

Gout mainly caused by the increase of uric acid level in serum poses a threat to human health. Inhibition on the activity of xanthine oxidase (XOD) usually an effective method for treating gout, so finding XOD inhibitors without side effects is crucial. In this study, two heteropolysaccharides were extracted from blackcurrant by microwave-assisted aqueous two-phase technology, and the top phase (PRNP-1) and bottom phase (PRNP-2) polysaccharides at high purity (>86%) were obtained after column chromatography separation. Methylation and NMR analyses confirmed the potential structural backbone of PRNP-1 may be composed of →3)-α-L-Araf-(1 → 3)-β-D-Galp-(1 → 4)-β-D-Manp-(1 → 5)-α-Araf-(1 → 4)-α-D-GalpA-(1 → 3,6)-β-D-Glup-(1→, while PRNP-2 exhibited a differing repeating unit of →4)-β-D-Manp-(1 → 3)-α-D-Araf-(1 → 3)-β-D-Galp-(1 → 5)-α-Araf-(1 → 4)-α-D-GalpA-(1 → 3,6)-β-D-Glup-(1→. Compared to PRNP-1 (4.87 × 104 kDa), PRNP-2 with low molecular weight (2.30 × 104 kDa) exhibited better dispersivity, homogeneity, water solubility and thermal stability, as well as XOD inhibitory activity. Both PRNP-1 and PRNP-2 demonstrated a competitive, reversible inhibition towards XOD and quenched its fluorescence through forming polysaccharide-XOD complexes. Molecular docking and molecular dynamics simulation assays revealed that PRNP-2 exhibited a better binding capacity with XOD than PRNP-1. PRNPs markedly decreased the serum concentration of uric acid and creatinine, and XOD activity in hyperuricemia mice model. Therefore, PRNPs may be the potential natural therapeutic agents for the treatment of gout.

Natural polysaccharides in the prevention of hyperuricemia: Source, classification, mechanism, application in food industry

Hyperuricemia (HUA) is one of the major threats to human health. In recent years, with the gradual increase in the incidence rate of Hua, the prevention and treatment of HUA has attracted more and more attention. Clinical pharmaceutical interventions, such as Allopurinol, Febuxostat, and so on, though effective, are usually accompanied by notable adverse effects. Therefore, alternative therapy with high-safety natural components has received more and more attention from scholars. The natural polysaccharides showed a significant potential in HUA therapy and more and more natural polysaccharides for treating HUA were being obtained. Therefore, in this review, the recent progress on natural polysaccharides in preventing HUA was presented focusing on the sources, classification, and biological activities (oxidative stress, anti-inflammatory, and UA-lowering) of natural polysaccharides. Furthermore, this review explores the mechanisms of action and application. It is beneficial to the development of polysaccharides for natural HUA therapy and the results of this review could offer guidance on preventing the occurrence of HUA in daily life.

Investigating the Role of Food-Derived Peptides in Hyperuricemia: From Mechanisms of Action to Structural Effects

Hyperuricemia, a disorder of purine metabolism associated with cardiovascular disease, gout, and kidney disease, can be alleviated by food-derived peptides. However, the precise mechanisms remain unclear, hindering their development. This study reviews uric acid-lowering peptides from various sources, focusing on two pathways: inhibiting uric acid production and promoting excretion. Low-molecular-weight peptides (<1000 Da) exhibited superior uric acid-lowering effects. We further explored the relationships between amino acid composition and their target interactions. Peptides rich in cyclic amino acids (tryptophan, phenylalanine, and histidine) and containing small amounts of linear amino acids (leucine, cysteine, and glycine) demonstrated significant potential for lowering uric acid. These findings provide theoretical support for developing novel functional foods for the management of hyperuricemia.

