Application of beta-nicotinamide mononucleotide in prevention and treatment of liver injury caused by aflatoxin B1

Abstract

The invention relates to an application of beta-nicotinamide mononucleotide (NMN) in prevention and treatment of liver injury caused by aflatoxin B1 (AFB1), the NMN has a good protection effect on the liver injury caused by exposure of the AFB1, and particularly, the serum transaminase activity and liver tissue pathological injury of a mouse using an NMN + AFB1 group are improved compared with those of a mouse in the AFB1 group, and the NMN has a good protection effect on the liver injury caused by exposure of the AFB1 group. Namely, the NMN has a certain protection effect on the mouse liver injury induced by exposure of the AFB1; the content of IL-6, IL-1beta and TNF-alpha in the liver of a mouse in an AFB1 group is remarkably increased, and the expression of IL-6, IL-1beta and TNF-alpha in the liver of the mouse infected with AFB1 is remarkably reduced by the NMN, namely, the NMN relieves the inflammatory response induced by the AFB1. The NMN can effectively relieve the development of mouse AFB1 subchronic poisoning and gradually recover the mouse AFB1 subchronic poisoning to a normal level, so that a new clue and an experimental basis are provided for research and development of an additive or a medicine for resisting AFB1 poisoning.

Description

Technical Field

[0001] The present invention relates to the field of biomedicine technology, in particular to the field of application technology of β-nicotinamide mononucleotide, and specifically to the application of β-nicotinamide mononucleotide in preventing and treating liver damage caused by aflatoxin B1. Background Art

[0002] Aflatoxin is a toxic secondary metabolite produced by Aspergillus flavus and Aspergillus parasiticus. It is widely found in cereal crops such as corn, wheat and barley and their by-products. It is classified as a human Class I carcinogen by the International Agency for Research on Cancer (IARC). Aflatoxin B1 (AFB1) is the most toxic and difficult to decompose aflatoxin. It is seriously polluted in the hot and humid southern regions of China, posing a serious threat to human and animal health.

[0003] Aflatoxin B1 is a primary carcinogenic fungal toxin. It is very easy to contaminate food crops such as peanuts and corn, or contaminate animal feed raw materials in a hot and humid environment. It is the primary detection indicator for food and feed safety inspections. When animals ingest contaminated feed with AFB1 content exceeding the standard limit, subchronic poisoning often occurs, resulting in decreased production performance and economic losses. Therefore, it is necessary to develop an effective, non-toxic feed additive to prevent and protect animals from subchronic or chronic AFB1 poisoning.

[0004] β-Nicotinamide mononucleotide (NMN), as one of the precursors of nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+), is widely involved in various biochemical reactions in organisms and is a nucleotide with important biological activity in the body. NAD+ is a key regulatory factor in the process of cell growth and differentiation, and plays an important role in DNA damage repair, cell apoptosis, cell autophagy, epigenetic modification, cell aging, etc. NMN can be directly converted to generate NAD+ and is the most efficient precursor for generating NAD+. Many studies have found that supplementing NAD+ produced by NMN in the body can prevent, treat and repair heart and brain damage, metabolic diseases, aging and related degenerative diseases. As an essential cofactor, NMN plays a key role in a variety of physiological metabolic processes and is a potential active substance for anti-aging, improving degenerative diseases and metabolic diseases.

[0005] Compared with the above studies, there are few studies on NAD+ and mycotoxin poisoning, and the protective mechanism of NMN against liver damage in AFB1-exposed mice is still unclear. Summary of the invention

[0006] In order to overcome at least one problem existing in the prior art, the present invention provides a NAD+ precursor compound β-nicotinamide mononucleotide (NMN) for use in preventing aflatoxin B1 (AFB1) poisoning. The present invention establishes a mouse model of aflatoxin B1 poisoning and verifies that NMN can effectively prevent liver damage and liver inflammation caused by aflatoxin B1 poisoning through long-term or acute NMN intervention.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention is to provide the use of β-nicotinamide mononucleotide in the preparation of a drug for preventing and / or treating subchronic or chronic poisoning by aflatoxin B1, or in the preparation of a drug for preventing and / or treating liver damage caused by aflatoxin B1.

