New use of glycyrrhiza protein extract

Abstract

The application provides application of a liquorice protein extract in preparation of a medicine for treating, preventing, reducing and / or relieving lung cancer. The application fully develops macromolecular components in liquorice, and provides a new thought and means for treatment of lung cancer.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of traditional Chinese medicine, and in particular, the present application relates to a new use of licorice protein extract. BACKGROUND

[0002] Glycyrrhiza uralensis Fisch is derived from the roots or stems of Glycyrrhiza, Glycyrrhiza inflata Bat. or Glycyrrhiza glabra L. of the Leguminosae family. It was first recorded in Shennong Bencao Jing and ranked as the top product of medicine, and is a commonly used traditional Chinese medicine, which is flat in nature, sweet in taste, and belongs to the heart, lung, spleen and stomach channels, and has the effects of tonifying the spleen and benefiting qi, clearing heat and detoxifying, relieving cough and phlegm, relieving pain, and regulating various drugs. The components of licorice are complex, and the main active ingredients include glycyrrhetic acid, glycyrrhizol A, glabridin, glycyrrhizin, glycyrrhizin, glycyrrhizin, isoglycyrrhizin, and small molecule substances such as licorice flavones, and the main macromolecular components include polysaccharides and proteins. Modern pharmacological studies have found that licorice has the effects of anti-tumor, anti-inflammatory and bactericidal, anti-virus, liver protection, anti-heart failure, immune regulation and anti-fibrosis.

[0003] The research reports that licorice has obvious inhibitory effect on various malignant tumors such as intestinal cancer, liver cancer, breast cancer and lung cancer, but the main research components are concentrated in small molecules, and the mechanisms are mainly related to inducing apoptosis, interfering with cell cycle, inducing autophagy, inhibiting glycolysis, regulating immunity, regulating miRNA and signal pathways. For example, glycyrrhetinic acid dose-dependently inhibits the proliferation of gastric cancer SGC7901 cells and promotes their apoptosis, while the expression of Bcl-2 protein in cells is weakened and the expression of Bax protein is enhanced, indicating that the mechanism of glycyrrhetinic acid anti-tumor is related to the regulation of Bcl-2 / Bax expression, and makes the cell cycle arrest in G2 / M phase. Glycyrrhetinic acid can reduce the viability of hepatocarcinoma cells, induce autophagy, and enhance the expression of LC3II in cells. Licorice chalcone A has an inhibitory effect on the survival of human breast cancer MDA-MB-231 cells, can promote their apoptosis, and the expression of Bcl-2 in cells is weakened and the expression of Bax is enhanced, while the level of mitochondrial MMP is reduced, its mechanism may be through regulating the expression of Bcl-2 / Bax, reducing MMP to cause mitochondrial dysfunction, and promoting tumor cell apoptosis. Licorice chalcone A can reduce the cell viability of breast cancer MDA-MB-231 cells, promote cell apoptosis, and the expression of intracellular ROS level and endoplasmic reticulum stress related proteins (CHOP), transcription activator 4 (ATF4), phosphorylated (p)-PERK, phosphorylated eukaryotic translation initiation factor 2α (p-eIF2α) increases in a concentration-dependent manner, suggesting that its mechanism is to increase the level of ROS, induce endoplasmic reticulum stress and promote tumor cell apoptosis. Isoliquiritigenin can inhibit the proliferation of SiHa human cervical cancer cells, and the expression of mTOR and P70S6K mRNA and protein is reduced, indicating that its mechanism of anti-cervical cancer is to inhibit the mTOR / P70S6K signal pathway. Isoliquiritigenin can inhibit the proliferation of human renal clear cell carcinoma 786-O cells, and the expression of PI3K, p-Akt and p-mTOR proteins in cells is reduced, suggesting that isoliquiritigenin achieves anti-tumor effect by inhibiting the PI3K / Akt / mTOR signal pathway. Glycyrrhizin 2 mmol·L -1The inhibition rate of glycyrrhizin on liver cancer MHCC97-H cells can reach 50%, and the expression of LC3 II protein is enhanced, and LC3 II / LC3 I is up-regulated, indicating that the mechanism of its anti-tumor effect is to enhance the autophagy activity of liver cancer cells and induce autophagic cell death. Glycyrrhizin induces autophagy of nasopharyngeal carcinoma CNE-2 cells by regulating autophagy protein LC3 II / LC3 I, inhibits proliferation and promotes apoptosis. Using triple-negative breast cancer MDA-MB-231 cells as the test object, it is confirmed that the light glycyrrhizin has an inhibitory effect on cell activity, and at the same time, it is found that light glycyrrhizin can reduce the amount of glucose uptake, and the expression of glucose transporter 1 (GLUT1) protein is down-regulated, indicating that its mechanism of action is to reduce the level of adenosine triphosphate (ATP), LDH activity and lactic acid (LD) concentration, regulate glycolysis, and play an anti-tumor role. Glycyrrhizin induces autophagy of human oral squamous cell carcinoma SCC-15 cells by regulating the AMPK / mTOR signaling pathway, inhibits cell proliferation, and promotes apoptosis. In vitro and in vivo studies have also confirmed that glycyrrhizin inhibits the proliferation of oral squamous cell carcinoma OSCCs cells and the growth of tumor volume in nude mice by inhibiting the PI3K / AKT / mTOR signaling pathway.

