Use of gamma-polyglutamic acid in preparation of a product for reducing uric acid

Abstract

The application discloses application of gamma-polyglutamic acid in preparation of a product for reducing uric acid. It is found that the gamma-polyglutamic acid and gamma-polyglutamic acid salt can reduce the uric acid level in blood and urine, wherein the medium molecular weight gamma-PGA (300-600 kDa) of 13.00 mg / kg can be a preferred object, and has the advantages of fast effect, good curative effect and stable effect. The gamma-polyglutamic acid and gamma-polyglutamic acid salt in the application can reduce the activity of xanthine oxidase, and reduce the synthesis of uric acid by changing the metabolic pathway, and can realize the treatment and health care effect on hyperuricemia.

Description

Technical Field

[0001] This invention relates to the fields of food nutrition, health care, and pharmaceutical technology, specifically to the application of γ-polyglutamic acid in the preparation of products that lower uric acid, such as those for treating hyperuricemia. Background Technology

[0002] Hyperuricemia (HUA) is a metabolic syndrome caused by an imbalance in purine metabolism. With rapid socioeconomic development, people's diets and lifestyles have undergone significant changes. Poor dietary habits and insufficient exercise have directly led to a continuous increase in the prevalence of hyperuricemia.

[0003] After hyperuricemia occurs, excess urate crystals in the body deposit in joints, soft tissues, kidneys, and other organs, leading to a series of diseases. Clinically, the main causes of gout and kidney stones are elevated blood uric acid levels. Hyperuricemia is currently considered a type of metabolic syndrome. Mechanistically, it increases inflammation and oxidative stress, leads to insulin resistance and dyslipidemia, and consequently affects the development of cardiovascular and other related metabolic diseases.

[0004] Hyperuricemia occurs through primary or secondary events leading to disruptions in purine metabolism or impaired uric acid excretion. The specific steps of the purine metabolic pathway include phosphorylation of adenine monophosphate to hypoxanthine, followed by conversion to xanthine by xanthine oxidase (XOD), and further oxidation to uric acid (2,6,8-trioxopurine). Therefore, XOD has become a popular target in research on therapeutic drugs for hyperuricemia. Allopurinol, a classic drug for treating hyperuricemia and gout, lowers blood uric acid levels by inhibiting xanthine oxidase. Although allopurinol is highly effective in treating hyperuricemia, it also has side effects. These include gastrointestinal discomfort, abnormal liver function, and skin rashes, with skin rashes being the most common. Furthermore, increasing research indicates that long-term or high-dose use of allopurinol may worsen the condition of patients with renal insufficiency. Currently, safe and effective XOD inhibitors remain a key focus in uric acid-lowering research. Summary of the Invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing an application of γ-polyglutamic acid in the preparation of uric acid-lowering products.

[0006] γ-Polyglutamic acid (γ-PGA), also known as natto gum, was first discovered in the highly viscous, stringy substance found in Japanese natto (fermented soybeans). The US FDA issued a GRAS Notice (GRN 000339) in 2010, confirming its good biocompatibility and safety. This invention aims to develop a method for lowering uric acid using multiple γ-PGA compounds.

[0007] To solve the above-mentioned technical problems, the present invention discloses the following technical solution:

[0008] In a first aspect, the present invention discloses the application of γ-polyglutamic acid or its salt in the preparation of uric acid-lowering products.

[0009] The weight-average molecular weight of the γ-polyglutamic acid or its salt is 2-2000 kDa, preferably 5-150 kDa, 250-700 kDa or 750-2000 kDa, and more preferably 10-100 kDa, 300-600 kDa or 800-2000 kDa, such as 300 kDa, 400 kDa, 500 kDa or 600 kDa.

[0010] The salt is any one or a combination of several of the following: potassium-type γ-polyglutamate, sodium-type γ-polyglutamate, calcium-type γ-polyglutamate, zinc-type γ-polyglutamate, and magnesium-type γ-polyglutamate.

[0011] Secondly, the present invention discloses a composition for lowering uric acid.

[0012] The active ingredient in the composition includes γ-polyglutamic acid or its salt.