Effect of konjac glucomannan on gut microbiota from hyperuricemia subjects in vitro: fermentation characteristics and inhibitory xanthine oxidase activity

Background

The disorder of uric acid metabolism is closely associated with gut microbiota and short-chain fatty acids (SCFAs) dysregulation, but the biological mechanism is unclear, limiting the development of uric acid-lowering active polysaccharides. Konjac glucomannan (KGM) could attenuate metabolic disturbance of uric acid and modulate the gut microbiota. However, the relationship between uric acid metabolism and gut microbiota is still unknown.

Methods

In this study, The fecal samples were provided by healthy volunteers and hyperuricemia (HUA) patients. Fecal samples from healthy volunteers was regarded as the NOR group. Similarly, 10% HUA fecal suspension was named as the HUA group. Then, fecal supernatant was inoculated into a growth basal medium containing glucose or KGM, and healthy fecal samples were designated as the NOR-GLU and NOR-KGM groups, while HUA fecal samples were designated as the HUA-GLU and HUA-KGM groups. All samples were cultured in an anaerobic bag system. After fermentation for 24 h, the samples were collected for further analysis of composition of intestinal microbiota, SCFAs concentration and XOD enzyme activity.

Results

The results showed that KGM could be utilized and degraded by the gut microbiota from HUA subjects, and it could modulate the composition and structure of their HUA gut microbiota to more closely resemble that of a healthy group. In addition, KGM showed a superior modulated effect on HUA gut microbiota by increasing Megasphaera, Faecalibacterium, Lachnoclostridium, Lachnospiraceae, Anaerostipes, and Ruminococcus levels and decreasing Butyricicoccus, Eisenbergiella, and Enterococcus levels. Furthermore, the fermentation solution of KGM showed an inhibitory effect on xanthine oxidase (XOD) enzyme activity, which might be due to metabolites such as SCFAs.

Conclusion

In conclusion, the effect of KGM on hyperuricemia subjects was investigated based on the gut microbiota in vitro. In the present study. It was found that KGM could be metabolized into SCFAs by HUA gut microbiota. Furthermore, KGM could modulate the structure of HUA gut microbiota. At the genus level, KGM could decrease the relative abundances of Butyricicoccus, Eisenbergiella, and Enterococcus, while Lachnoclostridium and Lachnospiraceae in HUA gut microbiota were significantly increased by the addition of KGM. The metabolites of gut microbiota, such as SCFAs, might be responsible for the inhibition of XOD activity. Thus, KGM exhibited a superior probiotic function on the HUA gut microbiota, which is expected as a promising candidate for remodeling the HUA gut microbiota.

Herbal remedies in the management of hyperuricemia and gout: A review of in vitro, in vivo and clinical evidences

Gout, or hyperuricemia is a multifactorial and multi-faceted metabolic disease that is quite difficult to manage and/or treat. Conventional therapies such as non-steroidal anti-inflammatory drugs (NSAIDs) such as allopurinol, corticosteroids and colchicine amongst others, have helped in its management and treatment to some extent. This study aimed to compile and analyze the different herbal remedies used in the management of hyperuricemia and gout. A literature search was conducted from key databases (PubMed, ScienceDirect, Cochrane Library, Google Scholar) using relevant keywords via the PRISMA model. Smilax riparia A.DC. from Traditional Chinese Medicine is used in many countries for its therapeutic effect on lowering serum urate levels. No single study was able to establish the efficacy of a specific traditionally used herb via in vitro, in vivo, and clinical studies. Patients were found to use a panoply of natural remedies, mainly plants to treat hyperuricemia and gout, which have been validated to some extent by in vitro, in vivo, and clinical studies. Nonetheless, further research is needed to better understand the ethnopharmacological relationship of such herbal remedies.

