Use of liquiritin in preparation of drug for treating atopic dermatitis

Abstract

A use of liquiritin in the preparation of a drug for treating atopic dermatitis. Animal experiments show that liquiritin can remarkably lessen the skin lesion severity of an atopic dermatitis mouse model, reduce the ear thickness and the epidermal thickness, and reduce the infiltration degree of dermal lymphocytes, thereby demonstrating that liquiritin has a significant therapeutic effect on atopic dermatitis, has no toxic and side effects on the liver, the spleen and the kidney, and has good clinical application prospects and enormous social benefits, and expanding a new application field for a conventional leguminous plant liquorice extract, i.e., liquiritin.

Description

Application of liquiritin in preparing medicine for treating atopic dermatitis Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to an application of liquiritin in preparing a medicine for treating atopic dermatitis. Background Art

[0002] Atopic dermatitis (AD) is a common, chronic, relapsing, inflammatory skin disease characterized by dry skin, chronic eczematous dermatitis, and intense pruritus. Furthermore, AD patients often suffer from allergic rhinitis and / or asthma, and approximately 40%-80% of patients have a family history of allergies. The pathogenesis of AD is highly complex, resulting from the interaction of multiple factors, including genetics, immunity, infection, and the environment. Current treatments for atopic dermatitis primarily involve topical medications such as glucocorticoids, calcineurin inhibitors, antimicrobial agents, and 2% diphenhydramine cream. Systemic treatments include glucocorticoids, immunosuppressants, immunomodulators, leukotriene antagonists, vitamin D, and BCG-PSNs. While these medications have good short-term therapeutic effects on atopic dermatitis, long-term use is associated with significant side effects and a high recurrence rate.

[0003] For example, glucocorticoids are the first-line treatment for AD and are often the preferred drug of choice. However, topical glucocorticoids may cause symptoms such as skin atrophy, capillary dilation, striae atrophica, purpura, and hirsutism. When local treatment is ineffective or the affected area exceeds 20%, systemic glucocorticoids may be considered. However, their side effects are significant, so their pros and cons must be carefully evaluated during clinical use, and the dosage should not be reduced too quickly, otherwise a hormone "rebound" phenomenon may occur.

[0004] Tacrolimus is a second-line medication for short-term and long-term intermittent treatment of AD. Some patients experience localized pruritus and erythema, nephrotoxicity, diabetes, and neurotoxicity after use. Immunosuppressants are effective for severe, chronic, and relapsing AD, but they are associated with numerous side effects, such as hematologic damage, infection, gastrointestinal reactions, abnormal liver function, dizziness, fatigue, arthralgia, and rash. Long-term use is not recommended.

[0005] Externally applied TCM medications have demonstrated advantages in improving clinical symptoms and reducing relapse rates in patients with mild to moderate atopic dermatitis. Chen Lifan conducted a randomized controlled trial demonstrating that topical lithospermum oil combined with internal Chinese medicine and basic treatment can effectively reduce the severity of skin lesions in patients with atopic dermatitis. Wang Haitang et al., using a randomized, controlled, double-blind approach, found that Fu Yue Kang lotion can improve clinical symptoms in patients with atopic dermatitis by reducing peripheral blood Th17 and IL-17 levels. Kushen decoction has been clinically proven to be effective for infantile eczema, with an overall efficacy rate of 95%. However, the efficacy of these externally applied TCM medications still needs to be further improved.

[0006] In my country, AD is showing a trend of high incidence and younger age, so it is urgent to find drugs with few side effects and significant efficacy to treat AD.

[0007] Summary of the Invention

[0008] The present invention aims to provide a use of liquiritin in the preparation of a medicament for treating atopic dermatitis, to study the improvement effect of liquiritin on atopic dermatitis, to clarify the therapeutic effect and safety of liquiritin in treating atopic dermatitis; and at the same time, to expand new application areas for liquiritin, a traditional legume extract of licorice.

[0009] The first aspect of the present invention relates to the use of liquiritin in the preparation of a medicament for treating atopic dermatitis.

[0010] Preferably, the chemical structural formula of the liquiritin is as shown in Formula I, and the molecular formula is C 21 H 22 O9, molecular weight 418.39, CAS number 551-15-5;

[0011] The second aspect of the present invention relates to a medicament for treating atopic dermatitis, comprising liquiritin.

[0012] Preferably, the concentration of liquiritin is 3.0%.

[0013] Preferably, in the medicine, liquiritin is used alone or in the form of a pharmaceutical composition.

[0014] Preferably, the drug is an external preparation prepared by using liquiritin as a raw material and adding medically acceptable excipients or auxiliary ingredients.

[0015] Preferably, the topical preparations include patches, pastes, ointments, creams, gels, oils, microneedles, film coatings, papules, sprays and dressings.

