Application of polydatin in resistance to eimeria tenella

Abstract

The invention belongs to the technical field of medicine, discloses application of polydatin in resisting eimeria tenella, and particularly discloses application of polydatin or pharmaceutically acceptable salt thereof in resisting chicken coccidiosis. The invention provides new application of polydatin or pharmaceutically acceptable salt thereof in treatment of chicken coccidiosis (such as eimeria tenella) infection, development and application of polydatin are expanded, and development and utilization of new anti-coccidiosis drugs are promoted at the same time. A cellular level test and an animal test are carried out on the anti-eimeria tenella infection effect of the polydatin, and results show that the polydatin has a remarkable effect of inhibiting eimeria tenella, the anti-coccidiosis index of the polydatin reaches up to 156.68, the lesion score reduction rate can reach 67.65%, and the anti-insect effect of the polydatin is remarkably superior to that of a conventional anti-insect drug. The prophylactic administration of the polydatin can effectively treat the chicken coccidiosis caused by the eimeria tenella infection.

Description

Technical Field

[0001] The present invention belongs to the technical field of medicine, and particularly relates to the application of polydatin in anti-Eimeria tenella. Background Art

[0002] Chicken coccidiosis is a parasitic protozoal disease that seriously endangers the intestinal health of chickens. This disease is caused by the infection of one or more Eimeria species, which can cause intestinal lesions, resulting in chicken death or losses such as poor digestion and absorption, diarrhea, dehydration, emaciation, and low feed conversion rate. There are 7 species of chicken coccidia, including Eimeria tenella, E. necatrix, E. brunetti, E. acervulina, E. maxima, E. mitis, and E. praecox. Eimeria tenella is one of the most severely harmful and widely prevalent species. Currently, the prevention and control of chicken coccidiosis still rely on the use of anticoccidial drugs. However, with the increasing severity of the drug resistance problem of chicken coccidia, the efficacy of most original anticoccidial drugs has significantly declined. Chicken coccidiosis has become one of the more difficult-to-control parasitic diseases that damage the intestinal tract of poultry. There is an urgent need for new anticoccidial drugs in production practice.

[0003] Inosine monophosphate dehydrogenase (IMPDH) is considered one of the drug targets of Eimeria tenella and is involved in the purine biosynthesis of chicken coccidia. IMPDH can catalyze the conversion of inosine monophosphate (IMP) to xanthosine monophosphate (XMP), and then synthesize guanine nucleotides. The reaction catalyzed by IMPDH is the first key and rate-limiting step in the de novo biosynthesis of guanine nucleotides. IMPDH is a regulator of the intracellular guanine nucleotide pool and is very important for the synthesis of DNA and RNA, signal transduction, energy transfer, glycoprotein synthesis, and other processes involved in cell proliferation in the parasite. Therefore, screening for new inhibitors of EtIMPDH through high-throughput screening methods provides new ideas for the development of new anticoccidial drugs. Summary of the Invention

[0004] The purpose of the first aspect of the present invention is to provide the application of polydatin or its pharmaceutically acceptable salt in anti-chicken coccidia.

[0005] The purpose of the second aspect of the present invention is to provide the application of polydatin or its pharmaceutically acceptable salt in inhibiting the activity of inosine monophosphate dehydrogenase.

[0006] The purpose of the third aspect of the present invention is to provide a method for inhibiting the development and reproduction of chicken coccidia.

[0007] The object of the fourth aspect of the present invention is to provide a method for inhibiting the activity of inosine monophosphate dehydrogenase.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] The first aspect of the present invention provides the use of polydatin or a pharmaceutically acceptable salt thereof in any one of (1) to (3);

[0010] (1) Against chicken coccidia;

[0011] (2) Preparing a product against chicken coccidia;

[0012] (3) Preparing a product for treating and / or preventing diseases caused by chicken coccidia infection.

[0013] In some embodiments of the present invention, the chicken coccidia include at least one of Eimeria tenella, Eimeria necatrix, Eimeria brunetti, Eimeria acervulina, Eimeria maxima, Eimeria mitis and Eimeria praecox.

[0014] In some embodiments of the present invention, the chicken coccidia is Eimeria tenella.

