Bionic nano-enzyme exoskeleton yeast derived polysaccharide as well as preparation method and pharmaceutical application thereof

Abstract

The invention discloses bionic nano-enzyme exoskeleton yeast derived polysaccharide as well as a preparation method and pharmaceutical application thereof, and relates to the technical field of biological medicines. The preparation method comprises the step of carrying out mixed reaction on yeast-derived polysaccharide, a natural polyphenol compound and Ce (NO3) 3.6 H2O under an alkaline condition to prepare the bionic nano-enzyme exoskeleton yeast-derived polysaccharide. The bionic nano-enzyme exoskeleton yeast derived polysaccharide provided by the invention has good biocompatibility, and has the ability of targeting and enriching at an inflammatory site in an inflammatory environment of IBD (Infectious Bursal Disease). By utilizing the antioxidant enzyme-like activity of the compound, active oxygen in an inflammation environment can be continuously removed, so that the intestinal inflammation environment is regulated, the oxidative stress level of intestinal tissues is reduced, and the intestinal barrier repair is promoted; meanwhile, due to the prebiotics effect, intestinal flora can be optimized, and nerve-related metabolites can be improved, so that IBD-related depression is relieved.

Description

Technical Field

[0001] The present invention relates to the field of biomedicine technology, and in particular to a bionic nanozyme exoskeletonized yeast-derived polysaccharide, a preparation method thereof and pharmaceutical use thereof. Background Art

[0002] Inflammatory bowel disease (IBD) is a chronic, relapsing immune-mediated disease that primarily affects the ileum, rectum, and colon, with the main subtypes being Crohn's disease and ulcerative colitis. Patients are usually diagnosed in early adulthood, but chronic inflammation persists throughout their lives. The impact of IBD is not limited to the gastrointestinal tract, and patients often have psychological comorbidities such as anxiety and depression. Compared with the general population, IBD patients are more likely to experience anxiety and depression, with approximately one-third of patients experiencing anxiety symptoms and one-quarter experiencing depressive symptoms. This comorbidity significantly reduces patients' quality of life, complicates clinical management, and increases the active period of the disease.

[0003] In recent years, many researchers have developed a number of functional bioengineering materials for IBD-related depression. For example, Professor Lu Xiong and others from the School of Medicine (Institute of Biomedical Engineering) of Southwest Jiaotong University jointly developed a nanomedicine based on the oral polyphenol armor strategy. This nanomedicine consists of small interfering RNA (siRNA) of anti-inflammatory factor (TNF-α) and bovine serum albumin (BSA) nanoparticles protected by graphene quantum dots (GAGQD) modified with gallic acid, and the surface is coated with a multilayer structure of chitosan and tannic acid (TA). This nanoparticle can be retained for a long time at the site of inflammation and release siRNA. Through endocytosis, siRNA enters immune cells, inhibits TNF-α expression, and alleviates intestinal inflammation. In addition, TA also regulates the balance of intestinal flora, promotes the growth of beneficial bacteria, and inhibits the reproduction of harmful bacteria. Through the interaction of the "gut-brain axis", the drug not only improves intestinal inflammation, but also significantly relieves anxiety, depression and cognitive dysfunction, reduces neuroinflammation in the brain, and repairs damaged neurons. Professor Zhou Min and others from the Second Affiliated Hospital of Zhejiang University School of Medicine proposed an oral hydrogel strategy (SP@Rh-gel) for the co-delivery of Spirulina platensis and rhein to treat IBD and its associated anxiety and depression by regulating the microbial-gut-brain axis. SP@Rh-gel showed significant enhancement in drug solubility, release characteristics, and intestinal retention, thereby effectively improving oral drug bioavailability. Oral administration of SP@Rh-gel can reduce intestinal inflammation and rebalance the disrupted intestinal microbial community to maintain intestinal homeostasis. In addition, SP@Rh-gel maintains intestinal barrier integrity, reduces the release of proinflammatory cytokines and lipopolysaccharides, and prevents them from entering the hippocampus through the blood-brain barrier, thereby inhibiting neuroinflammation and maintaining neuroplasticity.

