Application of kaempferol and / or kaempferol metabolites in the preparation of drugs for antiviral infections

Abstract

This invention relates to the use of kaempferol and / or its metabolites in the preparation of antiviral drugs, wherein the viruses include any one or a combination of at least two of influenza A virus, vesicular stomatitis virus, severe fever with thrombocytopenia syndrome virus, or Crimean-Congo hemorrhagic fever virus. This invention demonstrates that kaempferol and its metabolites can enhance and prolong the type I IFN-activated JAK / STAT pathway, enhance innate immunity, and possess broad-spectrum antiviral activity.

Description

Technical Field

[0001] This invention relates to the field of biomedicine, and more particularly to the use of kaempferol and / or kaempferol metabolites in the preparation of drugs for antiviral infection. Background Technology

[0002] Host antiviral immunity, particularly innate antiviral immunity, is a universal defense mechanism with non-specific effects against all pathogens. In the complex and rich innate antiviral immune response, the type I interferon (IFN-α / β) response is the first line of defense, playing a central role in the host's defense against viral invasion. Following viral infection, IFN expression is triggered. Subsequently, IFN secretion is recognized by IFN receptors (IFNARs) on the surface of infected and surrounding uninfected cells, initiating rapid signal transduction via the Janus kinase signaling transducer and transcriptional activator (JAK / STAT) pathway, thereby forming a transcriptional complex composed of phosphorylated STAT1, STAT2, and IRF9. This transcriptional complex is then transported to the cell nucleus and binds to specific interferon-stimulated response element (ISRE) motifs in the promoter regions of many interferon-stimulated genes (ISGs), most of which possess antiviral properties, thus triggering an antiviral state in the responding cell.

[0003] When new viruses first emerge, very few drugs are available to combat these newly emerging viral infections. Although some existing antiviral drugs, such as nucleoside analogues (ribavirin, acyclovir, favipiravir, or remdesivir), have broad-spectrum antiviral efficacy, their therapeutic effect is minimal when applied to newly emerging viruses. Therefore, there is an urgent need to develop new broad-spectrum antiviral agents to enhance our preparedness for future outbreaks of emerging pathogens.

[0004] CN110403941A discloses a broad-spectrum antiviral drug or composition, wherein the active ingredient of the drug or composition is compound RAF265 or a pharmaceutically acceptable salt thereof. It is the first discovery that RAF265 possesses broad-spectrum and highly effective antiviral activity, effectively inhibiting the infection of host cells and mice by 7 viruses from 6 families (PRV, HSV-1, PEDV, FMDV, NDV, VSV, IBDV), significantly reducing viral load in mice and alleviating infection symptoms. Furthermore, RAF265 exhibits low cytotoxicity (CC50 / IC50>100) and has no toxic side effects on chicken embryos and mice.

[0005] CN115379852A discloses an antiviral drug comprising a 2'-O-methylation-sensitive RNA-associated enzyme or a nucleic acid sequence encoding a 2'-O-methylation-sensitive RNA-associated enzyme. Pharmaceutical use comprising this 2'-O-methylation-sensitive RNA-associated enzyme or its encoding nucleic acid sequence is also provided. The 2'-O-methylation-sensitive RNA-associated enzyme is a ribonuclease MgR derived from Mycoplasma genitalium. The antiviral drug exhibits broad-spectrum antiviral activity and is substantially non-cytotoxic, and can be used to prevent viral infections in animals, plants, and humans.

[0006] Flavonoids are a large class of natural metabolites, particularly abundant in plants, and possess a variety of biological activities, such as antidiabetic, anti-inflammatory, antibacterial, antioxidant, antiviral, cytotoxic, and lipid-lowering activities. To date, as many as 19 flavonoids have been approved for prescription use, and another 20 are undergoing clinical trials.

[0007] In conclusion, developing a drug that enhances the host's innate immunity has become one of the most pressing problems to be solved in this field. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides the application of kaempferol and / or kaempferol metabolites in the preparation of drugs for antiviral infection. Kaempferol and / or kaempferol enhance innate immunity by strengthening and prolonging the JAK / STAT pathway activated by type I IFN, and thus have broad-spectrum antiviral activity.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides the use of kaempferol and / or kaempferol metabolites in the preparation of medicaments for antiviral infection.

