External preparation for treating atopic dermatitis and preparation method and application thereof

Abstract

The invention provides an external preparation for treating atopic dermatitis and a preparation method and application thereof, and belongs to the technical field of development of traditional Chinese medicine external preparations. The effective component of the external preparation for treating atopic dermatitis is neoliquiritin, and the concentration is 0.5 wt%-1.5 wt%. According to the application disclosed by the invention, the treatment effect and the safety of the neoliquiritin in treating atopic dermatitis are defined, and meanwhile, a new application field is expanded for the traditional leguminous plant liquorice extract neoliquiritin.

Description

Technical Field

[0001] The invention belongs to the technical field of development of external preparations of traditional Chinese medicine, and in particular relates to an external preparation for treating atopic dermatitis and a preparation method and application thereof. Background Art

[0002] Atopic dermatitis (AD) is a chronic, recurrent, inflammatory skin disease characterized by dry skin, chronic eczematoid dermatitis, and severe itching. Since patients often have other atopic diseases such as allergic rhinitis and asthma, and about 40%-80% of patients have a family history of allergies, it is considered a systemic disease. The pathogenesis of AD is affected by multiple factors and is the result of the interaction of multiple factors such as genetics, immunity, infection, and environment. At present, the treatment of AD mostly uses topical glucocorticoids, topical calcineurin inhibitors, oral antihistamines, systemic immunosuppressants, and glucocorticoids. These drugs have good short-term therapeutic effects on atopic dermatitis, but long-term use has great side effects and a high recurrence rate. For example, glucocorticoids are the first-line treatment for AD and are often used as the first choice for treatment, but long-term use of topical glucocorticoids may cause side effects such as skin atrophy, capillary dilation, striae atrophicis, purpura, and hirsutism.

[0003] Chinese medicine for external use has shown certain advantages in improving the clinical symptoms of patients with mild, moderate and severe atopic dermatitis and reducing the recurrence rate. In a randomized, double-blind clinical trial, Indigo Ointment can effectively reduce the severity of skin lesions and itching while ensuring safety. Many studies have found that Chinese medicine for external use can improve the skin lesions of AD mice and reduce the inflammatory indicators of serum and skin lesions. Licorice has the effects of clearing away heat and detoxifying, relieving acute pain, and has pharmacological effects such as anti-inflammatory, anti-tumor, antibacterial, and immunomodulatory. It is widely used in skin diseases. Its main ingredient, glycyrrhizin, has been shown to have multiple pharmacological activities such as anti-inflammatory, antioxidant, and inhibition of cell apoptosis. It can be used to treat a variety of skin diseases, such as photoaging, psoriasis, etc. As one of the active ingredients of licorice, neoliquiritin has also been shown to have powerful anti-inflammatory and antiviral effects. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an external preparation for treating atopic dermatitis, and a preparation method and application thereof, using neoliquiritin as an active ingredient to treat atopic dermatitis, which has obvious effects and expands new application fields for neoliquiritin.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] An external preparation for treating atopic dermatitis, wherein the active ingredient is neoliquiritin. Preferably, the concentration of the neoliquiritin is 0.5wt%-1.5wt%.

[0007] More preferably, the dosage forms of the external preparation include patches, pastes, ointments, creams, gels, oils, microneedles, coatings, papules, sprays and dressings.

[0008] Preferably, the external preparation further comprises a pharmaceutically acceptable excipient.

[0009] The present invention also provides an ointment for treating atopic dermatitis, which comprises the following components by mass concentration: 0.5%-1.5% of neoliquiritin, 4%-13% of solubilizer, 5%-25% of oil phase, 56%-87% of water phase, 2%-8% of emulsifier, and 0.05%-0.15% of preservative.

[0010] Preferably, the solvent is selected from one or more of diethylene glycol monoethyl ether, ethanol and propylene glycol.

[0011] Preferably, the oil phase is selected from one or more of mono- and distearic acid glyceryl, cetearyl alcohol, liquid paraffin, vaseline, and lanolin.

[0012] Preferably, the aqueous phase is selected from one or more of pure water, deionized water and glycerol.

