New application of extract

Abstract

The invention discloses a new application of an extract. Through a PRRSV-2 infected cell model experiment constructed by a PRRSVNADC30 virus strain, it is determined that an alcohol and water extract of onionskin kills viruses and inhibits adsorption and proliferation of the viruses by intervening a plurality of signal channels (an Axon Guidance signal channel, an Autophagy signal channel, an EGFR signal channel and an Apelin signal channel), so that the effects of preventing and treating PRRSV infection, preventing and treating inflammatory diseases and the like are achieved. The propagation of the porcine reproductive and respiratory syndrome in the swinery is reduced. The onion skin and the extract thereof have a wide application prospect when being applied to prevention and treatment of PRRSV virus infection.

Description

Technical Field

[0001] The present invention specifically relates to the use of onion skins and their extracts in the preparation of antiviral drugs. Background Art

[0002] Porcine reproductive and respiratory syndrome (PRRS), commonly known as blue ear disease, can cause reproductive disorders in sows and severe respiratory diseases in piglets, and is a swine infectious disease that seriously affects economic benefits. PRRS is mainly caused by porcine reproductive and respiratory syndrome virus (PRRSV). PRRSV is divided into two main genotypes: PRRSV-1, with the prototype strain being Lelystadvirus, and PRRSV-2, with the prototype strain being VR-2332. PRRSV-2 is mainly prevalent in China. PRRSV has caused huge losses to the pig industry, with the global economic losses caused by this virus reaching up to billions of dollars annually. The prevention and control of this virus is difficult, and there is currently no completely effective vaccine.

[0003] Onion skins are the outer dry skins of onions (Allium cepa L.), which are usually peeled off and discarded when eating onions. However, onion skins are actually a natural material with various biological activities, containing rich nutritional components and functional characteristics, and thus have wide application values in the fields of food, medicine, agriculture, etc. There are research reports that brown onion skins are rich in beneficial health components such as fiber, phenolic compounds, ketols, and sulfur compounds. Among them, flavonoid compounds have the effects of reducing blood pressure, protecting against myocardial ischemia-reperfusion injury, enhancing immune function, and anti-cancer, antibacterial and analgesic effects; the fiber therein can reduce the risks of cardiovascular diseases, gastrointestinal discomfort, colon cancer, type II diabetes, and obesity; phenolic compounds prevent coronary heart disease and cancer; sulfur compounds have antioxidant and anti-inflammatory effects, which can prevent platelet aggregation, improve blood circulation, and promote cardiovascular health.

[0004] There is currently no research report on the anti-animal virus infection of onion skins. Summary of the Invention

[0005] To solve the above problems, the present invention provides the use of onion skins and their extracts in the preparation of antiviral drugs, and the virus is PRRSV.

[0006] Further, the genotype of the PRRSV is PRRSV-2; the PRRSV-2 type strains include the NADC30 virus strain.

[0007] Further, the extract is an ethanol and / or water extract of onion skins.

[0008] Further, the extract is a 75% ethanol extract and a water extract of onion skins.

[0009] Furthermore, the drug is a drug for killing PRRSV.

[0010] Furthermore, the drug is a drug for inhibiting the adsorption of PRRSV.

[0011] Furthermore, the drug is a drug for inhibiting the penetration of PRRSV.

[0012] Furthermore, the drug is a drug for inhibiting the replication of PRRSV.

[0013] Furthermore, the drug is a preparation prepared from onion skin and / or its extract as an active ingredient, plus pharmaceutically acceptable excipients.

[0014] Furthermore, the preparation is an oral preparation or an injection.

[0015] Furthermore, the drug is a veterinary drug; the veterinary drug is a veterinary drug for pigs.

[0016] The use of onion skin and its extract of the present invention in the preparation of antiviral drugs is determined by experiments on a cell model infected with PRRSV-2 constructed with the PRRSV NADC30 virus strain. It is determined that the alcohol and water extracts of onion skin kill the virus by intervening in multiple signaling pathways (Axon Guidance signaling pathway, Autophagy signaling pathway, EGFR signaling pathway, Apelin signaling pathway), inhibit the adsorption and proliferation of the virus, thereby preventing and treating PRRSV infection and reducing the spread of porcine reproductive and respiratory syndrome in pig herds. Applying onion skin and its extract to the prevention and treatment of PRRSV virus infection has broad application prospects.

[0017] Obviously, based on the above content of the present invention, according to the common general knowledge and customary means in the art, without departing from the above basic technical idea of the present invention, various other forms of modifications, substitutions or changes can be made.

