WO2019015279A1

WO2019015279A1 - Use of sirt1 inhibitor in prevention and treatment of intestinal disease caused by radiation

Info

Publication number: WO2019015279A1
Application number: PCT/CN2018/072652
Authority: WO
Inventors: 华国强; 富国祥
Original assignee: 复旦大学
Priority date: 2017-07-20
Filing date: 2018-01-15
Publication date: 2019-01-24
Also published as: CN107362362B; CN107362362A

Abstract

Use of a SIRT1 inhibitor in the prevention and treatment of intestinal diseases caused by radiation. Specifically disclosed are use of an SIRT1 inhibitor in the preparation of a medicament, a pharmaceutical composition for preventing or treating intestinal damage caused by radiation, and a method for treating or preventing intestinal damage caused by radiation.

Description

Application of SIRT1 inhibitors in the prevention and treatment of radiation-induced intestinal diseases

Technical field

The invention belongs to the field of biomedical technology, in particular to the application of SIRT1 inhibitors in the prevention and treatment of radiation-induced intestinal diseases.

Background technique

The intestinal mucosa is highly sensitive tissue. The radiation damage of normal intestinal tissue is the biggest limiting factor for clinical abdominal tumor radiotherapy. About 50% of patients receiving radiotherapy for abdominal tumors will have secondary radiation-induced enteritis, aggravating the condition and affecting the quality of life of patients. In addition, in other extreme cases, such as nuclear leaks, nuclear terrorist attacks, and astronaut space exploration, human exposure to high doses of radiation can cause fatal intestinal necrosis. High doses of radiation inhibit the proliferation of small intestinal stem cells and cause a large number of stem cell death, leading to the destruction of most and even all crypts, the villus epithelial shedding, loss of barrier function and causing fatal intestinal damage. The main clinical manifestations are diarrhea, electrolyte imbalance, infection, septicemia, and ultimately animal death, commonly referred to as GI Syndrome.

Radiation enteritis is an intestinal tract caused by radiotherapy in pelvic, abdominal, and retroperitoneal malignancies. It can affect the small intestine, colon and rectum, respectively, of which the small intestine is the most sensitive. According to the size of the radiation dose, the length of time, and the urgency of the disease, the radiation diseases are generally classified into acute and chronic. In the early stage of intestinal mucosal epithelial cell renewal is inhibited, after the small arterial wall swelling, occlusion, causing intestinal wall ischemia, mucosal erosion. Late intestinal wall causes fibrosis, intestinal lumen is narrow or perforated, and abscesses, fistulas and intestinal adhesions form in the abdominal cavity. The high radiosensitivity of the intestine has always restricted the radiotherapy effect of abdominal tumors, and the intestinal complications caused by patients undergoing abdominal radiotherapy have reduced the quality of life of patients. Therefore, the search for an effective intestinal radiation protective agent has great clinical application value. At present, the treatment of radiation enteritis is generally treated with symptomatic treatment, which can only relieve the symptoms of the patient, but it does not effectively improve the intestinal mucosal injury. The clinical lack of effective prevention and treatment of radiation enteritis drug.

Intestinal acute radiation sickness refers to diseases caused by large doses of radiation in a single or short time (several days). According to its clinical characteristics and basic pathological changes, it is divided into three types: bone marrow type, intestinal type and brain type. Because intestinal epithelium is a radioactive tissue, intestinal radiation sickness is the leading cause of death from nuclear accidents. Intestinal acute radiation sickness is a basic disease characterized by intestinal damage, with frequent vomiting, severe diarrhea, and water-electrolyte metabolism disorder. It has severe acute radiation sickness with initial stage, pseudo-healing period and extreme three-stage course. After a large dose of radiation to the whole body or abdomen, extensive necrosis of the small intestine mucosa occurred. Nuclear wars, nuclear terrorist attacks, and nuclear accidents can cause a large number of patients with intestinal radiation sickness. In addition, considering that nuclear accidents or nuclear leaks often result in the transfer of a large number of people (usually about 24 hours), the National Nuclear Emergency Center or the hospital most hopes to develop drugs that can be administered 24 hours after radiation injury, and have therapeutic effects. However, there is currently no specific enteric radiation sickness drug, especially after 24 hours of irradiation. There are no FDA-approved drugs available for treatment. Once the animal or individual is exposed to a high dose of radiation, resulting in severe damage to the intestine, the hope of survival is almost zero. Therefore, it is a great medical prospect to fully study the radiation biology of the intestine, especially the intestinal stem cell radiation characteristics, and to develop corresponding radiation damage mitigation treatment drugs, which are urgently needed to be solved.