[0015] In some embodiments of the present invention, the polydatin or a pharmaceutically acceptable salt thereof inhibits the development and reproduction of chicken coccidia.

[0016] In some embodiments of the present invention, the disease in (3) includes chicken coccidiosis.

[0017] In some embodiments of the present invention, the disease includes intestinal lesions caused by chicken coccidia infection.

[0018] In some embodiments of the present invention, the pharmaceutically acceptable salt includes at least one of metal salts, ammonium salts, salts formed with inorganic acids, salts formed with organic bases, salts formed with organic acids, salts formed with basic amino acids, and salts formed with acidic amino acids.

[0019] In some embodiments of the present invention, the metal salt includes alkali metal salts and alkaline earth metal salts.

[0020] In some embodiments of the present invention, the alkali metal salt includes at least one of sodium salt and potassium salt.

[0021] In some embodiments of the present invention, the alkaline earth metal salt includes at least one of calcium salt, magnesium salt, barium salt and aluminum salt.

[0022] In some embodiments of the present invention, the salts formed with organic bases include salts formed with at least one of the following organic bases: trimethylamine, triethylamine, pyridine, methylpyridine, 2,6-dimethylpyridine, ethanolamine, diethanolamine, triethanolamine, cyclohexylamine, dicyclohexylamine, N,N'-dibenzylethylenediamine.

[0023] In some embodiments of the present invention, the salts formed with inorganic acids include salts formed with at least one of the following inorganic acids: hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid.

[0024] In some embodiments of the present invention, the salts formed with organic acids include salts formed with at least one of the following organic acids: formic acid, acetic acid, trifluoroacetic acid, phthalic acid, fumaric acid, oxalic acid, tartaric acid, maleic acid, citric acid, succinic acid, malic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid.

[0025] In some embodiments of the present invention, the salts formed with basic amino acids include salts formed with at least one of the following basic amino acids: arginine, lysine, ornithine.

[0026] In some embodiments of the present invention, the salts formed with acidic amino acids include salts formed with at least one of the following acidic amino acids: aspartic acid, glutamic acid.

[0027] In some embodiments of the present invention, the products described in (2)-(3) include at least one of reagents, drugs, and feed additives.

[0028] In some embodiments of the present invention, the drug or feed additive further includes pharmaceutically acceptable excipients.

[0029] In some embodiments of the present invention, the pharmaceutically acceptable excipients include at least one of solvents, propellants, solubilizers, cosolvents, emulsifiers, colorants, binders, disintegrants, fillers, lubricants, wetting agents, osmotic pressure regulators, stabilizers, glidants, flavoring agents, preservatives, suspending agents, coating materials, fragrances, antiadhesives, chelating agents, penetration enhancers, pH regulators, buffers, plasticizers, surfactants, foaming agents, defoaming agents, thickeners, clathrates, humectants, absorbents, diluents, flocculants and deflocculants, filter aids, release retardants, carriers.

[0030] In some embodiments of the present invention, the effective dose of polydatin or its pharmaceutically acceptable salt for anti-coccidiosis in chickens or for treating and / or preventing diseases caused by chicken coccidiosis infection is 100-500 mg / kg; further preferably 100-300 mg / kg.

[0031] The second aspect of the present invention provides the use of polydatin or a pharmaceutically acceptable salt thereof in (4) or (5);

[0032] (4) inhibiting the activity of inosine monophosphate dehydrogenase;

[0033] (5) preparing an inosine monophosphate dehydrogenase inhibitor.

[0034] In some embodiments of the present invention, the inosine monophosphate dehydrogenase includes Eimeria tenella inosine monophosphate dehydrogenase.

[0035] In some embodiments of the present invention, the nucleotide sequence of the inosine monophosphate dehydrogenase is as shown in SEQ ID NO:1, and the amino acid sequence is as shown in SEQ ID NO:2.

[0036] In some embodiments of the present invention, the effective dose of polydatin or a pharmaceutically acceptable salt thereof for inhibiting inosine monophosphate dehydrogenase is 10 - 1000 μM.

[0037] In some embodiments of the present invention, the pharmaceutically acceptable salt includes at least one of metal salts, ammonium salts, salts formed with inorganic acids, salts formed with organic bases, salts formed with organic acids, salts formed with basic amino acids, and salts formed with acidic amino acids.