[0018] The following is a further detailed description of the above content of the present invention through specific embodiments in the form of examples. However, this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention belong to the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Microscopic observation of Marc-145 cells under the action of different drugs (100X) DETAILED DESCRIPTION OF THE INVENTION

[0020] Example 1 Application Research on Onion Skin Inhibiting PRRSV

[0021] 1. Materials and Methods

[0022] 1.1 Cells and viruses

[0023] Cell line: Marc-145 (African green monkey embryonic kidney cells) was purchased from Wuhan Punosai Life Science Co., Ltd. and stored in this laboratory. Virus strain: PRRSV strain, clinically isolated and stored by the Animal Disease Detection Center of our unit, and identified as NADC30 virus strain.

[0024] 1.2 Drugs

[0025] Preparation of ethanol extract from onion skins: Take 1 kg of onion skins, reflux extract with 75% ethanol twice, 1 h each time, to obtain an ethanol extract. The ethanol was evaporated by reduced pressure concentration to obtain an ethanol extract of onion skins.

[0026] Preparation of water extract from onion skins: Take 1 kg of onion skins, add 20 kg of water, decoct twice, 1 h each time. The decoction was concentrated and dried to obtain a water extract of onion skins.

[0027] Preparation of water-ethanol mixed extract from onion skins: Take 1 kg of onion skins, reflux extract with 75% ethanol twice, 1 h each time, to obtain an ethanol extract. The ethanol was evaporated by reduced pressure concentration to obtain ethanol extract A of onion skins; the onion skins extracted with ethanol were then added with 20 kg of water and decocted twice, 1 h each time. The decoction was concentrated to obtain water extract B of onion skins. Combine liquid A and liquid B, and vacuum dry to obtain about 100 g of onion skin extract.

[0028] Ribavirin: Shanghai Aladdin Biochemical Technology Co., Ltd., purity 98%;

[0029] Quercetin: Chengdu Pufeide Biotechnology Co., Ltd., purity 99.99%.

[0030] 1.3 Experimental methods

[0031] 1.3.1 Preparation of cell culture medium

[0032] Cell growth medium: Sterilely prepare DMEM medium containing 10% FBS and store it at 4°C in the refrigerator for later use; Cell maintenance medium: Sterilely prepare DMEM medium containing 2% FBS and store it at 4°C in the refrigerator for later use.

[0033] 1.3.2 Determination of 50% tissue culture infective dose (TCID 50 )

[0034] The expanded PRRSV mother liquor was serially diluted 10-fold with cell maintenance medium to make the virus dilution 10 -1 -10 -10Marc-145 cells were seeded in 96-well plates. When they grew to about 80-90% confluence, the cell culture medium was discarded, and the cells were washed twice with sterilized PBS. The virus solution of each dilution was added to each well in sequence, 100 μL per well, with 8 replicates for each dilution. The cell control did not add the virus solution and was replaced with an equal volume of cell maintenance medium. It was cultured in a 37°C, 5% CO2 cell incubator for 48 h, and the cytopathic effect (CPE) was observed. The TCID of the virus was calculated according to the Reed-Muench formula. 50 。

[0035] 1.3.3 Determination of the maximum non-toxic concentration (MNTD) of the drug

[0036] Precisely weigh 10 mg of each of the water extract, alcohol extract, and water-alcohol mixed extract of onion peel, add 1 mL of cell maintenance medium to prepare a stock solution of 10 mg / mL. Precisely weigh 20 mg of ribavirin and quercetin each, add 1 mL of DMSO to prepare a stock solution of 20 mg / mL. After diluting each extract of onion peel to 1 mg / mL with cell maintenance medium, continuous two-fold serial dilutions were performed, with a total of 9 concentration gradients set. After diluting ribavirin and quercetin maintenance medium to 0.2 mg / mL, continuous two-fold serial dilutions were performed, with a total of 8 concentration gradients set, and the DMSO content was ≤1%. The DMEM cell maintenance medium containing the drug was added to the 96-well plates with monolayer Marc-145 cells, 100 μL per well, with 6 replicates for each concentration. Additionally, cell control wells and wells containing 1% DMSO maintenance medium were set as control groups. They were placed in an incubator at 37°C, 5% CO2, and cultured for 48 h. Cell cytotoxicity was detected according to the CCK8 kit instructions, the cell survival rate was calculated, and the maximum non-toxic concentration (MNTD) was calculated using GraphPad Prism 9.5.1 software. The concentration corresponding to a cell survival rate greater than 90% was the non-toxic concentration, and the maximum non-toxic concentration (MNTD) of the drug on the cells was selected for the next experiment.