Summary of the invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, an object of the present invention is to propose the use of a SIRT1 inhibitor for the prevention and treatment of radiation-induced intestinal diseases. Thus, the use of SIRT1 inhibitors can effectively prevent or treat intestinal epithelial damage caused by radiation, thereby significantly improving the survival rate of animals. Therefore, the present invention can effectively solve the problem that the radiation-induced intestinal damage lacks an ideal drug and an effective treatment method.

The present invention has been completed based on the following findings:

In response to radiation-induced intestinal damage, there is currently no appropriate FDA-approved symptomatic drug, mainly assisted by supportive therapy (anti-infection, electrolyte supplementation, etc.). For example, the use of antibiotics can only treat late complications such as bacterial infection, but can not protect the intestinal epithelium, and the symptoms are not cured, and the purpose of cure cannot be achieved. The existing radiation protection agent research is mostly used for pre-irradiation administration. For example, amifostine (WR-2721) with a sulfhydryl group can eliminate the reactive oxygen radical (ROS) caused by radiation and has certain radiation protection, but There is no therapeutic effect on the damage caused by radiation, and it is often several hours since the patient was exposed to radiation and was found to be sent to treatment. Therefore, the development of drugs that can exert therapeutic effects after radiation, especially 24 hours after irradiation, is a world problem.

Intestinal epithelial cells proliferate and renew rapidly, and are completely renewed every 3-4 days, resulting in radiation sensitivity. High doses of radiation cause DNA damage in intestinal epithelial cells and stem cells at the bottom of the crypt, and further inhibition of proliferation is an initial event in the pathogenesis of radiation-induced intestinal injury. Radiation causes a large number of epithelial cell deaths, causing most and even all crypts to be destroyed, fluff covered epithelial detachment, loss of barrier function, bacteria passing through the mucosa and infecting the body to cause fatal intestinal damage. The inventors have unexpectedly found that SIRT1 inhibitors can significantly improve the survival rate of intestinal crypt stem cells after irradiation, and promote the regeneration ability of epithelial cells after irradiation, and significantly improve the survival rate of animals after irradiation.

To this end, according to one aspect of the invention, the invention proposes the use of a SIRT1 inhibitor for the preparation of a medicament for the prevention or treatment of radiation-induced intestinal damage.

Therefore, by using the SIRT1 inhibitor, radiation-induced intestinal epithelial damage can be prevented or treated, radiation-induced epithelial cell death can be reduced, survival rate of small intestinal crypt stem cells can be improved, and regeneration ability of epithelial cells after irradiation can be promoted. Significantly increase the survival rate of animals. Therefore, the use of the SIRT1 inhibitor proposed by the present invention in the preparation of a medicament can effectively solve the problem of lack of an ideal drug and an effective treatment method for intestinal radiation sickness, and has broad market application prospects.

Further, the use of the SIRT1 inhibitor according to the above embodiment of the present invention in the preparation of a medicament may further have the following additional technical features:

In some embodiments of the invention, the SIRT1 inhibitor is at least one selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin, and niacinamide. Thereby, the survival rate of the animals after irradiation can be effectively and significantly improved.

In some embodiments of the invention, the intestinal lesion is a radiation enteritis and/or an intestinal acute radiation sickness. Thereby, the probability of various intestinal complications and intestinal necrosis caused by radiation can be effectively reduced, thereby improving the survival rate of the irradiated animal.