[0004] In the study of glycyrrhizin in the treatment of lung cancer, it is found that glycyrrhizin extract has a significant inhibitory effect on the proliferation of A549 lung cancer cells, can up-regulate the expression of Bax protein, and down-regulate the expression of Bcl-2, HIF-1α and GLUT1 protein. Glycyrrhizin has an inhibitory effect on human lung adenocarcinoma H1299 cells and can promote apoptosis, and its mechanism of action is related to the regulation of cell miR-216b-5p expression. Isoliquiritigenin has a time- and concentration-dependent inhibitory effect on the proliferation of human lung cancer NCI-H460 cells, and the expression of related proteins p-p65, IκBα / β and Bcl-2 is up-regulated, and the expression of Bax is down-regulated, indicating that isoliquiritigenin can inhibit the activation of the NF-κB signaling pathway, resulting in the inability of NF-κB p65 to exert transcriptional activity, affecting the expression of Bax / Bcl-2, and promoting cell apoptosis. Glycyrrhizin charlton B can significantly inhibit the proliferation of A549 cells, arrest A549 cells in the G0 / G1 phase, and significantly increase the Bax / Bcl-2 ratio and Caspase-3 protein expression, indicating that glycyrrhizin charlton B can inhibit the proliferation of non-small cell lung cancer A549 by blocking the cell cycle and inducing apoptosis.

[0005] In summary, the basic research of glycyrrhizin in the treatment of lung cancer and other malignant tumors mainly focuses on small molecules and the direct killing effect and mechanism of tumor cells.

[0006] However, the high-content macromolecular protein in glycyrrhizin has not been reported in anti-tumor research. At present, it is urgent to explore the effect and mechanism of glycyrrhizin protein in the immune pathway on lung cancer from the perspective of its immune function regulation. SUMMARY

[0007] In view of the above problems, the present application provides a new use of licorice protein extract, in particular, the present application provides a new use of licorice protein extract for treating lung cancer.

[0008] Specifically, the present application is realized by the following technical solutions:

[0009] The present application provides the use of licorice protein extract in the preparation of a medicament for treating, preventing, reducing and / or relieving lung cancer.

[0010] Preferably, the lung cancer is small cell lung cancer or non-small cell lung cancer.

[0011] Preferably, the protein content in the licorice protein extract is 50% to 70%, and the protein molecular weight in the licorice protein extract is 63 to 75 Kda.

[0012] Preferably, the licorice protein extract is obtained by the following method:

[0013] Step S1, taking licorice, adding an extraction solvent with a pH of 6.0 to 8.0 to extract, to obtain a crude licorice protein extract;

[0014] Step S2, removing small molecule compounds in the crude licorice protein extract to obtain a preliminary licorice protein extract;

[0015] Step S3, purifying the preliminary licorice protein extract by ion exchange chromatography, using Tris-HCl buffer as mobile phase A and NaCl Tris-HCI buffer as mobile phase B for elution, and collecting elution fractions when the mobile phase B is 40% to 45% and 95% to 100%, respectively;

[0016] Step S4, mixing, dialyzing and filtering the elution fractions to obtain licorice protein extract.

[0017] Preferably, in step S1, the extraction solvent is water or phosphate buffer.

[0018] Preferably, in step S3, the elution fractions are collected when the mobile phase B is 43% and 100%, respectively.

[0019] Preferably, the administration route of the licorice protein extract is oral, intravenous injection or intravenous infusion.