Research Progress on New Functions of Animal and Plant Proteins

Protein is composed of peptides, essential nutrients for human survival and health, and the easy absorption of peptides further promotes human health. According to the source of the protein, it can be divided into plants, animals, and micro-organisms, which have important physiological effects on the health of the body, especially in enhancing immunity. The most widely used raw materials are animal protein and plant protein, and the protein composition formed by the two in a certain proportion is called "double protein". In recent years, China's State Administration for Market Regulation has issued an announcement on the "Implementation Rules for the Technical Evaluation of New Functions and Products of Health Foods (Trial)", which provides application conditions and listing protection for the research and development of new functions of health foods. At present, some researchers and enterprises have begun to pay attention to the potential of animal and plant proteins to be used in new functions. In this article, the research progress of animal and plant proteins in the new functions of Chinese health food is reviewed in detail, and suggestions for future research on animal and plant proteins are put forward.

Ferulic acid ameliorates hyperuricemia by regulating xanthine oxidase

Hyperuricemia is characterized by elevated uric acid (UA) level in the body. The xanthine oxidase (XO) inhibitory ability is an important way to evaluate the anti-hyperuricemia effect of natural products. Ferulic acid (FA) is a phenolic acid compound, and it is a free radical scavenger with many physiological functions. The aim of this study was to investigate the structure-activity relationship, potential mechanism and interaction of FA as XO's inhibitor. In the cell experiment, using 1.25 mM adenosine to incubate for 24 h under the optimal conditions (37 °C, pH = 7.2) can increase the UA production by 1.34 folds. PCR analysis showed that FA could reduce the mRNA expression level of XO. FA inhibited XO in a mixed mode (IC50 = 13.25 μM). The fluorescence quenching of XO by FA occurs through a static mechanism, with an inhibition constant of Ki = 9.527 × 10-5 mol L-1 and an apparent coefficient of α = 1.768. The enthalpy and entropy changes were found as -267.79 KJ mol-1 and - 860.85 KJ mol-1, indicating that both hydrogen binding and hydrophobic are involved in the interaction of this polyphenolic natural compound with XO. Thus, FA supplementation may be a potential therapeutic strategy to improve hyperuricemia by reducing UA production.

Influence of konjac glucomannan and its derivatives on the oral pharmacokinetics of antimicrobial agent in antibiotics cocktails: Keep vigilant on dietary fiber supplement

In this study, konjac glucomannan (KGM) and its derivatives were gavaged as dietary fiber supplements, followed by a single dose of antibiotic cocktail (Abx) containing amoxicillin, neomycin, metronidazole and vancomycin in mice. The effects of dietary fiber on the pharmacokinetics and tissue distribution of each antibiotic were investigated. The results showed that the specific effects of KGM and its derivatives on the absorption, distribution, and elimination of certain antibiotics varied and depended on the nature of the fibers and the characteristics of the antibiotics. Explicitly, the ingestion of KGM and its derivatives enhanced the absorption of metronidazole by 1.7 times and hindered that of amoxicillin by nearly 36 % without affecting the absorption of neomycin sulfate and vancomycin. KGM and its derivatives had no effect on the distribution of amoxicillin and metronidazole, but DKGM and KGM hindered the distributions of neomycin sulfate (from 1.25 h to 1.62 h) and vancomycin (from 0.95 h to 1.14 h), respectively. KGM and its derivatives promoted the elimination of amoxicillin by nearly 38 % while prolonging that of metronidazole by >50 %. KOGM boosted the elimination of neomycin sulfate and vancomycin, but KGM differed from DKGM in acting on the elimination of both.

Corn Silk Flavonoids Ameliorate Hyperuricemia via PI3K/AKT/NF-κB Pathway

Hyperuricemia (HUA) is a widespread metabolic disease marked by an elevated level of uric acid, and is a risk factor for premature death. The protective effect of corn silk flavonoids (CSF) against HUA and its potential mechanisms were explored. Five important apoptosis and inflammation-related signaling pathways were identified by network pharmacological analysis. The CSF exhibited significant uric acid (UA)-lowering activity in vitro by decreasing xanthine oxidase (XOD) and increasing hypoxanthine-guanine phosphoribosyl transferase levels. In a potassium oxonate-induced HUA in vivo, CSF treatment effectively inhibited XOD activity and promoted UA excretion. Furthermore, it decreased the levels of TNF-α and IL-6 and restored pathological damage. In summary, CSF is a functional food component to improve HUA by reducing inflammation and apoptosis through the down-regulating PI3K/AKT/NF-κB pathway.