[0038] The third aspect of the present invention provides a method for inhibiting the development and reproduction of chicken coccidia, comprising the step of treating chicken coccidia with polydatin or a pharmaceutically acceptable salt thereof.

[0039] In some embodiments of the present invention, the effective dose for treatment with polydatin or a pharmaceutically acceptable salt thereof is 10 - 1000 μM.

[0040] In some embodiments of the present invention, the pharmaceutically acceptable salt includes at least one of metal salts, ammonium salts, salts formed with inorganic acids, salts formed with organic bases, salts formed with organic acids, salts formed with basic amino acids, and salts formed with acidic amino acids.

[0041] In some embodiments of the present invention, the chicken coccidia include at least one of Eimeria tenella, Eimeria necatrix, Eimeria brunetti, Eimeria acervulina, Eimeria maxima, Eimeria mitis, and Eimeria praecox; further preferably Eimeria tenella.

[0042] The fourth aspect of the present invention provides a method for inhibiting the activity of inosine monophosphate dehydrogenase, comprising the step of treating inosine monophosphate dehydrogenase with polydatin or a pharmaceutically acceptable salt thereof.

[0043] In some embodiments of the present invention, the effective dose of the treatment with polydatin or its pharmaceutically acceptable salt is 10-1000 μM.

[0044] In some embodiments of the present invention, the pharmaceutically acceptable salts include at least one of metal salts, ammonium salts, salts formed with inorganic acids, salts formed with organic bases, salts formed with organic acids, salts formed with basic amino acids, and salts formed with acidic amino acids.

[0045] The beneficial effects of the present invention are as follows:

[0046] The present invention discloses a new application of polydatin or its pharmaceutically acceptable salt in the treatment of chicken coccidiosis (such as Eimeria tenella infection). While expanding the development and application of polydatin, it also promotes the development and utilization of new anti-coccidial drugs. The present invention has conducted cell-level tests and animal tests on the anti-Eimeria tenella infection effect of polydatin. The results show that polydatin has a significant effect on inhibiting Eimeria tenella, with an anti-parasite index as high as 156.68 and a lesion score reduction rate of up to 67.65%. The anti-parasite effect is significantly better than that of conventional anti-parasite drugs, indicating that prophylactic administration of polydatin can effectively treat chicken coccidiosis caused by Eimeria tenella infection.

[0047] The present invention discloses that polydatin or its pharmaceutically acceptable salt can be used as an inhibitor of inosine monophosphate dehydrogenase, and can inhibit the development and reproduction of chicken coccidia by inhibiting the activity of inosine monophosphate dehydrogenase. Description of the Drawings

[0048] Figure 1 For the cloning of the EtIMPDH gene.

[0049] Figure 2 For the purification of the rEtIMPDH protein.

[0050] Figure 3 For the structure of the rEtIMPDH protein.

[0051] Figure 4 For the standard curve of autofluorescent NADH detected by fluorescence method.

[0052] Figure 5 For the in vitro inhibitory effect of the test compound on Eimeria tenella. Detailed Description of the Invention

[0053] The following further elaborates on the content of the present invention through specific examples.

[0054] It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention.

[0055] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Those not specified in the embodiments are carried out under conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not indicated with the manufacturer are all conventional products that can be obtained by purchasing in the market.

[0056] Compound T3427, namely polydatin, has a molecular formula of C 20 H 22 O8, with a CAS number of 27208-80-6 and a structural formula of

[0057] The features and properties of the present invention will be further described in detail below in conjunction with the embodiments.

[0058] Example 1 High-throughput screening for inhibitors targeting EtIMPDH

[0059] (1) Expression of EtIMPDH protein

[0060] The CDS sequence of the inosine monophosphate dehydrogenase gene of Eimeria tenella (Eimeria tenella IMPDH, EtIMPDH) is shown as SEQ ID NO:1 below, and the encoded amino acid sequence is shown as SEQ ID NO:2.