[0020] Compared with the prior art, the new use of licorice protein extract of the present application has at least the following beneficial effects:

[0021] Traditional Chinese medicine composition research is mostly directed to small molecule compounds, while macromolecular components such as proteins are generally removed as impurities. The present application has conducted in-depth research on the protein extract purified from Chinese medicine liquorice, and confirmed that it has obvious cell killing activity on lung cancer cells, thereby providing a brand new idea and means for the prevention and treatment of lung cancer. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Shown is the chromatographic peak of protein distribution elution in Example 2, and peak 1 and peak 2 are components eluted at 43% mobile phase B and 100% mobile phase B, respectively.

[0023] Figure 2 Shown is the SDS-PAGE diagram of peak 1 and peak 2 in Example 2.

[0024] Figure 3 Shown is the effect of liquorice protein extract on PBMC and A549 cell co-culture in Example 3.

[0025] Figure 4 Shown are the results of liquorice protein extract on PBMC cells for 72 hours in Example 3, wherein A is a column chart reflecting the relationship between liquorice protein extract concentration and killing rate on PBMC cells, and B is a curve chart reflecting the relationship between liquorice protein extract concentration and killing rate on PBMC cells.

[0026] Figure 5 Shown are the results of liquorice protein extract on A549 cells for 72 hours in Example 3, wherein A is a column chart reflecting the relationship between liquorice protein extract concentration and killing rate on A549 cells, and B is a curve chart reflecting the relationship between liquorice protein extract concentration and killing rate on A549 cells. DETAILED DESCRIPTION

[0027] In order to fully understand the purpose, features and effects of the present application, the present application will be described in detail through the following specific embodiments. The method of the present application adopts conventional methods or devices in the art except for the following content.

[0028] Unless otherwise specified, the technical and scientific terms involved in the present application have the meanings commonly understood by those skilled in the art.

[0029] Liquorice protein extract

[0030] In the present application, the licorice protein extract is an extract with protein as the main component obtained from licorice, wherein the protein content in the extract is 50% to 70%, preferably 52% to 68%, further preferably 55% to 66%, further preferably 57% to 64%, further preferably 59% to 61%. The protein molecular weight in the licorice protein extract is mainly 63-75Kda.

[0031] Preparation method of licorice protein extract

[0032] In the present application, the preparation method of the licorice protein extract mainly includes the steps of crude extraction, removal of small molecule substances, elution and dialysis.

[0033] As a preferred embodiment, the preparation method of the licorice protein extract comprises:

[0034] Step S1: taking licorice, adding an extraction solvent with a pH of 6.0 to 8.0 to extract, and obtaining a licorice protein crude extract.

[0035] The extraction solvent can be water or a phosphate buffer. The amount of extraction solvent and the extraction time are appropriate to completely leach the protein in licorice, and specific reference can be made to the related schemes in the prior art, which will not be repeated here.

[0036] After extraction, filtration is performed, the filtrate is discarded, and then the filtrate is centrifuged, and the supernatant is collected, which is the licorice protein crude extract.

[0037] Step S2: removing small molecule compounds in the licorice protein crude extract to obtain a licorice protein primary extract.

[0038] The method for removing small molecule compounds in the licorice protein crude extract can be a conventional method, for example, adding ethanol or ammonium sulfate to make hydrophilic proteins and other macromolecular components form a precipitate, or removing small molecule compounds by ultrafiltration. The specific operation method can be referred to the related schemes in the prior art, which will not be repeated here.

[0039] Step S3: eluting the licorice protein primary extract,

[0040] The ion exchange chromatography is used for elution and purification, wherein the mobile phase A is a Tris-HCl buffer, and the mobile phase B is a Tris-HCI buffer containing NaCl (for example, 0.5 mol / L). The elution components when the mobile phase B is 40% to 45% and 95% to 100% are collected respectively, and the elution components when the mobile phase B is 43% and 100% are collected respectively.

[0041] Step S4: mixing, dialysis and filtration

[0042] The collected components are mixed, then dialyzed and filtered, and the obtained material can be further lyophilized, and the specific operations can refer to the related schemes in the prior art, which will not be repeated here.

[0043] Use of licorice protein extract

[0044] The inventors of the present application found that licorice protein extract has a significant killing effect on lung cancer cells, and therefore proposed to use licorice protein extract for preparing a drug for treating, preventing, reducing and / or relieving lung cancer.

[0045] In the present application, licorice protein extract can be administered by oral administration, intravenous injection, intravenous infusion, etc. Preferably, a therapeutically effective amount of licorice protein extract can be prepared into a pharmaceutical composition together with a pharmaceutically acceptable excipient. More preferably, the pharmaceutical composition can be tablets, hard capsules, soft capsules, granules, pills, powders, oral liquids, inhalants or injections.

