Glycyrrhizic acid and bacterial cellulose compound for treating skin eczema

Abstract

The invention relates to a glycyrrhizic acid and bacterial cellulose compound for treating skin eczema, which comprises bacterial cellulose loaded with glycyrrhizic acid, and can be applied to local use in skin through transdermal administration to achieve a treatment effect on the skin with eczema.

Description

Technical Field

[0001] The present invention relates to a bacterial cellulose composite, and particularly to a glycyrrhizic acid bacterial cellulose composite and a preparation method thereof. Background Art

[0002] Bacterial cellulose is a relatively novel nanomaterial that has been less applied in drug delivery. It has been proven to have multiple special physical and chemical properties, including biodegradability, non-toxicity, high elastic modulus, high specific surface area, low density, non-abrasiveness, easy surface functionalization, high purity and crystallinity in chemical composition, high degree of polymerization (2000 - 8000), and high hardness. At the same time, bacterial cellulose is an inert material, so there has been relatively little direct research on bacterial cellulose as a drug carrier. Although glycyrrhizic acid is a commonly used clinical drug with anti-inflammatory and detoxifying effects, there is no practical background for topical use of glycyrrhizic acid.

[0003] Eczema (i.e., atopic dermatitis or atopic eczema) is the largest burden of disability due to skin diseases globally, affecting nearly 20% of children worldwide. Eczema can exist in multiple forms, including atopic and non-atopic forms. The atopic form is usually mediated by IgE, while the non-atopic type is mediated by non-IgE. Both forms can present with eosinophilia. Other variants of eczema include nummular eczema, seborrheic dermatitis, and hand eczema. Eczema may also appear as a skin manifestation of other systemic diseases, such as Wiskott–Aldrich syndrome, human immunodeficiency virus (HIV) infection, or food allergy. During the onset of eczema, the overproliferation of keratinocytes and the overexpression of inflammatory factors are obvious.

[0004] Therefore, clinical treatment of eczema remains a difficult problem that the industry urgently needs to overcome at present. Summary of the Invention

[0005] In view of the various defects of the above-mentioned prior art, the present invention provides a glycyrrhizic acid bacterial cellulose composite that can treat skin eczema and / or relieve the symptoms of eczema. The glycyrrhizic acid bacterial cellulose composite includes bacterial cellulose loaded with glycyrrhizic acid. The glycyrrhizic acid bacterial cellulose composite can effectively treat eczema and significantly relieve the symptoms of eczema when topically applied to the skin, which is beneficial to the clinical treatment of skin eczema and promotes the repair of eczema lesions.

[0006] In a specific embodiment, the present invention provides the use of the aforementioned glycyrrhizic acid bacterial cellulose composite in the preparation of a drug for treating eczema and / or relieving the symptoms of eczema.

[0007] In a specific embodiment, the symptoms include redness, edema, itching, or any combination thereof.

[0008] In a specific embodiment, the bacterial cellulose is derived from Acetobacterium Balch and has a molecular weight of 50,000 to 2,500,000.

[0009] In a specific embodiment, the bacterial cellulose has 300 to 15,000 glucosyl groups.

[0010] In a specific embodiment, the mass ratio of glycyrrhizic acid to bacterial cellulose is 1:0.1 to 10; preferably, the mass ratio of glycyrrhizic acid to bacterial cellulose is 1:5.

[0011] In a specific embodiment, the method for preparing the glycyrrhizic acid-bacterial cellulose complex comprises the following steps: 1) mixing water and freeze-dried bacterial cellulose to obtain hydrated bacterial cellulose; 2) dissolving glycyrrhizic acid in water to obtain an aqueous glycyrrhizic acid solution; and 3) dropping the aqueous glycyrrhizic acid solution into the hydrated bacterial cellulose to obtain the glycyrrhizic acid-bacterial cellulose complex.

[0012] In a specific embodiment, the hydrated bacterial cellulose and the aqueous glycyrrhizic acid solution are each stirred into a uniform solution.