[0037] 1.3.4 Inhibitory effect of the drug on PRRSV

[0038] Marc-145 cells were seeded in 24-well plates and grew to 80% confluence. The drug was diluted to a certain concentration with maintenance medium and mixed with 200 TCID 50The virus solution was mixed in equal volume, and the final concentrations of the water extract and alcohol extract of onion skin were 0.1 mg / mL; the final concentrations of the water-alcohol mixed extract of onion skin were 0.1, 0.05, 0.025, and 0.0125 mg / mL; the final concentrations of ribavirin and quercetin were 0.01 mg / mL. They were respectively added to a 24-well plate to treat the cells for 1 h, then the supernatant was aspirated, and the cells were rinsed twice with PBS to remove the unadsorbed virus. Subsequently, maintenance medium containing different drugs was added to each well, and the final concentrations were as follows: water extract and alcohol extract of onion skin: 0.1 mg / mL; water-alcohol mixture of onion skin 0.1, 0.05, 0.025, and 0.0125 mg / mL; ribavirin and quercetin 0.01 mg / mL. The cells were continued to be incubated at 37 °C and 5% CO2 for 48 h, and a virus control group (without drugs) was established simultaneously. After incubation, the cells and culture supernatant were collected, and the qRT-PCR method was used to detect the RNA copy number of the PRRSV ORF7 gene to evaluate the viral load.

[0039] 1.3.5 Study on the inhibitory activity of drugs on different stages of PRRSV

[0040] (1) Study on the direct inactivating effect of drugs on PRRSV

[0041] Marc-145 cells were inoculated in a 24-well plate and grown to 80% confluence. The water-alcohol mixed extract of onion skin was diluted with maintenance medium to a final concentration of 0.1 mg / mL, and ribavirin was diluted to a final concentration of 0.01 mg / mL. The two drug dilutions were respectively mixed with 200 TCID 50 virus solution in equal volume, incubated at 37 °C and 5% CO2 incubator for 1 h, then added to a 24-well plate respectively to allow the inactivated virus solution to adsorb the cells for 1 h, the virus solution was aspirated, the cells were rinsed twice with PBS, and cell maintenance medium was added and incubated in a 37 °C and 5% CO2 incubator for 48 h. At the same time, the virus without inactivation treatment was set as a control well. After incubation, the cells and culture supernatant were collected, and the qRT-PCR method was used to detect the RNA copy number of the PRRSV ORF7 gene to evaluate the viral load.

[0042] (2) Study on the effect of drugs on the adsorption stage of PRRSV (pre-treatment)

[0043] Marc-145 cells were inoculated in a 24-well plate and grown to 80% confluence. The water-alcohol mixed extract of onion skin was diluted with maintenance medium to a final concentration of 0.1 mg / mL, and ribavirin was diluted to a final concentration of 0.01 mg / mL. Then the two drug solutions were respectively added to treat the cells for 1 h, the drug solution was aspirated, the cells were rinsed twice with PBS, and then 100 TCID 50The virus solution was adsorbed for 1 h, then the virus solution was aspirated, and the cells were rinsed twice with PBS. Cell maintenance medium was added and the cells were incubated in an incubator at 37 °C with 5% CO2 for 48 h. Meanwhile, virus control wells were set up. After incubation, the cells and culture supernatant were collected, and the RNA copy number of the PRRSV ORF7 gene was detected by qRT-PCR to evaluate the viral load.

[0044] (3) Study on the effect of the drug on the penetration stage of PRRSV (co-treatment)

[0045] Marc-145 cells were seeded in a 24-well plate and grown to 80% confluence. The water-alcohol mixed extract of onion skin and ribavirin were diluted to a certain concentration with maintenance medium, and then were mixed with 200 TCID 50 virus solution in equal volume so that the final concentrations of the onion skin extract and ribavirin drug solution were 0.1 mg / mL and 0.01 mg / mL respectively. Then, the two drug solutions containing virus were added to the 24-well plate with cells and treated for 1 h. After that, the supernatant was aspirated, the cells were rinsed twice with PBS, cell maintenance medium was added, and the cells were incubated in an incubator at 37 °C with 5% CO2 for 48 h. Meanwhile, virus control wells were set up. After incubation, the cells and culture supernatant were collected, and the RNA copy number of the PRRSV ORF7 gene was detected by qRT-PCR to evaluate the viral load.