[0011] The chemical structures of kaempferol and its metabolite kaempferol are as follows: Figure 1 As shown. This invention demonstrates through research that kaempferol and its metabolites are IFN responsive agents that can synergistically work with type I IFNs to enhance innate immunity, thereby achieving a broad-spectrum antiviral effect.

[0012] Preferably, the virus includes DNA viruses and / or RNA viruses.

[0013] The kaempferol and its metabolites provided by this invention have broad-spectrum antiviral effects, so the types of viruses are not limited. In addition to currently known viruses, they can also be applied to the antiviral infection of newly emerging viruses that have not yet appeared.

[0014] Preferably, the DNA virus includes any one or a combination of at least two of hepatitis B virus, herpesvirus, human papillomavirus, or adenovirus.

[0015] Preferably, the RNA virus includes any one or a combination of at least two of the following: HIV, SARS, MERS, Ebola, influenza, parainfluenza, rabies, mumps, measles, respiratory syncytial virus, Echovirus, flavivirus, alphavirus, Bunyavirus, hepatitis A virus, Coxsackievirus, rhinovirus, enterovirus, poliovirus, dengue virus, rotavirus, Marburg virus, or novel coronavirus.

[0016] Preferably, the virus includes any one or a combination of at least two of the following: influenza A virus (IAV), vesicular stomatitis virus (VSV), severe fever with thrombocytopenia syndrome virus (SFTSV), or Crimean-Congo hemorrhagic fever virus (CCHFV).

[0017] Preferably, the kaempferol metabolite includes kaempferol.

[0018] Preferably, the drug further includes interferon.

[0019] This invention demonstrates that kaempferol and its metabolites, along with interferon, can synergistically enhance innate immunity.

[0020] Preferably, the interferon includes type I interferon and / or type III interferon.

[0021] Preferably, the type I interferon includes any one or a combination of at least two of IFN-α, IFN-β, IFN-κ, IFN-ε, or IFN-ω.

[0022] Preferably, the type III interferon includes IFN-λ.

[0023] This invention provides that IFN-β in type I interferon participates in enhancing innate immunity, and that the antiviral function of type III interferon overlaps with that of type I interferon. Therefore, it is reasonable to expect that type III interferon has a similar function to type I interferon.

[0024] Preferably, the dosage form of the drug includes any one of tablets, capsules, pellets, solutions, aerosols, sprays, ointments, or films.

[0025] Preferably, the drug further includes pharmaceutically acceptable excipients.

[0026] Preferably, the excipients include any one or a combination of at least two of the following: carrier, diluent, binder, wetting agent, disintegrant, emulsifier, cosolvent, solubilizer, osmotic pressure regulator, surfactant, coating material, colorant, pH adjuster, antioxidant, antibacterial agent, or buffer.

[0027] Secondly, the present invention provides the use of kaempferol and / or kaempferol metabolites in the preparation of JAK / STAT signaling pathway activators.

[0028] Preferably, the activator of the JAK / STAT signaling pathway includes type I IFN and / or type III IFN.

[0029] This invention demonstrates that kaempferol and its metabolites, along with interferon, can synergistically enhance innate immunity. Kaempferol and / or its metabolites can be used in conjunction with type I IFN to develop more potent JAK / STAT signaling pathway activators.

[0030] Thirdly, the present invention provides the use of kaempferol and / or kaempferol metabolites in the preparation of JAK / STAT signaling pathway activators for non-disease diagnosis and / or treatment purposes.

[0031] In this invention, it was discovered that kaempferol and / or kaempferol metabolites can be used in synergy with type I IFN to develop more potent JAK / STAT signaling pathway activators. Therefore, these activators can be used to prepare JAK / STAT signaling pathway activators for purposes other than disease treatment, and for research on the basic behavior of the JAK / STAT signaling pathway.

[0032] Fourthly, the present invention provides the use of kaempferol and / or kaempferol metabolites in the preparation of formulations that enhance intracellular type I IFN and / or type III IFN.

[0033] Preferably, the type I IFN includes any one or a combination of at least two of IFN-α, IFN-β, IFN-κ, IFN-ε, or IFN-ω.

[0034] Preferably, the type III IFN includes IFN-λ.

[0035] Preferably, the enhancement of type I IFN within cells specifically involves prolonging the time that type I IFN activates the JAK / STAT signaling pathway.