[0013] In a specific embodiment, the stirred hydrated bacterial cellulose and aqueous glycyrrhizic acid solution are each further subjected to ultrasonic treatment.

[0014] In a specific embodiment, the dropping is carried out under ultrasonic conditions.

[0015] In a specific embodiment, the freeze-dried bacterial cellulose and water are mixed at a weight ratio of 1:10 to 15.

[0016] In a specific embodiment, the glycyrrhizic acid and water are mixed at a weight ratio of 1:0.5 to 1.5.

[0017] Specifically, the glycyrrhizic acid-bacterial cellulose complex provided by the present invention is white and viscous, and the bacterial cellulose structure is loaded with glycyrrhizic acid, which can effectively treat skin eczema.

[0018] The present invention also provides glycyrrhizic acid bacterial cellulose complexes with different ratios, and compares the therapeutic effects of the complexes on skin eczema. As can be seen from the above, the glycyrrhizic acid bacterial cellulose complexes provided by the present invention significantly inhibit the progression of lesions in eczema-occurring skin and can repair the lesioned sites. The present invention utilizes the amphiphilicity of glycyrrhizic acid and the biocompatibility, non-toxicity and reticular structure of bacterial cellulose to obtain a substance that can treat skin eczema. According to the research results of skin eczema treatment and in combination with the requirements of pharmaceutical preparations, the most suitable amounts of glycyrrhizic acid and bacterial cellulose can be further selected and the relevant topical pharmaceutical preparations can be prepared using the feeding ratio with the best therapeutic effect on skin eczema. Due to the amphiphilic nature of glycyrrhizic acid itself and the characteristics of bacterial cellulose itself, including non-toxicity, high biocompatibility, and a background of use as a carrier for skin care products, the present invention can be applied to the development and research of transdermal topical preparations for treating eczema and promoting the repair of eczema skin. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The embodiments of the present application are illustrated by exemplary reference drawings:

[0020] Figure 1 SEM diagrams showing Comparative Example 1, Comparative Example 3 and Example 5 are shown.

[0021] Figure 2 Bar graph for comparing the scratching times of rats in Comparative Experimental Examples 1 to 5 and Experimental Examples 1 to 3.

[0022] Figures 3 to 5 To show the concentrations of different inflammatory indicators related to eczema in serum.

[0023] Figure 6 Histological staining diagrams of the skin of SD rats in Comparative Experimental Examples 1, 2 and 5 and Experimental Example 3 (i.e., using the glycyrrhizic acid bacterial cellulose complex of Example 10) stained with hematoxylin-eosin (HE staining). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following specific embodiments illustrate the embodiments of the present application. Those skilled in the art can easily understand the advantages and effects of the present application from the content described in this specification. The present application can also be implemented or applied through other different embodiments. The details in this specification can also be given different modifications and changes based on different viewpoints and applications without departing from the spirit described in the present application. In addition, all ranges and values herein are inclusive and combinable. Any numerical value or point falling within the ranges described herein, such as any integer, can be used as the minimum or maximum value to derive sub-ranges, etc.

[0025] Glycyrrhizic acid is a commonly used drug in clinical practice, with functions such as anti - inflammation and detoxification. It belongs to triterpenoid compounds and has amphiphilicity, thus showing the characteristics of surfactants. The aggregates or micelles of glycyrrhizic acid can form host - guest inclusion complexes with hydrophobic drugs, which can effectively increase the solubility of drugs and avoid the precipitation of drugs.

[0026] Bacterial cellulose has the characteristics of biodegradability, non - toxicity, high - elasticity film, high specific surface area, low density, non - abrasive, easy surface functionalization, high purity and crystallinity in chemical composition, high degree of polymerization (2000 - 8000), high hardness, etc. However, bacterial cellulose is extremely inert, and there are few related studies on applying bacterial cellulose to local drug carriers including promoting hair growth.