According to a second aspect of the present invention, the present invention also provides a pharmaceutical composition for preventing or treating radiation-induced intestinal damage, the pharmaceutical composition comprising a SIRT1 inhibitor.

Thus, by using the pharmaceutical composition for preventing or treating radiation-induced intestinal damage according to the above embodiment of the present invention, it can be administered after irradiation, and can fundamentally protect and treat radiation-induced intestinal epithelial damage, Reduce radiation-induced epithelial cell death, improve survival of small intestine crypt stem cells after radiation, especially for radiation enteritis and intestinal acute radiation sickness, and further promote regeneration of epithelial cells after irradiation To improve the survival rate of animals. In addition, the pharmaceutical composition for preventing or treating radiation-induced intestinal damage of the above embodiments of the present invention is also suitable for large-scale application in a sudden nuclear accident, and has broad market application prospects.

Further, the pharmaceutical composition for preventing or treating radiation-induced intestinal damage according to the above embodiment of the present invention may further have the following additional technical features:

In some embodiments of the invention, the SIRT1 inhibitor is at least one selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin, and niacinamide. Thereby, not only can the activity of the animal after irradiation be significantly improved, but also the large-scale application of the pharmaceutical composition for preventing or treating intestinal damage caused by radiation can be realized.

In some embodiments of the invention, the intestinal lesion is radiation enteritis. Thereby, the probability of various intestinal complications and intestinal necrosis caused by radiation can be effectively reduced, thereby improving the survival rate of the irradiated animal.

In some embodiments of the invention, the pharmaceutical composition is in the form of an injection, a tablet, a capsule, an oral granule, an enemas. Thus, the pharmaceutical composition of the present invention for preventing or treating radiation-induced intestinal damage can be prepared into any pharmaceutical dosage form which is convenient for administration.

In some embodiments of the invention, the pharmaceutical composition for preventing or treating radiation-induced intestinal damage further comprises a pharmaceutically acceptable excipient selected from the group consisting of a binder, a filler, and a coating film. At least one of a polymer, a plasticizer, a glidant, a disintegrant, and a lubricant. Thus, the pharmaceutical composition of the present invention for preventing or treating radiation-induced intestinal damage can be prepared into any pharmaceutical dosage form which is convenient for administration.

According to a third aspect of the invention, the invention also provides a method of treating or preventing radiation-induced intestinal damage, according to an embodiment of the invention, the method comprising providing the animal with the pharmaceutical composition of the preceding embodiment .

Thus, by providing the animal with the pharmaceutical composition described in the preceding examples, it is possible to effectively treat intestinal damage caused by nuclear radiation, therapeutic radiation, etc., and can fundamentally protect and treat intestinal intestinal epithelial damage caused by radiation, and further Successfully protect epithelial cells, reduce epithelial cell death caused by radiation, and promote the ability of epithelial cells to regenerate after irradiation, significantly improving animal survival. Further, the method of treating or preventing radiation-induced intestinal damage according to the above embodiment of the present invention is also suitable for large-scale application in a sudden nuclear accident.

Further, the method for treating or preventing radiation-induced intestinal damage according to the above embodiment of the present invention may further have the following additional technical features:

In some embodiments of the invention, the animal is provided with the pharmaceutical composition after the animal is irradiated. Thereby, the intestinal epithelial damage caused by radiation can be fundamentally protected and treated, thereby successfully protecting the epithelial cells, reducing the epithelial cell death caused by radiation, and promoting the regeneration ability of the epithelial cells after irradiation, and significantly improving the survival rate of the animals.

DRAWINGS

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a technical roadmap for studying the anti-radiation effect of SIRT1 inhibitors at the level of organ-like organs cultured in vitro according to one embodiment of the present invention.

2 is a comparative diagram of the morphology of a treatment group treated with X-ray 6Gy after irradiation with X-ray 6Gy and treated with 10 mM of nicotinamide 24 hours after irradiation according to an embodiment of the present invention.