[0046] (4) Study on the effect of the drug on the intracellular replication stage of PRRSV (post-treatment)

[0047] Marc-145 cells were seeded in a 24-well plate and grown to 80% confluence. After adding 100 TCID 50 virus solution and adsorbing for 1 h, the virus solution was aspirated, the cells were rinsed twice with PBS, the water-alcohol mixed extract of onion skin and ribavirin were diluted to concentrations of 0.1 mg / mL and 0.01 mg / mL respectively with maintenance medium, and the two drug solutions were added to the 24-well plate and incubated in an incubator at 37 °C with 5% CO2 for 48 h. Meanwhile, virus control wells were set up. After incubation, the cells and culture supernatant were collected, and the RNA copy number of the PRRSV ORF7 gene was detected by qRT-PCR to evaluate the viral load.

[0048] 1.3.6 Establishment of the PRRSV viral load detection method

[0049] To achieve the absolute quantification of porcine reproductive and respiratory syndrome virus (PRRSV) RNA, in this study, the ORF7 gene (Gene ID: 1494888) of PRRSV was used as the target to construct a standard quality plasmid containing this gene fragment. The ORF7 gene encodes the viral nucleocapsid protein (N protein), which is a commonly used conserved region in PRRSV detection. The construction and sequencing verification of the standard quality plasmid were completed by Chengdu Youkang Xing Biotechnology Co., Ltd. The concentration and purity of the plasmid were measured, and the copy number (copies / μL) was calculated according to the following formula:

[0050]

[0051] The plasmid was serially diluted 10-fold (from 10 -1 to 10 -11 copies / μL) and used as the template for the quantitative real-time PCR (qRT-PCR) reaction. The logarithm of the copy number (log 10 ) was used as the abscissa, and the corresponding CT value was used as the ordinate to plot the standard curve.

[0052] Viral RNA in the samples was extracted using Viral DNA / RNA Mini Kit, and the ORF7 gene was quantitatively detected by qRT-PCR. The copy number (copies / μL) of viral RNA in each cell sample was calculated through the standard curve, thereby achieving the absolute quantitative analysis of PRRSV load. The synthesis of the primers was completed by Chengdu Youkang Xing Biotechnology Co., Ltd. The primer sequences are shown in Table 1.

[0053] Table 1 Primer information

[0054]

[0055] 1.3.7 Data statistics and analysis

[0056] All data were statistically analyzed using Graph Pad Prism 9.5 software, and the results were presented using . For the content involving statistical inference, one-way analysis of variance was used, and Turkey was selected for the post hoc test. A significant difference was marked as *p < 0.05, and an extremely significant difference was marked as **p < 0.01.

[0057] 2 Results and analysis

[0058] 2.1 PRRSV TCID 50 Determination results

[0059] PRRSV TCID 50 The determination results are shown in Table 2. According to the Reed-Muench calculation method, the TCID of the virus solution was obtained50 is 10 -4 / 100 μL, that is, when the virus solution is diluted to 10 -4 , every 100 μL of virus inoculation amount can cause typical cytopathic effect (CPE) in 50% of the cells.

[0060] Table 2 PRRSV TCID 50 Determination statistical table

[0061]

[0062] 2.2 Detection of the effect of drugs on the viability of Marc-145 cells by CCK-8 method, namely MNTD

[0063] According to the CCK-8 method, detect the OD 450 nm value of the cells, and calculate the cell survival rate according to the formula. When the cell survival rate is greater than 90%, this concentration is the maximum non-toxic dose. The experimental results show that the maximum non-toxic concentration (MNTD) of onion skin extract (water extract, alcohol extract, water-alcohol extraction mixture) on Marc-145 cells is 0.1 mg / mL; the maximum non-toxic concentrations (MNTD) of quercetin and ribavirin on Marc-145 cells are 0.01 mg / mL respectively.

[0064] 2.3 Inhibition of PRRSV infection by drugs

[0065] After incubation for 48 h, by observing the cytopathic effect (CPE), it was found that there was obvious cytopathic effect in the PRRSV control group, while no obvious CPE was observed in the water extract, alcohol extract, water-alcohol extraction mixture of onion skin, and quercetin. The effect of ribavirin in improving cytopathic effect was weak. As Figure 1 shown. The results of virus load detection after harvesting cells and supernatants also showed that the water-alcohol extraction mixture of onion skin could effectively inhibit the infection of PRRSV, and was significantly better than the positive compound ribavirin, the water extract of onion skin, the alcohol extract of onion skin and quercetin. Among them, compared with ribavirin, the virus load decreased by 4 orders of magnitude; compared with quercetin, the virus load decreased by 3 orders of magnitude; compared with the water extract of onion skin and the alcohol extract of onion skin, the virus load decreased by 1 order of magnitude; as Figure 1 and Table 3.