[0009] Furthermore, the medicine includes a livestock medicinal preparation with β-nicotinamide mononucleotide as the main active ingredient.

[0010] Furthermore, the livestock medicinal preparations include solid preparations and liquid preparations.

[0011] Furthermore, the livestock pharmaceutical preparation is a liquid preparation, which is prepared by dissolving β-nicotinamide mononucleotide in double distilled water to obtain a solution with a concentration of 30 to 100 mg / mL; preferably, a solution with a concentration of 60 mg / mL is prepared.

[0012] Furthermore, the drug is a drug that alleviates liver tissue pathological changes, liver function abnormalities, and liver inflammation.

[0013] Furthermore, the pathological changes in liver tissue include: disordered liver tissue structure, bile duct hyperplasia, vacuolar degeneration of cells, reduced or dissolved nuclei, and unclear cell boundaries; the abnormal liver function includes: increased activity of biochemical indicators ALT, AST, and ALP in serum; the liver inflammation includes: increased expression of inflammatory factors IL-6, IL-1β, and TNF-α in the liver.

[0014] Furthermore, when the administration subject is a mouse, the administration dose of β-nicotinamide mononucleotide is 250-400 mg / kg / d, preferably 300 mg / kg / d. It is understood that the administration dose of β-nicotinamide mononucleotide can be adaptively adjusted according to different administration subjects.

[0015] The second aspect of the present invention is to provide the use of β-nicotinamide mononucleotide in the preparation of a feed additive for resisting subchronic or chronic poisoning by aflatoxin B1, or in the preparation of a feed additive for alleviating liver damage caused by aflatoxin B1.

[0016] The third aspect of the present invention is to provide a drug or feed additive for resisting subchronic or chronic poisoning of aflatoxin B1, or alleviating liver damage caused by aflatoxin B1. The drug is for poultry and livestock, and the drug or feed additive contains β-nicotinamide mononucleotide.

[0017] The third aspect of the present invention is to provide a feed for livestock, which contains a basic feed and the feed additive as described in the third aspect.

[0018] Furthermore, the feed additive can be a powder that is stored in a dark place. When used, the feed additive is directly mixed with the basic feed in a dark place.

[0019] Furthermore, the basic feed can be directly obtained from the market, or can be prepared by oneself.

[0020] Compared with the prior art, the present invention adopts the above technical solution to have the following beneficial effects:

[0021] The present invention first discovered that β-nicotinamide mononucleotide (NMN) has a good protective effect on liver damage caused by aflatoxin B1 (AFB1) exposure, specifically: mice exposed to AFB1 for 14 consecutive days had dull fur and low activity. Histopathological examination found that liver tissue damage changed significantly, liver tissue structure was disordered, cells showed vacuolar degeneration, and cell boundaries were unclear. The serum transaminase activity and liver tissue pathological damage of mice in the NMN+AFB1 group were improved compared with those in the AFB1 group. Therefore, NMN has a certain protective effect on liver damage induced by AFB1 exposure in mice. The contents of IL-6, IL-1β and TNF-α in the liver of mice in the AFB1 group were significantly increased, while NMN significantly reduced the expression of IL-6, IL-1β and TNF-α in the liver of AFB1-infected mice, so NMN alleviated the inflammatory response induced by AFB1. The above experimental results show that NMN can effectively alleviate the development of subchronic poisoning of AFB1 in mice and gradually restore it to normal levels, which provides new clues and experimental basis for the development of additives or drugs against AFB1 poisoning. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of the pathological histological changes in the liver of mice in which NMN was used to intervene in AFB1 poisoning mice in one embodiment of the present invention (HE staining, scale bar: 50 μm);

[0024] Figure 2This is a schematic diagram of using NMN to intervene in the changes in liver function levels of AFB1-poisoned mice in one embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the changes in expression of mouse liver verification factors in AFB1-poisoned mice using NMN intervention in one embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work belong to the scope of protection of the present invention. The experimental methods without specific conditions in the following embodiments are usually measured according to national standards. The experimental materials without the source indicated in the following embodiments are all commercially available raw materials. The equipment used in each step in the following embodiments is conventional equipment. If there is no corresponding national standard, it is carried out according to the general international standards, conventional conditions, or according to the conditions recommended by the manufacturer. Unless otherwise specified, all parts are weight parts and all percentages are mass percentages. Unless otherwise defined or specified, all professional and scientific terms used in the present invention have the same meaning as those familiar to those skilled in the art. In addition, any method and material similar or equal to the recorded content can be applied to the method of the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention is further described below in conjunction with the drawings and specific embodiments, but is not intended to be a limitation of the present invention.