[0004] The above technologies all regulate intestinal inflammation through TNF inhibitors or anti-inflammatory drugs to achieve the treatment of IBD-related depression, but the stability of small drug molecules in the complex environment of the intestine is poor and they are easily decomposed by intestinal flora or hydrolases, resulting in reduced efficacy. Based on this, the present invention intends to achieve the treatment of IBD diseases and the relief of related depression by constructing a material with stable performance and the ability to regulate intestinal inflammatory environment and intestinal flora. Summary of the invention

[0005] The purpose of the present invention is to provide a biomimetic nanozyme exoskeletonized yeast-derived polysaccharide and its preparation method and pharmaceutical use to solve the problems existing in the above-mentioned prior art. The biomimetic nanozyme exoskeletonized yeast-derived polysaccharide is suitable for the treatment of IBD-related depression and has broad clinical application prospects.

[0006] The present invention proposes a strategy inspired by the exoskeletonization process of insects, integrating nanozymes with yeast-derived polysaccharides to construct a series of nanozyme exoskeletonized yeast-derived polysaccharides (NZEP) for the treatment of IBD-related depression. Oral administration of NZEP can effectively stay and accumulate in the site of intestinal inflammation and reverse the imbalance of intestinal inflammatory homeostasis caused by IBD, promoting intestinal barrier repair. In addition, NZEP can regulate the abundance and diversity of intestinal flora, reverse microbial imbalance, and optimize the composition of microbial metabolites, thereby alleviating anxiety and depression symptoms associated with IBD.

[0007] Based on this, the present invention provides the following solutions:

[0008] The invention provides a method for preparing a bionic nanozyme exoskeletonized yeast-derived polysaccharide, comprising the steps of mixing yeast-derived polysaccharide, natural polyphenol compounds and Ce(NO3)3·6H2O under alkaline conditions to prepare the bionic nanozyme exoskeletonized yeast-derived polysaccharide.

[0009] Furthermore, the yeast-derived polysaccharide is extracted from baker's yeast cells by acid-base extraction.

[0010] Furthermore, the acid-base extraction method comprises the following steps: dispersing baker's yeast cells in a 1-5 mol / L NaOH solution, reacting at 75°C to 100°C, and centrifuging to obtain a first precipitate; resuspending the first precipitate with a 1-5 mol / L HCl solution, reacting at 75°C to 100°C, centrifuging again, collecting to obtain a second precipitate, and washing and drying the second precipitate to obtain the yeast-derived polysaccharide.

[0011] Furthermore, the natural polyphenol compound is at least one of tannic acid (TA), epigallocatechin gallate (EGCG), gallic acid (GA), caffeic acid (CA) and ellagic acid (EA).

[0012] Furthermore, the alkaline condition is pH 8.0.

[0013] Furthermore, the reaction ratio of the yeast-derived polysaccharide, the natural polyphenol compound and the Ce(NO3)3·6H2O is (20-200) g: (0.0002-0.001) mol: (0.0002-0.001) mol.

[0014] The present invention also provides a bionic nanozyme exoskeletonized yeast-derived polysaccharide prepared according to the above preparation method.

[0015] The present invention also provides the use of the bionic nanozyme exoskeletonized yeast-derived polysaccharide in the preparation of the drug described in (1) or (2);

[0016] (1) Drugs for the treatment of inflammatory bowel disease;

[0017] (2) Drugs to relieve depression associated with inflammatory bowel disease.

[0018] The present invention also provides a drug for treating inflammatory bowel disease or alleviating inflammatory bowel disease-related depression, wherein the active ingredient includes the above-mentioned bionic nanozyme exoskeletonized yeast-derived polysaccharide.

[0019] Furthermore, the medicine also includes pharmaceutically acceptable excipients.

[0020] The present invention discloses the following technical effects:

[0021] The present invention utilizes the residues (amino groups) exposed during the processing of yeast-derived polysaccharides (YGPs), and further innovatively constructs a series of NZEPs by mimicking the exoskeletonization strategy of insects, which can effectively integrate nanozyme materials and yeast-derived polysaccharide materials.