[0061]

[0062] MADGWDAEKVFNSTVYGFTYDDLILMPGHIGFSIDSVDLSTKLTRGITLRLPLVSSPMDTVTEHRMAIGVALMGGIGIIHNNMEISQQVQQVRKTKRFENGFITEPFVLKPTDTVYDVDCIKKKYGYSSVPITSTGTLGGKLVGIVTSRDIDFITDRHTQLNEVMTTDLIVGHEPLNLTQANEIMRKSKKGKLPIVNANFELVALVSRNDLKKNREYPLASKDNNKQLLVGAALSTRAADLERAKALLQVGADVLVVDSSQGDSVFQVDIVKQLKSAYPNTQIIGGNVVTARQAKSLIDAGVDALRIGMGSGSICTTQVVCAVGRAQATAVYHVSKYAREVANIPCIADGGIQNSGHVVKALALGASTVMVGSLLAATEEAPGAYYFHNGARVKSYRGMGSIEAMRAASGGGGAQQPQGDGSSTPKAAAPYGSAARYFAEGQNVRVAQGVTGCLVDKGSIRNLIPYVMQGVKHGLQDAGVSTIQELHEKLYSGQVRFDVRSAAAQREGNVHNLTVFEGGASKS(SEQ ID NO:2).

[0063] 1) Construction of recombinant expression plasmid

[0064] Total RNA of sporulated oocysts of Eimeria tenella Guangdong strain was extracted by using the TRIzol method. Using the total RNA as a template, specific primers (Table 1) were designed according to SEQ ID NO:1, and the CDS sequence of EtIMPDH was amplified by RT-PCR. The PCR products were verified by 1% agarose gel electrophoresis. The PCR products were purified with a DNA gel extraction kit, the recovered PCR products were ligated with the pMD19-T vector, and then transformed into competent E. coli DH5α cells. Positive clones were identified by colony PCR( Figure 1) and the positive cloned bacteria were sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing analysis. After alignment and analysis, the CDS sequence of EtIMPDH (SEQ ID NO: 1) was obtained. The cloned EtIMPDH CDS sequence was optimized with E. coli as the host codon, and the optimization result was as shown in SEQ ID NO: 2. It was synthesized by Changzhou Jiyu Biotechnology Co., Ltd., and the pET-43.1a(+)-EtIMPDH recombinant plasmid was constructed. After sequencing verification, the pET-43.1a(+)-EtIMPDH plasmid with correct sequencing was obtained.

[0065] Table 1 PCR amplification primer pairs for the identification of positive cloned bacteria in the cloning and recombinant expression of the EtIMPDH gene

[0066]

[0067] 2) Induced expression of the recombinant expression plasmid in Escherichia coli

[0068] The pET-43.1a(+)-EtIMPDH plasmid was transformed into E. coli Rosetta(DE3) competent cells. Positive clones were identified by colony PCR (primers are shown in Table 1). The positive cloned bacteria were cultured on a large scale and induced to express overnight at 16 °C with IPTG, and the bacterial solution was collected by centrifugation. The target protein was purified by Ni 2+ column affinity chromatography, and the miscellaneous proteins were eluted with elution buffers of different concentrations of imidazole to obtain soluble rEtIMPDH soluble protein, and SDS-PAGE analysis was performed ( Figure 2 ).

[0069] (2) High-throughput screening of inhibitors targeting EtIMPDH

[0070] 1) Based on the sequence information of SEQ ID NO: 2, the structure of the EtIMPDH protein was predicted using AlphaFold 2 (as shown in Figure 3 ).

[0071] 2) Phytochemicals were screened from the TargetMol compound library; and EtIMPDH was analyzed using Pocket v3 software to establish a pharmacophore model.

[0072] 3) Virtual screening

[0073] Based on the server, batch docking of the compound library was performed using docking software such as QuickVina, iDock, Smina, AutoDock Vina, LeDock, and rDock. Compounds with high scores from each analysis software were integrated, and the binding energy ≤ -8 kcal / mol. The screened compounds were screened for drug accessibility, ADME characteristics, and druglikeness characteristics to further screen out regular small molecule compounds.