[0013] The weight-average molecular weight of the γ-polyglutamic acid or its salt is 2-2000 kDa, preferably 5-150 kDa, 250-700 kDa or 750-2000 kDa, and more preferably 10-100 kDa, 300-600 kDa or 800-2000 kDa, such as 300 kDa, 400 kDa, 500 kDa or 600 kDa.

[0014] The salt is any one or a combination of several of the following: potassium-type γ-polyglutamate, sodium-type γ-polyglutamate, calcium-type γ-polyglutamate, zinc-type γ-polyglutamate, and magnesium-type γ-polyglutamate.

[0015] Thirdly, this invention discloses a uric acid-lowering preparation.

[0016] The formulation includes the composition described in the second aspect above.

[0017] The dosage form of the preparation is an oral dosage form, preferably a liquid or solid dosage form; the solid dosage form is preferably a powder, granule, tablet, or capsule.

[0018] In this invention, the γ-polyglutamic acid is a polymer formed by the polymerization of D-type or L-type glutamic acid through γ-amide bonds, and can be synthesized by fermentation of Bacillus microorganisms, including but not limited to Bacillus subtilis NX-2, Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus velutipes, etc.

[0019] In this invention, the salts, such as potassium-type γ-polyglutamate, sodium-type γ-polyglutamate, calcium-type γ-polyglutamate, zinc-type γ-polyglutamate, and magnesium-type γ-polyglutamate, can be purchased directly or prepared according to existing technologies.

[0020] In this invention, the uric acid reduction includes lowering uric acid in the blood and / or urine, such as for the treatment of hyperuricemia.

[0021] In this invention, the therapeutically effective amount of the composition or preparation is 0.3-6.0 mg γ-polyglutamic acid and its salt / kg (human), such as 0.5-1.5 mg γ-polyglutamic acid and its salt / kg (human), such as 2-3 mg γ-polyglutamic acid and its salt / kg (human), such as 3.5-4.5 mg γ-polyglutamic acid and its salt / kg (human), such as 5-6 mg γ-polyglutamic acid and its salt / kg (human).

[0022] In this invention, the product includes medicine, ordinary food, and health food, which can be taken orally to reduce the uric acid level in the blood and urine of people with hyperuricemia.

[0023] This invention further discloses the molecular mechanism of medium molecular weight γ-PGA in treating hyperuricemia. Specifically, the potential mechanism of action of γ-PGA in treating hyperuricemia is mainly reflected in two aspects: first, it reduces uric acid production by inhibiting xanthine oxidase (XOD) activity; XOD activity can be inhibited at a concentration of 0.15-20 μg / mL, with a maximum inhibition rate of 32%; second, it reduces purine synthesis by regulating metabolic pathways such as amino acid metabolism (glycine / serine / threonine metabolism), fatty acid metabolism (linoleic acid metabolism), starch / sucrose metabolism, and galactose metabolism. This study provides a theoretical basis for developing γ-PGA for the treatment of hyperuricemia.

[0024] Beneficial effects:

[0025] This invention is the first to discover that γ-polyglutamic acid has a significant uric acid-lowering effect, especially medium molecular weight γ-PGA (300-600 kDa), which has the most significant effect on reducing uric acid in blood and urine, and is superior to the positive control allopurinol, with the advantages of rapid onset, good efficacy, and stable effect. Simultaneously, this invention is the first to elucidate the potential mechanism of action of γ-PGA in treating hyperuricemia: firstly, by inhibiting xanthine oxidase (XOD) activity to reduce uric acid production; secondly, by regulating metabolic pathways such as amino acid metabolism (glycine / serine / threonine metabolism), fatty acid metabolism (linoleic acid metabolism), starch / sucrose metabolism, and galactose metabolism to reduce purine synthesis. Attached Figure Description

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0027] Figure 1 The effect of different doses of γ-PGA (600 kDa) on the uric acid content in the blood of mice in each group; (A) Week 1 of the experiment; (B) Week 2 of the experiment; (C) Week 3 of the experiment; (D) Week 4 of the experiment; Compared with the normal control group, #p<0.05; Compared with the pathological model group, *p<0.05; Compared with the positive control, $p<0.05.