[0027] Therefore, the present invention utilizes the amphiphilicity of glycyrrhizic acid to develop bacterial cellulose as a local drug carrier. Through research, it is found that the glycyrrhizic acid - bacterial cellulose complex can promote the growth and development of hair follicles in the skin. As described above, the present invention uses glycyrrhizic acid as the drug to be delivered and bacterial cellulose as the carrier. Due to the amphiphilicity of glycyrrhizic acid, glycyrrhizic acid is loaded into the network structure of bacterial cellulose to generate a new structure, and the formed glycyrrhizic acid - bacterial cellulose complex can significantly promote the growth and development of hair follicles in the skin.

[0028] In a specific embodiment, the glycyrrhizic acid is loaded on the bacterial cellulose to form a glycyrrhizic acid - bacterial cellulose complex.

[0029] In a specific embodiment, the bacterial cellulose is derived from Acetobacterium Balch bacteria and has a molecular weight of 50,000 to 2,500,000, a molecular weight of 100,000 to 2,500,000, a molecular weight of 500,000 to 2,500,000, a molecular weight of 1,000,000 to 2,500,000, a molecular weight of 1,500,000 to 2,500,000, a molecular weight of 2,000,000 to 2,500,000, a molecular weight of 50,000 to 2,000,000, a molecular weight of 50,000 to 1,500,000, a molecular weight of 50,000 to 1,000,000, a molecular weight of 50,000 to 500,000 or a molecular weight of 50,000 to 100,000. For example, a molecular weight of 50,000, 100,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, 500,000, 550,000, 600,000, 650,000, 700,000, 750,000, 800,000, 850,000, 900,000, 950,000, 1,000,000, 1,500,000, 2,000,000 or 2,500,000. In another specific embodiment, the bacterial cellulose is obtained by fermentation of Acetobacterium.

[0030] In a specific embodiment, the bacterial cellulose has 300 to 15,000 glucosyl groups, 1,000 to 15,000 glucosyl groups, 2,000 to 15,000 glucosyl groups, 3,000 to 15,000 glucosyl groups, 4,000 to 15,000 glucosyl groups, 5,000 to 15,000 glucosyl groups, 6,000 to 15,000 glucosyl groups, 7,000 to 15,000 glucosyl groups, 8,000 to 15,000 glucosyl groups, 9,000 to 15,000 glucosyl groups, 10,000 to 15,000 glucosyl groups, 11,000 to 15,000 glucosyl groups, 12,000 to 15,000 glucosyl groups, 13,000 to 15,000 glucosyl groups, 14,000 to 15,000 glucosyl groups, 300 to 14,000 glucosyl groups, 300 to 13,000 glucosyl groups, 300 to 12,000 glucosyl groups, 300 to 11,000 glucosyl groups, 300 to 10,000 glucosyl groups, 300 to 9,000 glucosyl groups, 300 to 8,000 glucosyl groups, 300 to 7,000 glucosyl groups, 300 to 6,000 glucosyl groups, 300 to 5,000 glucosyl groups, 300 to 4,000 glucosyl groups, 300 to 3,000 glucosyl groups, 300 to 2,000 glucosyl groups or 300 to 1,000 glucosyl groups. For example, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1,000, 1,500, 2,000, 2,500, 3,000, 3,500, 4,000, 4,500, 5,000, 5,500, 6,000, 6,500, 7,000, 7,500, 8,000, 8,500, 9,000, 10,000, 10,500, 11,000, 11,500, 12,000, 12,500, 13,000, 13,500, 14,000, 14,500 or 15,000 glucosyl groups. Specifically, the bacterial cellulose has the chemical general formula of (C 6 H 10 O 5 ) n and is a polysaccharide composed of linear chains (glycosidic bonds) of hundreds to thousands of β(1→4)-linked D-glucose units. In other words, the bacterial cellulose is a macromolecular polysaccharide composed of D-glucose with β-1,4-glycosidic bonds.