Transdermal delivery of allopurinol to acute hyperuricemic mice via polymer microneedles for the regulation of serum uric acid levels

Allopurinol (AP) is widely used to treat hyperuricemia which may cause severe side effects upon oral administration. Alternative means for the treatment of hyperuricemia are demanded to simultaneously facilitate drug absorption, patient compliance, and fewer side effects. In this study, a new polymer microneedle (MN) system was developed for the transdermal delivery of AP to acute hyperuricemic mice. This study aims to achieve the controllable regulation of serum uric acid (SUA) levels with fewer side effects compared with oral administration. The matrix of polymer MNs consisted of polyvinylpyrrolidone (PVP) and polycaprolactone (PCL), in which the rapid dissolution of PVP offers a rapid dissolution of AP into the blood and the biodegradability of PCL resulting in a sustainable drug release behavior. An in vivo study demonstrated that the AP-loaded MN system can effectively reduce the SUA levels as oral administration with lower side effects, which will be conducive to reducing the adverse reactions and improving the bioavailability of AP. This MN-mediated strategy can facilitate transcutaneous hyperuricemia treatment and provide a new alternative for the exploration of clinical treatment of hyperuricemia and improvement of patient compliance.

Action mechanisms of two key xanthine oxidase inhibitors in tea polyphenols and their combined effect with allopurinol

BACKGROUND

Tea polyphenols have been reported to have the effect of lowering uric acid. However, there are few studies on the inhibitory effects and molecular mechanisms of specific catechins on the urate-metabolizing enzyme xanthine oxidase (XO). In this research, multiple spectroscopic methods and computer simulations were used to determine the inhibitory ability and mechanisms of epigallocatechin gallate (EGCG) and gallocatechin gallate (GCG) on XO.

RESULTS

Herein, EGCG and GCG reversibly inhibited XO activity in a mixed manner, with IC₅₀ values of 40.50 ± 0.32 and 33.60 ± 0.53 μmol L^-1 , and also decreased the superoxide anion radical (O₂ ^- ) of the catalytic system by reducing the XO molecule and inhibiting the formation of uric acid. The combination of EGCG or GCG with allopurinol showed synergistic inhibition on XO. The binding of EGCG or GCG to XO with moderate affinity formed a stable complex by hydrogen bonds and van der Waals forces. The presence of EGCG and GCG made the structure of XO more stable and compact. The two inhibitors bound to the vicinity of flavin adenine dinucleotide (FAD) in XO, hindering the entry of substrate; thus the activity of XO was suppressed.

CONCLUSION

Both EGCG and GCG are excellent natural XO inhibitors, and inhibited the activity of XO by occupying the channel of the substrate to enter the active center and interfering with the dual substrate reaction catalyzed by XO. These findings provide a scientific basis for the application of catechins in dietary supplements and medicines with lowering uric acid effects. © 2022 Society of Chemical Industry.

Anserine beneficial effects in hyperuricemic rats by inhibiting XOD, regulating uric acid transporter and repairing hepatorenal injury