[0016] The third aspect of the present invention relates to the use of liquiritin in the preparation of a medicament for inhibiting epidermal proliferation and / or inhibiting dermal lymphocyte infiltration.

[0017] Compared with the prior art, the present invention has the following significant beneficial effects:

[0018] The present invention provides a new use of liquiritin in the preparation of a medicament for treating atopic dermatitis. Using an MC903 (calcipotriol)-induced mouse atopic dermatitis model, the invention studies and confirms that topical liquiritin can be used to treat atopic dermatitis. The liquiritin can significantly reduce the thickness of the auricle and epidermis and reduce the degree of dermal lymphocyte infiltration, thereby improving the severity of skin lesions in the atopic dermatitis mouse model. The liquiritin has no toxic side effects on the liver, spleen, and kidneys, and has the advantages of clear and significant efficacy, safety, economy, and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In Figure 1, (a) is a typical photograph of the auricle lesions of mice in each group and the changes in the lesions (Day 14); (b) is the auricle thickness of mice in each group and (c) is the EASI score of the lesions (n=4) (Note: compared with the model group, **p<0.01, ***p<0.001; compared with the normal control group, ##p<0.01, ###p<0.001).

[0020] Figure 2, (a) shows the histopathological changes of the auricle of mice in each group (×100, Bar=250μm) (n=4); (b) shows the quantitative comparison of the epidermal thickness of the auricle of mice in each group and (c) shows the number of dermal lymphocytes (n=4) (Note: Compared with the model group, ***p<0.001; compared with the normal control group, ###p<0.001).

[0021] FIG3 shows the pathological changes of liver, spleen and kidney in mice of each group (×200, Bar=100 μm) (n=4). DETAILED DESCRIPTION

[0022] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0023] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to be comprehensive. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in any of a number of ways.

[0024] As people have higher requirements for quality of life and physical health, they are increasingly demanding more comprehensive treatment methods. The clinical treatment plan for atopic dermatitis should follow the principles of being safer, more effective, economical and convenient.

[0025] Liquiritin is a flavonoid compound that is often found in the medicinal part of the legume plant licorice. According to current reports, liquiritin can be used to treat skin diseases such as chloasma and photoaging.

[0026] The present invention provides a new use of liquiritin in preparing a medicine for treating atopic dermatitis. The medicine comprising the traditional Chinese medicine monomer liquiritin is used to treat atopic dermatitis, and has good efficacy, no toxic side effects, and liquiritin is widely available and low in cost.

[0027] In an exemplary embodiment of the present invention, there is provided a use of liquiritin in the preparation of a medicament for treating atopic dermatitis.

[0028] Preferably, the chemical structural formula of the liquiritin is as shown in Formula I, and the molecular formula is C 21 H 22 O9, molecular weight 418.39, CAS number 551-15-5;

[0029] In another exemplary embodiment of the present invention, a medicament for treating atopic dermatitis is provided, wherein the medicament comprises liquiritin.

[0030] Preferably, the concentration of liquiritin is 3.0%.

[0031] Preferably, in the medicine, liquiritin is used alone or in the form of a pharmaceutical composition.

[0032] Preferably, the drug is an external preparation prepared by using liquiritin as a raw material and adding medically acceptable excipients or auxiliary ingredients.

[0033] Preferably, the topical preparations include patches, pastes, ointments, creams, gels, oils, microneedles, film coatings, papules, sprays and dressings.

[0034] In another exemplary embodiment of the present invention, there is provided a use of liquiritin in the preparation of a medicament for inhibiting epidermal proliferation and / or inhibiting dermal lymphocyte infiltration; wherein the concentration of liquiritin is 3.0%.

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] In the following examples, unless otherwise specified, all methods are conventional.

[0037] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0038] Example 1

[0039] 1. Weigh 10 parts of polyethylene glycol-7-stearate, 3 parts of cetyl alcohol, 8 parts of medium-chain triglycerides, 2 parts of mono- and distearic glyceryl, and 0.1 parts of ethylparaben as component A;

[0040] 2. Weigh 61.4 parts of pure water as component B;

[0041] 3. Weigh 15 parts of diethylene glycol monoethyl ether and add 0.5 parts of liquiritin, and sonicate for 5 minutes to fully dissolve as component C;

[0042] 4. Heat components A and B to 85°C, mix thoroughly with stirring, and homogenize for 3 minutes;

[0043] 5. When the mixture of A and B drops to about 55°C, add component C and continue homogenizing for 3 minutes;

[0044] 6. When the sample cools to 40℃, it can be packaged.

