Application of schisandra chinensis protein peptide in preparation of product for improving immune injury caused by chemotherapeutic drugs

Abstract

The invention belongs to the technical field of biological medicine, and particularly relates to application of schisandra chinensis protein peptide in preparation of a product for improving immune injury caused by chemotherapeutic drugs. The preparation method of the schisandra chinensis protein peptide comprises the following steps: removing pulp of schisandra chinensis, degreasing, carrying out alkali extraction and acid precipitation, dialyzing, and intercepting protein with the molecular weight of 8000Da-14000Da to obtain schisandra chinensis protein; and carrying out freeze drying and enzymolysis on the schisandra chinensis protein to obtain the schisandra chinensis protein peptide. According to the invention, a modeling method for causing immune injury by using international general chemotherapeutic drugs is adopted; it is verified that the schisandra chinensis protein peptide can effectively improve weight reduction, immune organ index reduction, spleen lymphocyte proliferation ability reduction, peritoneal macrophage phagocytic ability reduction, spleen CD8 + T lymphocyte number reduction and CD4 + T lymphocyte cytokine expression reduction of immune injury mice, and has a remarkable immune enhancing effect; the compound is expected to become a key component for researching and developing chemotherapy adjuvant drugs, and has a wide medical application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of biological medicine, and particularly relates to application of Schisandra protein peptide in preparation of a product for improving immune damage caused by a chemotherapeutic drug. BACKGROUND

[0002] Chemotherapy is a systemic treatment method for treating cancer by using chemical drugs with cytotoxicity. Its core mechanism is to interfere with the proliferation, infiltration and metastasis of cancer cells, and ultimately induce cancer cell death. As one of the cornerstone methods in the comprehensive treatment system of tumors, chemotherapy has been confirmed by a large number of clinical studies to be able to effectively reduce tumor load, inhibit tumor progression, and play a key role in the treatment of many malignant tumors, which helps to improve the survival prognosis of patients.

[0003] The conventional chemotherapeutic drugs represented by cyclophosphamide, cisplatin, doxorubicin, vinorelbine and actinomycin D mainly exert anti-tumor effects by non-selectively killing rapidly dividing cells due to the lack of tumor cell-specific targeting ability. This mechanism, while inhibiting the proliferation of cancer cells, will widely damage rapidly renewing healthy tissues such as bone marrow hematopoietic cells and gastrointestinal mucosal cells, thereby inducing adverse reactions such as bone marrow suppression, severe gastrointestinal reactions, fatigue, insomnia, decreased resistance, and ultimately leading to a significant decrease in the quality of life of patients.

[0004] Abnormal function of the immune system is the main reason for the decreased resistance, susceptibility to infection and recurrence of most chemotherapy patients. The immune system is composed of a complex network of immune organs, immune cells and immune molecules, which work together to recognize and eliminate foreign or abnormal cells, including tumor cells. Among them, immune cells are the smallest unit of the immune system, which need to constantly proliferate and differentiate to maintain the function of the entire immune system. Therefore, while killing tumor cells, chemotherapeutic drugs will inevitably cause damage to immune cells, leading to immunosuppression or disorder.

[0005] At present, the adjuvant drugs for improving immune damage caused by chemotherapeutic drugs include granulocyte colony-stimulating factor (G-CSF), interleukin and other immune enhancers, which usually exert therapeutic effects on a single level and can cause allergic reactions such as skin rash, low fever, anaphylactic shock, or cardiovascular system reactions such as capillary leak syndrome and anemia. That is, the current chemotherapy adjuvant drugs can only exert therapeutic effects on a single level and cause multiple adverse reactions. SUMMARY

[0006] In order to solve the problem that the chemotherapy adjuvant drugs in the prior art can only exert therapeutic effects on a single level and cause multiple adverse reactions, the application provides application of Schisandra protein peptide in preparation of a product for improving immune damage caused by a chemotherapeutic drug.

[0007] To achieve the above object, the present application adopts the following technical solutions.