[0031] In a specific embodiment, the mass ratio of glycyrrhizic acid to bacterial cellulose is 1:0.1 to 10, for example, 1:0.1, 1:0.11, 1:0.13, 1:0.14, 1:0.17, 1:0.2, 1:0.3, 1:0.33, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10. Preferably, the mass ratio of glycyrrhizic acid to bacterial cellulose is 1:5.

[0032] The method for preparing the glycyrrhizic acid - bacterial cellulose complex provided by the present invention includes the following steps: 1) Mix water and freeze - dried bacterial cellulose to obtain hydrated bacterial cellulose; 2) Dissolve glycyrrhizic acid in water to obtain an aqueous glycyrrhizic acid solution; and 3) Dropwise add the aqueous glycyrrhizic acid solution into the hydrated bacterial cellulose to obtain the glycyrrhizic acid - bacterial cellulose complex.

[0033] In a specific embodiment, the freeze - dried bacterial cellulose and water are mixed at a weight ratio of 1:10 to 15, for example, a weight ratio of 1:10, 1:11, 1:12, 1:13, 1:14 or 1:15.

[0034] In a specific embodiment, the glycyrrhizic acid and water are mixed at a weight ratio of 1:0.5 to 1.5, for example, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1:1.5.

[0035] The following further details the present application through specific examples, but the scope of the present application is not limited by the examples.

[0036] Preparation Example: Glycyrrhizic Acid - Bacterial Cellulose Complex

[0037] Glycyrrhizic acid (93%, G810520 - 25g, Shanghai Macklin Biochemical Co., Ltd.) was added to distilled water, stirred evenly and then sonicated for 10 minutes to obtain an aqueous glycyrrhizic acid solution. At the same time, bacterial cellulose derived from Acetobacter (nano - bacterial cellulose freeze - dried tablets, Jiaopeng Biotechnology Co., Ltd.) was added to distilled water, stirred evenly and then sonicated for 10 minutes to obtain hydrated bacterial cellulose; under ultrasonic conditions, the aqueous glycyrrhizic acid solution was dropwise added to the hydrated bacterial cellulose at a rate of 5 drops per 10 seconds, stirred evenly and then sonicated for 15 minutes to obtain the glycyrrhizic acid - bacterial cellulose complex.

[0038] According to the method of the foregoing preparation example, the bacterial cellulose complexes of Examples 1 to 19 were respectively prepared with the compositions shown in Table 1 below, and the mass ratios of glycyrrhizic acid and bacterial cellulose in the prepared glycyrrhizic acid - bacterial cellulose complexes (finished products) were listed.

[0039] Table 1: Examples 1 to 19

[0040]

[0041] Comparative Example 1: Glycyrrhizic acid aqueous solution

[0042] 10 mg of glycyrrhizic acid (93%, G810520 - 25 g, Shanghai Macklin Biochemical Co., Ltd.) was added to 1.6 mL of distilled water. After stirring evenly, it was sonicated for 10 minutes to obtain a glycyrrhizic acid aqueous solution.

[0043] Comparative Example 2: Hydrous bacterial cellulose

[0044] 50 mg of bacterial cellulose derived from Acetobacter (nano - bacterial cellulose freeze - dried tablets, Jiaopeng Biotechnology Co., Ltd.) was added to 1.3 mL of distilled water. After stirring evenly, it was sonicated for 10 minutes to obtain hydrous bacterial cellulose.

[0045] Comparative Example 3: Baicalin - bacterial cellulose

[0046] 10 mg of baicalin (8802695 - 5 g, Shanghai Macklin Biochemical Co., Ltd.) was added to 0.8 mL of distilled water. After stirring evenly, it was sonicated for 10 minutes to obtain a baicalin aqueous solution. Meanwhile, 100 mg of bacterial cellulose derived from Acetobacter (nano - bacterial cellulose freeze - dried tablets, Jiaopeng Biotechnology Co., Ltd.) was added to 1.3 mL of distilled water. After stirring evenly, it was sonicated for 10 minutes to obtain hydrous bacterial cellulose; under ultrasonic conditions, the baicalin aqueous solution was dropped into the hydrous bacterial cellulose, stirred evenly and sonicated for 15 minutes, and then obtained the baicalin - bacterial cellulose complex after rotary evaporation.