[0036] Fifthly, the present invention provides the use of kaempferol and / or kaempferol metabolites in the preparation of formulations for enhancing intracellular type I IFN for non-disease diagnosis and / or treatment purposes.

[0037] This invention has discovered that kaempferol and / or kaempferol metabolites can prolong the time that type I IFN activates the JAK / STAT signaling pathway, and can be applied to the study of the basic behavior of the JAK / STAT signaling pathway.

[0038] Sixthly, this invention provides the use of kaempferol and / or kaempferol metabolites in the preparation of vaccine adjuvants, sustained-release drug formulations, controlled-release drug formulations, or targeted drug delivery formulations. Compared with the prior art, this invention has the following beneficial effects:

[0039] This invention investigates the physiological effects of kaempferol and its metabolites. The results show that kaempferol and its metabolite kaempferol are IFN responsive agents that can enhance and prolong the JAK / STAT pathway activated by type I IFNs. They work synergistically with type I IFNs to enhance innate immunity and inhibit IAV, VSVG, CCHFV and SFTSV viruses, demonstrating broad-spectrum antiviral potential. Attached Figure Description

[0040] Figure 1 Here are the chemical structure diagrams of kaempferol and kaempferol;

[0041] Figure 2 To identify kaempferol as an effective enhancer of the JAK / STAT signaling pathway activated by type I IFN, the following diagrams are presented: Figure A shows the dose-response curve of ISRE reporter gene activity after IFN-β treatment; Figure B shows the quality control and signal-to-noise ratio of the IFN signaling regulator screening system based on ISRE reporter; Figure C shows the results of primary screening of flavonoid compound library for activators or enhancers of the JAK / STAT signaling pathway; Figure D shows the verification results of the top 5 major enhancers that hit the JAK / STAT signaling pathway by IFN activation; and Figure E shows the cytotoxicity test results of kaempferol.

[0042] Figure 3 The results of kaempferol enhancing type I IFN-induced cell antiviral status are shown in Figure A, where Figure A shows the results of kaempferol IFN-β inducing ISG expression, and Figure B shows the results of kaempferol antiviral ability assessed using IAV-Fluc and VSV-GFP, respectively.

[0043] Figure 4 Figure 1 shows the antiviral assay results of kaempferol against highly pathogenic viruses. Figure 2 shows the relative RNA level of the S fragment of SFTSV after treatment with kaempferol and IFN-β, Figure 3 shows the N protein expression of SFTSV after treatment with kaempferol and IFN-β, Figure 4 shows the relative RNA level of the S fragment of CCHFV after treatment with kaempferol and IFN-β, and Figure 5 shows the N protein expression of CCHFV after treatment with kaempferol and IFN-β.

[0044] Figure 5 Figure 1 shows the results of the analysis of the mechanism of action of kaempferol on the activation of the JAK / STAT signaling pathway by type I IFN. Figure 2 shows the effect of kaempferol on the activity of ISRE reporter genes induced by different concentrations of IFN-β. Figure 3 shows the temporal results of kaempferol enhancing the activity of ISRE reporter genes activated by IFN-β. Figure 4 shows the results of kaempferol on the phosphorylation of STAT1 and STAT2 induced by IFN-β. Figure 5 shows the results of kaempferol on the expression of SOCS1 and SOCS3 induced by IFN-β.

[0045] Figure 6 The results of kaempferol enhancing type I IFN-induced antiviral status of cells are shown in Figure A, which shows the ISRE reporter activity results of kaempferol stimulated by IFN-β; Figure B shows the cytotoxicity test results of kaempferol; Figure C shows the ISG expression results induced by IFN-β induced by kaempferol; and Figure D shows the results of kaempferol antiviral ability assessment using IAV-Fluc.

[0046] The data in the figure are shown as mean ± standard deviation of 3 replicates. *, p<0.05, **, p<0.01, ***, p<0.001, t-test. Detailed Implementation

[0047] To further illustrate the technical means and effects of this invention, the following description, in conjunction with embodiments and accompanying drawings, provides a further explanation of the invention. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it.