[0074] 4) Inhibitor screening results

[0075] Using the above virtual screening method, potential inhibitors were preliminarily screened out as shown in Table 2

[0076] Table 2 Screening results of potential inhibitors of EtIMPDH

[0077]

[0078] (3) Screening of inhibitors targeting EtIMPDH

[0079] Taking EtIMPDH as the target, an enzyme inhibition kinetic reaction system was used to detect the inhibitory effect of small molecule compounds (Table 2) on the enzyme activity of rEtIMPDH, and the screening of inhibitors targeting EtIMPDH was achieved. The specific process is as follows:

[0080] 1) Sample preparation

[0081] Compounds T0228, T1035, T2815, and T3427 were purchased from Shanghai TargetMol Co., Ltd.

[0082] Prepare rEtIMPDH protein according to (1). Dilute the compounds in the TargetMol compound library (10 mM) to a concentration of 1 mM with 100% DMSO, and prepare different concentration compound solutions (0, 0.1 μM, 1 μM, 10 μM, 100 μM, 1 mM) with buffer (Tris-HCl 5 mM, KCl 100 mM, β-mercaptoethanol 1 mM, pH 9).

[0083] 2) Enzyme inhibition kinetic experiment

[0084] The fluorescence method was used to detect the production of NADH products catalyzed by EtIMPDH, and a Thermo Varioskan TM LUX multi-functional microplate reader was used. The excitation wavelength for detection was 340 nm and the emission wavelength was 460 nm. The enzyme inhibition kinetic reaction system (100 μL): 60 μL Buffer (Tris-HCl 5 mM, KCl 100 mM and β-mercaptoethanol 1 mM, pH 9), 10 μL IMP (100 mM), 10 μL NAD + (100 mM), 10 μL rEtIMPDH (100 mM), and 10 μL of different concentration test compounds. The reaction temperature was 37 °C, and the RFU values of NADH in each group were monitored for 60 min. Calculate the inhibition rate of different concentration test compounds, and then use the inhibition rate as the dependent variable and the sample concentration as the independent variable. According to the regression equation ( Figure 4 ) calculate the sample concentration IC at which the inhibition rate is 50% 50Inhibition rate = (1 - V0 of the test compound group ÷ rEtIMPDH control group V0) × 100%.

[0085] The IC 50 values of each test compound are shown in Table 3. T2815 and T3427 have better inhibitory effects on EtIMPDH.

[0086] Table 3 IC 50 values of different compounds on EtIMPDH

[0087]

[0088] Example 2

[0089] Based on the MDBK cell culture model of Eimeria tenella, evaluate the effects of each test compound (T0228, T1035, T2815, T3427) on the development and reproduction of Eimeria tenella at the cellular level to clarify the inhibitory effects of the screened compounds on Eimeria tenella.

[0090] (1) Sample preparation

[0091] Compounds T0228, T1035, T2815, and T3427 were purchased from Shanghai TargetMol Biotechnology Co., Ltd., sulfachloropyrazine sodium was purchased from Beijing Puxitang Biotechnology Co., Ltd., and MDBK cells were preserved by the Institute of Animal Health, Guangdong Academy of Agricultural Sciences.

[0092] (2) Determine the effect on coccidia at the cellular level

[0093] Establish a fluorescence quantitative method using the conserved gene (actin) of coccidia to detect the content of coccidia in different treatment groups, representing the effects on the development and reproduction of coccidia under different drug concentration treatments, as follows:

[0094] Evaluate the anti-coccidial effect using the E. tenella MDBK cell culture model. First, digest MDBK cells that have grown to a confluence state of over 80% with 0.25% trypsin digestion solution, and plate them in a 12-well cell culture plate at a cell concentration of 4×10 5 cells / well, and culture them in an incubator at 37°C with 5% CO2 for 24 h. When the cells in the 12-well culture plate grow to a confluence state of 80% or more, inoculate 10×10 4Subsporozoites / mL. After 4 h, the medium was discarded, washed 3 times with PBS to wash away the suspended subsporozoites, and 2 mL of fresh medium was added. 20 μL of different test compounds (1 mM) were added to the detection wells, with 3 replicates set, and a blank control (1% DMSO solvent control) and a positive control (sulfachloropyrazine sodium drug control) were also set. It was continued to be cultured in an incubator at 37 °C with 5% CO2. After culturing for 48 h, the medium was discarded, washed 3 times with PBS, and the total RNA of the samples in each well was extracted. RT-PCR was used to detect the effects of each test compound on the development and reproduction of coccidia. The Real-time PCR primers are shown in Table 4. The effects of each test drug on the growth and development of coccidia at the cell culture level were calculated by the ΔΔC T method, and the ΔCT = C T [Et actin] - C T [H actin] of the test compound group and the control group were obtained through Real-time RT-PCR, ΔΔC T = ΔC T [exp] - ΔC T [ref], ΔC T [exp] = C T [Et actin] in the test drug group - C T [H actin] in the test drug group, ΔC T [ref] = C T [Et actin] in the control group infected with coccidian subsporozoites without adding drugs - C T [Hactin] in the control group infected with coccidian subsporozoites without adding drugs. Finally, the anti-coccidial effect of the drug to be screened was obtained,