[0008] The present application provides the application of the schisandra protein peptide in the preparation of the product for improving the immune damage caused by the chemotherapy drugs, and the preparation method of the schisandra protein peptide comprises the following steps: The schisandra is soaked, the pulp is removed, washed, dried, and crushed, then petroleum ether is added according to the material-liquid ratio of 1:5 for defatting; after defatting, defatted powder is obtained; the defatted powder is subjected to alkali extraction and acid precipitation, dialysis, and then the protein with the molecular weight of 8000 Da to 14000 Da is intercepted, the small molecular impurities are removed, the protein component with potential biological activity (improving immune deficiency) is retained, and the schisandra protein is obtained; the schisandra protein is subjected to freeze-drying and enzymolysis, and the schisandra protein peptide is obtained.

[0009] Compared with the immune enhancers (such as granulocyte colony-stimulating factor (G-CSF) and interleukin) in the chemotherapy auxiliary drugs, the schisandra has higher safety as the medicinal and edible traditional Chinese medicinal material and can jointly play the immune regulation role from multiple aspects. There are many studies on the schisandra extract for improving the immune function, but currently there is no related study to show that the protein peptide extracted from the schisandra can enhance the immunity. The present application provides the application of the protein peptide extracted from the traditional Chinese medicine schisandra in the preparation of the product for improving the immune damage caused by the chemotherapy drugs, the schisandra protein peptide can play the immune regulation role from multiple levels such as immune organs, immune cells, and immune molecules, and improve the functional damage of macrophages and spleen lymphocytes caused by the chemotherapy drugs. Therefore, the application of the schisandra protein peptide in the preparation of the product for improving the immune damage caused by the chemotherapy drugs provides important theoretical support and experimental basis for the development of the new type of immune health care product of the schisandra, meets the market and clinical patient's demand, and provides power for the development of the health industry. Moreover, the schisandra protein peptide extracted from the medicinal and edible traditional Chinese medicinal material schisandra provided in the present application has the effect of significantly improving the immune deficiency caused by the chemotherapy drugs, jointly plays the therapeutic role from multiple aspects such as body weight, immune organs, immune cells, and cytokines, and multiple angles such as innate immunity and adaptive immunity, can be added as a functional additive into the immune active health care product, can safely and effectively improve the immune deficiency caused by the chemotherapy drugs, and further solves the problem that the current chemotherapy auxiliary drugs can only play the curative effect from a single level and may cause multiple adverse reactions.

[0010] Preferably, the preparation method of the schisandra protein peptide comprises the following steps: The schisandra protein after freeze-drying is subjected to water reconstitution to obtain a substrate solution with the mass fraction of 2.9% to 3.1%.

[0011] adding alkaline protease to the substrate solution for enzymolysis; wherein the enzymolysis conditions are temperature 54℃-56℃, pH=8.4-8.6, and enzymolysis time 3.8h-4.2h; and wherein the mass ratio of the alkaline protease to the substrate solution is 1:100.

[0012] After the enzymolysis, the enzyme is inactivated, the temperature is cooled to room temperature, the pH is adjusted to neutral, centrifuged, and the supernatant is frozen and dried to obtain the Schisandra chinensis protein peptide.

[0013] Preferably, the centrifugation conditions are 3950r / min-4050r / min for 18min-22min.

[0014] Preferably, the method for preparing the Schisandra chinensis protein comprises the following steps: After the defatted powder is mixed with water, the pH is adjusted to 9.4-9.6 for protein extraction to obtain a protein solution; the protein solution is centrifuged, and the supernatant is collected; the supernatant is adjusted to pH 3.3-3.5, and then placed at 3.8℃-4.2℃ for centrifugation, and the supernatant is discarded and the precipitate is collected; the precipitate is dissolved, the pH is adjusted to neutral, and then dialysis is performed, and proteins with a molecular weight of 8000Da-14000Da are collected, and the dialyzed liquid is frozen and dried to obtain the Schisandra chinensis protein.