[0028] Figure 2 The effect of different doses of γ-PGA (600 kDa) on the urinary uric acid content in mice of different groups; (A) Week 1 of the experiment; (B) Week 2 of the experiment; (C) Week 3 of the experiment; (D) Week 4 of the experiment; Compared with the normal control group, #p<0.05; Compared with the pathological model group, *p<0.05; Compared with the positive control, $p<0.05.

[0029] Figure 3 The effect of different molecular weights of γ-PGA on the uric acid content in the blood of mice in each group; (A) Week 1 of the experiment; (B) Week 2 of the experiment; (C) Week 3 of the experiment; (D) Week 4 of the experiment; Compared with the normal control group, #p<0.05; Compared with the pathological model group, *p<0.05; Compared with the positive control, $p<0.05.

[0030] Figure 4 The effect of different molecular weights of γ-PGA on the uric acid content in the urine of mice in each group; (A) Week 1 of the experiment; (B) Week 2 of the experiment; (C) Week 3 of the experiment; (D) Week 4 of the experiment; Compared with the normal control group, #p<0.05; Compared with the pathological model group, *p<0.05; Compared with the positive control, $p<0.05.

[0031] Figure 5The effects of different polyglutamate salts on the uric acid content in the blood and urine of mice in each group were investigated. (A) Effect of different polyglutamate salts on the uric acid content in the blood of mice in each group during week 4 of the experiment; (B) Effect of different polyglutamate salts on the uric acid content in the urine of mice in each group during week 4 of the experiment. Compared with the normal control group, #p<0.05; compared with the pathological model group, *p<0.05.

[0032] Figure 6 This is due to the inhibitory effect of γ-PGA on xanthine oxidase (XOD).

[0033] Figure 7 The effects of γ-PGA on urinary metabolites in hyperuricemic mice; (A) Differential metabolic pathway diagram between the normal control group and the pathological model group; (B) Differential metabolic pathway diagram between the γ-PGA group and the pathological model group.

[0034] Figure 8 This is a network diagram of urinary metabolites-genes for γ-PGA-mediated hyperuricemia; red, pink, and purple nodes and lines represent differential metabolites, related metabolites, genes, and biochemical reactions, respectively.

[0035] Figure 9 This is a network diagram of γ-PGA candidate targets, metabolite-related targets, urinary differential metabolites, metabolic pathways, and diseases; blue nodes: diseases, orange nodes: metabolic pathways, green nodes: metabolites, purple nodes: metabolite-related genes, pink nodes: drug therapy candidate targets, gray nodes: drugs, and yellow nodes: key targets. Detailed Implementation

[0036] The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the descriptions in the embodiments are for illustrative purposes only and should not, and will not, limit the invention as detailed in the claims.

[0037] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0038] Based on previous research, the applicant obtained multi-component weight-average molecular weight γ-polyglutamic acid through Bacillus bio-fermentation; the Bacillus species include, but are not limited to, Bacillus subtilis NX-2, Bacillus amyloliquefaciens, Bacillus licheniformis, and Bacillus velutipes.

[0039] Example 1: Effects of different amounts of γ-PGA additives on uric acid levels in mouse blood and urine

[0040] Sixty-four male Kunming mice, aged 5 weeks and weighing (20±2) g, were used for acclimatization. The animals were housed under standardized conditions with free access to food and water for one week. From day one, the positive control group and the γ-PGA group were administered allopurinol (APC) (10 mg / kg / day, mouse body weight) and different amounts of γ-PGA (3.25, 6.50, 13.00, 26.00, and 52.00 mg / kg / day, mouse body weight) by gavage, respectively. The molecular weight of γ-PGA is 600 kDa. The blank control group and the pathological model group received an equal volume of physiological saline. One hour after administration each day, all groups except the blank control group were simultaneously administered potassium oxonate 200 mg / kg + adenine 70 mg / kg by gavage for 4 weeks. Blood and urine were collected weekly to measure uric acid levels.