This study aims to investigate the anti-hyperuricemia effect and mechanism of anserine in hyperuricemic rats. Hyperuricemic rats were induced with a combination of 750 mg per kg bw d potassium oxazinate (PO) and 200 mg per kg bw d hypoxanthine for a week, and the rats were separately orally administered anserine (20, 40, 80 mg kg^-1) and allopurinol (10 mg kg^-1) for three weeks. The results show that the content of serum uric acid (SUA) decreased by approximately 40% and 60% after the intervention of anserine and allopurinol, respectively. The activity of superoxide dismutase (SOD) was increased and the levels of malondialdehyde (MDA), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were significantly decreased in the anserine groups. After the administration of anserine, the contents of blood urea nitrogen (BUN) and creatinine (Cr) were reduced in the kidney, and the levels of the proinflammatory cytokines IL-1β, IL-6β, TNF-α and TGF-β and inflammatory cell infiltration were reduced in both the liver and kidney. Moreover, the gene expressions of xanthine oxidase (XOD), renal urate transporter 1 (URAT1) and glucose transporter type 9 (GLUT9) were downregulated by anserine administration, and the gene expressions of ATP-binding cassette transporter G2 (ABCG2), organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3) were upregulated at the same time. These findings suggest that hepatorenal injury was repaired by anserine, which further regulated the expression of hepatic XOD and renal URAT1, GLUT9, ABCG2, OAT1 and OAT3 to relieve hyperuricemia in rats.

Dietary Ferulic Acid Ameliorates Metabolism Syndrome-Associated Hyperuricemia in Rats via Regulating Uric Acid Synthesis, Glycolipid Metabolism, and Hepatic Injury

Ferulic acid is a well-known phenolic acid compound and possesses multiple health-promoting and pharmacological effects. Metabolic syndrome (MetS) and hyperuricemia (HUA) have become health problems worldwide and are closely connected. The aim of this study was to explore the influence of ferulic acid on MetS-related HUA and its underlying mechanisms. Rats were administered high-fructose and high-fat diet (HFFD) with or without ferulic acid (0.05 and 0.1%) for 20 weeks. Intake of HFFD resulted in obesity, hyperglycemia, insulin resistance, and dyslipidemia, which were alleviated by ferulic acid consumption. Treatment of rats with ferulic acid diminished the levels of lipids and inflammatory cytokines and enhanced the activities of antioxidant enzymes in the liver caused by HFFD. Additionally, administration of ferulic acid blocked a HFFD-induced elevation in activities and mRNA expression of enzymes involving in uric acid (UA) synthesis. Molecular docking analysis denoted that ferulic acid bound to the active center of these enzymes, indicative of the potential interaction with each other. These two aspects might partially be responsible for the decrement in serum UA content after ferulic acid ingestion. In conclusion, ferulic acid supplementation ameliorated lipid and glucose metabolic abnormalities, hepatic damage, and UA formation in MetS rats. There was a dose correlation between lipid deposition and UA synthesis-related indicators. These findings implied that ferulic acid could be applied as a promising dietary remedy for the management of MetS-associated HUA.

Highly Synergistic Sensor of Graphene Electrode Functionalized with Rutile TiO2 Microstructure to Detect L-Tryptophan Compound

Electrochemical processes are an effective method for detecting dangerous food ingredients. The synergetic between the reduction-oxidation (redox) processes inspired several papers and spurred research towards studying the new materials that can further adapt to optimize the rapid detection of chemical compounds. In this study, we report the eco-synthesis using graphene/TiO₂ rutile (G/TiO₂) electrode microstructures easily prepared through the physical method by mixing graphene and TiO₂ powder and its application for sensing L-tryptophan (Trp) compound. The material characterization results show that the graphene surface is smoother than the G/TiO₂ material. Graphene has been detected using X-ray diffraction (XRD) at a value of 2 thetas 26.39° and TiO₂ forms rutile crystals (110). The FTIR spectrum exhibits the functional groups from graphene of -OH, C-H, C=C, C-O, and TiO₂ identified with Ti-O bonds. The electrochemical test against G/TiO₂ electrode microstructures for Trp compound shows that 0.5 g TiO₂ rutile was the best composition functionalized with graphene material under 0.1M K₃[Fe(CN)₆] + 0.1M NaNO₃ electrolyte with a scan rate of 0.1 V/s. Determination of the detection limit was obtained at 0.005 mg/L with a HorRat value of 1.05%. The stability test was carried out for 25 days, and the addition of Pb(NO₃)₂ as an interference compound had a significant effect on the decrease in electrode performance.