[0022] The biomimetic nanozyme exoskeletonized yeast-derived polysaccharide (NZEP) provided by the present invention has good biocompatibility, and its antioxidant enzyme activity and prebiotic performance are stable, and it has the ability to target and enrich in the inflammatory site under the inflammatory environment of IBD. Utilizing its antioxidant enzyme activity, it can continuously remove the reactive oxygen in the inflammatory environment, thereby achieving the regulation of the intestinal inflammatory environment, reducing the level of oxidative stress in intestinal tissue, and promoting intestinal barrier repair; at the same time, it can also optimize the intestinal flora and improve nerve-related metabolites through its prebiotic effect, thereby alleviating IBD-related depression.

[0023] The NZEP of the present invention is suitable for the treatment of IBD-related depression and has broad clinical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 Transmission electron microscope image and EDS element mapping image of NZEP;

[0026] Figure 2 Schematic diagram of the reaction between glucosamine (Gluc) and gallic acid (GA);

[0027] Figure 3 is the H NMR spectrum of the model molecular reactant;

[0028] Figure 4 is the mass spectrum of the model molecule reactant;

[0029] Figure 5 The test results of the antioxidant capacity of NZEP are shown in Figure 1. TA-Ce The test results of the ability to scavenge DPPH free radicals; b is NZEP TA-Ce The test results of the ability to scavenge ABTS free radicals; c is NZEP TA-Ce The test results of the ability to scavenge hydroxyl radicals; d is NZEP TA-Ce The test results of the ability to remove superoxide anions; e is NZEP TA-Ce The test results of hydrogen peroxide removal ability; f is NZEP TA-Ce Conceptual diagram of SOD-like activity and CAT-like activity;

[0030] Figure 6 For NZEP TA-Ce The evaluation result diagram of the ability to remove reactive oxygen species in macrophages; A is the laser confocal detection diagram; B is the fluorescence intensity quantitative analysis diagram of A;

[0031] Figure 7 The figure is the evaluation result of NZEP regulating the macrophage polarization process; A is the laser confocal detection figure; B is the fluorescence intensity statistical figure of CD86; C is the fluorescence intensity statistical figure of CD206;

[0032] Figure 8 This is a diagram evaluating the targeting and enrichment effects of NZEP in IBD inflammatory sites;

[0033] Fig. 9 The blood in stool test of mice in each group;

[0034] Fig.10 Schematic diagram of colon length of mice in each group;

[0035] Fig.11 is the histogram of the relative abundance of different species at the family level in each group;

[0036] Fig.12 Heat map of the relative abundance of various microbial components at the species level for each group;

[0037] Fig.13 This is the result diagram of the open field test experiment;

[0038] Fig.14 This is the result of the elevated plus maze experiment. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0040] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0041] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0042] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0043] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0044] Example 1

[0045] A biomimetic nanozyme exoskeletonized yeast-derived polysaccharide NZEP for the treatment of IBD-related depression TA-Ce Preparation method:

[0046] (1) Preparation of Yeast-derived Polysaccharides (YGPs)

[0047] The baker's yeast cells were dispersed in a 1 mol / L (up to 5 mol / L) NaOH solution and stirred and heated at 90°C (75°C to 100°C to achieve the same effect) for 1 hour. After centrifugation, the supernatant was discarded and the precipitate was collected. Then, the precipitate was further treated with a 1 mol / L (up to 5 mol / L) HCl solution and incubated at 75°C (75°C to 100°C to achieve the same effect) for 2 hours. After centrifugation again, it was thoroughly washed three times each with deionized water, isopropanol, and acetone. Finally, the collected precipitate was washed with isopropanol and acetone and vacuum dried to obtain white powder YGPs.

[0048] (2)NZEP TA-Ce Preparation

[0049] Add 100 μL of tannic acid (TA) aqueous solution (24 mM, the concentration can be selected in the range of 2 to 100 mM), 600 μL of Ce(NO3)3·6H2O solution (24 mM, the concentration can be selected in the range of 2 to 100 mM), and 40 mg of YGPs (the mass can be selected in the range of 20 to 200 mg) to 50 mL of deionized water and stir for 3 hours. Then, add 2 mol / L of NaOH solution to adjust the pH value of the solution to 8.0. Allow the reaction to proceed for 12 hours (up to 24 hours). Finally, collect the synthesized NZEP by centrifugation. TA-Ce and washed three times with deionized water.