[0028] The present invention is exemplified below.

[0029] Example 1 - Construction of AFB1 poisoning mouse model and drug intervention treatment

[0030] In this example, a mouse model of aflatoxin B1 (AFB1) poisoning was constructed, and β-nicotinamide mononucleotide (NMN) was used to intervene in the treatment of AFB1 poisoning mice. The specific steps include:

[0031] (1) Preparation of experimental drugs;

[0032] NMN (purchased from Hubei Jianchu Biotechnology Co., Ltd.): Accurately weigh 0.6 g of NMN, add 10 mL of double distilled water, stir to dissolve and prepare an NMN solution with a concentration of 60 mg / mL and a working solution concentration of 300 mg / kg / d.

[0033] AFB1 (purchased from Sigma, USA): The intragastric dose of AFB1 group mice was 0.75 mg / kg BWAFB1. Preparation method: AFB1 powder was first dissolved in DMSO to prepare a 25 mg / mL stock solution, and then diluted with corn oil to a 0.15 mg / mL working solution for intragastric administration.

[0034] (2) Construction of animal models and drug intervention;

[0035] The experiment was conducted using 7-week-old C57BL / 6 male mice without specific pathogens purchased from Jiangsu Jicui Pharmaceutical Biotechnology Co., Ltd. The entire experimental process was carried out at the Experimental Animal Center of Nanjing Agricultural University. The mice were first adaptively raised under suitable temperature and humidity conditions for 7 days. After the adaptive feeding, the mice were separated into cages to ensure that the error between each cage was minimized. After separation, ear tags were made to record the corresponding weight changes. The mice were randomly divided into three groups, including a blank control group (CON group), aflatoxin B1 group (AFB1 group), and aflatoxin B1 and β-nicotinamide mononucleotide co-treatment group (AFB1+NMN group). The mice in the CON group were gavaged with an equal amount of normal saline every day; the mice in the AFB1 group were gavaged with 0.75 mg / kg B.W.AFB1 every day according to their body weight; the mice in the AFB1+NMN group were gavaged with 0.75 mg / kg BWAFB1 every day according to their body weight, and 300 mg / kg BWNMN every day according to their body weight. The entire experiment lasted for 14 days. After the experimental period, mice in each group were fasted for 12 h, blood was collected from the retro-orbital vein, and the mice were killed to collect liver tissue for subsequent experiments.

[0036] The liver is the largest solid organ in the animal body. It has important functions of metabolism and detoxification and is the primary detoxification organ for exogenous toxic substances. AFB1 sub-toxic liver histopathological changes, blood biochemical indicators, liver function enzyme activity, and liver inflammatory factor expression can all be used as indicators for evaluating animal liver toxicity. Under normal physiological conditions, the activities of ALT, AST, and ALP in the body's blood are stable at a low level; when liver cells are damaged, liver cell enzymes will be released into the blood in large quantities, so the activities of ALT, AST, and ALP in the serum increase. The liver is an important detoxification organ for removing exogenous toxic substances from the body. After AFB1 enters the body, it activates various signaling pathways, releases a variety of cytokines to cause inflammatory reactions, and induces cell apoptosis and necrosis. Therefore, in the subsequent embodiments, the application effect of NMN was verified from the aspects of mouse liver pathological histological changes, mouse blood biochemical indicators, and liver inflammatory factor expression.

[0037] Example 2-Effect of NMN on AFB1 exposure-induced liver pathological changes in mice

[0038] This example uses hematoxylin-eosin (H&E) staining of liver tissue to verify the pathological histological changes of AFB1-induced liver in mice induced by NMN intervention, which specifically includes the following steps:

[0039] (1) First, fix the liver tissue. Take a 0.5 cm × 0.5 cm piece of liver and place it in a 4% paraformaldehyde solution to prevent it from sticking to the wall. Suspend it in the solution and fix it for 24 hours before dehydration.