[0095] Table 4 PCR amplification primer pairs of actin genes of Eimeria tenella and MBDK cells

[0096]

[0097] The inhibition rates of each test compound on Eimeria tenella under cell culture conditions at a concentration of 10 μM are shown in Table 5 and Figure 5 , among which, the inhibition rate of T3427 is relatively high.

[0098] Based on the inhibitory effects of each compound on EtIMPDH and on Eimeria tenella, T3427 was finally selected for further verification.

[0099] Table 5 Inhibition rates of test compounds on Eimeria tenella

[0100]

[0101] Example 3

[0102] Taking the infection of slow-growing large broilers with Eimeria tenella GD strain as a model, the prophylactic treatment effect of T3427 on the infection of Eimeria tenella GD strain was evaluated.

[0103] 1. Sample preparation

[0104] Compound T3427 was purchased from Shanghai Jizhi Biochemical Technology Co., Ltd., sulfachloropyrazine sodium was purchased from Beijing Pusitang Biotechnology Co., Ltd., slow-growing large broilers were purchased from Guangdong Zhiwei Agricultural Technology Co., Ltd., and feed without coccidiostat was purchased from Guangzhou Jiangfeng Industrial Co., Ltd.

[0105] 2. Experimental grouping

[0106] The slow-growing large broilers were raised to 12 days old and randomly divided into 6 groups with 20 chickens in each group. Groups G1 - G3 were the groups infected with Eimeria tenella after administration of T3427, group G4 was the group infected with Eimeria tenella after administration of the control drug (sulfachloropyrazine sodium), and in addition, a control group G5 infected with Eimeria tenella without drug administration and a control group G6 not infected with Eimeria tenella without drug administration were set up. Each drug experimental group started drug administration at 12 days old. In groups G1 - G4, drug administration was carried out by mixing with feed, and the control drug sulfachloropyrazine sodium was mixed with feed at 600 ppm. Each drug experimental group and the group infected with Eimeria tenella without drug administration were orally inoculated with 1.0×10 4 sporulated oocysts of Eimeria tenella per chicken on the 14th day. All experimental chickens in each group were allowed to eat and drink freely until the end of the experiment on the 7th day after infection. Information such as grouping, drug administration dose, and method is shown in Table 6.

[0107] Table 6 Experimental design and grouping

[0108]

[0109] 3. Evaluation indicators

[0110] 3.1 Production performance

[0111] The mental state and survival of chickens during the experimental period were observed, and the weight gain was statistically analyzed.

[0112] 3.2 Fecal score

[0113] Observe the feces 5 days after infection. Refer to the method in "Morehouse NF, Baron RR. Coccidiosis: evaluation of coccidiostats by mortality, weight gains, and fecal scores. Exp Parasitol. 1970, 28(1): 25-29." and score the feces according to the following criteria: 0, normal feces; 1, small amount of bloody feces; 2, moderate amount of bloody feces; 3, a lot of bloody feces; 4, no normal feces. Evaluate the drug effect by the ratio of the average fecal score of the drug-administered infected group to that of the non-drug-administered infected group.

[0114] Evaluation criteria: Fecal score ratio ≥ 50%, partial anticoccidial effect of the drug; fecal score ratio < 50%, the drug is effective.

[0115] 3.3 Anticoccidial index (ACI)

[0116] ACI calculation formula: ACI = (survival rate + relative weight gain rate) - (average lesion score × 10 + oocyst count per million × 0.4)

[0117] Evaluation criteria: ACI is the main indicator to evaluate the coccidial resistance ability of each drug. ACI < 120, the anticoccidial effect is not achieved; 120 ≤ ACI < 160, moderate anticoccidial effect; ACI ≥ 160, good anticoccidial effect.