[0048] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0049] The methods or sources for culturing materials such as cells, viruses, and antibodies in this invention are as follows:

[0050] Human embryonic kidney cells (HEK293T, ATCC, CRL-3216) were cultured in Dulbecco modified Eagle medium (DMEM) supplemented with 10% fetal bovine serum (FBS). Human embryonic kidney cells (HEK293, ATCC, CRL-1573) were cultured in Eagle's Minimum Essential Medium (EMEM) supplemented with 10% FBS. All cells were cultured at 37°C and 5% CO2.

[0051] The reporter influenza A virus IAV Fluc (PR8-NSCE2-Fluc) and the single-cycle infectious reporter vesicular stomatitis virus VSV-GFP (VSVΔG / GFP-VG) were preserved in our laboratory. Severe fever with thrombocytopenia syndrome virus (SFTSV) and Crimean-Congo hemorrhagic fever virus (CCHFV) were provided by the State Key Laboratory of Virology and the Center for Biosafety, Chinese Academy of Sciences.

[0052] Anti-CCHFV NP, anti-SFTSV NP, anti-β-actin, anti-pSTAT1, anti-STAT1, anti-pSTAT2, anti-STAT2, and horseradish peroxidase-labeled goat anti-mouse antibodies were provided by the State Key Laboratory of Virology and the Center for Biosafety, Chinese Academy of Sciences. The flavonoid library (HY-L068) and related compounds were purchased from MedChemExpress (MCE; Monmouth Junction, NJ, USA). Recombinant human IFN-β was purchased from Proteintech (Rosemont, IL, USA).

[0053] Example 1: Identification of a novel interferon-activated JAK / STAT signal enhancer

[0054] (1) Construction of the 293T / ISRE-Fluc cell screening platform:

[0055] HEK293T cells were transfected with the ISRE promoter luciferase reporter plasmid (pISRE-Luc, 2 μg / plate / 10cm culture dish) using the Lipofectamine 2000 protocol. After 5 hours, the cells were washed and suspended, then plated on 2×10⁻⁶ plates. 4 Cells were placed in 96-well white plates. After 18 hours, cells were transiently transfected with different concentrations of IFN-β and incubated at 37°C for 24 hours. Luciferase detection was then performed using the Britelite plus reporter gene assay system (PerkinElmer, Waltham, MA, USA). The cell culture medium grown in the 96-well plates was discarded, and 50 μL of PBS and 50 μL of substrate were added sequentially. After shaking for 10 min, luminescence was immediately detected using a BioTek SYNERGY neo2 microplate reader (BioTek, Winooski, VT, USA).

[0056] (2) Identification of JAK / STAT activators:

[0057] 5 μM compounds extracted from a flavonoid library were used to treat transiently transfected HEK293T cells and incubated at 37°C for 24 hours, followed by luciferase detection.

[0058] (3) Identification of type I IFN-activated JAK / STAT pathway enhancers:

[0059] HEK293T cells were transiently transfected with 6 ng / mL IFN-β and incubated with a 5 μM flavonoid library for 24 h before luciferase detection.

[0060] like Figure 2 As shown in Figure A, IFN-β treatment stimulated ISRE-mediated Fluc expression in a dose-dependent manner. 293T / ISRE-Fluc cells were successfully engineered as a screening platform for JAK / STAT signaling pathway agonists.

[0061] like Figure 2 As shown in Figure B, 293T / ISRE-Fluc cells were modified into a screening platform for identifying type I IFN-activated JAK / STAT pathway enhancers in the presence of 6 pg / mL IFN-β. 6 pg / mL IFN-β drove detectable but far from saturated Fluc expression, resulting in an ideal signal-to-noise ratio (S / N) and Z' value of 38 and 0.56, respectively.

[0062] like Figure 2 As shown in Figure C, the median signal in 293T / ISRE-Fluc cells treated with flavonoids was significantly increased in the presence of IFN-β, while the median signal was comparable to that in the absence of IFN-β. These results indicate that flavonoids enhance the JAK / STAT pathway activated by type I IFN.

[0063] like Figure 2 As shown in Figure D, the top five compounds that enhanced the expression of ISRE reporter genes activated by IFN were selected for dose-response analysis. The results showed that all five compounds were dose-dependent, with kaempferol showing the strongest potential among the others.

[0064] like Figure 2 As shown in Figure E, kaempferol did not exhibit cytotoxicity even at a concentration of 50 μM.