[0015] The dialysis step is as follows: after the precipitate is dissolved, the pH is adjusted to neutral, and then the dialysis bag with a MW of 8000Da-14000Da is loaded, and dialysis is performed at 3.8℃-4.2℃ for 46h-50h. Collecting proteins in this molecular weight range can enrich functional peptides with clear biological activity, such as antioxidant peptides, neuroprotective peptides, and immunomodulatory peptides. Meanwhile, comparative studies show that,<14000Da small molecular weight proteins / peptides are more likely to penetrate cell membranes and directly act on intracellular targets (such as mitochondria and nuclear receptors), significantly improving the ability to resist oxidative stress (higher efficiency in clearing hydroxyl radicals and DPPH radicals). Moreover, by collecting proteins in this molecular weight range, small molecular functional units with specific pharmacological activity in Schisandra chinensis can be enriched, avoiding the metabolic inertia and low permeability of large molecular weight proteins (>20000Da). Components with a molecular weight of <8000Da may contain small molecular impurities such as inorganic salts, monosaccharides, and organic acids; >14000Da is prone to mix non-target large molecular weight proteins (such as prolamin and glutelin).

[0016] Preferably, the immune damage is caused by cyclophosphamide or vinorelbine.

[0017] Preferably, the medicine takes the Schisandra chinensis protein peptide as the active ingredient, and is prepared into a pharmaceutically corresponding dosage form with a pharmaceutically acceptable excipient.

[0018] ​Preferably, the medicine comprises any one or more of a liquid agent, a solid agent and a semi-solid agent.

[0019] Preferably, the excipient comprises any one or more of a liquid excipient, a solid excipient and a semi-solid excipient.

[0020] Preferably, the liquid excipient comprises any one or more of water, ethanol, polysorbate, sodium chloride, glucose and sucrose; the solid excipient comprises any one or more of starch, lactose, sodium carboxymethyl starch, povidone and magnesium stearate; and the semi-solid excipient comprises any one or more of glycerol, propylene glycol, lanolin, gum arabic and sodium bisulfite.

[0021] Preferably, the medicine is a solution.

[0022] The solution is obtained by compounding the schisandra protein peptide and a solvent.

[0023] The solvent is any one of water and a PBS buffer solution.

[0024] Preferably, the concentration of the schisandra protein peptide in the solution is 34 µg / mL to 35 mg / mL. The solution medicine has a large dispersity, fast absorption, rapid action and good bioavailability; the effective components are uniformly dispersed, can be accurately measured and used, and is particularly suitable for pediatric and elderly patients; the size of the dose is easy to adjust and control; the local irritation of some easily soluble medicines can be reduced; and the stability and safety of some medicines can be increased. Therefore, the above-mentioned medicine provided by the present application is in the form of a solution.

[0025] Compared with the prior art, the present application has the following beneficial effects: The present application provides a schisandra protein peptide, and a preparation method thereof. After the pulp of schisandra is removed, the schisandra is defatted to obtain defatted powder. The defatted powder is subjected to alkali extraction and acid precipitation, dialysis, and then the protein with a molecular weight of 8000 Da to 14000 Da is cut off to obtain schisandra protein. The schisandra protein is subjected to freeze-drying and enzymolysis to obtain the schisandra protein peptide. The schisandra protein peptide provided by the present application has the effect of significantly improving immune deficiency caused by chemotherapeutic drugs. From multiple aspects such as body weight, immune organs, immune cells and cytokines, and from multiple angles such as innate immunity and adaptive immunity, the schisandra protein peptide jointly plays a therapeutic role, can be added as a functional additive to immune active health care products, and can safely and effectively improve immune deficiency caused by chemotherapeutic drugs, thereby solving the problem that the existing chemotherapeutic adjuvant drugs can only play a therapeutic effect from a single level and may cause multiple adverse reactions. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The figure shows the preparation process of the schisandra protein peptide in the present application.

[0027] Figure 2 Figure 1 is a schematic diagram of the effect of the Schisandra protein peptide on the body weight of the immunodeficient mice in the present application.

