Use of hyaluronic acid or salt thereof in preparing antimicrobial peptide inducer

Abstract

The present application provides use of hyaluronic acid or a salt thereof in preparing an antimicrobial peptide inducer, and relates to the technical field of antimicrobial care. A reducing end of the hyaluronic acid or the salt thereof comprises a uronic acid group. It has been discovered for the first time that hyaluronic acid with a specific terminal structure has the effect of inducing the generation of an antimicrobial peptide. This discovery provides a new direction for elucidating the correlation between the structure and efficacy of hyaluronic acid, and also offers a new effective ingredient for regulating cellular background defense to inhibit pathogenic bacterial invasion.

Description

Application of hyaluronic acid or its salt in preparing antimicrobial peptide inducers

[0001] This application claims priority to a Chinese patent application filed with the Patent Office of China on November 30, 2023, with application number "202311634295.3" and entitled "Application of hyaluronic acid or its salts in the preparation of antimicrobial peptide inducers", the entire contents of which are incorporated herein by reference;

[0002] This application also claims priority to a Chinese patent application filed with the Patent Office of China on January 18, 2024, with application number "202410080031.6" and invention name "Application of hyaluronic acid or its salts in the preparation of antimicrobial peptide inducers", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of antimicrobial care technology, and in particular to the use of hyaluronic acid or its salts in the preparation of antimicrobial peptide inducers. Background Art

[0004] In daily life, people are exposed to potential hazards in the external environment, such as pathogenic microorganisms, chemicals, and allergens, which can infect the skin, mouth, intestines, urinary tract, and respiratory tract. Therefore, regulating cellular background defenses to inhibit the invasion of pathogens is of great significance.

[0005] Antimicrobial peptides, also known as antimicrobial peptides or polypeptide antibiotics, are a class of small peptides with broad-spectrum resistance and are important components of innate immunity. Keratinocytes in the skin secrete antimicrobial peptides to resist pathogens, kill microorganisms, and regulate microbial balance. There are many different types of antimicrobial peptides, among which human β-defensin 2 (HBD2) is a major inducible peptide that plays a crucial role in host defense. Summary of the Invention

[0006] The inventors of the present application unexpectedly discovered through research that hyaluronic acid, when having a specific terminal structure, has the function of inducing the production of human β-defensin 2 (HBD2), thereby completing the present application.

[0007] In one aspect, the present application provides the use of hyaluronic acid or a salt thereof in the preparation of an antimicrobial peptide inducer, wherein the reducing end of the hyaluronic acid or the salt thereof comprises a uronic acid group.

[0008] On the other hand, the present application provides the use of hyaluronic acid or a salt thereof as an antimicrobial peptide inducer, wherein the reducing end of the hyaluronic acid or the salt thereof comprises a uronic acid group.

[0009] On the other hand, the present application provides the use of hyaluronic acid or a salt thereof in preparing a product for promoting the expression of antimicrobial peptides, wherein the reducing end of the hyaluronic acid or the salt thereof comprises a glucuronic acid group.

[0010] Optionally, the molecular weight of the hyaluronic acid or its salt is less than 5000 Da.

[0011] More optionally, the molecular weight of the hyaluronic acid or its salt is less than 5000 Da and greater than 300 Da.

[0012] More optionally, the molecular weight of the hyaluronic acid or its salt is 800-4999 Da.

[0013] More optionally, the molecular weight of the hyaluronic acid or its salt is 800-1000 Da.

[0014] It will be appreciated that the molecular weight of the hyaluronic acid or its salt can be selected from any one of 300 Da, 400 Da, 500 Da, 600 Da, 700 Da, 800 Da, 900 Da, 1100 Da, 1200 Da, 1300 Da, 1400 Da, 1500 Da, 2000 Da, 2500 Da, 3000 Da, 3500 Da, 4000 Da, 4500 Da, 4600 Da, 4700 Da, 4800 Da, 4900 Da, and 4999 Da.

[0015] Furthermore, the structural formula of the hyaluronic acid or its salt is shown in formula (I):

[0016] Wherein, X is selected from one of H, K, Na, Ca or Zn, and n is any integer selected from 0-5.

[0017] Optionally, X is Na.

[0018] Said n is any integer selected from 0 to 5. n can be selected from any integer of 0, 1, 2, 3, 4, 5.

[0019] Optionally, the hyaluronic acid or its salt is used at a concentration of 0.0001%-5% in terms of mass concentration percentage; more optionally, the hyaluronic acid or its salt is used at a concentration of 0.01%-1%.