[0050] Example 2

[0051] A biomimetic nanozyme exoskeletonized yeast-derived polysaccharide NZEP for the treatment of IBD-related depression EGCG-Ce Preparation method:

[0052] (1) Preparation of YGPs

[0053] Same as Example 1.

[0054] (2)NZEP EGCG-Ce Preparation

[0055] Epigallocatechin gallate (EGCG) aqueous solution (100 μL, 24 mM), Ce(NO3)3·6H2O solution (600 μL, 24 mM) and 40 mg YGPs were added to 50 mL of deionized water and stirred for 3 hours. Then, 2 mol / L NaOH solution was added to adjust the pH value of the solution to 8.0. The reaction was allowed to proceed for 12 hours. Finally, the synthesized NZEP was collected by centrifugation. EGCG-Ce and washed three times with deionized water.

[0056] Example 3

[0057] A biomimetic nanozyme exoskeletonized yeast-derived polysaccharide NZEP for the treatment of IBD-related depression GA-Ce Preparation method:

[0058] (1) Preparation of YGPs

[0059] Same as Example 1.

[0060] (2)NZEP GA-Ce Preparation

[0061] Gallic acid (GA) aqueous solution (100 μL, 24 mM), Ce(NO3)3·6H2O solution (600 μL, 24 mM) and 40 mg YGPs were added to 50 mL of deionized water and stirred for 3 hours. Then, 2 mol / L NaOH solution was added to adjust the pH value of the solution to 8.0. The reaction was allowed to proceed for 12 hours. Finally, the synthesized NZEP was collected by centrifugation. GA-Ce and washed three times with deionized water.

[0062] Example 4

[0063] A biomimetic nanozyme exoskeletonized yeast-derived polysaccharide NZEP for the treatment of IBD-related depression CA-Ce Preparation method:

[0064] (1) Preparation of YGPs

[0065] Same as Example 1.

[0066] (2)NZEP CA-Ce Preparation

[0067] Caffeic acid (CA) aqueous solution (100 μL, 24 mM), Ce(NO3)3·6H2O solution (600 μL, 24 mM) and 40 mg YGPs were added to 50 mL of deionized water and stirred for 3 hours. Then, 2 mol / L NaOH solution was added to adjust the pH value of the solution to 8.0. The reaction was allowed to proceed for 12 hours. Finally, the synthesized NZEP was collected by centrifugation. CA-Ce and washed three times with deionized water.

[0068] Example 5

[0069] A biomimetic nanozyme exoskeletonized yeast-derived polysaccharide NZEP for the treatment of IBD-related depression EA-Ce Preparation method:

[0070] (1) Preparation of YGPs

[0071] Same as Example 1.

[0072] (2)NZEP EA-Ce Preparation

[0073] Ellagic acid (EA) aqueous solution (100 μL, 24 mM), Ce(NO3)3·6H2O solution (600 μL, 24 mM) and 40 mg YGPs were added to 50 mL of deionized water and stirred for 3 hours. Then, 2 mol / L NaOH solution was added to adjust the pH value of the solution to 8.0. The reaction was allowed to proceed for 12 hours. Finally, the synthesized NZEP was collected by centrifugation. EA-Ce and washed three times with deionized water.

[0074] Effect verification example 1

[0075] 1 mg of NZEP prepared in Examples 1-5 was added to 10 mL of deionized water and dispersed evenly by ultrasonication to obtain NZEP solution. The solution was then dripped onto a copper mesh. After the water dried, the microscopic morphology and element distribution of NZEP were observed by transmission electron microscopy. The results are shown in Figure 1 .

[0076] from Figure 1 It can be found that the series of NZEPs formed still maintain the morphology of YGPs. Further element distribution scanning revealed that nanocerium is distributed on the surface of the YGPs shell, which confirms that the above two components of nanocerium and YGPs are effectively integrated through the insect exoskeletonization strategy.

[0077] Effect verification example 2

[0078] In order to confirm whether the amino groups on the surface of YGPs can react with polyphenols, the present invention selected glucosamine (Gluc) and gallic acid (GA) as verification model molecules. Under alkaline conditions, the catechol hydroxyl group is oxidized by oxygen to form a quinone structure, which then reacts with the amino group through nucleophilic addition (Schiff base or Michael addition) ( Figure 2 ), the product was analyzed by nuclear magnetic resonance hydrogen spectrum and mass spectrometry, the results are shown in Figure 3 and Figure 4 .