[0041] The study found that one week after drug administration to the model group, compared with the pathological model group, the levels of UA in the blood of mice were significantly reduced when γ-PGA was added at doses of 13.00, 26.00, and 52.00 mg / kg (*p<0.05), and the levels of UA in the blood of mice at doses of 13.00 and 26.00 mg / kg were significantly lower than those in the positive control ($p<0.05). Figure 1 A). This indicates that a certain dose of γ-PGA has a faster and more efficient uric acid-lowering effect. During weeks 2, 3, and 4 of the model-setting treatment, all treatment groups significantly reduced the level of UA in the mouse blood (A). Figure 1 (BD). This indicates that different amounts of medium molecular weight γ-PGA can significantly reduce uric acid (UA) levels in the urine of hyperuricemic model mice, showing a clear dose-dependent effect. Among them, the reduction in blood uric acid was most significant when γ-PGA was added at a dose of 13.00 mg / kg.

[0042] The study found that one week after modeling and drug administration, compared with the pathological model group, the urinary UA levels in mice with added γ-PGA doses of 13.00, 26.00, and 52.00 mg / kg were significantly lower (*p<0.05) and significantly lower than the positive control ($p<0.05). At this time, the urinary UA levels in mice with added γ-PGA doses of 6.5 and 3.25 mg / kg, and in the positive control group (allopurinol), showed no significant change (*p>0.05). Figure 2 A). This indicates that a certain dose of γ-PGA has a faster and more efficient uric acid-lowering effect, a result consistent with the blood uric acid-lowering effect. During weeks 2, 3, and 4 of the model-setting treatment, all treatment groups significantly reduced UA levels in mouse urine (A). Figure 2(BD). This indicates that different amounts of medium molecular weight γ-PGA can significantly reduce uric acid (UA) levels in the urine of hyperuricemic model mice, showing a clear dose-dependent effect. Among them, the reduction in urinary uric acid was most significant when γ-PGA was added at a dose of 13.00 mg / kg, which was superior to the positive control.

[0043] Example 2: Effects of different molecular weights of γ-PGA on uric acid levels in mouse blood and urine

[0044] Sixty-four male Kunming strain mice, aged 5 weeks and weighing (20±2) g, were used. The animals were housed in a standardized environment with free access to food and water for one week for acclimatization. From day one, the positive control group and the γ-PGA group were administered allopurinol (APC) (10 mg / kg / day, mouse body weight) and different molecular weights of γ-PGA (2, 100, 300, 600, 800, 2000 kDa) by gavage, respectively. The γ-PGA group received an additional dose of 13.00 mg / kg / day (mouse body weight). The blank control group and the pathological model group received an equal volume of physiological saline. One hour after administration each day, except for the blank control group, all other groups were simultaneously administered potassium oxonate 200 mg / kg + adenine 70 mg / kg by gavage for 4 weeks. Blood and urine were collected weekly to measure uric acid levels.

[0045] The study found that, one week after modeling and administration, compared with the pathological model group, mice supplemented only with γ-PGA with a molecular weight of 300 or 600 kDa had significantly lower blood UA levels (*p<0.05), while mice supplemented with other molecular weight γ-PGA doses showed a decrease in blood UA levels, but not a significant one (*p>0.05). Figure 3 A). During weeks 2, 3, and 4 of drug administration, all drug-treated groups showed a significant reduction in serum UA levels in mice. Figure 3 (BD). This indicates that γ-PGA of different molecular weights can significantly reduce the level of UA in the blood of hyperuricemic mice, but there is no obvious molecular weight dependence. The reduction of uric acid in the blood is most significant when medium molecular weight γ-PGA (300-600kDa) is added, which is better than the positive control. The most effective γ-PGA molecular weight is 600kDa.

[0046] The study found that, one week after modeling and administration, compared with the pathological model group, mice supplemented only with γ-PGA with a molecular weight of 300 or 600 kDa showed a significant decrease in urinary UA levels (*p<0.05), while mice supplemented with other molecular weight γ-PGA doses showed a decrease in urinary UA levels, but not a significant one (*p>0.05). Figure 4 A). During weeks 2, 3, and 4 of the model-setting drug administration, all drug administration groups significantly reduced the level of UA in mouse urine ( Figure 4(BD). This indicates that γ-PGA of different molecular weights can significantly reduce UA levels in the urine of hyperuricemic model mice, but no obvious molecular weight dependence was observed. The reduction in urinary uric acid was most significant when medium molecular weight γ-PGA (300-600kDa) was added, which was better than the positive control. The most effective γ-PGA molecular weight was 600kDa.