[0046] In the present application, "effective amount" or "therapeutically effective amount" refers to a non-toxic but sufficient amount of a drug or agent to provide the desired effect. In the pharmaceutical composition of the present application, the "effective amount" of one component or preparation unit refers to the amount of the component effective to provide the desired effect when used in combination with other components. The "effective amount" varies from subject to subject, depending on age and general condition of the individual, specific active drug, etc. Therefore, it is not always possible to refer to the exact "effective amount", however, the appropriate "effective amount" in any individual case can be determined by a person of ordinary skill in the art using routine experimental methods.

[0047] In the present application, the pharmaceutically acceptable excipients include fillers, disintegrants, lubricants, suspending agents, binders, sweeteners, flavoring agents, preservatives, bases, etc. Fillers include starch, pregelatinized starch, lactose, mannitol, chitin, microcrystalline cellulose, sucrose, etc.; disintegrants include starch, pregelatinized starch, microcrystalline cellulose, sodium carboxymethyl starch, cross-linked polyvinylpyrrolidone, low-substituted hydroxypropyl cellulose, cross-linked sodium carboxymethyl cellulose, etc.; lubricants include magnesium stearate, sodium lauryl sulfate, talc, silicon dioxide, etc.; suspending agents include polyvinylpyrrolidone, microcrystalline cellulose, sucrose, agar, hydroxypropyl methyl cellulose, etc.; binders include starch paste, polyvinylpyrrolidone, hydroxypropyl methyl cellulose, etc.; sweeteners include sodium saccharin, aspartame, sucrose, cyclamate, glycyrrhetinic acid, etc.; flavoring agents include sweeteners and various flavors; preservatives include nipagin, benzoic acid, sodium benzoate, sorbic acid and its salts, benzalkonium bromide, chlorhexidine acetate, eucalyptus oil, etc.; bases include PEG6000, PEG4000, insect wax, etc.

[0048] The licorice (licorice decoction) described in the present application is all collected in the Chinese Pharmacopoeia (2020 edition) and meets the various provisions under the Pharmacopoeia.

[0049] The inventors have found that licorice protein can significantly induce the proliferation of human peripheral blood mononuclear cells (PBMCs) and stimulate them to release a large amount of cytokines, and increase the death of human non-small cell lung cancer cell line (A549) cell strain. Compared with the negative control group, in the absence of PBMCs, licorice protein only has weak cytotoxicity to lung cancer A549 cell line. Therefore, licorice protein can kill lung cancer A549 cells through immune regulation mediation, and the mechanism is different from the anti-tumor mechanism of small molecule substances in licorice reported in the existing research, and also different from the anti-tumor mechanism of Chinese herbal medicine licorice.

[0050] EMBODIMENT

[0051] The present application will be further described by way of examples, but the present application is not limited in the scope of the examples. The experimental methods in the following examples without specific conditions are selected according to conventional methods and conditions, or according to the instructions of the commodity.

[0052] Example 1: Preparation of licorice protein extract

[0053] Step S1, crude extraction of licorice protein

[0054] The licorice decoction is crushed into powder, and phosphate buffer (0.02 mol / L, pH 7.2) is added to make the ratio of licorice decoction powder to buffer 1:5. The mixture is extracted at 4℃ for 24h, filtered with gauze, and the filtrate is discarded. The filtrate is centrifuged at 4700rpm for 15min at 4℃, and the supernatant, i.e. the crude licorice protein extract, is collected.

[0055] Step S2, ethanol fractionation

[0056] Ethanol is slowly added to the crude licorice protein extract to a saturation degree of 40%, and the mixture is left to stand for 24h. The mixture is centrifuged at 4700rpm for 20min, and the precipitate is discarded. Ethanol is slowly added to the supernatant to a saturation degree of 60%, and the mixture is left to stand for 24h. The mixture is centrifuged at 4700rpm for 20min, and the supernatant and precipitate are separated. The precipitate is fully dissolved in Tris-HCl buffer (0.1 mol / L, pH 8.0) to obtain the initial licorice protein extract.

[0057] Step S3, ion exchange chromatography

[0058] Take 100 mL of the initial licorice protein extract and load it onto a chromatography column. Mobile phase A: Tris-HCI buffer (0.02 mol / L, pH 8.0); mobile phase B: Tris-HCI buffer containing 0.5 mol / L NaCl (0.02 mol / L, pH 8.0); flow rate 1 mL / min, stepwise elution of the licorice protein using 43% and 100% mobile phase B, respectively, and collection of the eluted peak fractions.