[0040] (2) Dehydration and wax immersion. Remove the tissue from the fixative and trim the target area with a scalpel in a fume hood. Place the trimmed tissue and the corresponding label in a dehydration box and then in a dehydrator. The dehydration process is as follows: dehydration with 75% ethanol for 4 h, dehydration with 85% ethanol for 2 h, dehydration with 90% ethanol for 2 h, dehydration with 95% ethanol for 1 h, dehydration with 100% ethanol for 30 min, twice, benzene for 5-10 min, xylene for 5-10 min, twice, and finally melt the paraffin at 65°C for 1 h three times.

[0041] (3) Embedding: Place the melted wax into the embedding frame, remove the dehydrated tissue before the wax completely solidifies, and place it into the embedding frame according to the cross section and the corresponding mouse number. Place the embedding frame on a -20°C platform to cool and solidify, and remove the wax block after it is completely solidified.

[0042] (4) Start slicing. Place the wax block in a paraffin slicer and slice it into 4 μm thick slices. After slicing, the sliced ​​tissue will float in warm water. Use a glass slide to pick it up flat and place it in an oven for baking. After the water and wax are dried, take it out and place it at room temperature.

[0043] (5) Dehydrate and stain the sections. First, place the sections in xylene for 20 minutes, twice. Then, take them out and place them in anhydrous ethanol for 5 minutes, twice. Then, place them in 75% ethanol for 5 minutes. Finally, wash off the excess ethanol with tap water. After dehydration, staining begins. Place the sections in hematoxylin stain for 3 to 5 minutes, rinse with tap water, differentiate with differentiation solution, add blueing solution after rinsing with tap water, and finally rinse the sections with running water. Then, place the sections in 85% and 95% ethanol for gradient dehydration. After dehydration, place them in eosin stain for 5 minutes for staining.

[0044] (6) Finally, the sections were sealed by placing them in anhydrous ethanol for 5 min three times, then taken out and placed in xylene for 5 min twice. After becoming transparent, they were sealed with neutral gum and observed under an ordinary optical microscope.

[0045] The above HE staining results are as follows Figure 1As shown, the liver lobules of mice in the CON group were complete and clear in morphology, the liver cell cords were arranged radially, the cell morphology did not change significantly, the liver cell nucleus was in the center of the cell, the nucleolus was clear, the cytoplasm was full, the arrangement was tight, and the boundaries were clear; the liver tissue structure of mice in the AFB1 group was disordered, there was bile duct hyperplasia, the cells showed vacuolar degeneration, the nucleus was reduced or dissolved, and the cell boundaries were unclear; the pathological changes of the liver tissue of mice in the AFB1+NMN group were alleviated, there was still a small amount of inflammatory cell infiltration, the cells were arranged more neatly, and the degeneration and necrosis were reduced. The above experimental results show that NMN can significantly alleviate the damage of AFB1 to liver tissue cells.

[0046] Example 3-Effects of NMN on blood biochemical indices of mice induced by AFB1 exposure

[0047] In this example, the blood biochemical indexes of mice induced by AFB1 exposure after NMN intervention were measured. The serum collected when the mice were killed was used to measure the ALT, AST and ALP levels in the serum according to the instructions of the instructions. The experimental kits were purchased from Nanjing Jiancheng Bioengineering Research Institute Co., Ltd. (Jiangsu, China). The specific description is briefly described as follows:

[0048] (1) The measurement instructions of ALT and AST are shown in Table 1:

[0049] Table 1 - ALT and AST determination steps

[0050]

[0051] (2) The determination of ALP is shown in Table 2:

[0052] Table 2 - ALP determination steps

[0053]

[0054] When damage occurs in mice, it will cause abnormal increase or decrease in biochemical indicators in serum. Figure 2 As shown in the figure, the serum ALT, AST, and ALP activities of mice in the AFB1 group were significantly higher than those in the blank control group, while the serum ALT, AST, and ALP activities of mice in the AB1+NMN group were significantly lower than those in the AFB1 group. The above experimental results show that NMN can effectively alleviate the abnormal liver function caused by AFB1.