[0047] Example 3: Effects of different γ-polyglutamate salts on uric acid levels in mouse blood and urine

[0048] Sixty-four male Kunming strain mice, aged 5 weeks and weighing (20±2) g, were used. The experimental animals were housed in a standardized environment with free access to food and water, and underwent acclimatization feeding for one week. From the first day of the experiment, the positive control group and the γ-PGA group were administered allopurinol (APC) (10 mg / kg / day, based on mouse body weight) and different γ-polyglutamate salts (γ-polyglutamic acid, γ-polyglutamate potassium salt, γ-polyglutamate sodium salt, γ-polyglutamate calcium salt, γ-polyglutamate zinc salt, and γ-polyglutamate magnesium salt) by gavage. The weight-average molecular weight of polyglutamic acid and its salts in the γ-PGA group was 600 kDa, and the dosage was 13.00 mg / kg / day (based on mouse body weight). The blank control group and the pathological model group received an equal volume of physiological saline. One hour after administration each day, except for the blank control group, all other groups were simultaneously administered potassium oxonate 200 mg / kg + adenine 70 mg / kg by gavage for 4 weeks. Blood and urine were collected from the mice in the fourth week to measure uric acid levels.

[0049] The study found that during week 4 of modeling and drug administration, all drug groups significantly reduced the levels of UA in the blood and urine of mice. Figure 5 This indicates that different polyglutamate salts can significantly reduce UA levels in the blood and urine of hyperuricemic mice. Among them, γ-polyglutamate calcium showed the most significant reduction in uric acid levels in both blood and urine among different polyglutamate salts.

[0050] Example 4: Inhibition system of xanthine oxidase by γ-PGA

[0051] Xanthine oxidase (XOD) is a key enzyme in uric acid synthesis; therefore, the inhibition of XOD activity by γ-PGA was measured. γ-PGA (molecular weight 600 kDa) was dissolved in pure water to prepare solutions of different masses. 50 μL of γ-PGA solution was mixed with 150 μL of XOD solution (0.05 U / mL), and 150 μL of xanthine solution (0.48 mmol / L) was added. The mixture was reacted at 37 °C for 60 min, and then 150 μL of HCl (1 M) was added to terminate the reaction. The absorbance was measured at 290 nm. 150 μL of deionized water was used as a blank control instead of XOD solution, 50 μL of deionized water was used as a negative control instead of γ-PGA solution, and 200 μL of deionized water was used as a blank negative control instead of both XOD and γ-PGA solutions.

[0052] The XOD inhibition rate is calculated as follows:

[0053]

[0054] Where A1 is the absorbance of the sample, A2 is the absorbance of the blank control, A3 is the absorbance of the negative control, and A4 is the absorbance of the blank negative control.

[0055] Studies have shown that when the mass concentration of γ-PGA is between 0.15 and 20 μg / mL, its inhibitory effect on XOD gradually increases with increasing concentration. Figure 6 At concentrations of 10-20 μg / mL, the inhibitory effect gradually stabilized, with a maximum inhibition rate of 32%, indicating that γ-PGA has a certain inhibitory effect on xanthine oxidase.

[0056] Example 5: Effects of γ-PGA on urinary metabolites and metabolic pathways in hyperuricemic mice

[0057] Animal Experiments: Based on the studies in Examples 1 and 2, γ-PGA showed the best therapeutic effect against hyperuricemia at a concentration of 13 mg / kg and a weight-average molecular weight of 600 kDa. Therefore, mice with a molecular weight of 600 kDa and a γ-PGA concentration of 13 mg / kg were selected for this mechanistic study. The specific protocol was as follows: Fifteen male 5-week-old Kunming mice, weighing (20±2) g, were used. The mice had free access to food and water at 22-26℃ and 45-55% humidity, and underwent a 12 / 12-hour light / dark cycle. They were acclimatized to the environment for one week before the experiment. The mice were randomly divided into three groups of five mice each, as follows: Normal control group: Administered 10 g / 0.1 mL of physiological saline by gavage daily for weeks 1-4. Pathological model group: Administered 10 g / 0.1 mL of physiological saline by gavage daily for weeks 1-4, followed by 200 mg / kg potassium oxonate and 70 mg / kg adenine by gavage one hour later, for four consecutive weeks. γ-PGA administration group: During weeks 1-4 of the experiment, mice were administered γ-PGA (600 kDa, 13 mg / kg) by gavage daily. One hour later, they were administered potassium oxonate (200 mg / kg) and adenine (70 mg / kg) by gavage. This administration was continued for four weeks. After the last administration, the mice were placed in a metabolic environment, and 24-hour urine samples were collected for metabolomics analysis.