[0059] Step S4, dialysis

[0060] After mixing the collected fractions, they are loaded into pretreated dialysis bags (8000-10000) and placed in Tris-HCl (0.02 mol / L, pH 8.0) buffer for 12 h, during which time the buffer is changed at least five times. The dialysate is filtered through a 0.45 μm filter membrane, lyophilized, and stored for use, obtaining a licorice protein extract.

[0061] Example 2: Protein concentration determination

[0062] Take the initial protein extract prepared in step S2 of Example 1 and purify it by ion exchange chromatography. Mobile phase A: Tris-HCI buffer (0.02 mol / L, pH 8.0); mobile phase B: Tris-HCI buffer containing 0.5 mol / L NaCl (0.02 mol / L, pH 8.0); flow rate 1 mL / min, linear elution of the mobile phase B at 0-100% over 10 column volumes, and protein distribution in the eluted chromatographic peaks Figure 1 , respectively, collection of the fractions eluted at 43% (peak 1) and 100% (peak 2) of the mobile phase B, and protein determination and SDS-PAGE.

[0063] The eluted proteins are determined by BCA kit (Bi Yun Tian Biological Technology, P0012), and the results show that the protein concentrations in the protein extracts obtained from peaks 1 and 2 are 30.32 mg / mL and 9.43 mg / mL, respectively. The SDS-PAGE results are shown in Figure 2 It can be seen that the protein content in the 63-75 Kda band in peak 1 is relatively high, accounting for more than 90%, and the protein bands of peaks 1 and 2 are consistent. Therefore, the protein eluates from peaks 1 and 2 are mixed, and the protein concentration after mixing is 17.57 mg / mL. The mixed protein solution is dialyzed and freeze-dried, and the protein content in the protein freeze-dried powder is 60.09%.

[0064] The above results show that the initial licorice protein extract is enriched and purified by ion exchange chromatography.

[0065] Example 3: Effect of licorice protein extract on co-culture of human PBMC cells and A549 cells

[0066] PBMC and A549 co-culture with different concentrations of licorice protein extract, to observe the effect of licorice protein extract on PBMC killing tumor cells. To exclude the effect of licorice protein extract on PBMC or A549, PBMC cells and A549 cells were treated with corresponding concentrations of licorice protein extract, respectively. Cell activity was detected by CTG method.

[0067] Preparation of different licorice protein solutions:

[0068] The licorice protein freeze-dried powder obtained in Example 2 was dissolved in cell culture medium to prepare solutions with concentrations of 3000 nM, 2000 nM, 1000 nM, 300 nM, 100 nM, and 30 nM.

[0069] Pharmacodynamic experiment:

[0070] 1. Effect of licorice protein on PBMC and A549 cell co-culture

[0071] In a 96-well black-bottom transparent plate, 3000 cells / well of A549 cells were inoculated and cultured for 24 h. Then, 60000 cells / well of human PBMC (XW0801074W) cells were added to each well, and co-cultured for 24 h. Different concentrations of licorice protein (3000 nM, 2000 nM, 1000 nM, 300 nM, 100 nM, and 30 nM) were added to each well at 5 μL / well. Centrifugation at 1000 rpm for 1 min, and incubation for 72 h.

[0072] Cells were detected by CTG kit. Centrifuge at 1000 rpm for 1 min. Discard 100 μL supernatant, and add 100 μL / well CTG. Vibrate plate at 350 rpm for 3 min, and incubate in the dark for 30 min (RT). Load into the multi-mode reader, and analyze CTG data.

[0073] 2. Effect of licorice protein on PBMC cells

[0074] In a 96-well black-bottom transparent plate, 60000 cells / well of human PBMC (XW0801074W) cells were inoculated and cultured for 24 h. Different concentrations of licorice protein (3000 nM, 2000 nM, 1000 nM, 300 nM, 100 nM, and 30 nM) were added to each well at 5 μL / well. Centrifugation at 1000 rpm for 1 min, and incubation for 72 h.

[0075] Cells were detected by CTG kit. Centrifuge at 1000 rpm for 1 min. Discard 100 μL supernatant, and add 100 μL / well CTG. Vibrate plate at 350 rpm for 3 min, and incubate in the dark for 30 min (RT). Load into the multi-mode reader, and analyze CTG data.