[0065] Example 2: Effects of kaempferol on typical antiviral genes ISGs in IFN response

[0066] HEK293T cells were treated with 6 pg / mL IFN-β alone or in combination with the test compound in 24-well plates. After 24 h, total RNA was extracted from the cells and analyzed using PrimeScript. TMReverse transcription was performed using RT Master Mix (Takara, Japan), followed by RT-qPCR analysis. RT-qPCR was performed using the TB Green Premix Ex Taq II kit (Takara, Japan) and the CFXConnect real-time PCR detection system (Bio-Rad, Germany). The following program was used to analyze the samples: 95℃, 30s; 95℃, 5s, 60℃, 30s, 40 cycles. The relative expression levels of ISGs were calculated using the 2-ΔΔCT method. GAPDH was used as an internal reference. Primers used for qPCR analysis are listed in Table 1.

[0067] Table 1

[0068]

[0069]

[0070] like Figure 3 As shown in Figure A, treatment of HEK293T cells with 6 pg / mL IFN-β increased the expression of various ISGs, including ISG15, MxA, ISG20, IFIT1, and IFITM3, compared with the DMSO control.

[0071] Example 3: Determination of Kaempferol's Anti-IAV and VSV Virus Activity

[0072] HEK293T cells were treated with different concentrations of IFN-β, and then treated with either 2 or 10 μM kaempferol, respectively. After 24 hours, the IFN-β / kaempferol-containing culture medium was removed, and the cells were infected with reporter viruses IAV-Fluc or VSV-GFP, respectively. After 8 hours, the infectivity of IAV-Fluc and VSV-GFP was determined using luciferase and fluorescence imaging methods.

[0073] The results are as follows Figure 3 As shown in Figure B, pretreatment of cells with IFN-β reduced the infectivity of IAV-Fluc and VSV-GFP in a dose-dependent manner, and kaempferol further enhanced the antiviral activity. This indicates that kaempferol can specifically enhance the antiviral activity of type I IFN by enhancing the JAK / STAT signaling pathway.

[0074] Example 4: Antiviral activity of kaempferol against highly pathogenic viruses SFTSV and CCHFV

[0075] HEK293 cells were pretreated with different concentrations of IFN-β alone or in combination with kaempferol. Cells were infected with SFTSV or CCHFV at an MOI of 0.05 TCID50 / cell for 2 h, followed by incubation with kaempferol for 24 h. Cells were lysed in RIPA lysis buffer containing a protease inhibitor (Solarbio, Beijing, China), and protein samples were separated on a 10% SDS-PAGE gel. Proteins were transferred to polyvinylidene fluoride (PVDF) membranes for Western blot analysis. The PVDF membranes were blocked with 5% BSA in TBST, and then incubated sequentially with the primary antibody and the corresponding secondary antibody conjugated to horseradish peroxidase. Protein bands were detected using an enhanced chemiluminescence (ECL) kit (Thermo Fisher, Carlsbad, CA, USA). RT-qPCR was performed according to Example 2.

[0076] like Figure 4 As shown in Figures A and B, IFN-β treatment inhibited the accumulation of SFTSV S-segment RNA in a dose-dependent manner, while kaempferol further enhanced the antiviral activity of different concentrations of IFN-β. Furthermore, kaempferol alone also showed some inhibitory effect, possibly by enhancing the role of the endogenous IFNs-driven JAK / STAT signaling pathway in viral infection.

[0077] like Figure 4 As shown in Figures C and D, kaempferol alone can inhibit the replication of CCHFV S fragment RNA and the expression of viral NP protein to a certain extent, while the combined use of kaempferol and IFN-β showed a synergistic effect.

[0078] Example 5: Study on the mechanism of kaempferol enhancing IFN signal transduction

[0079] HEK293T cells transfected with ISRE were treated with different concentrations of IFN-β and 10 μM kaempferol in 24-well plates. Luciferase assay was performed after 24 h of incubation. The activity of the ISRE reporter gene was also measured at different time points using the same treatment method.

[0080] like Figure 5 As shown in Figure A, the activity of kaempferol is independent of the concentration of IFN-β, and the plateau signal induced by saturated IFN-β is also significantly increased, indicating that kaempferol cannot exert its effect by increasing the affinity of IFN-β for IFNR.