[0066] Table 3 Virus load

[0067]

[0068] Note: Compared with the virus control group, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001

[0069] 2.4 Inhibition of PRRSV Infection by Mixed Extracts of Alcohol-Water Extracts from Onion Skin with Different Concentration Gradients

[0070] After incubation for 48 h, cells and supernatants were harvested for virus load detection. The results showed that the mixed extracts of alcohol-water extracts from onion skin could significantly inhibit PRRSV infection at the concentrations of 0.1 / 0.05 / 0.025 / 0.0125 mg / mL, and showed a dose-dependent trend, as shown in Table 4.

[0071] Table 4 Virus Load

[0072]

[0073] Note: Compared with the virus control group, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001

[0074] 2.5 Mechanism of the Drug in Inhibiting PRRSV Infection

[0075] To determine the mechanism of the mixed extracts of alcohol-water extracts from onion skin in inhibiting PRRSV, Marc-145 cells were treated before PRRSV infection, during adsorption, and after infection, as well as directly killing the virus, and four methods were studied. After incubation for 48 h, cells and supernatants were harvested for virus load detection. The results showed that the mixed extracts of alcohol-water extracts from onion skin not only had a certain effect of directly killing PRRSV, but also mainly played an antiviral role by inhibiting the intracellular replication of the virus, and its effect was better than that of the positive control ribavirin. As shown in Tables 5 and 6.

[0076] Table 5 Study on the Mode of Action of the Mixed Extracts of Alcohol-Water Extracts from Onion Skin against PRRSV

[0077]

[0078] Note: Compared with the virus control group, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001

[0079] Table 6 Study on the Mode of Action of Ribavirin against PRRSV

[0080]

[0081] Note: Compared with the virus control group, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001

[0082] 2.6 Proteomic Mechanism Study of the Mixed Extracts of Alcohol-Water Extracts from Onion Skin against PRRSV

[0083] 2.6.1 Experimental Method:

[0084] Cells were inoculated in T25 flasks and grown to 80% confluence, and then 100 TCID 50 After the virus solution was adsorbed for 1 h, the virus solution was aspirated, and the cells were rinsed 3 times with PBS. The mixed extract of onion skin water-alcohol extract was diluted to a final concentration of 0.1 mg / mL with cell maintenance medium and added to the T25 flasks. Incubated in an incubator at 37 °C and 5% CO2 for 48 h to obtain the onion skin drug group. At the same time, a cell group and a virus group were set up.

[0085] 2.6.2 Experimental results

[0086] The results of proteomics observation showed that the onion skin extract could act on PRRSV virus infection through the following mechanisms.

[0087] (1) The Axon Guidance signaling pathway plays an important role in the immune system and virus infection. PRRSV infection may cause abnormal activation of the Axon Guidance signaling pathway, leading to increased susceptibility of host cells to the virus. The proteomics results showed that the Axon Guidance signaling pathway was significantly upregulated in the virus group, while it was significantly downregulated in the onion skin extract group.

[0088] (2) PRRSV infection can upregulate the Autophagy signaling pathway, enhance its replication in host cells, and achieve immune escape, while the signaling pathway is downregulated after the intervention of onion skin extract.

[0089] (3) Proteomics research found that PRRSV infection promotes virus replication and transmission by activating the ErbB signaling pathway (also known as the EGFR signaling pathway). After the intervention of onion skin extract, the signaling pathway was downregulated. At the same time, the activation of EGFR can inhibit apoptosis through the PI3K / Akt pathway, thus helping the virus evade host immune surveillance.

[0090] (4) Proteomics research found that PRRSV may inhibit the host immune response by upregulating the Apelin signaling pathway, helping the virus evade the immune response, thereby enhancing the survival and replication ability of the virus. After the intervention of onion skin, this signaling pathway was downregulated.

[0091] The above experimental results showed that: the mixed extract composed of the alcohol extract and water extract of onion skin could prevent PRRSV infection by intervening in multiple signaling pathways and from multiple ways of virus infection, namely virus adsorption, penetration, and replication, and at the same time kill PRRSV virus, thus playing a role in preventing and treating PRRSV infection, and the effect was better than that of ribavirin commonly used at present, as well as the monomeric compounds and effective extraction parts in onion skin.