[0118] Survival rate = (number of surviving chickens in the experimental group at the end of the experiment ÷ number of chickens in the experimental group) × 100%.

[0119] Relative weight gain rate = (average weight gain of the experimental group ÷ average weight gain of the non-drug-administered and non-infected control group) × 100%.

[0120] The average intestinal lesion score is based on the method in "Johnson J, Reid WM. Anticoccidial drugs: lesion scoring techniques in battery and floor-pen experiments with chickens. Exp Parasitol. 1970, 28(1): 30-36.", and the oocyst count is the total oocyst production from the 6th to 7th day after infection.

[0121] 3.4 Reduction rate of lesion score (RLS)

[0122] RLS calculation formula: RLS = (average lesion score of the non-drug-administered infected control group - average lesion score of the drug-administered infected group) ÷ average lesion score of the non-drug-administered infected control group × 100%.

[0123] Evaluation criteria: If RLS ≥ 50%, the drug is effective; if RLS ≤ 49, the drug has partial anticoccidial effect.

[0124] 4. Test results

[0125] Animal test results showed that prophylactic administration of high-dose (300 ppm) T3427 by mixing it into the feed could significantly reduce intestinal lesions caused by coccidia infection. The reduction rate of lesion score (RLS) was 67.65%, and no bloody stool was observed. The ACI value reached 156.68. For the control group of sulfachloropyrazine sodium, the reduction rate of lesion score (RLS) was 41.18%, bloody stool was observed, and the ACI value was 145.52 (Table 7). Thus, prophylactic administration of T3427 can effectively treat chicken coccidiosis caused by Eimeria tenella infection.

[0126] In summary, the compound T3427 in the present invention has the potential for application in coccidiosis treatment drugs, with extremely high economic value and medical value.

[0127] Table 7 Therapeutic effect of T3427 on Eimeria tenella GD strain infection

[0128]

[0129] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art to which the present invention pertains, various changes can be made without departing from the gist of the present invention. In addition, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

Claims

1. The use of polydatin or a pharmaceutically acceptable salt thereof in any one of (1) to (3); (1) Against chicken coccidia; (2) Preparing a product against chicken coccidia; (3) Preparing a product for treating and / or preventing diseases caused by chicken coccidia infection.

2. The application according to claim 1, characterized in that, The chicken coccidia includes at least one of Eimeria tenella, Eimeria necatrix, Eimeria brunetti, Eimeria acervulina, Eimeria maxima, Eimeria mitis and Eimeria praecox.

3. The application according to claim 1, characterized in that The polydatin or a pharmaceutically acceptable salt thereof inhibits the development and reproduction of chicken coccidia.

4. The application according to any one of claims 1 to 3, characterized in that, The diseases described in (3) include chicken coccidiosis; Preferably, the diseases include intestinal lesions caused by chicken coccidia infection.

5. The application according to any one of claims 1 to 3, characterized in that, The pharmaceutically acceptable salt includes at least one of metal salts, ammonium salts, salts formed with inorganic acids, salts formed with organic bases, salts formed with organic acids, salts formed with basic amino acids, and salts formed with acidic amino acids.

6. The application according to claim 5, wherein The products described in (2) to (3) include at least one of reagents, drugs, and feed additives.

7. The use of polydatin or a pharmaceutically acceptable salt thereof in (4) or (5); (4) Inhibiting the activity of inosine monophosphate dehydrogenase; (5) Preparing an inosine monophosphate dehydrogenase inhibitor.

8. The application according to claim 7, wherein The pharmaceutically acceptable salt includes at least one of metal salts, ammonium salts, salts formed with inorganic acids, salts formed with organic bases, salts formed with organic acids, salts formed with basic amino acids, and salts formed with acidic amino acids.

9. A method for inhibiting the development and reproduction of chicken coccidia, comprising the step of treating chicken coccidia with polydatin or a pharmaceutically acceptable salt thereof.

10. A method for inhibiting the activity of inosine monophosphate dehydrogenase, comprising the step of treating inosine monophosphate dehydrogenase with polydatin or a pharmaceutically acceptable salt thereof.

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