[0047] Please refer to Figure 1 ... Analyze Comparative Example 1, Comparative Example 3 and Example 5 respectively with a scanning electron microscope (FEI Quanta 400 FEI, America FEI scanning electron microscope), and the obtained SEM images are shown in Figure 1 ... As Figure 1 shown, only the glycyrrhizic acid - bacterial cellulose complex prepared in Example 5 has a structure in which glycyrrhizic acid is encapsulated in the reticular structure of bacterial cellulose.

[0048] To test the therapeutic effects of different samples on eczema, an eczema model was established using SD rats, and untreated SD rats (i.e., the blank group) were used as Comparative Experiment Example 1. Then, the writhing times of the rats after applying each sample were counted, the inflammation indexes related to eczema in the serum were detected, and the skin tissues were stained with HE, as detailed below.

[0049] Comparative Experiment Example 2: Rats with DNCB - induced eczema model

[0050] Prior to the experiment, the back skin of SD rats in a 3 cm x 3 cm area was depilated. On the 1st and 3rd days after the start of the experiment, 2% dinitrotoluene (DNCB) (Thermo Fisher Scientific Inc.) was applied to the depilated area. On the 6th day of the experiment, 0.5% DNCB was applied, and then 0.5% DNCB was applied once every 3 days (i.e., on the 9th, 12th, 15th, and 18th days of the experiment) to continuously stimulate the skin, obtaining DNCB-induced eczema model rats.

[0051] Comparative Experiment Example 3: Eczema model rats treated with aqueous glycyrrhizic acid solution

[0052] For the eczema model rats obtained as in the aforementioned Comparative Experiment Example 2, Comparative Example 1 was applied on the 7th day of the experiment.

[0053] Comparative Experiment Example 4: Eczema model rats treated with aqueous bacterial cellulose

[0054] Same as the aforementioned Comparative Experiment Example 3, except that Comparative Example 1 applied on the 7th day of the experiment was replaced with Comparative Example 2.

[0055] Comparative Experiment Example 5: Eczema model rats treated with mometasone furoate cream

[0056] Same as the aforementioned Comparative Experiment Example 3, except that Comparative Example 1 applied on the 7th day of the experiment was replaced with mometasone furoate cream (0.1% (5 g: 5 mg), Bayer Healthcare (Shanghai) Co., Ltd., 220908).

[0057] Experiment Example 1: Eczema model rats treated with glycyrrhizic acid-bacterial cellulose complex

[0058] Same as the aforementioned Comparative Experiment Example 3, except that Comparative Example 1 applied on the 7th day of the experiment was replaced with Example 1.

[0059] Experiment Example 2: Eczema model rats treated with glycyrrhizic acid-bacterial cellulose complex

[0060] Same as the aforementioned Comparative Experiment Example 3, except that Comparative Example 1 applied on the 7th day of the experiment was replaced with Example 5.

[0061] Experiment Example 3: Eczema model rats treated with glycyrrhizic acid-bacterial cellulose complex

[0062] Same as the aforementioned Comparative Experiment Example 3, except that Comparative Example 1 applied on the 7th day of the experiment was replaced with Example 10.

[0063] At 30 minutes after applying the sample on the 18th day of the experiment, the number of scratching (writhing) times of the rats within 20 minutes was counted, and the results are shown in Figure 2 as follows.Figure 2 As shown, the glycyrrhizic acid bacterial cellulose complexes of Application Examples 1, 5, and 10 can produce an antipruritic effect on the eczema area of the skin, achieving an effect equivalent to or even better than that of existing drugs for treating eczema (i.e., Comparative Experimental Example 5).