[0079] With quinone 1Compared with the H NMR spectrum, two new peaks (H1 and H2, H3 and H4) appeared in the reaction mixture, and the original peak signals (Hb, Hc) weakened, indicating that Michael addition and Schiff base reaction occurred simultaneously during the entire reaction process. Subsequently, the chemical structure of these nucleophilic addition products was further confirmed by matrix-assisted laser desorption / ionization-time of flight mass spectrometry (MALDI-TOF MS). MALDI-TOF / MS mass spectrometry data analysis showed that the reaction products contained molecular ion peaks corresponding to Schiff base (Glu-Sb-GA) and Michael addition (Glu-Ma-GA) reaction products.

[0080] Effect verification example 3

[0081] The significant feature of using nanocerium as the exoskeleton of YGPs is that it gives yeast-derived polysaccharides a strong ability to cope with oxidative stress environments. In order to verify the antioxidant capacity of NZEP, the present invention selected NZEP with the highest degree of nanozyme exoskeletonization. TA-Ce The experiment was carried out. 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-aminobis(3-ethylbenzothiazole-6-sulfonic acid) (ABTS) were selected for free radical scavenging experiments, and three representative reactive oxygen species with biological relevance, H2O2, ·O 2- and ·OH to study the active oxygen scavenging activity of NZEP. The results are shown in Figure 5 .

[0082] Use 150 μg / mL NZEP TA-Ce After treatment, about 40% of DPPH free radicals and 80% of ABTS free radicals were removed, and NZEP TA-Ce It showed significant ROS scavenging activity in a concentration-dependent manner. 150 μg / mL NZEP TA-Ce About 50% of ·OH can be eliminated. Using 150μg / mL NZEP TA-Ce After treatment, about 60% of the O 2- The surface material showed superoxide dismutase (SOD)-like activity. In addition, at a concentration of 150 μg / mL, nearly 90% of H2O2 was effectively removed, indicating that NZEP TA-Ce It also has catalase (CAT)-like activity.

[0083] Effect verification example 4

[0084] In order to study the antioxidant activity of NZEP on immune cells under oxidative stress conditions, tert-butyl hydroperoxide (tBHP) was co-cultured with macrophages (RAW264.7) to simulate the physiological environment of inflammatory bowel disease, and DCFH-DA (a probe that emits green fluorescence in the presence of reactive oxygen species) was used to evaluate the oxidative stress state in the cells. The test was divided into five groups, namely the normal group, the model group, the YGPs group, the nanocerium group, and the NZEP group. The treatment methods of each group are as follows:

[0085] 1. The normal group cultured RAW264.7 under normal conditions without any material treatment;

[0086] 2. The model group added tBHP to the culture medium to simulate the inflammatory microenvironment, and no other materials were added for treatment;

[0087] 3. The YGPs group added tBHP to the culture medium to simulate the inflammatory microenvironment, and then added YGPs for treatment;

[0088] 4. The nanocerium group was treated by adding tBHP to the culture medium to simulate the inflammatory microenvironment and adding nanocerium;

[0089] 5. NZEP group: tBHP was added to the culture medium to simulate the inflammatory microenvironment, and NZEP was added for treatment, wherein NZEP was the material constructed in Example 1. Figure 6 .

[0090] The RAW264.7 cells treated with tBHP in the model group showed strong green fluorescence in the cells, indicating an increase in the level of intracellular oxidative stress. After subsequent treatment with YGPs, the green fluorescence of some cells decreased. There was almost no green fluorescence in the cells treated with nanocerium and NZEP. The level of intracellular oxidative stress was further quantitatively analyzed by flow cytometry, and the results showed that YGPs had a slight alleviating effect on reducing the level of intracellular oxidative stress, while nanocerium and NZEP could significantly alleviate the level of intracellular oxidative stress.