Hypouricemic, hepatoprotective and nephroprotective roles of oligopeptides derived from Auxis thazard protein in hyperuricemic mice

The oligopeptides derived from Auxis thazard protein (ATO) are a class of small peptides with molecular weight <1 kDa and good bioactivity. This paper aimed to explore the hypouricemic, hepatoprotective, and nephroprotective effects of ATO and its potential mechanisms in hyperuricemia in mice induced by potassium oxonate. The results showed that ATO significantly reduced serum UA, serum creatinine levels, inhibited XOD and ADA activities in the liver (p < 0.05), and accelerated UA excretion by downregulating the gene expression of renal mURAT1 and mGLUT9 and upregulating the gene expression of mABCG2 and mOAT1. ATO could also reduce the levels of liver MDA, increase the activities of SOD and CAT, and reduce the levels of IL-1β, MCP-1 and TNF-α. Histological analysis also showed that ATO possessed hepatoprotective and nephroprotective activities in hyperuricemic mice. Thus, ATO could reduce the serum UA level in hyperuricemic mice by decreasing UA production and promoting UA excretion from the kidney, suggesting that ATO could be developed as a dietary supplement for hyperuricemia treatment.

Anti-hyperuricemic and nephroprotective effects of whey protein hydrolysate in potassium oxonate induced hyperuricemic rats

BACKGROUND

Hyperuricemia (HUA) is a serious public health concern globally that needs to be solved. It is closely related to gout and other metabolic diseases. To develop a safe and effective dietary supplementation for alleviating HUA, we investigated the effects of whey protein hydrolysate (WPH) on HUA and associated renal dysfunction and explored their underlying mechanism.

RESULTS

Potassium oxonate was used to induce HUA in model rats, who were then administered WPH for 21 days. The results showed that WPH significantly inhibited xanthine oxidase and adenosine deaminase activity in serum and liver, decreased uric acid (UA), creatinine, and blood urea nitrogen levels in serum, and increased the UA excretion in urine. In addition, WPH downregulated the expression of urate transporter 1 and upregulated the expression of organic anion transporter 1, adenosine triphosphate binding cassette subfamily G member 2, organic cation/carnitine transporters 1 and 2, and organic cation transporter 1 in kidneys.

CONCLUSION

These findings demonstrated for the first time that WPH could alleviate HUA by inhibiting UA production and promoting UA excretion, and improve the renal dysfunction caused by HUA. Thus, WPH may be a potential functional ingredient for the prevention and treatment of HUA and associated renal dysfunction. © 2021 Society of Chemical Industry.

Hypouricemia effects of corn silk flavonoids in a mouse model of potassium oxonated-induced hyperuricemia

The hypouricemic effect of corn silk flavonoids (CSFs) in vivo that were extracted by ethanol and fractionated by continuous elution with 40% (CSF-A) and 60% (CSF-B) ethanol solutions on polyamide column were investigated in this study. CSFs reduced serum uric acid (UA) level in a mouse model of potassium oxonate-induced hyperuricemia. CSF-B had the best hypouricemic effect, as it decreased the serum UA level by 26.69% and xanthine oxidase (XO) activity in the serum by 11.29%. The mechanism of action of CSF-B was related to the inhibition of XO activity and the promotion of UA excretion. CSF-B was found to contain 12 kinds of major flavonoids, five of which were speculated to influence its activity in the hyperuricemia mice. The five flavonoids were apigenin-6-C-glucoside-7-O-glucoside, kaempferol-3-O-rutinoside, luteolin-7-glucoside, luteolin-3',7-di-O-glucoside, and naringenin, respectively. Structure analysis revealed that C-4', C5 hydroxyl groups, and C2=C3 double bonds in CSF-B gave the latter its hypouricemic effect. PRACTICAL APPLICATIONS: The prevalence of hyperuricemia has increased in recent times. Current hypouricemic drugs have side effects and can easily lead to various complications. Therefore, it is of great practical significance to find safer and more effective hypouricemic drugs. This study demonstrated that corn silk flavonoids may be used as a dietary supplement to manage hyperuricemia.