[0064] On the nineteenth day after the experiment, the rats were sacrificed, and the skin and serum of the depilated area were collected for HE staining and detection of inflammatory indicators, respectively. Please refer to Figures 3 to 5 . Figures 3 to 5 It shows the concentrations of eczema-related inflammatory indicators in the serum detected by enzyme-linked immunosorbent assay (ELISA), namely immunoglobulin E (IgE), interleukin-4 (IL-4), and histamine. As Figures 3 to 5 shown, the glycyrrhizic acid bacterial cellulose complexes of Application Examples 1, 5, and 10 can significantly reduce the eczema inflammatory indicators IgE, IL-4, and histamine. In addition, Figure 6 It shows the HE staining map of the skin of SD rats to compare the effects of different samples on the skin. As Figure 6 shown, the cortex layer of the skin area treated with the glycyrrhizic acid bacterial cellulose complex of Application Example 10 is dense, and the thickness of the epidermis layer increases.

[0065] In summary, the glycyrrhizic acid bacterial cellulose complex of the present invention has glycyrrhizic acid in the three-dimensional network structure of bacterial cellulose, can effectively treat skin eczema and relieve its symptoms. In addition, the manufacturing process of the glycyrrhizic acid bacterial cellulose complex provided by the present invention is simple, and the ratio of glycyrrhizic acid and bacterial cellulose contained in the complex can be easily adjusted, which actually has application prospects.

[0066] The above embodiments are only illustrative and not intended to limit this application. Any person skilled in the art can modify and change the above embodiments without departing from the spirit and scope of this application. Therefore, the scope of the rights protection of this application is defined by the claims attached to this application, and should be covered by this disclosed technical content as long as it does not affect the effects and implementation purposes of this application.

Claims

1. Use of a glycyrrhizic acid bacterial cellulose complex in the preparation of a drug for treating eczema and / or alleviating the symptoms of eczema, characterized in that: The glycyrrhizic acid bacterial cellulose composite comprises bacterial cellulose loaded with glycyrrhizic acid.

2. The use according to claim 1, characterized in that The symptoms include redness, edema, itching or any combination thereof.

3. The use according to claim 1, characterized in that: The bacterial cellulose is derived from Acetobacterium Balch and has a molecular weight of 50,000 to 2,500,000.

4. The use according to claim 1, characterized in that The bacterial cellulose has 300 to 15,000 glucose groups.

5. The use according to any one of claims 1 to 4, characterized in that: The mass ratio of glycyrrhizic acid to bacterial cellulose is 1:0.1 to 10.

6. The use according to claim 5, characterized in that: The mass ratio of the glycyrrhizic acid to the bacterial cellulose is 1:

5.

7. The use according to any one of claims 1 to 4, characterized in that The preparation method of the glycyrrhizic acid bacterial cellulose composite comprises the following steps: 1) mixing water and freeze-dried bacterial cellulose to obtain aqueous bacterial cellulose; 2) dissolving glycyrrhizic acid in water to obtain a glycyrrhizic acid aqueous solution; and 3) adding the glycyrrhizic acid aqueous solution dropwise to the aqueous bacterial cellulose to obtain the glycyrrhizic acid-bacterial cellulose composite.

8. The use according to claim 7, characterized in that: The aqueous bacterial cellulose and the glycyrrhizic acid aqueous solution are each stirred to form a uniform solution.

9. The use according to claim 7, characterized in that: The stirred aqueous bacterial cellulose and glycyrrhizic acid aqueous solution are each further subjected to ultrasonic treatment.

10. The use according to claim 7, characterized in that: The dropwise addition is performed under ultrasound.

11. The use according to claim 7, characterized in that: The freeze-dried bacterial cellulose and water were mixed in a weight ratio of 1:10 to 15.

12. The use according to claim 7, characterized in that: The glycyrrhizic acid and water are mixed in a weight ratio of 1:0.5 to 1.5.

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