[0013] Preferably, the emulsifier is selected from one or more of polyethylene glycol-7-stearate, polyoxyethylene (21) stearyl alcohol ether, polyoxyethylene (2) stearyl alcohol ether, polyglycerol oleate, and sodium lauryl sulfate; and the preservative is selected from one or more of ethylparaben, methylparaben, and phenoxyethanol.

[0014] The present invention also provides a preparation method of the cream, comprising the following steps: (1) weighing an oil phase, an emulsifier and a preservative to form a first mixture, weighing an aqueous phase to form a second mixture, and dissolving neoliquiritin with a dissolving agent to form a third mixture; (2) heating the first mixture and the second mixture, mixing and homogenizing, and then adding the third mixture and homogenizing again; and (3) cooling to obtain the cream.

[0015] The present invention also provides the use of the external preparation in preparing a drug for treating atopic dermatitis and in preparing a drug for inhibiting epidermal proliferation and / or dermal lymphocyte infiltration.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention uses the new liquiritigenin as the active ingredient of the external preparation for treating atopic dermatitis, provides a new option for the treatment of atopic dermatitis, and has many significant advantages.

[0018] In terms of safety, new licorice glycosides have no adverse effects on the normal growth of skin cells and have good safety, which provides an important prerequisite for its topical treatment. It has no obvious toxic side effects on important organs when used externally. Compared with traditional therapeutic drugs such as long-term topical glucocorticoids that may cause skin atrophy, capillary dilation, atrophic striae, purpura, hirsutism and other side effects, new licorice glycosides have outstanding safety advantages and reduce the risk of adverse reactions to drug treatment in patients.

[0019] From the perspective of therapeutic effects, neoliquiritin can effectively intervene in the inflammatory response process of atopic dermatitis at the cellular level, regulate immune-related inflammatory signaling pathways from the root, and lay the foundation for alleviating skin inflammation. Neoliquiritin has a significant improvement effect on the skin symptoms of atopic dermatitis, and can effectively reduce symptoms such as skin inflammation, erythema, edema, and scaling, and improve the health of the skin. Neoliquiritin can also effectively regulate the pathological structure of skin tissue, promote the repair and normalization of skin tissue, and enhance the skin's barrier function and immune homeostasis.

[0020] The formula design of the new licorice glycoside cream of the present invention ensures the stability, effectiveness and safety of the preparation, enables the drug to better exert its therapeutic effect, improves the bioavailability and durability of the drug, and provides a reliable preparation basis for clinical application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The effect of the new liquiritin solution on the activity of HaCaT cells; in the figure, a is the chemical structure of the new liquiritin; b is the effect of different concentrations of the new liquiritin solution on the proliferation activity of HaCaT cells; c is the effect of 2μM and 10μM concentrations of the new liquiritin solution on the mRNA expression of inflammatory factors IL-4 and IL-13 in HaCaT cells;

[0022] Figure 2 The skin lesions and dermatitis scores of different drug groups in the atopic dermatitis mouse model; in the figure, a is a typical photo of the auricle skin lesions of mice in different drug groups and the changes of the skin lesions (Day 12) (n=5); b is the auricle thickness of mice in different drug groups (n=5); c is the EASI score of the skin lesions of mice in different drug groups (n=5);

[0023] Figure 3 The histopathological conditions of different drug groups in the atopic dermatitis mouse model; in the figure, a is the histopathological changes of the auricle of mice in different drug groups (×100) (n=5); b is the epidermal thickness of the auricle of mice in different drug groups (n=5); c is the quantitative comparison of the number of dermal lymphocytes in mice in different drug groups (n=5);

[0024] Figure 4Pathological changes of liver, spleen and kidney in mice after external application of new liquiritigenin (×200);

[0025] Note: Figure 1-3 Compared with the model group, ** p<0.01, *** p<0.001; compared with the normal control group, ## p<0.01, ### p<0.001. DETAILED DESCRIPTION

[0026] The invention provides an external preparation for treating atopic dermatitis, the effective component of which is neoliquiritigenin.