[0020] The concentration of the hyaluronic acid or its salt can be selected from any one of 0.0001%, 0.0005%, 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, and 5%.

[0021] In an optional embodiment, the hyaluronic acid or its salt is sodium hyaluronate, which can be purchased from Bloomage Biotechnology Co., Ltd. under the trade name of Micro-Zhen.

[0022] Furthermore, the antimicrobial peptide includes human β-defensin 2 (HBD2).

[0023] This application first discovered that hyaluronic acid or its salts with a uronic acid group at the reducing end can act as an antimicrobial peptide inducer to promote the production of antimicrobial peptides in cells, thereby inhibiting the growth and proliferation of harmful bacteria in the human body, thereby regulating the human microecology and improving the cell's background defense capabilities, thereby achieving the purpose of inhibiting the invasion of pathogenic bacteria.

[0024] In an optional embodiment, the cells include epithelial cells and mucosal cells.

[0025] In an optional embodiment, the epithelial cells include skin epithelial cells, reproductive tract epithelial cells, intestinal epithelial cells, oral epithelial cells, urinary tract epithelial cells, and keratinocytes.

[0026] In an optional embodiment, the epithelial cells include keratinocytes, vaginal epithelial cells, and intestinal epithelial cells.

[0027] In an optional embodiment, the mucosal cells include skin mucosal cells, genital tract mucosal cells, intestinal mucosal cells, oral mucosal cells, and urinary tract mucosal cells.

[0028] In an optional embodiment, the mucosal cells include oral mucosal cells.

[0029] On the other hand, the present application also provides the use of the above-mentioned hyaluronic acid or its salt in promoting the production of antimicrobial peptides in cells.

[0030] On the other hand, the present application also provides an antimicrobial peptide inducer, which includes the above-mentioned hyaluronic acid or a salt thereof.

[0031] On the other hand, the present application also provides the use of the above-mentioned hyaluronic acid or its salt in regulating human microecology, wherein the reducing end of the hyaluronic acid or its salt contains a uronic acid group.

[0032] Among them, the human microecology includes oral microecology, urinary tract microecology, intestinal microecology, reproductive tract microecology, and skin microecology.

[0033] Furthermore, regulating the human microecology includes inhibiting the growth and proliferation of harmful bacteria in the human body.

[0034] Furthermore, the inhibiting of the growth and proliferation of bacteria harmful to the human body includes promoting the production of antimicrobial peptides in cells.

[0035] Furthermore, the harmful bacteria include bacteria, and the bacteria include Gram-positive bacteria and / or Gram-negative bacteria.

[0036] Furthermore, the Gram-positive bacteria include Staphylococcus bacteria.

[0037] Furthermore, the Staphylococcus bacteria include Staphylococcus aureus.

[0038] Optionally, the inhibition rate of the hyaluronic acid or its salt against Staphylococcus aureus is 97%.

[0039] Furthermore, the Gram-negative bacteria include Pseudomonas bacteria.

[0040] Furthermore, the Pseudomonas bacteria include Pseudomonas aeruginosa.

[0041] Optionally, the inhibition rate of the hyaluronic acid or its salt against Pseudomonas aeruginosa is 99%.

[0042] Furthermore, the Gram-negative bacteria include Escherichia bacteria.

[0043] Furthermore, the Escherichia bacteria include Escherichia coli.

[0044] Optionally, the inhibition rate of the hyaluronic acid or its salt on Escherichia coli is 97%.

[0045] On the other hand, the present application also provides the use of the above-mentioned hyaluronic acid or its salt in improving the cell defense ability.

[0046] Furthermore, the cell defense capability is the cell background defense capability.

[0047] This application has the following beneficial effects:

[0048] This application discovered for the first time that hyaluronic acid with a specific terminal structure has the function of inducing the production of antimicrobial peptides, which points out a new direction for clarifying the correlation between hyaluronic acid structure and efficacy, and also provides a new active ingredient for regulating cell background defense to inhibit the invasion of pathogenic bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0050] FIG1 is a graph showing the relative fluorescence quantitative results of HBD2 expression in keratinocytes;

[0051] FIG2 is a graph showing relative fluorescence quantification of HBD2 expression in vaginal cells;

[0052] FIG3 is a graph showing relative fluorescence quantification of HBD2 expression in intestinal cells;

[0053] FIG4 is a graph showing the relative fluorescence quantification results of HBD2 expression in oral cells. DETAILED DESCRIPTION

[0054] In order to more clearly illustrate the overall concept of the present application, the following is a detailed description of the embodiments in conjunction with the accompanying drawings. In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0055] If no specific conditions are specified in the examples, the experiments were carried out according to conventional conditions or conditions recommended by the manufacturer.