[0028] Figure 3 Figure 2 is a schematic diagram of the effect of the Schisandra protein peptide on the thymus index of the immunodeficient mice in the present application.

[0029] Figure 4 Figure 3 is a schematic diagram of the effect of the Schisandra protein peptide on the spleen lymphocyte proliferation ability of the immunodeficient mice in the present application; wherein, Figure 4 Figure 3A is a schematic diagram of the effect of the Schisandra protein peptide on the spleen B lymphocyte proliferation ability; Figure 4 Figure 3B is a schematic diagram of the effect of the Schisandra protein peptide on the spleen T lymphocyte proliferation ability.

[0030] Figure 5 Figure 4 is a schematic diagram of the effect of the Schisandra protein peptide on the peritoneal macrophage phagocytosis ability of the immunodeficient mice in the present application.

[0031] Figure 6 Figure 5 is a schematic diagram of the effect of the Schisandra protein peptide on the spleen CD8 + T lymphocyte number of the immunodeficient mice in the present application.

[0032] Figure 7 Figure 6 is a schematic diagram of the effect of the Schisandra protein peptide on the spleen T lymphocyte expression of cytokines of the immunodeficient mice in the present application; wherein, Figure 7 Figure 6A is a schematic diagram of the effect of the Schisandra protein peptide on the number of CD4 + T lymphocytes expressing IFN-γ; Figure 7 Figure 6B is a schematic diagram of the effect of the Schisandra protein peptide on the number of CD4 + T lymphocytes expressing IL-4.

[0033] Figure 8 Figure 7 is a schematic diagram of the effect of the Schisandra protein peptide on the Jurkat T cell proliferation ability in the present application; wherein, Figure 8 Figure 7A is a schematic diagram of the effect of the Schisandra protein peptide on the cytotoxicity; Figure 8 Figure 7B is a schematic diagram of the effect of the Schisandra protein peptide on the Jurkat T cell proliferation ability of the immunodeficient mice in the present application. DETAILED DESCRIPTION

[0034] The present application will be described in detail below with reference to the drawings and specific embodiments, but should not be understood as limiting the present application. If not specifically stated, the technical means used in the following examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following examples, if not specifically stated, can be obtained from commercial channels.

[0035] The experimental materials involved in the following examples are as follows: Female SPF C57BL / 6J mice, 7 weeks old, were provided by Sibeifu (Beijing) Biotechnology Co., Ltd., weighing 18 g~20 g, and were housed in a 12 h light-dark cycle, with a room temperature of 22°C~24°C and a relative humidity of 55%~65%. The animals were fed and watered freely. The animal experiment operation was approved by the Ethics Committee of Beijing University of Chinese Medicine and was strictly conducted in accordance with the animal ethics requirements, with the ethical review number BUCM20250428-009.

[0036] Example 1 I. Extraction of Schisandra Protein Peptide The Schisandra was soaked for 24 h, and after removing the pulp, the obtained seeds were cleaned and placed in an oven for low-temperature drying, crushed through a 65-mesh sieve, and then petroleum ether (boiling range: 60~90°C) was added at a ratio of 1:5, and stirred at room temperature for 24 h. Centrifugation was performed at 4000 r / min for 15 min to obtain a precipitate. After the petroleum ether was evaporated, the precipitate was passed through a 60-mesh sieve to obtain Schisandra defatted powder.

[0037] The Schisandra defatted powder was weighed, and deionized water was added at a ratio of 1:35 for homogenization. The pH value of the original solution was adjusted to 9.5 with 1 mol / L NaOH solution, and stirring extraction was performed at 35°C for 3 h. Centrifugation was performed at 3500 r / min for 15 min, and the precipitate was discarded. The pH value of the supernatant was adjusted to 3.4, and it was placed at 4°C for 2 h before centrifugation to discard the supernatant. The precipitate was dissolved with deionized water, and then the pH value was adjusted to neutral. The solution was loaded into a dialysis bag (MW: 8000 Da~14000 Da) and dialyzed at 4°C for 48 h, with deionized water being replaced every 2 h. The liquid in the dialysis bag was freeze-dried, and the freeze-dried material was Schisandra protein, which was stored at -20°C for use.