[0027] Neoliquiritin is a flavonoid compound that is often found in the medicinal part of the leguminous plant licorice. It has multiple pharmacological activities such as anti-inflammatory and antiviral. Its chemical structure is as follows Figure 1 a, the molecular formula is C 21 H 22 O9, molecular weight 418.4, CAS number 5088-75-5.

[0028] In the present invention, the concentration of neoliquiritin is preferably 0.5wt%-1.5wt%, more preferably 0.8wt%-1.5wt%, and even more preferably 1wt%.

[0029] In the present invention, the dosage forms of the external preparations preferably include patches, pastes, ointments, creams, gels, oils, microneedles, film coatings, cataplasms, sprays and dressings; further preferably, the external preparations also include pharmaceutically acceptable excipients. The present invention does not specifically limit the preparation methods of the excipients and external preparations, and the excipients and conventional preparation methods commonly used in the pharmaceutical field can be used.

[0030] The present invention also provides an ointment for treating atopic dermatitis, which comprises the following ingredients by mass concentration: 0.5%-1.5% of neoliquiritigenin, 4%-13% of solubilizer, 5%-25% of oil phase, 56%-87% of water phase, 2%-8% of emulsifier, and 0.05%-0.15% of preservative; further preferably, 0.8%-1.2% of neoliquiritigenin, 6%-10% of solubilizer, 10%-20% of oil phase, 65%-75% of water phase, 3%-5% of emulsifier, and 0.08%-0.12% of preservative; more preferably, 1% of neoliquiritigenin, 8.3% of solubilizer, 14.0% of oil phase, 71.9% of water phase, 4.7% of emulsifier, and 0.1% of preservative.

[0031] In the present invention, the dissolving agent is preferably selected from one or more of diethylene glycol monoethyl ether, ethanol, and propylene glycol; more preferably diethylene glycol monoethyl ether.

[0032] Preferably, the oil phase is selected from one or more of mono- and distearic acid glyceryl, cetostearyl alcohol, liquid paraffin, vaseline, and lanolin; more preferably, mono- and distearic acid glyceryl, cetostearyl alcohol, and liquid paraffin; more preferably, mono- and distearic acid glyceryl:cetostearyl alcohol: liquid paraffin = 3:5:6.

[0033] Preferably, the aqueous phase is selected from one or more of pure water, deionized water, and glycerol; more preferably, pure water and glycerol; more preferably, pure water:glycerol=9.3:1.

[0034] Preferably, the emulsifier is selected from one or more of polyethylene glycol-7-stearate, polyoxyethylene (21) stearyl alcohol ether, polyoxyethylene (2) stearyl alcohol ether, polyglycerol oleate, and sodium lauryl sulfate; further preferably, polyethylene glycol-7-stearate, polyoxyethylene (21) stearyl alcohol ether, polyoxyethylene (2) stearyl alcohol ether, and polyglycerol oleate; more preferably, polyethylene glycol-7-stearate:polyoxyethylene (21) stearyl alcohol ether:polyoxyethylene (2) stearyl alcohol ether:polyglycerol oleate=4:9:9:6.

[0035] Preferably, the preservative is selected from one or more of ethylparaben, methylparaben, and phenoxyethanol; more preferably, ethylparaben.

[0036] The present invention also provides a method for preparing the above-mentioned cream for treating atopic dermatitis, comprising the following steps:

[0037] (1) weighing an oil phase, an emulsifier and a preservative to form a first mixture, weighing an aqueous phase to form a second mixture, and dissolving neoliquiritin in a dissolving agent to form a third mixture;

[0038] (2) After the first mixture and the second mixture are heated, mixed and homogenized, the third mixture is added and homogenized again; preferably, the first mixture and the second mixture are heated to 85° C., mixed, homogenized for 3 min, cooled to 60° C., and the third mixture is added and homogenized again for 3 min;

[0039] (3) Cooling the cream to obtain the cream, preferably cooling to 40° C. before packaging.

[0040] The present invention also provides the use of the external preparation in preparing a drug for treating atopic dermatitis and in preparing a drug for inhibiting epidermal proliferation and / or dermal lymphocyte infiltration.