[0056] Among them, sodium hyaluronate-1 and sodium hyaluronate-2 were purchased from Bloomage Biotechnology; DMEM culture medium was purchased from Gibco; Staphylococcus aureus ATCC29213, Pseudomonas aeruginosa ATCC9027, and pathogenic Escherichia coli ATCC8739 were purchased from the American Type Culture Collection (ATCC). The specific product information is shown in Table 1.

[0057] Unless otherwise specified, in the following embodiments, the reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased from the market.

[0058] Unless otherwise stated, the experimental methods, detection methods, and preparation methods disclosed in this application all adopt conventional techniques in molecular biology, biochemistry, chromatin structure and analysis, analytical chemistry, cell culture, recombinant DNA technology, and related fields conventional in the art, and can be specifically carried out according to Molecular Cloning: A Laboratory Manual (Fourth Edition).

[0059] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" are open-ended terms and should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present application, but the description is based on the general principles of the specification and is not intended to limit the scope of the present application. The scope of protection of this application shall be as defined by the attached claims.

[0060] Table 1

[0061] Example 1 Identification of the reducing end of hydrolyzed hyaluronic acid

[0062] Principle: Using the Morgan-Elson reaction, determine the reducing end of sodium hyaluronate by colorimetry. If the color turns red, it indicates that the reducing end is N-acetylglucosamine; if it does not turn red, it indicates that the reducing end is glucuronic acid.

[0063] Reaction buffer: alkaline boric acid solution (dissolve 1.73 g H3BO3 and 0.78 g KOH in 10 mL water, and add one-tenth of its volume of 0.8 g / mL K2CO3 before use); p-dimethylaminobenzaldehyde solution (dissolve 2 g p-dimethylaminobenzaldehyde in 2.5 mL concentrated hydrochloric acid and 7.5 mL glacial acetic acid, and dilute with 4 times the volume of glacial acetic acid before use).

[0064] Experimental steps: Take 400 μL of 10 g / L sodium hyaluronate (sodium hyaluronate-1, sodium hyaluronate-2) solution, add 110 μL of alkaline boric acid solution, boil for 4 minutes, add 1.5 mL of p-dimethylaminobenzaldehyde solution, and incubate at 37°C for 20 minutes.

[0065] The results are shown in Table 2. Sodium hyaluronate-1 did not show red color after the Moran-Elson reaction, indicating that the reducing end was uronic acid; sodium hyaluronate-2 showed red color after the Moran-Elson reaction, indicating that the reducing end was N-acetylglucosamine.

[0066] Table 2

[0067] Example 2 Antimicrobial peptide HBD2 expression experiment

[0068] Hyaluronic acid-1 and hyaluronic acid-2 were prepared in DMEM medium to create different experimental solutions. Their effects on the expression of the antimicrobial peptide HBD2 in primary keratinocytes and human vaginal epithelial cells were examined. The specific method involved co-culturing primary keratinocytes (HEKn cells, isolated from neonatal foreskin and cryopreserved at the end of primary culture) and human vaginal epithelial cells (VK2 / E6E7, purchased from ATCC #CRL2616) with the different experimental solutions for one day. The experimental solutions were then removed, the cells fixed with methanol, and blocked with blocking solution for 1 hour. After washing with PBS, the cells were incubated with HBD2 primary antibody overnight at 4°C. After staining with diluted secondary antibody for 1.5 hours, the sections were mounted with anti-quenching agent, and photographed using a fluorescence microscope. Relative fluorescence intensity was semi-quantitatively analyzed using ImageJ. The results for the keratinocyte group are shown in Figure 1 and Table 3; the results for the vaginal epithelial group are shown in Figure 2 and Table 4.