[0045] Example 2

[0046] 1. Weigh 10 parts of polyethylene glycol-7-stearate, 3 parts of cetyl alcohol, 8 parts of medium-chain triglycerides, 2 parts of mono- and distearic glyceryl, and 0.1 parts of ethylparaben as component A;

[0047] 2. Weigh 60.4 parts of pure water as component B;

[0048] 3. Weigh 15 parts of diethylene glycol monoethyl ether and add 1.5 parts of liquiritin, and sonicate for 5 minutes to fully dissolve as component C;

[0049] 4. Heat components A and B to 85°C, mix thoroughly with stirring, and homogenize for 3 minutes;

[0050] 5. When the mixture of A and B drops to about 55°C, add component C and continue homogenizing for 3 minutes;

[0051] 6. When the sample cools to 40℃, it can be packaged.

[0052] Example 3

[0053] 1. Weigh 10 parts of polyethylene glycol-7-stearate, 3 parts of cetyl alcohol, 8 parts of medium-chain triglycerides, 2 parts of mono- and distearic glyceryl, and 0.1 parts of ethylparaben as component A;

[0054] 2. Weigh 58.9 parts of pure water as component B;

[0055] 3. Weigh 15 parts of diethylene glycol monoethyl ether and add 3.0 parts of liquiritin, and sonicate for 5 minutes to fully dissolve as component C;

[0056] 4. Heat components A and B to 85°C, mix thoroughly with stirring, and homogenize for 3 minutes;

[0057] 5. When the mixture of A and B drops to about 55°C, add component C and continue homogenizing for 3 minutes;

[0058] 6. When the sample cools to 40℃, it can be packaged.

[0059] Example 4

[0060] {Drug Preparation}

[0061] Drug preparation: as shown in Examples 1 to 3.

[0062] {Experimental Methods}

[0063] [Group intervention]

[0064] Male, 6-8-week-old C57BL / 6 mice weighing 20 g ± 2 g were randomly divided into five groups, with four mice in each group. The mice were housed in a sterile, temperature-controlled environment (20-26°C) and provided with standard feed and water. The grouping and treatment schedule were as follows:

[0065] (1) Normal control group (NC 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 pause and another 5-day application.

[0066] (2) Model group (MC903 group): 20 μL of 2 nmol calcipotriol (MC903) in ethanol was applied to the inner and outer sides of both ears of mice every day for 5 days, followed by a 2-day pause and another 5-day application.

[0067] (3) 0.5% glycyrrhizin group (MC903 + 0.5% LIQ group): 20 μL of 2 nmol of calcipotriol (MC903) in ethanol was applied to the inner and outer sides of both auricles of the mice daily (after 5 days of application, stop for 2 days, and then apply for 5 days). 6 hours later, the 0.5% glycyrrhizin cream prepared in Example 1 was applied to the inner and outer sides of both auricles of the mice, 5 mg per ear, for 14 consecutive days.

[0068] (4) 1.5% glycyrrhizin group (MC903+1.5% LIQ group): 20 μL of 2 nmol of calcipotriol (MC903) in ethanol was applied to the inner and outer sides of both auricles of the mice daily (after 5 days of application, stop for 2 days, and then apply for 5 days). 6 hours later, the 1.5% glycyrrhizin cream prepared in Example 2 was applied to the inner and outer sides of both auricles of the mice, 5 mg per ear, for 14 consecutive days.

[0069] (5) 3.0% glycyrrhizin group (MC903+3.0% LIQ group): 20 μL of 2 nmol of calcipotriol (MC903) in ethanol was applied to the inner and outer sides of both auricles of the mice daily (apply for 5 days, stop for 2 days, and apply again for 5 days). 6 hours later, the 3.0% glycyrrhizin cream prepared in Example 3 was applied to the inner and outer sides of both auricles of the mice, 5 mg per ear, for 14 consecutive days.

[0070] All treatments started from the day of calcipotriol application (day 0) and were administered once a day for 14 consecutive days. 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 (No. YYLAC-2022-160-10).

[0071] [Observation indicators]

[0072] The mice's ears were photographed on days 1, 5, 8, 12, and 14. The thickness of the ear skin at the same location was measured with a vernier caliper and the values ​​were recorded. The severity of ear skin inflammation was scored according to the Atopic Dermatitis Area and Severity Index (EASI), which includes four components: erythema, edema or exudate, scaling, and lichenification. The scores indicate severity: 0 (none), 1 (mild), 2 (moderate), and 3 (severe).

[0073] {Histopathology}

[0074] On day 14, after recording the above data, the mice were euthanized. Skin tissue (1 x 1 cm) was collected from both ears of each group of mice. The tissue was fixed in 4% formalin for 48 hours, embedded in paraffin, and sectioned and stained with hematoxylin-eosin (H&E). Four high-power fields were randomly selected from each section to measure epidermal thickness, and the average value was calculated.

[0075] {Statistical Methods}

[0076] Experimental data were analyzed using GraphPad Prism 9. All data are expressed as mean ± standard deviation (SD). Multiple comparisons between groups were performed using one-way analysis of variance (ANOVA) and Tukey's analysis of variance. A p value < 0.05 was considered statistically significant.