[0076] 3. Effect of Glycyrrhiza extract on A549 cells

[0077] Inoculate 3000 cells / well of A549 cells in 96-well black-bottom transparent plates, and incubate for 24 h. Add 5 μL / well of different concentrations of Glycyrrhiza extract (3000 nM, 2000 nM, 1000 nM, 300 nM, 100 nM, 30 nM). Centrifuge at 1000 rpm for 1 min, and incubate for 72 h.

[0078] Detect the cells using a CTG kit. Centrifuge at 1000 rpm for 1 min. Discard 100 μL of supernatant, and add 100 μL / well of CTG. Vibrate the plate at 350 rpm for 3 min, and incubate in the dark for 30 min (RT). Load into a multi-mode reader, and analyze the CTG data.

[0079] Results of pharmacodynamic experiments:

[0080] 1. Effect of Glycyrrhiza extract on co-culture of PBMC and A549 cells

[0081] Figure 3 The effect of Glycyrrhiza extract on co-culture of PBMC and A549 cells is shown. Figure 3 The results show that Glycyrrhiza extract has an inhibitory effect on A549 cell activity in the range of 300-3000 nM, and the mechanism of action can be to stimulate PBMC cells to release immune factors and enhance the inhibitory effect on A549 cell activity. However, whether the inhibitory effect of Glycyrrhiza extract on A549 cells is related to direct killing of tumor cells needs to be further verified by cell experiments.

[0082] 2. Effect of Glycyrrhiza extract on PBMC cells

[0083] Figure 4 The effect of Glycyrrhiza extract on PBMC cells is shown, and the A columnar chart and B curve chart show that Figure 4 The results show that Glycyrrhiza extract has an inhibitory effect on A549 cell activity in the range of 300-3000 nM, and the mechanism of action can be to stimulate PBMC cells to release immune factors and enhance the inhibitory effect on A549 cell activity. However, whether the inhibitory effect of Glycyrrhiza extract on A549 cells is related to direct killing of tumor cells needs to be further verified by cell experiments.

[0084] 3. Effect of Glycyrrhiza extract on A549 cells

[0085] Figure 5 The effect of Glycyrrhiza extract on A549 cells is shown, and the A columnar chart and B curve chart show that Figure 5As shown in the A column chart and B curve chart, licorice protein significantly inhibited the activity of A549 cells in the concentration range of 300-3000 nM for 72 h, and had a concentration-dependent effect. In the concentration range of 0-300 nM, licorice protein had no significant effect on the activity of A549 cells.

[0086] As shown in the A column chart and B curve chart, licorice protein significantly inhibited the activity of A549 cells in the concentration range of 300-3000 nM for 72 h, and had a concentration-dependent effect. In the concentration range of 0-300 nM, licorice protein had no significant effect on the activity of A549 cells.

[0087] As shown in the A column chart and B curve chart, licorice protein significantly inhibited the activity of A549 cells in the concentration range of 300-3000 nM for 72 h, and had a concentration-dependent effect. In the concentration range of 0-300 nM, licorice protein had no significant effect on the activity of A549 cells.

Claims

1. Use of a licorice protein extract in the preparation of a medicament for treating lung adenocarcinoma, the medicament containing human PBMC cells; wherein The licorice protein extract is obtained by the following method: Step S1, crushing licorice decoction pieces into powder, adding phosphate buffer with pH of 6.0-8.0, extracting at 4℃, filtering with gauze, discarding the residue, centrifuging the filtrate, collecting the supernatant, and obtaining a crude licorice protein extract; Step S2, slowly adding ethanol to the crude licorice protein extract to a saturation degree of 40%, standing, centrifuging, and discarding the precipitate, continuing to slowly add ethanol to the supernatant to a saturation degree of 60%, standing, centrifuging, separating the supernatant and the precipitate, fully dissolving the precipitate with Tris-HCl buffer, and obtaining a primary licorice protein extract; Step S3, purifying the primary licorice protein extract by ion exchange chromatography, using Tris-HCl buffer as mobile phase A and Tris-HCl buffer containing 0.5 mol / L NaCl as mobile phase B, eluting, and collecting elution components when mobile phase B is 40%-45% and 95%-100%, respectively; Step S4, mixing, dialyzing, filtering, and lyophilizing the elution components to obtain a licorice protein extract.

2. Use according to claim 1, characterized in that, In step S3, elution components when mobile phase B is 43% and 100% are collected, respectively.

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