[0041] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0042] Example 1

[0043] An external cream for treating atopic dermatitis, the preparation method of which is as follows:

[0044] (1) Weigh 36 g of glyceryl mono- and distearate, 60 g of cetostearyl alcohol, 72 g of liquid paraffin, 1.2 g of ethylparaben, 8 g of polyethylene glycol-7-stearate, 18 g of polyoxyethylene (21) stearyl ether, 18 g of polyoxyethylene (2) stearyl ether, and 12 g of polyglycerol oleate as component A;

[0045] (2) Weigh 1978.8 g of pure water and 84 g of glycerol as component B;

[0046] (3) Weigh 100 g of diethylene glycol monoethyl ether and add 12 g of neoliquiritin, and sonicate for 30 min to fully dissolve as component C;

[0047] (4) After heating component A and component B to 85°C, mix component A and component B thoroughly under stirring and homogenize for 3 minutes;

[0048] (5) When the temperature of the mixture of A and B drops to about 60°C, add component C and continue homogenizing for 3 minutes;

[0049] (6) When the sample has cooled to about 40°C, it can be packaged.

[0050] Example 2

[0051] An external cream for treating atopic dermatitis, the preparation method of which is as follows:

[0052] (1) Weigh 36 g of glyceryl mono- and distearate, 60 g of cetostearyl alcohol, 72 g of liquid paraffin, 1.2 g of ethylparaben, 8 g of polyethylene glycol-7-stearate, 18 g of polyoxyethylene (21) stearyl ether, 18 g of polyoxyethylene (2) stearyl ether, and 12 g of polyglycerol oleate as component A;

[0053] (2) Weigh 778.8 g of pure water and 84 g of glycerol as component B;

[0054] (3) Weigh 100 g of diethylene glycol monoethyl ether and add 12 g of neoliquiritin, and sonicate for 30 min to fully dissolve as component C;

[0055] (4) After heating component A and component B to 85°C, mix component A and component B thoroughly under stirring and homogenize for 3 minutes;

[0056] (5) When the temperature of the mixture of A and B drops to about 60°C, add component C and continue homogenizing for 3 minutes;

[0057] (6) When the sample has cooled to about 40°C, it can be packaged.

[0058] Example 3

[0059] An external cream for treating atopic dermatitis, the preparation method of which is as follows:

[0060] (1) Weigh 36 g of glyceryl mono- and distearate, 60 g of cetostearyl alcohol, 72 g of liquid paraffin, 1.2 g of ethylparaben, 8 g of polyethylene glycol-7-stearate, 18 g of polyoxyethylene (21) stearyl ether, 18 g of polyoxyethylene (2) stearyl ether, and 12 g of polyglycerol oleate as component A;

[0061] (2) Weigh 378.8 g of pure water and 84 g of glycerol as component B;

[0062] (3) Weigh 100 g of diethylene glycol monoethyl ether and add 12 g of neoliquiritin, and sonicate for 30 min to fully dissolve as component C;

[0063] (4) After heating component A and component B to 85°C, mix component A and component B thoroughly under stirring and homogenize for 3 minutes;

[0064] (5) When the temperature of the mixture of A and B drops to about 60°C, add component C and continue homogenizing for 3 minutes;

[0065] (6) When the sample has cooled to about 40°C, it can be packaged.

[0066] Example 4

[0067] HaCaT cell activity assay

[0068] Weigh 20 mg of neoliquiritin, dissolve it in PBS after ultrasound, and prepare a mother solution with a final concentration of 50.00 mM according to the minimum solubility of DMSO. Store it in a refrigerator at 4°C for subsequent experiments.

[0069] Cell culture and treatment: HaCaT cells were purchased from Cell Lines Service (Eppelheim, 300493) and cultured in DMEM medium containing 10% fetal bovine serum. The above cell lines were incubated at 37°C in a 5% CO2 incubator and routinely passaged for 3 generations before subsequent experiments.