[0091] Effect verification example 5

[0092] In order to study the effect of NZEP on the polarization process of immune cells under inflammatory conditions, RAW264.7 was treated with lipopolysaccharide (LPS) and interferon (IFN-γ), and then different material components were added to the culture medium for co-culture for 12 hours, and further systematic evaluation was performed by laser confocal microscopy. The test was divided into five groups, namely the normal group, the model group, the YGPs group, the nanocerium group and the NZEP group (Example 1). The results are shown in Figure 7 shown.

[0093] LPS- and IFN-γ-induced RAW264.7 cells showed upregulation of M1 macrophage markers (CD86) and downregulation of M2 macrophage markers (CD206), while YGPs slightly reversed these changes. Since nanocerium lacks the ability to regulate immune cell polarization, it mainly reduces the expression of M1 markers, and the increase in M2 markers is not obvious. It is worth noting that after NZEP treatment, the expression of M1 macrophage markers (CD86) was significantly reduced, and the expression of M2 macrophage markers (CD206) was significantly increased. Surface NZEP has a strong immune regulatory ability.

[0094] Effect Verification Example 6

[0095] In order to study the process of NZEP targeting the inflammatory part of IBD after oral administration, first, NZEP was labeled with Cy5.5, and the specific steps were as follows: 5 mg of NZEP was evenly dispersed in a beaker containing 50 mL of water. Subsequently, Cy5.5-NHS (1 mg / mL) dissolved in 20 μL of DMSO was added to the beaker, stirred overnight, and then centrifuged at 5000 rpm with water and washed 3 times. Finally, Cy5.5-labeled NZEP was successfully obtained.

[0096] Afterwards, the Cy5.5-labeled NZEP was fed to mice with IBD induced by dextran sodium sulfate (DSS) by oral gavage, and the enrichment and retention of NZEP in the intestine of mice was further monitored by in vivo imaging. The test was divided into two groups, namely the normal group and the model group. Figure 8 shown.

[0097] The fluorescence intensity of NZEP (Example 1) in the peritoneal cavity of different mice was monitored by an in vivo live imaging system at 6, 12, 18 and 24 hours. After oral administration, the fluorescence intensity of NZEP in the peritoneal cavity of DSS-induced IBD mice was 2.28, 2.13, 2.96 and 3.0 times that of the normal group at 6, 12, 18 and 24 hours, respectively. This shows that NZEP has a longer retention and enrichment effect in the inflamed intestine.

[0098] Effect verification example 7

[0099] In order to verify the therapeutic effect of NZEP on IBD after oral administration, 3% DSS was used to induce an IBD mouse model, and a 12-day treatment process was carried out. The test was divided into 5 groups, namely the normal group, the model group, the YGPs group, the nano-cerium group and the NZEP group. The treatment methods of each group are as follows:

[0100] 1. The normal group consisted of normal mice that were treated with normal saline orally for five days;

[0101] 2. The model group consisted of IBD mice that were treated with oral saline for five days;

[0102] 3. The YGPs group consisted of IBD mice that were orally treated with saline containing 87 μg / mL YGPs for five days;

[0103] 4. The nano-cerium group consisted of IBD mice that were orally treated with saline containing 63 μg / mL nano-cerium for five days;

[0104] 5. The NZEP group consisted of IBD mice that were orally treated with saline containing 150 μg / mL NZEP (Example 1) for five days. After the treatment, the blood in the stool and the length of the colon were monitored to determine the therapeutic effect. The results were as follows: Figure 9-10 shown.

[0105] The model group still had blood in the stool after 12 days of treatment; however, after 12 days of treatment with the material, the blood in the anus of the mice improved significantly. In IBD, inflammation and accumulation of extracellular matrix are usually confined to the colon mucosa and submucosa, which can lead to thickening of the mucosal muscularis, which may cause shortening or stiffness of the colon and impaired movement. When comparing the length of colon tissue, it was found that the average colon length of the model group was 41.6% less than that of the normal group, while the average reduction of mice treated with NZEP was only 10%. It is confirmed that NZEP has a therapeutic effect on IBD.

[0106] In order to verify the regulation and optimization process of NZEP on intestinal flora, the feces of mice were collected for flora analysis after 12 days of treatment. The results are as follows: Figure 11-Figure 12 shown.