[0077] {Experimental Results}

[0078] [Liquiritin improves skin lesions and dermatitis scores in a calcipotriol-induced atopic dermatitis mouse model]

[0079] Typical photos and skin lesions of the auricles of mice in each group are shown in Figure 1a. The study found that the thickness of the auricle skin of mice induced by calcipotriol (MC903 group) was significantly increased (###p<0.001), and the ear thickness of the three concentrations of LIQ groups was significantly reduced compared with the MC903 group (**p<0.01, ***p<0.001) (Figure 1b).

[0080] The EASI score was significantly higher in the MC903 group than in the NC group (##p<0.01, ###p<0.001), while it was significantly lower in the 1.5% LIQ and 3.0% LIQ groups than in the MC903 group (**p<0.01, ***p<0.001) (Figure 1c). There was no significant difference in the EASI score between the 0.5% LIQ group and the MC903 group.

[0081] The above results show that 1.5% LIQ and 3.0% LIQ can improve the appearance of skin lesions and auricle thickness in AD-like mice, and their therapeutic effects are positively correlated with drug concentration.

[0082] [Liquiritin can improve the histopathological changes of mice with atopic dermatitis induced by calcipotriol]

[0083] In view of the above results, we preferred 1.5% LIQ and 3.0% LIQ for subsequent studies.

[0084] The results showed that after 14 days of treatment, the skin lesions of the two LIQ groups were significantly improved compared with those of the MC903 group (Figure 2). Histopathological sections of mice in each group showed (Figure 2a, Bar = 250μm) that the MC903 group had epidermal hyperplasia, inflammatory cell infiltration in the dermis, and thickening of the stratum spinosum. Both the 1.5% LIQ group and the 3.0% LIQ group had slight thickening of the epidermis, less inflammatory cell infiltration in the dermis, and less obvious thickening of the stratum spinosum. The improvement was more obvious in the 3.0% LIQ group.

[0085] Furthermore, quantification by ImageJ showed that the epidermal thickness of the MC903 group was significantly increased compared with the NC group (###p<0.001); the epidermal thickness of the 1.5% LIQ group and the 3.0% LIQ group was significantly decreased compared with the MC903 group (***p<0.001) (Figure 2b).

[0086] At the same time, the number of skin lymphocytes in the MC903 group was significantly increased compared with the NC group (###p<0.001); the number of skin lymphocytes in the 1.5% LIQ group and the 3.0% LIQ group was significantly decreased compared with the MC903 group (***p<0.001) (Figure 2c).

[0087] The 3.0% LIQ group was superior to the 1.5% LIQ group in terms of epidermal thickness and skin lymphocyte count, and the next step of safety study was carried out.

[0088] [Topical application of liquiritin has no effect on the liver, spleen, and kidneys of mice with calcipotriol-induced atopic dermatitis]

[0089] Pathological sections of the liver, spleen, and kidney tissues of mice in each group showed no significant difference among the NC group, AD group, and 3.0% LIQ group ( FIG3 , Bar=100 μm), indicating that LIQ administration did not produce toxic side effects on the liver, spleen, and kidneys.

[0090] As can be seen from the above, the Chinese medicinal monomer of the present invention significantly reduces erythema, dryness, scratches, and epidermal erosion and shedding on the skin of the affected mice, has a significant therapeutic effect, and is worthy of promotion.

[0091] The drug containing liquiritin in the present invention is a traditional Chinese medicine monomer for preventing / treating atopic dermatitis with definite efficacy, safety, economy and convenience, and can solve the problems of side effects of topical glucocorticoids and poor efficacy and inconvenient operation of existing topical drugs.

[0092] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. Use of liquiritin in the preparation of a drug for treating atopic dermatitis.

2. The application according to claim 1, characterized in that, The chemical structural formula of liquiritin is shown in Formula I, with the molecular formula C 21 H 22 O9, a molecular weight of 418.39, and a CAS number of 551-15-5; 3. A drug for treating atopic dermatitis, characterized in that, The drug contains liquiritin.

4. The drug according to claim 3, characterized in that, The concentration of liquiritin is 3.0%.

5. The drug according to claim 3, characterized in that, In the drug, liquiritin is used alone or in the form of a pharmaceutical composition.

6. The drug according to claim 3, characterized in that, The drug is a topical preparation prepared from liquiritin by adding pharmaceutically acceptable excipients or auxiliary components.

7. The medicament according to claim 6, wherein The topical preparation includes patches, pastes, ointments, creams, gels, oils, microneedles, film-forming agents, cataplasms, sprays and dressings.

8. Use of liquiritin in the preparation of a drug for inhibiting epidermal proliferation and / or inhibiting dermal lymphocyte infiltration.

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