[0092] Experimental Example 2 Verification Test on the Clinical Effect of Onion Skin Extract on Pigs Infected with PRRSV

[0093] 1 Materials

[0094] 1.1 Experimental Animals and Reagents

[0095] Thirty pigs weighing 10 - 20 kg were provided by a farm in Sichuan.

[0096] Viral DNA / RNAMini Kit (RC323 - 01), HiScript III All-in-one RT SuperMix Perfect for qPCR (R333 - 01), and ChamQ SYBR qPCR Master Mix (Q311 - 02) were all provided by Nanjing Novoprotein Biological Technology Co., Ltd.

[0097] 1.2 Animal Grouping

[0098] Thirty piglets with respiratory symptoms were clinically selected and confirmed as PRRSV-infected cases by PCR diagnosis method, and were evenly divided into 2 groups, namely the experimental group and the control group.

[0099] 2 Methods

[0100] 2.1 Administration Method

[0101] The experimental group was given the onion skin water-alcohol mixed extract prepared in Example 1 at a dosage of 400 g / ton of feed for 14 consecutive days, and the control group was not given any drug.

[0102] 2.2 Evaluation Criteria

[0103] Blood was collected from the anterior vena cava of the pigs in the experimental group and the control group on the day before the experiment and 14 days after drug administration, and the PRRSV infection was detected by PCR.

[0104] 2.3 Result Judgment Criteria

[0105] According to the PRRSV detection results, if the virus is negative and the clinical respiratory symptoms are eliminated (counted as cured);

[0106] If the PRRSV detection result shows that the virus is positive and the clinical respiratory symptoms are obvious (counted as ineffective).

[0107] 3 Results

[0108] The results are shown in Table 7.

[0109] Table 7 PRRSV Detection Results

[0110]

[0111] As can be seen from Table 6, for 30 piglets in the experimental group and the control group, blood samples were collected 1 day before administration, and the PCR test results were all positive, indicating a positive PRRSV infection before administration, and the selected cases met the experimental requirements; 14 days after administration, the positive rate of PRRSV detection in piglets in the experimental group was 6.67%, and the negative conversion rate was 93.33%. The clinical manifestation was that the respiratory symptoms gradually alleviated, and the respiratory symptoms disappeared 7 days after administration. In the control group, the positive rate remained 100%, and the respiratory symptoms were obvious. It shows that the mixed extract of ethanol and water extracts from onion skins can significantly inhibit and eliminate PRRSV in piglets and effectively control the occurrence of respiratory symptoms.

[0112] In summary, in the experimental study of the cell model infected with PRRSV-2 constructed with the PRRSV NADC30 virus strain in the present invention, it was determined that the mixed extract composed of the ethanol extract and the water extract of onion skins can kill the virus by intervening in multiple signaling pathways (Axon Guidance signaling pathway, Autophagy signaling pathway, EGFR signaling pathway, Apelin signaling pathway), inhibit the adsorption and proliferation of the virus, thereby preventing and treating PRRSV infection; the animal clinical trial verified that the mixed extract composed of the ethanol extract and the water extract of onion skins has a significant effect on reducing the transmission of porcine reproductive and respiratory syndrome in the pig population.

Claims

1. Use of onion skin and its extract in the preparation of antiviral drugs, characterized in that: The virus is PRRSV.

2. The use according to claim 1, wherein: The genotype of the PRRSV is PRRSV-2; the PRRSV-2 type strains include the NADC30 virus strain.

3. The use according to claim 1, wherein: The extract is an ethanol and / or water extract of onion skins.

4. The use according to claim 3, characterized in that: The extract is a 75% ethanol extract and a water extract of onion skins.

5. The use according to claim 1, characterized in that: The drug is a drug for killing PRRSV.

6. The use according to claim 1, wherein: The drug is a drug for inhibiting the adsorption of PRRSV.

7. The use according to claim 1, characterized in that: The drug is a drug for inhibiting the penetration of PRRSV.

8. The use according to claim 1, characterized in that: The drug is a drug for inhibiting the replication of PRRSV.

9. The use according to any one of claims 1 to 7, characterized in that: The drug is a preparation prepared with onion skins and / or their extract as the active ingredient, plus pharmaceutically acceptable excipients; the preparation is an oral preparation or an injection.

10. The use according to claim 9, wherein: The drug is a veterinary drug; the veterinary drug is a veterinary drug for pigs.

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