Anti-Hyperuricemic Effects of Astaxanthin by Regulating Xanthine Oxidase, Adenosine Deaminase and Urate Transporters in Rats

This study was designed to investigate the effects and underlying mechanisms of Astaxanthin (AST) on high-fructose-induced hyperuricemia (HUA) from the perspectives of the uric acid (UA) synthesis and excretion in rat models. Following six weeks of a 10% fructose diet, the level of serum UA effectively decreased in the AST groups as compared to the model group. The enzymatic activities of xanthine oxidase (XOD) and adenosine deaminase (ADA) were significantly inhibited, and the mRNA expression levels of XOD and ADA significantly decreased after the AST administration. These results suggested that the AST reduced UA synthesis by inhibiting the mRNA expressions and enzyme activities of XOD and ADA, thereby contributing to HUA improvement. On the hand, the relative expressions of the mRNA and protein of kidney reabsorption transport proteins (GLUT9 and URAT1) were significantly down-regulated by AST, while that of the kidney secretion proteins (OAT1, OAT3 and ABCG2) were significantly up-regulated by AST. These results indicated that the AST promoted UA excretion by regulating the urate transport proteins, and thus alleviated HUA. This study suggested that the AST could serve as an effective alternative to traditional medicinal drugs for the prevention of fructose-induced HUA.

Effects and Mechanisms of Dendrobium officinalis Six Nostrum for Treatment of Hyperuricemia with Hyperlipidemia

Objectives. Hyperuricemia (HUA) is a disease caused by increased production of uric acid (UA) or reduced excretion of UA in the body. Results of an epidemiological survey show that 60% of patients with HUA have hyperlipidemia (HPA). Dendrobium officinalis (DOF) six nostrum (DOS) is based on the theory of traditional Chinese medicine for the transformation of the traditional Chinese nostrum Si Miao Wan. In this article, we aim to discuss the efficacy and mechanism of DOS in reducing UA and regulating lipid metabolism. The rat model of HUA with HPA was induced by potassium oxonate (PO) combined with high-fat sorghum feed. We monitored the serum UA and blood lipids. Liver xanthine oxidase (XOD), adenosine deaminase (ADA), lipoprotein lipase (LPL), and fatty acid-binding protein (FABP1) activities were measured by enzyme-linked immunosorbent assay (ELISA) after the last administration of DOS. We performed a histopathological examination of rat kidney and intestine. Immunohistochemistry (IHC) was used to detect the expression of renal inflammatory proteins NLRP3 / Caspase-1 and intestinal inflammatory proteins TLR4 / NLRP3. We used western blot for measurement of liver hypoxanthine-guanine phosphoribosyl transferase (HPRT1) protein expression and renal PDZ domain protein kidney 1 (PDZK1) protein expression. DOS administration significantly reduced serum UA, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) level, and improved liver steatosis in the model rat. At the same time, DOS treatment effectively inhibited liver XOD and ADA, increased the level of liver HPRT1, and reduced the production of UA. Additional studies had shown that DOS can restore normal UA excretion function in the intestine and kidney and regulated liver lipids metabolism. IHC and histopathological sections showed that DOS reduced the level of kidney, intestinal inflammatory body (NLRP3, Caspase-1, and TLR4), improved inflammation of the kidney and intestinal tract in rats. DOS is a promising drug that can effectively reduce serum UA and lipid level in the model rat. The mechanism of action may be related to inhibition of UA production, promotion of UA excretion, regulation of lipids metabolism, and anti-inflammatory response.