[0081] like Figure 5As shown in Figure B, the activity of the ISRE reporter gene peaked 12 hours after IFN-β treatment and then rapidly declined, while kaempferol did not affect ISRE reporter gene expression until 12 hours after IFN-β treatment. Furthermore, kaempferol treatment maintained a relatively high signal level without attenuation for 12–24 hours after IFN-β treatment, indicating that kaempferol prolonged the duration of IFN-β-stimulated JAK / STAT signaling.

[0082] Example 6: Kaempferol inhibits SOCS3-mediated negative feedback, prolonging type I IFN-activated JAK / STAT signaling.

[0083] HEK293 cells were treated with 20 μM kaempferol or DMSO as controls, with or without the addition of IFN-β (5 ng / mL). Six hours after treatment, cells were collected, lysed, and subjected to Western blot analysis, following the procedure described in Example 4.

[0084] Cytokine signal transduction inhibitors 1 and 3 (SOCS1 and SOCS3) are two typical feedback inhibitors of IFN signaling. The expression levels of SOCS1 and SOCS3 were detected with and without IFN-β treatment. The RT-qPCR procedure was performed according to Example 2.

[0085] like Figure 5 As shown in Figure C, the addition of kaempferol had no effect on the expression of IFN-β activated ISRE reporter genes, and the phosphorylation levels of STAT1 and STAT2 did not increase significantly.

[0086] like Figure 5 As shown in Figure D, kaempferol did not affect SOCS1 expression levels at either baseline or IFN-β-induced levels, but significantly downregulated SOCS3 expression levels. Kaempferol may prolong the IFN-activated JAK / STAT signaling pathway by inhibiting SOCS3-mediated negative feedback.

[0087] Example 7: Determination of the antiviral activity of kaempferol, a metabolite of kaempferol

[0088] When administered in vivo, kaempferol may be partially oxidized to kaempferol by liver microsomes. Therefore, the effects of kaempferol on type I IFN-driven ISG expression and cellular antiviral status were investigated. The experimental procedures were performed according to Examples 2, 3 and 4.

[0089] like Figure 6 As shown in Figure A, kaempferol significantly increased the activity of the IFN-β-stimulated ISRE promoter in a dose-dependent manner.

[0090] like Figure 6As shown in Figure B, kaempferol did not exhibit cytotoxicity even at a concentration of 50 μM.

[0091] like Figure 6 As shown in Figure C, RT-qPCR analysis indicated that kaempferol treatment increased the expression of classical antiviral ISGs induced by IFN-β, with ISG15 and MxA expression increasing by approximately 4-fold.

[0092] like Figure 6 As shown in Figure D, kaempferol significantly enhanced the antiviral activity of IFN-β against IAV-Fluc.

[0093] In summary, this invention has investigated the physiological effects of kaempferol and its metabolites. The results show that kaempferol and its metabolite kaempferol are IFN responders that can enhance and prolong the JAK / STAT pathway activated by type I IFNs, synergize with type I IFNs, enhance innate immunity, and inhibit IAV, VSVG, CCHFV and SFTSV viruses, demonstrating broad-spectrum antiviral potential.

[0094] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. The use of kaempferol and / or kaempferol in the preparation of drugs for treating severe fever with thrombocytopenia syndrome virus (SFTSV) infection or Crimean-Congo hemorrhagic fever virus (CCHFV) infection.

2. The application according to claim 1, characterized in that, The drug also includes interferon IFN-β.

3. The application according to claim 1, characterized in that, The dosage form of the drug includes any one of tablets, capsules, pellets, solutions, aerosols, sprays, ointments, or films.

4. The application according to claim 1, characterized in that, The drug also includes pharmaceutically acceptable excipients.

5. The application according to claim 4, characterized in that, The excipients include any one or a combination of at least two of the following: carrier, diluent, binder, wetting agent, disintegrant, emulsifier, cosolvent, solubilizer, osmotic pressure regulator, surfactant, coating material, colorant, pH adjuster, antioxidant, antibacterial agent, or buffer.

6. The use of kaempferol and / or kaempferol in the preparation of sustained-release or controlled-release formulations of drugs against SFTSV infection or CCHFV infection, wherein the sustained-release or controlled-release formulations of drugs against SFTSV infection or CCHFV infection further include interferon IFN-β.

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