[0038] The protein content in the above Schisandra protein was determined by the BSA method, and the mixture was incubated at 37°C for 30 min in the dark. The absorbance was measured at 562 nm by an enzyme-labeled instrument, and a standard curve was drawn to calculate the protein concentration in the Schisandra protein sample. The method for determining the protein content in the above Schisandra protein includes the following steps:

[0039] 0 μL, 1 μL, 2 μL, 4 μL, 6 μL, 8 μL and 10 μL of bovine serum albumin (BSA) standard solution (2 mg / mL) were added to a 96-well microplate, and ultrapure water was added to make up to 20 μL. 2 μL of Schisandra protein sample solution was added, and ultrapure water was added to make up to 20 μL. 180 μL of BSA working solution mix [A liquid: B liquid = 50:1] was added to each well.

[0040] Deionized preparation substrate concentration of 3% (w / v) Schisandra protein solution, select alkaline protease on the Schisandra protein enzymolysis, enzymolysis conditions for 55℃, pH = 8.5, enzymolysis 4h, enzyme substrate ratio is 1% (w / w). Enzymolysis after boiling in 100 ℃ water bath for 15 min, cooling to room temperature, adjust the pH to neutral, 4000r / min centrifugal 20min, take the supernatant, and then freeze-drying, namely Schisandra protein enzymolysis peptide. Schisandra protein enzymolysis peptide is Schisandra protein peptide.

[0041] In which, the preparation (extraction) process of Schisandra protein peptide is as shown in Figure 1

[0042] II. The effect of Schisandra protein peptide on improving cyclophosphamide-induced immune injury in mice and its evaluation method 1. Method Female SPF C57BL / 6J mice, 7 weeks old, were randomly divided into control group, model group, Schisandra protein peptide group (350mg / kg), 5 in each group. Except for the control group, the rest of the groups were given 80 mg / kg cyclophosphamide intraperitoneal injection, 200 μL / one, 1 time / day, for 3 days. From the 10th day, the model group was given 0.9% saline, and the Schisandra protein peptide group was given 350 mg / kg Schisandra protein peptide solution, 200 μL / one, 1 time / day, for 11 days.

[0043] After the experiment, the mice were sacrificed under pentobarbital sodium anesthesia, and the tissue samples were collected for subsequent detection, and the data were analyzed and processed.

[0044] The experimental data were analyzed and plotted using GraphPad Prism software. The comparison of significant differences used independent sample t test method, and the differences between the control group and the test group were analyzed, and the results were expressed as mean + standard error, P <0.05 indicates significant difference.

[0045] 2. Results: The results are shown in Figure 2 and Figure 3 The body weight of the mice in the model group was significantly lower than that in the control group ( P <0.0001), and the body weight of the mice in the Schisandra protein peptide group was significantly higher than that in the model group ( P <0.05) Figure 2 It can be seen from Figure 3 Compared with the control group, the thymus index of the mice in the model group decreased significantly ( P <0.01), and the Schisandra protein peptide intervention could effectively improve the thymus index ( P <0.05).

[0046] The results are shown in​Figure 4 As shown, the proliferation rate of T / B lymphocytes in the model group was significantly lower than that in the control group ( P <0.05, the proliferation rate of T / B lymphocytes in the Schisandra chinensis protein peptide group was significantly higher than that in the model group ( P <0.05).

[0047] The results are as follows Figure 5 As shown, compared with the control group, the phagocytic function of peritoneal macrophages in the model group mice was significantly reduced ( P <0.01), while Schisandra chinensis protein peptide intervention can effectively restore the function of peritoneal macrophages in mice with low immunity ( P <0.05).