[0070] (1) HaCaT cell activity detection

[0071] The experiment of the new liquiritin solution was divided into a blank control group and different concentration groups of 2, 5, 10, 20 and 50 μM, with 4 replicates in each group. HaCaT cells were inoculated into a 96-well plate. When the cells grew to more than 80%, the original culture medium was aspirated and discarded, and 0.1 mL of culture medium containing different concentrations of drugs was added to each well. The blank control group was added with a full culture medium without drugs, and then placed in an incubator for continued culture. 48 hours after the cells were treated with new liquiritin, the original culture medium was aspirated and discarded, 100 μL / well of PBS buffer was used to wash once, and 110 μL / well of CCK-8 working solution (CCK-8 working solution was configured according to the ratio of CCK8 reagent: cell full culture medium = 1:10) was added. Place in an incubator and continue to incubate for 2 hours. Subsequently, the 96-well plate was placed in a multifunctional microplate reader to read the absorbance value at a wavelength of 450 nm, and the cell survival rate was calculated based on the absorbance value.

[0072] The results are as follows Figure 1 As shown in b. CCK-8 was used to detect the effect of neoliquiritin on the proliferation activity of HaCaT cells at different concentrations to screen the effective concentration of neoliquiritin in vitro, and subsequent experiments were carried out. Specifically, after 48 hours of treatment with 2, 5, 10, 20 and 50 μM neoliquiritin solutions, there was no significant difference in cell proliferation rate compared with the control group, indicating that 2 to 50 μM neoliquiritin solutions did not have the effect of inhibiting the proliferation of HaCaT cells, and at the same time suggested that the safety of the monomer component was good.

[0073] (2) 2 μM and 10 μM concentrations of neoliquiritin solution were used to perform RT-qPCR on TSLP-stimulated HaCaT cells to detect their effects on the mRNA of inflammatory factors IL-4 and IL-13. The specific method is as follows:

[0074] The cells were cultured in 6-well plates and divided into a blank control group (NC) and different drug concentration groups (0, 2, 10 μM), with 4 replicates in each group. When the HaCaT cells reached about 70% or more, human thymic stromal lymphopoietin (TSLP) was added to the complete culture medium at a predetermined concentration (100 ng / mL) to simulate the inflammatory environment of atopic dermatitis. TSLP and 2 mL of different concentrations of neoliquiritin solution were added to the culture medium to stimulate the cells for 48 h.

[0075] Total mRNA from HaCaT cells was extracted by the Trizol method (Biyuntian, Shanghai, China). The concentration and purity of RNA were determined by measuring the absorbance 260 / 280 ratio using a UV spectrophotometer. cDNA was prepared using a reverse transcription kit and reverse transcriptase was used for reverse transcription. -ΔΔCT Methods Analysis of relative quantitative data. Polymerase chain reaction primers are shown in Table 1.

[0076] Table 1 Polymerase chain reaction primers

[0077]

[0078] The results are as follows Figure 1 As shown in Figure c, the mRNA expression of inflammatory factors IL-4 and IL-13 in HaCaT cells decreased at 2 μM and 10 μM concentrations, with 10 μM being the most significant (compared with the TSLP group, * p<0.05, ** p<0.01).

[0079] Example 5

[0080] Atopic dermatitis mouse model test

[0081] 1. Drug preparation: Prepare as shown in Examples 1 to 3.

[0082] 2. Experimental Methods

[0083] 2.1. Group intervention

[0084] Male, 6-8 weeks old, 20 g ± 2 g C57BL / 6 mice were randomly divided into 6 groups, 5 mice in each group. The mice were kept in a specific sterile environment with temperature control (20-26°C) and provided with standard feed and water. The grouping and treatment scheme were as follows:

[0085] (1) Normal control group: 20 μL of anhydrous ethanol was applied to the inner and outer sides of both auricles of mice daily for 5 days, followed by a 2-day break and then another 5-day application.

[0086] (2) Model group (MC903 group): 20 μL of 2 nmol calcipotriol (MC903) ethanol solvent was applied to the inner and outer sides of both auricles of mice every day for 5 days, followed by a 2-day break and then another 5-day application.

[0087] (3) 0.5% Neoliquiritin group (MC903+0.5% Neoliquiritin group): 20 μL of 2 nmol calcipotriol (MC903) ethanol solvent was applied to the inner and outer sides of both auricles of mice daily. 6 hours later, 0.5% Neoliquiritin cream prepared in Example 1 was applied to the inner and outer sides of both auricles of mice, 5 mg per ear. The application lasted for 12 days in total.