Antihyperuricemic and nephroprotective effects of extracts from Orthosiphon stamineus in hyperuricemic mice

OBJECTIVES

To investigate the antihyperuricemia and nephroprotective effects of Orthosiphon stamineus extracts on hyperuricemia (HUA) mice and explore the potential mechanisms.

METHODS

Orthosiphon stamineus extracts were extracted using 50% ethanol and enriched using ethyl acetate, and characterised utilising UPLC/ESI-MS. A potassium oxonate (PO) induced hyperuricemic mouse model was used to evaluate antihyperuricemia and nephroprotective effects of O. stamineus ethyl acetate extracts (OSE).

KEY FINDINGS

Eight constituents from OSE were identified and OSE treatment ameliorated HUA by regulating key indicators of kidney dysfunction and xanthine oxidase, adenosine deaminase activity and urate transporters in hyperuricemic mice. Moreover, in renal histopathology analysis, OSE significantly alleviated kidney injury.

CONCLUSIONS

These findings demonstrate that OSE has antihyperuricemic and nephroprotective effects on PO-induced HUA mice and those results indicate that OSE could be a safe and effective agent or functional ingredient for treating HUA.

Stevia residue extract alone and combination with allopurinol attenuate hyperuricemia in fructose-PO-induced hyperuricemic mice

The current project was designed to utilize flavonoids and chlorogenic acids enriched stevia residue extract (STVRE) against hyperuricemia (HU). The in vitro results showed that STVRE potently and synergistically inhibits Xanthine oxidase (XO) with allopurinol. The AFM results predicted that STVRE compounds bind with XO and alter its structure which further prevents the entrance of substrate with XO. These in vitro results were further confirmed in fructose-PO-induced hyperuricemic mice model. The results showed that supplementation of STVRE with allopurinol significantly attenuated HU, oxidative stress, and inflammation caused by UA via inhibiting the production of uric acid and lowering cyclooxygenase-2, tumor necrosis factor-alpha, prostaglandin E2, interleukin-6, and interleukin 1-beta levels in serum and renal tissues. Moreover, STVRE and allopurinol treatment attenuated, tubular dilation, infiltration of inflammatory cells, improved structure disorder of podocyte, and foot process fusion, and decreased glomerular basement membrane thickness. These findings suggested that STVRE can be used as an antihyperuricemic agent along with allopurinol. PRACTICAL APPLICATIONS: The results of present study showed that STVRE has a beneficial effect against fructose-PO-induced hyperuricemia by decreasing uric acid level, xanthine oxidase activity, improving oxidative stress and inflammation. These findings suggested that by-product of stevia (STVRE) enriched with polyphenolic compounds can be used as a functional ingredient against hyperuricemia and related diseases.

Prebiotic, Immunomodulating, and Antifatigue Effects of Konjac Oligosaccharide

Irregular and long time work schedules not only makes people feel fatigue, but also brings great risks of diseases, due to gastrointestinal disorder and immune dysfunction. Therefore, it has positive significance to help challenged people stay energetic and healthy with food supplement. Konjac oligosaccharide has shown various physiological benefits and been recommended in the fortification of functional foods. However, there have been few reports on its application aimed to simultaneously relieve physical fatigue and keep body healthy. In this paper, the potential prebiotic, immunoregulatory, and antifatigue activities of konjac oligosaccharide were evaluated in vitro and in vivo. The results showed that konjac oligosaccharide could promote probiotics growth and short chain fatty acids production in mice cecum. At the concentration of 50 to 200 μg/mL, konjac oligosaccharide could activate murine macrophage RAW 264.7 to secret NO and cytokines of IL-10 and IL-6. Moreover, this oligosaccharide could alleviate physical fatigue by prolonging exhaustive time, improving the level of superoxide dismutases and glutathione peroxidase, increasing the content of blood glucose, and decreasing the content of blood urea nitrogen. The results suggested that konjac oligosaccharide had prebiotic, immunoregulatory, and antifatigue effects, providing its application potential in functional food aimed at people with irregular and long time work.