[0058] Biological sample pretreatment: 100 μL of urine sample from the above experiment was placed in a 1.5 mL centrifuge tube, and 500 μL of pre-cooled extraction buffer (methanol:water = 4:1) containing the internal standard (myristic acid-d27, 15 μg / mL) was added. The mixture was shaken for 10 min, centrifuged at 14000 rpm and 4 °C for 10 min, and the supernatant was collected and evaporated to dryness in a vacuum concentrator. After evaporation, 30 μL of methoxyamine pyridine (15 mg / mL) was added for reconstitution, and the mixture was vortexed for 10 min and allowed to stand at room temperature for 16 h for oxime reaction. Then, 30 μL of freshly prepared trimethylsilylating reagent (N-methyl-N-(trimethylsilyl)) was added for derivatization at room temperature for 1 h. 30 μL of heptane solution containing the external standard (methyl myristic acid, 30 μg / mL) was added, the mixture was shaken and centrifuged, and 60 μL of the supernatant was transferred to a sample tube for GC-MS analysis.

[0059] Analysis of mouse urinary metabolites using gas chromatography-mass spectrometry (GC-MS): GC analysis was performed using an HP-5MS capillary column (30m × 250μm × 0.25μm). The injection port temperature was set to 250℃, the injection port pressure to 8.809psi, the injection flow rate to 24.00mL / min, and the injection volume to 1μL. High-purity helium (He, purity 99.999%) was used as the carrier gas at a flow rate of 1.0mL / min. A programmed temperature ramp was employed, with the following steps: initial temperature of 70℃ held for 3 min, followed by ramping to 310℃ at a rate of 10℃ / min and holding at 310℃ for 6 min. An electron impact ionization source was used as the ion source, with an operating temperature set to 230℃. The ionization parameters were: accelerating voltage 70eV and electron beam current 3.0mA. To minimize solvent peak interference, a solvent delay time of 5 minutes was used. Data acquisition employed a full-ion scan mode, covering a range of 50 to 550 m / z, with a scan rate of 20 mass spectra per second. The detector voltage was adjusted to -1650 V to optimize signal detection efficiency.

[0060] Data processing and differential metabolite enrichment analysis: Chem Station software automatically acquired total ion chromatograms and characteristic ion information. The AMDIS system was used to deconvolve the detected characteristic ions to obtain key parameters such as retention time, characteristic fragments, and peak area for each chromatographic peak. Experimental data were compared and analyzed with NIST 2.0 (2008 version) and the Wiley spectral library. MetaboAnalyst 5.0 online analysis platform (http: / / www.metaboanalyst.ca / MetaboAnalyst / ) was used for metabolomics data analysis. The expression fold change (FC value) and significance level (p value) of each metabolite were calculated; combined with variable projection importance (VIP value), statistically significant differential metabolites were screened. The screening criteria were set as follows: VIP value greater than 1, FC value ≥ 1.2 or ≤ 0.83, and p value less than 0.05. The screened differential metabolites were imported into the MetaboAnalyst platform, and pathway enrichment analysis was performed using its built-in metabolic pathway database.