[0055] Example 4-Effect of NMN on the expression of inflammatory factors in mouse liver induced by AFB1 exposure

[0056] This example uses real-time fluorescence quantitative PCR (qRT-PCR) to detect the expression level of inflammatory factors in the liver of mice induced by AFB1 exposure after NMN intervention, which specifically includes the following steps:

[0057] (1) Extraction of total RNA from tissues;

[0058] ① Grinding: Precool the rotor in the tissue grinder to -20℃ in advance, take out the liver tissue from the -80℃ refrigerator, wash it in physiological saline, remove the intestinal contents and absorb the excess water on filter paper, cut a part with scissors and weigh it on an electronic balance, about 20mg ileum tissue is enough, put the tissue in a 2mL centrifuge tube, mark the corresponding number with a marker, and after all the weighing is completed, enter the clean bench for extraction, add 3 RNase-free zirconium oxide grinding beads with a diameter of 3mm and 500μL pre-cooled Trizol, cover the tube cap, place the centrifuge tube symmetrically in the tissue homogenizer, close the lid, select the program and start grinding.

[0059] ② Extraction: After grinding, add 100 μL of pre-cooled chloroform into the centrifuge tube, vortex it on a vortexer for 15 seconds, and then place it in a high-speed centrifuge and centrifuge it at 4°C and 12,000 r / min for 15 minutes.

[0060] ③Precipitation: After centrifugation, use a pipette to draw 200 μL of supernatant into a sterile enzyme-free tube, add 200 μL of pre-cooled isopropanol, turn it upside down until the oil disappears, and let it stand at room temperature for 10 minutes for precipitation. After the end, place the centrifuge tube in a high-speed centrifuge and centrifuge it at 4°C and 12000r / min for 10 minutes.

[0061] ④ Washing: Take out the centrifuge tube and discard the supernatant. The white flake substance at the bottom of the tube is RNA. Add 1 mL of pre-cooled 75% ethanol and centrifuge in a high-speed centrifuge at 4°C, 7500 r / min for 7-8 minutes. Discard the supernatant and add 1 mL of pre-cooled 75% ethanol and centrifuge for 3 minutes.

[0062] ⑤Dissolution: Discard the supernatant, wipe off the excess ethanol in the tube with laboratory paper, dry it naturally until there is no water, and then add 100μL of DEPC water to dissolve it.

[0063] ⑥ Concentration measurement: First, mix the extracted RNA thoroughly and centrifuge it, turn on the Nanodrop 2000 instrument, add 1 μL of double distilled water to zero it, and then start measuring the concentration after zeroing to ensure that the sample purity A260 / 280 is within the range of 1.8 to 2.0 before use.

[0064] ⑦ After the measurement, place it in a -80℃ refrigerator to prevent repeated freezing and thawing.

[0065] (2) Reverse transcription;

[0066] Take the successfully extracted RNA and perform reverse transcription according to the Evo M-MLV reverse transcription premix kit of Hunan Aikerui Biotechnology Co., Ltd. to reverse transcribe the RNA into cDNA. Follow the instructions as shown in Table 3 below.

[0067] Table 3-20μL inversion system

[0068]

[0069]

[0070] The required volume of RNA needs to be calculated according to its concentration. Add it in sequence according to the above instructions, vortex to mix and centrifuge. Place the centrifuge tube in an ordinary PCR instrument, cover it with a lid, and set the program, which includes three stages. The first stage is 37°C, 15 minutes; the second stage is 85°C, 5 seconds; and the third stage is 4°C, +∞.

[0071] (3) Fluorescence quantitative PCR;

[0072] 1) Design and synthesize primers;

[0073] According to the required target gene, its sequence was queried on the NCBI website, and the primer specificity was verified by Primer blast. The delivered primer sequence was synthesized by Shanghai Sangon Biotechnology Co., Ltd. The sequences used are shown in Table 1.

[0074] Table 1 - Primer sequences for fluorescent quantitative PCR

[0075]

[0076] 2) Fluorescence quantitative PCR;

[0077] The cDNA that has been reverse transcribed was taken and fluorescent quantitative PCR was performed using the SYBR Green ProTaq HS Premix Kit of Hunan Aikerui Biotechnology Co., Ltd. According to the instructions as shown in Table 2 below, the sample was loaded on ice.