[0048] The results are as follows Figure 6 As shown, the CD8 model group + The proportion of T cells decreased significantly ( P <0.001). Compared with the model group, Schisandra chinensis protein peptide intervention can effectively increase CD8. + T cell ratio ( P <0.01).

[0049] The results are as follows Figure 7 As shown, the model group expresses CD4+ of IFN-γ. + T cells were significantly lower than in the control group ( P <0.01), Schisandra chinensis protein peptides can significantly restore CD4 expression of IFN-γ. + The number of T cells ( P <0.05). The model group expressed IL-4 on CD4. + T cells were significantly lower than in the control group ( P <0.001), Schisandra chinensis protein peptides can significantly restore CD4 expression of IFN-γ. + The number of T cells ( P <0.05).

[0050] The results show: (1) Combination Figure 2 and Figure 3 The results showed that Schisandra chinensis protein peptides increased the body weight and immune organ index in immune-damaged mice.

[0051] (2) Combination Figure 4 The results showed that Schisandra chinensis protein peptides enhanced the proliferation capacity of spleen lymphocytes in immune-damaged mice.

[0052] (3) Combination Figure 5 The results showed that Schisandra chinensis protein peptides enhanced the phagocytic capacity of peritoneal macrophages in immune-damaged mice.

[0053] (4) Combination Figure 6The results showed that Schisandra chinensis protein peptides enhanced CD8+ in the spleen of immune-damaged mice. + T cell count.

[0054] (5) Combination Figure 7 The results showed that Schisandra chinensis protein peptides increased the levels of IFN-γ and IL-4 secreted by spleen T lymphocytes in immune-damaged mice.

[0055] III. Efficacy and Evaluation Method of Schisandra chinensis Protein Peptide in Improving Jurkat T Cell Injury Induced by Vinpocetine in Vitro Immune Cells 1. Investigation into the cytotoxicity and immune-damaging effects of Schisandra chinensis protein peptides (1) Investigation on the cytotoxicity of Schisandra chinensis protein peptides Jurkat cell lines were cultured in RPMI-1640 medium. Cells were seeded in 96-well plates at a concentration of 5 × 10⁶ cells / well. 5 Cells were cultured at 100 µL per well at 37°C under 5% CO2 (v / v) conditions. After 24 h, cells were treated with different concentrations of Schisandra chinensis protein peptides (concentration settings: Schisandra chinensis protein peptide concentration gradient (0 µg / mL, 34 µg / mL, 68 µg / mL, 136 µg / mL, 272 µg / mL and 544 µg / mL) respectively). After co-culturing for 24 h, the cells were centrifuged, the supernatant was removed, and the cells were washed with 100 µL PBS. Cell viability was then assessed using a CCK-8 assay kit.

[0056] like Figure 8 As shown, Schisandra chinensis protein peptides showed no cytotoxicity in the concentration range of 0 µg / mL to 544 µg / mL. Figure 8 (Figure A in the text).

[0057] (2) Schisandra chinensis protein peptides improve vinorelbine-induced Jurkat T cell damage Modeling method: Jurkat cell lines were cultured in RPMI-1640 medium, with vinorelbine used as an inducer of low immunity. Cells were seeded in 96-well plates at a concentration of 5 × 10⁶ cells / well. 5 T cell proliferation was measured at 100 µL per well, with separate control, model, low-dose (136 µg / mL), medium-dose (272 µg / mL), and high-dose (544 µg / mL) groups of schisandra protein peptides. Except for the control group, all other groups were simultaneously administered vinorelbine (5 µM) and different drugs. T cell proliferation was assessed after 24 hours of co-culturing.

[0058] The results are as follows Figure 8 As shown, the cell proliferation capacity of the model group was significantly lower than that of the control group. P<0.0001%, medium and high doses of Schisandra chinensis protein peptides can significantly restore the decreased immune cell proliferation capacity caused by modeling. P <0.001, P <0.0001)( Figure 8 (Figure B in the diagram).

[0059] The above results indicate that Schisandra chinensis protein peptides have no cytotoxicity to immune cells in the concentration range of 0~544µg / mL.