[0088] (4) 1.0% Neoliquiritin group (MC903+1.0% Neoliquiritin group): 20 μL of 2 nmol calcipotriol (MC903) ethanol solvent was applied to the inner and outer sides of both auricles of mice daily. 6 hours later, 1.0% Neoliquiritin cream prepared in Example 2 was applied to the inner and outer sides of both auricles of mice, 5 mg per ear. The application lasted for 12 days in total.

[0089] (5) 1.5% Neoliquiritin group (MC903+1.5% Neoliquiritin group): 20 μL of 2 nmol calcipotriol (MC903) ethanol solvent was applied to the inner and outer sides of both auricles of mice daily. 6 hours later, 1.5% Neoliquiritin cream prepared in Example 3 was applied to the inner and outer sides of both auricles of mice, 5 mg per ear. The application lasted for 12 days in total.

[0090] All treatments started from the day of calcipotriol application (day 1). All animal experiments were approved by the Ethics Committee of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine.

[0091] 2.2. Observation indicators

[0092] The appearance of the mouse ears was photographed on days 1, 5, 8, and 12, and the thickness of the ear skin at the same site was measured with a vernier caliper and the values ​​were recorded. The severity of mouse ear skin inflammation was scored according to the Atopic Dermatitis Area and Severity Index (EASI) scoring criteria, including erythema, edema or exudation, scaling, and lichenoid changes. The score indicated the severity: 0 (none), 1 (mild), 2 (moderate), and 3 (severe).

[0093] 3. Histopathology

[0094] After recording the above data on the 12th day, the mice were euthanized, and 1×1 cm skin tissues of both ears of mice in each group were taken, fixed with 4% formalin solution for 48 hours, embedded in paraffin, and stained with hematoxylin-eosin (H&E) after sectioning. Four high-power fields were randomly selected from each section to measure the epidermal thickness and the average was taken.

[0095] 4. Statistical methods

[0096] The experimental data were analyzed using GraphPadPrism 9, and all data were expressed as mean ± standard deviation (SD). Multiple comparisons between groups were performed using one-way analysis of variance (ANOVA) and Tukey analysis of variance. p value < 0.05 was considered statistically significant.

[0097] 5. Experimental Results

[0098] 5.1. Neoliquiritigenin can improve skin lesions and dermatitis scores in a mouse model of atopic dermatitis induced by calcipotriol

[0099] Typical photos of ear lesions of mice in each group and the lesion conditions are shown in the figure. Figure 2 a. The study found that the thickness of the auricle skin of mice induced by calcipotriol (MC903 group) was significantly increased ( ###p<0.001), the ear thickness of the 1.0% Neoliquiritin group and the 1.5% Neoliquiritin group was significantly reduced compared with the MC903 group ( * p<0.05, ** p<0.01)( Figure 2 b). There was no significant difference in the thickness of the auricle skin of mice in the 0.5% Neoliquiritin group compared with the MC903 group. In terms of EASI score, the MC903 group was significantly higher than the Control group ( ### p<0.001, the three concentrations of Neoliquiritin groups were significantly lower than those of the MC903 group ( ** p<0.01, *** p<0.001)( Figure 2 c). The above results show that both 1.0% Neoliquiritin and 1.5% Neoliquiritin can improve the appearance of skin lesions and auricle thickness in AD-like mice, and the therapeutic effect of the 1.0% Neoliquiritin group is better than that of the 1.5% Neoliquiritin group.