[0061] Metabolomics analysis of urine samples from experimental animals was performed using GC-MS. PCA analysis showed significant differences in metabolism between the normal control group and the pathological model group, as well as between the γ-PGA administration group and the pathological model group, with clear cluster separation. γ-PGA samples were distributed between the two groups. Compared with the blank control group, 41 differentially expressed metabolites were identified in the pathological model group, mainly including pyrophosphate, stearic acid, D-sorbitol, and phenylacetylglycine. Compared with the pathological model group, 38 differentially expressed metabolites were identified in the γ-PGA administration group, mainly including galactopyric acid, D-gluconic acid, hippuric acid, and cholesterol. A total of 18 common differentially expressed metabolites were found between the two groups, mainly including hippuric acid, cholesterol, stearic acid, and D-glucose (Table 2).

[0062] Differential metabolic pathway studies have shown that, compared with the normal control group, the pathological model group of hyperuricemia exhibited significant changes in five metabolic pathways, including galactose metabolism and starch / sucrose metabolism. Figure 7 A). Compared with the pathological model group, the pathway enrichment results of the γ-PGA administration group showed that the anti-hyperuricemia effect of γ-PGA mainly involves six metabolic pathways, including glycine / serine / threonine metabolism and glyoxylic acid / dicarboxylic acid metabolism. Figure 7 B).

[0063] Table 2. Information and trends of differentially metabolites in mouse urine.

[0064]

[0065]

[0066] Example 6: Analysis of the metabolite target genes and regulatory network mechanisms of γ-PGA affecting hyperuricemia

[0067] Using the Plug-in Metscape plugin in Cytoscape software, differentially expressed urinary metabolites of γ-PGA can be input to obtain a metabolite-gene network diagram. The metabolite-gene network diagram shows that γ-PGA affects urinary metabolite targets in hyperuricemic mice, primarily including 126 genes such as FATP2 (fatty acid transporter 2), SORD (sorbitol dehydrogenase), GAA (α-glucosidase), and LCT (lactase). Figure 8 ).

[0068] Comprehensive analysis of urine sample metabolomics and network pharmacology data ( Figure 9 The results showed that γ-PGA may mainly affect 12 metabolic genes, including HK3, MGAM, HK1, and GAA (α-glucosidase), through its action on PYMG-related pathways, thereby regulating four metabolic pathways, namely linoleic acid metabolism, galactose metabolism, and glycine / serine / threonine metabolism, to improve hyperuricemia.

[0069] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. Application of γ-polyglutamic acid or its salts in the preparation of uric acid-lowering products.

2. The application according to claim 1, characterized in that, The weight-average molecular weight of the γ-polyglutamic acid or its salt is 2-2000 kDa, preferably 5-150 kDa, 250-700 kDa or 750-2000 kDa, and more preferably 10-100 kDa, 300-600 kDa or 800-2000 kDa.

3. The application according to claim 1, characterized in that, The salt is any one or a combination of several of the following: potassium-type γ-polyglutamate, sodium-type γ-polyglutamate, calcium-type γ-polyglutamate, zinc-type γ-polyglutamate, and magnesium-type γ-polyglutamate.

4. A composition for lowering uric acid, characterized in that, The active ingredient of the composition includes γ-polyglutamic acid or a salt thereof.

5. The composition according to claim 4, characterized in that, The weight-average molecular weight of the γ-polyglutamic acid or its salt is 2-2000 kDa, preferably 5-150 kDa, 250-700 kDa or 750-2000 kDa, and more preferably 10-100 kDa, 300-600 kDa or 800-2000 kDa.

6. The composition according to claim 4, characterized in that, The salt is any one or a combination of several of the following: potassium-type γ-polyglutamate, sodium-type γ-polyglutamate, calcium-type γ-polyglutamate, zinc-type γ-polyglutamate, and magnesium-type γ-polyglutamate.

7. A preparation for lowering uric acid, characterized in that, The composition includes any one of claims 4-6.

8. The formulation according to claim 7, characterized in that, The dosage form of the preparation is an oral dosage form, preferably a liquid or solid dosage form; the solid dosage form is preferably a powder, granule, tablet, or capsule.

9. The application according to claim 1, the composition according to claim 4, or the formulation according to claim 7, characterized in that, The uric acid-lowering treatment includes the treatment of hyperuricemia.

10. The composition according to any one of claims 4-6 or the formulation according to claim 7 or 8, characterized in that, The therapeutically effective amount of the composition or preparation is 0.3-6.0 mg γ-polyglutamic acid and its salts per kg of human body weight.

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