[0069] Hyaluronic acid-1 and hyaluronic acid-2 were prepared into different experimental sample solutions using McCoy's 5A medium (Procell, #PM150710) to examine their effects on the expression of the antimicrobial peptide HBD2 in human intestinal epithelial cells. The specific method involved co-culturing HT29 human colon cancer cells (purchased from Procell, #CL-0118) with the different experimental sample solutions for one day. The experimental solution was then removed, the cells fixed with methanol, and blocked with blocking solution for 1 hour. After washing with PBS, the cells were then incubated with HBD2 primary antibody overnight at 4°C. After staining with diluted secondary antibody for 1.5 hours, the sections were mounted with anti-quenching agent, and photographed using a fluorescence microscope. Relative fluorescence intensity was semi-quantitatively analyzed using ImageJ. The results of the intestinal epithelial cell experimental group are shown in Figure 3 and Table 5.

[0070] Hyaluronic acid-1 and hyaluronic acid-2 were prepared into different experimental sample solutions using culture medium (Procell, #SNPM-H151) to detect their effects on the expression of the antimicrobial peptide HBD2 in human oral mucosal cells. The specific method includes: selecting human oral mucosal cells (SNP-H151) as a commonly used in vitro test cell for mucosal research, co-culturing oral mucosal cells (SNP-H151, purchased from Procell, #SNPM-H151) with different experimental sample solutions for 1 day, removing the experimental sample solution, fixing the cells with methanol, adding blocking solution for 1 hour, washing with PBS, adding HBD2 primary antibody, incubating overnight at 4°C, adding diluted secondary antibody for staining for 1.5 hours, mounting with anti-fluorescence quencher, and photographing under a fluorescence microscope. ImageJ fluorescence semi-quantitative analysis is used to calculate the relative fluorescence intensity. The results are shown in Figure 4 and Table 6.

[0071] On the basis of meeting the requirements of significant difference, the stronger the relative fluorescence intensity, the better the cell's own defense effect.

[0072] Table 3 Expression results of antimicrobial peptide HBD2 in keratinocytes

[0073] Table 4 Expression results of antimicrobial peptide HBD2 in vaginal epithelial cells

[0074] Table 5 Expression results of antimicrobial peptide HBD2 in intestinal epithelial cells

[0075] Table 6 Expression results of antimicrobial peptide HBD2 in oral mucosal cells

[0076] As shown in Table 3-6 and Figure 1-4, sodium hyaluronate-1 treatment significantly promoted the expression of the antimicrobial peptide HBD2 in keratinocytes, vaginal epithelial cells, intestinal epithelial cells, and oral mucosal cells, while sodium hyaluronate-2 had no promoting effect. This demonstrates that hyaluronic acid with uronic acid termini can promote the expression of the antimicrobial peptide HBD2 in cells.

[0077] Example 3 Antibacterial efficacy experiment

[0078] 1. Sample preparation:

[0079] 1.1 Test group sample solution

[0080] Sodium hyaluronate-1 and sodium hyaluronate-2 were diluted to a concentration of 0.5% (w / v) using DMEM culture medium (Gibco#100569010) to obtain a test group A sample solution and a test group B sample solution.

[0081] Keratinocytes (HEKn) were isolated from neonatal foreskin in the laboratory and cryopreserved at the end of primary culture. The cells were co-cultured with the sample solutions of test groups A and B at 37°C and 5% CO2 for 1 day. The solutions were then removed, washed with PBS, and lysed with RPMI lysis buffer (Solarbio). The supernatants were collected by centrifugation as test groups C and D, respectively.

[0082] Vaginal epithelial cells (VK2 / E6E7, purchased from ATCC #CRL2616) were co-cultured with the sample solutions of test group A and test group B at 37°C under 5% CO2 for 1 day. The solution was then removed, washed with PBS, and lysed with RPMI lysis buffer (Solarbio). The supernatants were collected by centrifugation as test groups E and F, respectively.

[0083] Sodium hyaluronate-1 and sodium hyaluronate-2 were diluted to a concentration of 0.5% (w / v) using McCoy's 5A culture medium (Procell, #PM150710) to obtain sample solutions of test group a and test group b, respectively.

[0084] Intestinal epithelial cells (HT29, purchased from Procell, #CL-0118) were co-cultured with the sample solutions of test group a and test group b at 37°C under 5% CO2 for 1 day. The solutions were then removed, washed with PBS, and lysed with RPMI lysis buffer (Solarbio). The supernatants were collected by centrifugation as test groups G and H, respectively.

[0085] Sodium hyaluronate-1 and sodium hyaluronate-2 were diluted to a concentration of 0.5% (w / v) using Procell, #SNPM-H151 to obtain the test group a' sample solution and the test group b' sample solution.

