Application of tannin compounds in the preparation of drugs against porcine reproductive and respiratory syndrome virus

Abstract

The present invention discloses the use of tannin compounds in the preparation of drugs against porcine reproductive and respiratory syndrome virus. The inventors of the present invention screened the activities of tannin compounds of natural origin and found that the tannin compounds shown in Formula 1 all have excellent anti-PRRSV activity, and their EC 50 values are lower than or significantly lower than the EC 50 value of ribavirin; this indicates that the inhibitory effect of these compounds on PRRSV is greater than, and even far greater than, that of the positive control drug ribavirin. These compounds have an unexpected anti-PRRSV effect.

Description

Technical Field

[0001] The present invention relates to the field of medicinal chemistry, and particularly to the application of tannin compounds in the preparation of drugs or medicated feed additives against porcine reproductive and respiratory syndrome virus. Background Art

[0002] Porcine reproductive and respiratory syndrome (PRRS), also known as swine blue ear disease, is an acute, highly febrile and highly contagious disease of pigs caused by the infection of porcine reproductive and respiratory syndrome virus (PRRSV). This infectious disease can cause obvious respiratory symptoms in pigs of different reproductive ages. In severe infections, it can lead to the death of pigs and often cause reproductive disorders such as abortion, stillbirth, and mummified fetuses in sows, seriously endangering the healthy development of the global pig farming industry and causing billions of dollars in economic losses to the global pig farming industry every year.

[0003] At present, there is no effective means to prevent and control PRRS. The main prevention and control methods for PRRS are vaccination. However, due to the high gene mutation rate of PRRSV and frequent recombination between different strains, a large number of mutant strains are produced, which results in the inability of vaccination to effectively block virus infection and poor prevention and control effects. Therefore, the research on anti-PRRSV drugs is of great significance in the prevention and control of PRRS. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an application of tannin compounds in the preparation of anti-PRRSV drugs in order to overcome the insufficient development of anti-PRRSV drugs in the prior art.

[0005] The tannin compounds described in the present invention are mainly derived from Punica granatum L., Phyllanthus emblica L., Oenothera biennis L., Sanguisorba officinalis, and Terminalia chebula Retz., and are a class of known compounds. Through retrieval and analysis, it has been reported in the literature that such compounds have inhibitory effects on viruses such as influenza virus, human immunodeficiency virus (HIV), and hepatitis B virus (HBV), but their anti-PRRSV effects have not been reported. In the field of medicinal chemistry, the antiviral effects of drugs are relatively unpredictable. Just because a certain compound has an inhibitory effect on a certain virus does not mean it also has an inhibitory effect on other viruses. For example, the commonly used anti-influenza virus drug oseltamivir phosphate only has an inhibitory effect on influenza virus and has no inhibitory effect or no obvious inhibitory effect on other viruses. That is to say, based on the fact that such compounds have inhibitory effects on certain viruses disclosed in the literature, those skilled in the art cannot predict that such compounds also have inhibitory effects on PRRSV.

[0006] The above technical problems to be solved by the present invention are achieved by the following technical solutions:

[0007] The present invention provides the use of tannin compounds in the preparation of drugs against porcine reproductive and respiratory syndrome virus (PRRSV), and the tannin compounds are any one of the following compounds:

[0008] Punicalagin (1), corilagin (2), punicalin (3), 2-O-galloylpunicalin (4), chebulagic acid (5), chebulinic acid (6), oenothein B (7), gemin D (8), lagerstannin C (9), granatin A (10), granatin B (11), tellimagrandinⅠ(12), tellimagrandin II (13), casuarinin (14), punigluconin (15), pedunculagin (16), terflavin A (17), terflavin D (18), (+)-castalin (19), (-)-strictinin (20), hippomanin A (21), punicacortein C (22), tercatain (23), heterophylliin A (24), castalagin (25), casuarictin (26), sanguiin H1 (27), sanguiin H4 (28), (-)-vescalin (29), punicafolin (30), cornusiin A (31), cornusiin B (32), cornusiin C (33), woodfordin B (34), woodfordin H (35), casuariin (36), 2,3-(S)-HHDP-D-glucose (37), eucalbanin A (38), eucalbanin B (39), emblicanin A (40), emblicanin B (41), mallotusinin (42), rugosin B (43) and isoterchebulin (44), the structures of which are shown in FormulaⅠ:

[0009]

[0010]

[0011]

[0012]

[0013] Preferably, the drug is a drug for treating porcine reproductive and respiratory syndrome.

[0014] Preferably, the tannin compounds are compound 1, 5, 14, 17, 22 and / or 44.

[0015] Preferably, the dosage form of the drug is powder, oral liquid or injection.

[0016] The present invention also provides that the above-mentioned tannin compounds can also be added to animal feed as feed additives, that is, used as feed additives.

[0017] The present invention also provides an anti-porcine reproductive and respiratory syndrome virus drug containing the above-mentioned tannin compounds as active ingredients.