[0060] An immune injury model was constructed using vinorelbine, and it was observed that Schisandra chinensis protein peptides could significantly improve cell death induced by the model.

[0061] In vitro and in vivo experiments have shown that the Schisandra chinensis protein peptides with a molecular weight of 8,000 to 14,000 Da obtained by the above extraction method can significantly improve the immune damage caused by chemotherapy. It exerts a therapeutic effect from multiple levels, including body weight, immune organs, immune cells, and cytokines, as well as from multiple angles such as innate immunity and adaptive immunity, and safely and effectively enhances the body's immunity.

[0062] It should be noted that when numerical ranges are involved in this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. To avoid redundancy, this invention describes preferred embodiments.

[0063] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments, all of which fall within the scope of the invention.

Claims

1. The use of Schisandra protein peptide in the preparation of a product for improving immune damage caused by chemotherapy drugs, characterized in that, The preparation method of the Schisandra protein peptide comprises the following steps: After the pulp of Schisandra is removed, defatting is performed to obtain defatted powder; the defatted powder is subjected to alkali extraction and acid precipitation, dialysis, and then the protein with a molecular weight of 8000 Da to 14000 Da is cut to obtain Schisandra protein; the Schisandra protein is subjected to freeze-drying and enzymolysis to obtain the Schisandra protein peptide.

2. Use according to claim 1, characterized in that, The preparation method of the Schisandra protein peptide comprises the following steps: The Schisandra protein after freeze-drying is subjected to water re-dissolution to obtain a substrate solution; Alkaline protease is added to the substrate solution for enzymolysis; wherein the enzymolysis conditions are temperature of 54°C to 56°C, pH of 8.4 to 8.6, and enzymolysis time of 3.8 h to 4.2 h; After the enzymolysis is completed, the enzyme is inactivated, cooled to room temperature, the pH is adjusted to neutral, centrifuged, and the supernatant is frozen and dried to obtain the Schisandra protein peptide.

3. Use according to claim 2, characterized in that, The centrifugation conditions are 3950 r / min to 4050 r / min for 18 min to 22 min.

4. Use according to claim 1, characterized in that, The preparation method of the Schisandra protein comprises the following steps: The defatted powder is mixed with water, and the pH is adjusted to 9.4 to 9.6 for protein extraction to obtain a protein solution; the protein solution is centrifuged, and the supernatant is collected; the pH of the supernatant is adjusted to 3.3 to 3.5, and the supernatant is discarded after being centrifuged at 3.8°C to 4.2°C, and the precipitate is collected; the precipitate is dissolved, the pH is adjusted to neutral, and dialysis is performed, and the protein with a molecular weight of 8000 Da to 14000 Da is cut, and the dialyzed liquid is freeze-dried to obtain the Schisandra protein; The dialysis step is as follows: the precipitate is dissolved, the pH is adjusted to neutral, and then the dialysis bag with a MW of 8000 Da to 14000 Da is loaded, and dialysis is performed at 3.8°C to 4.2°C for 46 h to 50 h.

5. The use according to claim 1, characterized in that, The immune injury is caused by cyclophosphamide or vinorelbine.

6. Use according to claim 1, characterized in that, The medicine takes the Schisandra protein peptide as an active ingredient, and is supplemented with a pharmaceutically acceptable adjuvant to prepare a pharmaceutically corresponding dosage form.

7. Use according to claim 6, characterized in that, The medicine comprises any one or more of liquid, solid and semi-solid preparations.

8. Use according to claim 6, characterized in that, The adjuvant comprises any one or more of liquid, solid and semi-solid adjuvants.

9. Use according to claim 6, characterized in that, The medicine is a solution; The solution is obtained by compounding the Schisandra protein peptide and a solvent; The solvent is any one of water and PBS buffer solution.

10. Use according to claim 9, characterized in that, The concentration of the Schisandra protein peptide in the solution is 34 µg / mL to 35 mg / mL.

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