[0100] 5.2. Neoliquiritigenin can improve the pathological changes of calcipotriol-induced atopic dermatitis in mice

[0101] In view of the above results, three concentrations of Neoliquiritin were selected for follow-up research. The results showed that at 12 days, the skin lesions of mice in the three concentrations of Neoliquiritin groups were significantly improved compared with those in the MC903 group ( Figure 3 ), the histopathological sections of mice in each group showed ( Figure 3 a, scale bar = 250 μm), epidermal hyperplasia, inflammatory cell infiltration in the dermis, and spinous layer hypertrophy were observed in the MC903 group; slight epidermal thickening, less inflammatory cell infiltration in the dermis, and no obvious spinous layer thickening were observed in the three concentrations of Neoliquiritin groups, among which the improvement in the 1.0% Neoliquiritin group was more obvious. Furthermore, quantitative analysis by ImageJ showed that the epidermal thickness of the MC903 group was significantly higher than that of the Control group ( ### p<0.001); the thickness of the epidermis in the three concentrations of Neoliquiritin group was significantly decreased compared with the MC903 group ( *** p<0.001)( Figure 3 b). At the same time, the number of skin lymphocytes in the MC903 group was significantly higher than that in the Control group ( ### p<0.001); the number of skin lymphocytes in the three concentrations of Neoliquiritin groups was significantly decreased compared with the MC903 group ( *** p<0.001)( Figure 3c). The 1.0% Neoliquiritin group was superior to the 0.5% Neoliquiritin group and the 1.5% Neoliquiritin group in terms of epidermal thickness and skin lymphocyte count, and the next step of safety study was carried out.

[0102] 5.3. External application of new liquiritigenin has no effect on the liver, spleen and kidney of mice with atopic dermatitis induced by calcipotriol

[0103] Pathological sections of liver, spleen and kidney tissues of mice in each group showed ( Figure 4 , scale bar = 100 μm), there was no significant difference between the Control group and the 1.0% Neoliquiritin group, which proved that neoliquiritin had no toxic side effects on the liver, spleen and kidneys during the administration.

[0104] The Chinese medicine monomer-neoliquiritigenin of the present invention can obviously reduce skin erythema, dryness, scratches, epidermal erosion and shedding of mice, has significant therapeutic effect and is worthy of promotion.

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An external preparation for treating atopic dermatitis, characterized in that: The active ingredient of the external preparation is neoliquiritin.

2. The external preparation according to claim 1, characterized in that The concentration of the neoliquiritin is 0.5wt%-1.5wt%.

3. The external preparation according to claim 2, characterized in that The dosage forms of the external preparation include patches, pastes, ointments, creams, gels, oils, microneedles, film coatings, papules, sprays and dressings.

4. The external preparation according to any one of claims 1 to 3, characterized in that The external preparation further comprises pharmaceutically acceptable excipients.

5. A cream for treating atopic dermatitis, characterized in that: The composition comprises the following components by mass concentration: neoliquiritin 0.5%-1.5%, dissolving agent 4%-13%, oil phase 5%-25%, water phase 56%-87%, emulsifier 2%-8%, and preservative 0.05%-0.15%.

6. The cream according to claim 5, characterized in that The solvent is selected from one or more of diethylene glycol monoethyl ether, ethanol, and propylene glycol; the oil phase is selected from one or more of mono- and distearic acid glyceryl, cetostearyl alcohol, liquid paraffin, vaseline, and lanolin; and the water phase is selected from one or more of pure water, deionized water, and glycerin.

7. The cream according to claim 5, characterized in that The emulsifier is selected from one or more of polyethylene glycol-7-stearate, polyoxyethylene (21) stearyl alcohol ether, polyoxyethylene (2) stearyl alcohol ether, polyglycerol oleate, and sodium lauryl sulfate; the preservative is selected from one or more of ethylparaben, methylparaben, and phenoxyethanol.

8. The method for preparing the cream according to any one of claims 5 to 7, characterized in that: The following steps are involved: (1) weighing an oil phase, an emulsifier and a preservative to form a first mixture, weighing an aqueous phase to form a second mixture, and dissolving neoliquiritin in a solvent to form a third mixture; (2) heating the first mixture and the second mixture, mixing and homogenizing, and then adding the third mixture and homogenizing again; (3) cooling to obtain the cream.

9. Use of the external preparation according to claim 1 or 2 in the preparation of a drug for treating atopic dermatitis.

10. Use of the external preparation according to claim 1 or 2 in the preparation of a medicament for inhibiting epidermal proliferation and / or dermal lymphocyte infiltration.

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