[0018] Beneficial effects:

[0019] The inventors of the present invention screened the activities of tannin compounds from natural sources and found that the tannin compounds shown in Formula 1 all have excellent anti-PRRSV activities, and their EC 50 values are lower than or significantly lower than the EC 50 values of ribavirin; this shows that the inhibitory effects of these compounds on PRRSV are greater than or even far greater than the positive control drug ribavirin. These compounds have unexpected anti-PRRSV effects. Specific embodiments

[0020] The following specific embodiments are used to further explain the present invention, but the embodiments do not limit the invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

[0021] Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0022] The structures of tannin compounds are shown in Formula 1, specifically punicalagin (1), corilagin (2), punicalin (3), 2-O-galloylpunicalin (4), chebulagic acid (5), chebulinic acid (6), oenothein B (7), geminD (8), lagerstannin C (9), granatin A (10), granatin B (11), tellimagrandinⅠ(12), tellimagrandin II (13), casuarinin (14), punigluconin (15), pedunculagin (16), terflavin A (17), terflavin D (18), (+)-castalin (19), (-)-strictinin (20), hippomanin A (21), punicacortein C (22), tercatain (23), heterophylliin A (24), castalagin (25), casuarictin (26), sanguiin H1 (27), sanguiin H4 (28), (-)-vescalin (29), punicafolin (30), cornusiin A (31), cornusiin B (32), cornusiin C (33), woodfordin B (34), woodfordin H (35), casuariin (36), 2,3-(S)-HHDP-D-glucose (37), eucalbanin A (38), eucalbanin B (39), emblicanin A (40), emblicanin B (41), mallotusinin (42), rugosin B (43), and isoterchebulin (44), and their structures are shown in Formula Ⅰ:

[0023]

[0024]

[0025]

[0026]

[0027] Example 1: In vitro anti-PRRSV activity test

[0028] Cytotoxicity experiment: 6×10 4 Marc-145 cells per mL were seeded in 96-well plates and incubated overnight in a 5% CO2, 37 °C cell culture incubator. Then, the test compound (at a total of 6 concentrations) serially diluted 2-fold with DMEM (cell maintenance medium) containing 2% FBS and 1% double antibiotics (penicillin-streptomycin) was added. Meanwhile, a cell control group (added with maintenance medium without the compound) was set up. Three replicate wells were set for each concentration of the compound and the cell control group. They were continued to be cultured in the cell culture incubator for 72 hours. The old culture medium was aspirated, and DMEM containing 10% MTS was added and continued to be cultured for 0.5 - 2 hours. Then, the OD value was measured, and the half-maximal cytotoxic concentration (CC 50 ) of the compound was calculated using Graphpad Prime6.0 software. The positive control drug was Ribavirin.

[0029] Anti-PRRSV activity by cytopathic effect (CPE) method: 6×10 4 Marc-145 cells per mL were seeded in 96-well plates and incubated overnight in a 5% CO2, 37 °C cell culture incubator. The old liquid was aspirated, and 100 μL of 100 TCID 50 PRRSV virus solution diluted with the maintenance medium was added to each well. At the same time, the test compound (at a total of 6 concentrations) serially diluted 2-fold with the cell maintenance medium was added as the compound treatment group. In the virus control group, 100 μL of DMEM culture medium containing 2% FBS and 100 μL of virus solution were added to each well. The cell control group was only added with 200 μL of maintenance medium. Three replicate wells were set for each group and cultured in a 37 °C, 5% CO2 cell culture incubator for 2 - 3 days. The cell pathological changes and fluorescence were observed every day, the cell pathological changes of each well were recorded and photographed. 0 - 25%: +; 25% - 50%: ++; 50 - 75%: +++; 75 - 100%: ++++. The EC 50 was calculated by the Reed and Muench method, and the results are shown in Table 1. The positive control drug was Ribavirin.

[0030] The CC 50 of compounds 1 - 44 in formula 1 and the positive control drug Ribavirin against the host cell Marc-145 cells and the PRRSV CHR6 / Li11 virus strain, as well as the IC50 The values, and the specific results are shown in Table 1.

[0031] Table 1. Test results of the anti-PRRSV activity of tannin compounds

[0032]

[0033]

[0034] It can be seen from the in vitro anti-PRRSV activity test results in Table 1 that the tannin compounds shown in Formula 1 have inhibitory effects on both PRRSV CHR6 and Li11, and their antiviral activities are equivalent to or better than that of the positive control drug ribavirin. It is worth noting that the EC 50 of Compounds 1, 5, 14, 17, 22, and 44 against PRRSV is less than 10 μM, and their activities are dozens of times better than that of ribavirin.

Claims

1. Use of tannin compounds in the preparation of drugs against porcine reproductive and respiratory syndrome virus, wherein the tannin compounds are any of the following compounds: Formula 1.

2. The application according to claim 1, wherein The drug is for treating porcine blue ear disease.

3. The application according to claim 1, wherein The dosage form of the drug is powder, oral liquid or injection.

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