[0086] Human oral mucosal cells (SNP-H151, purchased from Procell, #SNPM-H151) were co-cultured with the sample solutions of test groups a' and b' at 37°C under 5% CO2 for 1 day. The solution was then removed, washed with PBS, and lysed with RPMI lysis buffer (Solarbio). The supernatants were collected by centrifugation as test groups I and J, respectively.

[0087] 1.2 Control group sample solution

[0088] Sterile PBS was used as the control group.

[0089] 2. Preparation of bacterial suspension:

[0090] Staphylococcus aureus ATCC29213 was cultured in nutrient broth at 37°C with shaking for 48 h, Pseudomonas aeruginosa ATCC9027 was cultured in nutrient broth at 37°C with shaking for 18 h, and pathogenic Escherichia coli ATCC8739 was cultured in nutrient broth at 37°C with shaking for 48 h. They were diluted with sterile PBS to prepare 1×10 5 -9×10 5 CFU / mL of bacterial suspension.

[0091] 3. Detection of antibacterial effects on Staphylococcus aureus, Pseudomonas aeruginosa and pathogenic Escherichia coli:

[0092] The control group, experimental group A, experimental group B, experimental group C, and experimental group D were mixed with Staphylococcus aureus and Pseudomonas aeruginosa suspensions at a ratio of 1000 μL:100 μL, respectively (total volume 3 mL), to prepare mixed solutions. Each mixed solution for the experimental group and control group was incubated simultaneously in a 37°C incubator for 3 hours. 500 μL of each mixed solution was aspirated and diluted to 1 / 10 and 1 / 100 with sterile PBS. 100 μL of each sample solution was aspirated and incubated on plates at 32.5°C for 41 hours. Plate counts were performed using TSA agar (trypticase soy agar). Three plates were prepared for each sample solution, and the mean of the three replicate plate counts was used to calculate the inhibition rate. The specific inhibition results are shown in Table 7.

[0093] The control group, experimental group A, experimental group B, experimental group a, experimental group b, experimental group E, experimental group F, experimental group G, and experimental group H were each mixed with a pathogenic Escherichia coli suspension at a ratio of 1000 μL:100 μL (total volume 3 mL) to prepare a mixed solution. Each mixed solution for the experimental group and control group was incubated simultaneously in a 37°C incubator for 3 hours. 500 μL of the mixed solution was aspirated and diluted to 1 / 10 and 1 / 100 with sterile PBS. 100 μL of each sample solution was aspirated and incubated on plates at 32.5°C for 41 hours. Plate counts were performed using TSA agar (trypticase soy agar). Three plates were prepared for each sample solution, and the mean of the three replicate plate counts was used to calculate the inhibition rate. The specific inhibition results are shown in Tables 8 and 9.

[0094] The control group, experimental group a', experimental group b', experimental group I, and experimental group J were each mixed with a Staphylococcus aureus suspension at a ratio of 1000 μL:100 μL (total volume 3 mL) to prepare a mixed solution. Each mixed solution for the experimental group and control group was incubated simultaneously in a 37°C incubator for 3 hours. 500 μL of the mixed solution was aspirated and diluted to 1 / 10 and 1 / 100 with sterile PBS. 100 μL of each sample solution was aspirated and incubated on plates at 32.5°C for 41 hours. Plate counts were performed using TSA agar (trypticase soy agar). Three plates were prepared for each sample solution, and the mean of the three replicate plate counts was used to calculate the inhibition rate. The specific inhibition results are shown in Table 10.

[0095] Bacterial inhibition rate (%) = (average value of control group - average value of test group) ÷ average value of control group × 100%.

[0096] Refer to the "Evaluation Method for Antibacterial and Antibacterial Effects" standard number: WS / T 650-2019 issued by the National Health Commission. If the inhibition rate is ≥50%-90%, it is judged to have antibacterial effect; if the inhibition rate is ≥90%, it is judged to have a strong antibacterial effect; if it is less than 50%, it is considered to have no antibacterial effect.