[0078] Table 2-qRT-PCR reaction system

[0079]

[0080] Add the above reagents to the 8-tube PCR tube, centrifuge it with a handheld centrifuge, mix it well, put it into the fluorescent quantitative PCR instrument, and set the program according to the instructions: 95℃, 30s; 95℃, 10s, 40 cycles; 60℃, 30s, 40 cycles; 95℃, 15s; 60℃, 60s; 95℃, 15s. After the experiment, record the CT value, use GAPDH as the housekeeping gene, and use 2 -ΔΔCtThe changes of target genes were calculated.

[0081] The results of liver histopathology showed that liver damage in AFB1-poisoned mice was accompanied by inflammatory response. Therefore, the expression levels of some inflammation-related genes (IL-6, IL-1β and TNF-α) in the liver of mice in different treatment groups were detected. The changes in the expression levels of inflammatory genes in the liver of mice in each group are shown in Figure 3 .from Figure 3 The results show that the expression of IL-6, IL-1β and TNF-α in the liver of mice in the AFB1 group was significantly higher than that in the CON group, while the expression of IL-6, IL-1β and TNF-α in the liver of mice in the AFB1+NMN group was significantly lower than that in the AFB1 group. The above experimental results show that NMN can effectively inhibit the expression of liver inflammatory genes induced by AFB1.

[0082] It can be seen from the above examples that the present invention is the first to discover that β-nicotinamide mononucleotide (NMN) has a good protective effect on liver damage caused by aflatoxin B1 (AFB1) exposure, and can effectively alleviate the development of AFB1 subchronic poisoning in mice and gradually restore it to normal levels, specifically: alleviate liver tissue pathological changes, reduce ALT, AST and ALP activities in serum, and reduce the expression of liver inflammatory factors. This provides new clues and experimental basis for the development of additives or drugs against AFB1 poisoning.

[0083] The specific embodiments of the present invention are described in detail above, but they are only examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions made to the present invention are also within the scope of the present invention. Therefore, the equalization changes and modifications made without departing from the spirit and scope of the present invention should be included in the scope of the present invention.

Claims

1. Use of β-nicotinamide mononucleotide in the preparation of a drug for preventing and / or treating subchronic or chronic poisoning by aflatoxin B1, or in the preparation of a drug for preventing and / or treating liver damage caused by aflatoxin B1.

2. The use according to claim 1, characterized in that: The medicine is a livestock medicinal preparation with beta-nicotinamide mononucleotide as the main active ingredient.

3. The use according to claim 2, characterized in that: The livestock medicinal preparations include solid preparations and liquid preparations.

4. The use according to claim 3, characterized in that: The livestock medicinal preparation is a liquid preparation, which is prepared by dissolving β-nicotinamide mononucleotide in double distilled water to obtain a solution with a concentration of 30 to 100 mg / mL.

5. The use according to claim 1, characterized in that: The medicine is a medicine for alleviating liver tissue pathological changes, liver function abnormalities, and liver inflammation.

6. The use according to claim 5, characterized in that: The pathological changes in liver tissue include: disordered liver tissue structure, bile duct hyperplasia, vacuolar degeneration of cells, reduced or dissolved nuclei, and unclear cell boundaries; the abnormal liver function includes: increased activity of biochemical indicators ALT, AST, and ALP in serum; the liver inflammation includes: increased expression of inflammatory factors IL-6, IL-1β, and TNF-α in the liver.

7. The use according to claim 1, characterized in that: When the administration subject is a mouse, the administration dose of β-nicotinamide mononucleotide is 250 to 400 mg / kg / d.

8. Use of β-nicotinamide mononucleotide in the preparation of a feed additive for resisting subchronic or chronic poisoning by aflatoxin B1, or in the preparation of a feed additive for alleviating liver damage caused by aflatoxin B1.

9. A drug or feed additive for resisting subchronic or chronic poisoning of aflatoxin B1, or alleviating liver damage caused by aflatoxin B1, characterized in that: The medicine is for poultry and livestock, and the medicine or feed additive contains β-nicotinamide mononucleotide.

10. A feed for poultry and livestock, characterized in that: The feed contains a basic feed and the feed additive according to claim 9.

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