[0107] Analysis of the abundance of microbiota in different groups showed that beneficial bacteria such as Muribaculaceae, Prevotellaceae, Rikenellaceae, and Clostridia-UCG-014 were increased in the NZEP group. Notably, clinical data showed that the relative abundance of Muribaculaceae was higher in healthy individuals than in IBD patients. In addition, Prevotellaceae is known to produce short-chain fatty acids (SCFAs). In contrast, pathogenic bacteria such as Enterobacteriaceae and Tannerellaceae, which are associated with IBD exacerbation, were significantly reduced in the NZEP group. Species-level cluster analysis further revealed that NZEP treatment significantly upregulated the abundance of anti-inflammatory bacteria such as Faecalibacteriumprausnitzii and Alistipes. It also enhanced the abundance of bacteria involved in SCFA synthesis, including uncultured bacterium g_Muribaculaceae, Clostridialesbacterium g_Lachnospiraceae NK4A136 group, uncultured bacterium g_Prevotellaceae UCG-001, and uncultured bacterium g_Roseburia. In addition, the treatment significantly downregulated the abundance of harmful bacteria such as Escherichia coli and Streptomyces.

[0108] To verify the therapeutic effect of NZEP on IBD-related depression, behavioral analysis was performed on mice after treatment. Figure 13-14 shown.

[0109] In the open field test, the longer time mice spend in the central area is usually interpreted as showing lower anxiety levels, while the longer time spent in the edge area indicates that they show higher anxiety levels. The total time that mice in the NZEP group treated with the drug stayed in the central area in the open field was not significantly different from that in the normal group. In the elevated plus maze test, the mice in the model group explored the open arms in the elevated maze less, indicating a decrease in risk-taking behavior, and the time spent in the crossing area was also significantly reduced, while the NZEP group significantly increased the time mice spent in the open arms and the frequency of crossing. The above experimental results show that NZEP has a certain effect on the treatment of IBD-related depression and can reduce the manifestation of depression-related behaviors.

[0110] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a biomimetic nanozyme exoskeletonized yeast-derived polysaccharide, characterized in that: The method comprises the steps of mixing yeast-derived polysaccharides, natural polyphenol compounds and Ce(NO3)3·6H2O under alkaline conditions to prepare the bionic nanozyme exoskeletonized yeast-derived polysaccharides.

2. The preparation method according to claim 1, characterized in that: The yeast-derived polysaccharide is extracted from baker's yeast cells by adopting an acid-base extraction method.

3. The preparation method according to claim 2, characterized in that: The acid-base extraction method comprises the following steps: dispersing baker's yeast cells in a 1-5 mol / L NaOH solution, reacting at 75°C-100°C, and centrifuging to obtain a first precipitate; resuspending the first precipitate with a 1-5 mol / L HCl solution, reacting at 75°C-100°C, centrifuging again, collecting to obtain a second precipitate, and washing and drying the second precipitate to obtain the yeast-derived polysaccharide.

4. The preparation method according to claim 1, characterized in that: The natural polyphenol compound is at least one of tannic acid, epigallocatechin gallate, gallic acid, caffeic acid and ellagic acid.

5. The preparation method according to claim 1, characterized in that: The alkaline condition is pH 8.

0.

6. The preparation method according to claim 1, characterized in that: The reaction ratio of the yeast-derived polysaccharide, the natural polyphenol compound and the Ce(NO3)3·6H2O is (20-200) g: (0.0002-0.001) mol: (0.0002-0.001) mol.

7. A biomimetic nanozyme exoskeletonized yeast-derived polysaccharide prepared according to the preparation method according to any one of claims 1 to 6.

8. Use of the biomimetic nanozyme exoskeletonized yeast-derived polysaccharide as claimed in claim 7 in the preparation of the drug as described in (1) or (2); (1) Drugs for the treatment of inflammatory bowel disease; (2) Drugs to relieve depression associated with inflammatory bowel disease.

9. A drug for treating inflammatory bowel disease or alleviating inflammatory bowel disease-related depression, characterized in that: The active ingredient includes the biomimetic nanozyme exoskeletonized yeast-derived polysaccharide as described in claim 7.

10. The drug according to claim 9, characterized in that The drug also includes pharmaceutically acceptable excipients.

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