[0097] Table 7 Antibacterial results of keratinocyte lysate treatment group

[0098] Table 8 Antibacterial results of vaginal epithelial cell lysate treatment group

[0099] Table 9 Antibacterial results of intestinal epithelial cell lysate treatment group

[0100] Table 10 Antibacterial results of oral mucosal cell lysate treatment group

[0101] From Table 7, we can see that the initial concentration of Staphylococcus aureus liquid is 2.8×10 5 CFU / mL, the inhibition rate of the control group was 10%, and the inhibition rate of Staphylococcus aureus in the cell lysate treated with sodium hyaluronate-1 was 97%. The results showed that the cell lysate treated with sodium hyaluronate-1 could inhibit the growth of Staphylococcus aureus, while the cell lysate treated with sodium hyaluronate-2 had no obvious antibacterial effect. In addition, the initial concentration of Pseudomonas aeruginosa was 2.9×10 5CFU / mL. As can be seen from Table 7, the inhibition rate of the control group was 8%, and the inhibition rate of Pseudomonas aeruginosa in the group treated with keratinocyte lysate treated with sodium hyaluronate-1 was 99%. The results showed that the keratinocyte lysate treated with sodium hyaluronate-1 can inhibit the growth of Pseudomonas aeruginosa, while the keratinocyte lysate treated with sodium hyaluronate-2 has no obvious antibacterial effect.

[0102] From Table 8, we can see that the initial concentration of pathogenic Escherichia coli is 1.64×10 6 CFU / mL, the inhibition rate of the control group was 11%, and the inhibition rate of Staphylococcus aureus in the cell lysate group treated with sodium hyaluronate-1 was 99%. The results showed that vaginal epithelial cell lysate treated with sodium hyaluronate-1 can inhibit the growth of pathogenic Escherichia coli, while vaginal epithelial cell lysate treated with sodium hyaluronate-2 has no obvious antibacterial effect.

[0103] From Table 9, we can see that the initial concentration of pathogenic Escherichia coli is 5.9×10 5 CFU / mL, the inhibition rate of the control group was 11%, and the inhibition rate of pathogenic Escherichia coli bacteria in the cell lysate group treated with sodium hyaluronate-1 was 98%. The results showed that the intestinal epithelial cell lysate treated with sodium hyaluronate-1 can inhibit the growth of pathogenic Escherichia coli, while the intestinal epithelial cell lysate treated with sodium hyaluronate-2 has no obvious antibacterial effect.

[0104] From Table 10, we can see that the initial concentration of Staphylococcus aureus liquid is 4.8×10 5 CFU / mL, the inhibition rate of the control group was 18%, and the inhibition rate of pathogenic Escherichia coli bacteria in the cell lysate group treated with sodium hyaluronate-1 was 97%. The results showed that the cell lysate treated with sodium hyaluronate-1 can inhibit the growth of Staphylococcus aureus, while the cell lysate treated with sodium hyaluronate-2 has no obvious antibacterial effect.

[0105] As can be seen from Tables 7-10, sodium hyaluronate-1 and sodium hyaluronate-2 have no antibacterial effect on their own. However, sodium hyaluronate-1, a hyaluronic acid with a uronic acid terminal, can promote the expression of the cellular antimicrobial peptide HBD2, thereby enhancing the cells' own antimicrobial effect. This provides a new inducer for the production of antimicrobial peptides and points to a new direction for clarifying the correlation between hyaluronic acid structure and efficacy.

[0106] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. Use of hyaluronic acid or its salt in the preparation of antimicrobial peptide inducers, characterized in that: The reducing end of the hyaluronic acid or its salt comprises a uronic acid group.

2. The use according to claim 1, characterized in that: The molecular weight of the hyaluronic acid or its salt is less than 5000Da.

3. The use according to claim 1, characterized in that: The structural formula of the hyaluronic acid or its salt is shown in formula (I): Wherein, X is selected from one of H, K, Na, Ca or Zn, and n is any integer selected from 0-5.

4. The use according to claim 1, characterized in that: The antimicrobial peptides include human β-defensin 2.

5. The use according to claim 1, characterized in that: The application of the hyaluronic acid or its salt in regulating human microecology.

6. The use according to claim 5, characterized in that: The regulating of human microecology includes inhibiting the growth and proliferation of harmful bacteria in the human body.

7. The use according to claim 6, characterized in that: The harmful bacteria include bacteria.

8. The use according to claim 7, characterized in that: The bacteria include Gram-positive bacteria and / or Gram-negative bacteria.

9. The use according to claim 8, characterized in that: The Gram-positive bacteria include Staphylococcus bacteria, and the Gram-negative bacteria include Pseudomonas bacteria and Escherichia bacteria.

10. The use according to claim 9, characterized in that: The Staphylococcus bacteria include Staphylococcus aureus, the Pseudomonas bacteria include Pseudomonas aeruginosa, and the Escherichia bacteria include Escherichia coli.

11. The use according to claim 1, characterized in that: The hyaluronic acid or its salt is used to enhance the cell defense capability.

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