Fig. 3 is a graph comparing the survival rates of the treatment group administered with nicotinamide (administered 24 hours after irradiation) and the control group organs after 5 days of culture according to one embodiment of the present invention.

Figure 4 is a graph comparing the size of organs in the treatment group administered with nicotinamide for 5 days after administration (administered 24 hours after irradiation) and the control group according to one embodiment of the present invention.

Figure 5 is a graphical comparison of the morphology of a control group treated with X-ray 8Gy after irradiation with X-ray 8Gy and administered with 10 mM nicotinamide 24 hours after irradiation.

Fig. 6 is a graph showing the comparison of the survival rates of the control group (administered 24 hours after irradiation) and the control group organs after 5 days of culture according to still another embodiment of the present invention.

Fig. 7 is a graph showing the comparison of the size of organs in the treatment group administered with nicotinamide for 5 days after administration (administered 24 hours after irradiation) and the control group according to still another embodiment of the present invention.

Figure 8 is a graphical comparison of the morphology of a control group treated with X-ray 8Gy and a control group treated with EX527 at 24 hours after irradiation, in accordance with one embodiment of the present invention.

Figure 9 is a graph comparing the survival rates of the treatment group administered with EX527 (administered 24 hours after irradiation) and the control group organs after 5 days of culture according to one embodiment of the present invention.

Figure 10 is a graph comparing the survival rates of the treatment group administered with Sirtinol (administered 24 hours after irradiation) and the control group organs after 5 days of culture according to one embodiment of the present invention.

Figure 11 is a graph comparing the survival rates of the treatment group administered with Salermide (administered 24 hours after irradiation) and the control group organs after 5 days of culture according to one embodiment of the present invention.

Figure 12 is a graph comparing the survival rates of the treatment group administered with Inauhzin (administered 24 hours after irradiation) and the control group organs after 5 days of culture according to one embodiment of the present invention.

Figure 13 is a graph comparing the survival rates of the control group (administered 24 hours after irradiation) with the control group organs after 5 days of culture according to a comparative example of the present invention.

Figure 14 is a topographical comparison of the small intestine cross section of the control group and the niacinamide intraperitoneal injection group after 3.5 days of irradiation with X-rays, in accordance with one embodiment of the present invention.

Figure 15 is a graph showing the number of regenerative crypts in a control group administered with niacinamide intraperitoneally after a period of 3.5 days after X-ray irradiation and after 24 hours of irradiation according to an embodiment of the present invention.

Figure 16 is a graph showing the survival of a treated group and a control group after X-ray irradiation according to an embodiment of the present invention.

Figure 17 is a graph showing the survival of a treated group and a control group after X-ray irradiation according to still another embodiment of the present invention.

Figure 18 is a graph showing the survival rate of small intestinal organs in the control group and the treatment group after 5 days of irradiation with different doses of X-ray irradiation according to an embodiment of the present invention.

Figure 19 is a graph showing changes in acetylated P53 and total P53 at various time points after X-ray irradiation and after treatment with SIRT1 inhibitors, in accordance with one embodiment of the present invention.

Fig. 20 is a graph showing the comparison of the survival rates of small intestinal organs in the control group and the treatment group after 5 days of irradiation with different doses of X-ray irradiation according to still another embodiment of the present invention.

Figure 21 is a graph showing changes in body weight over time in control and treated groups of mice irradiated with X-rays, in accordance with one embodiment of the present invention.

Figure 22 is a graph showing changes in fecal occult blood index over time in a control group and a treatment group irradiated with X-rays according to an embodiment of the present invention.

Figure 23 is a graph comparing days of fecal occult blood index greater than 1 in a control group and a treatment group irradiated with X-rays according to an embodiment of the present invention.

Figure 24 is a graph showing changes in diarrhea index over time in a control group and a treatment group irradiated with X-rays according to an embodiment of the present invention.

Figure 25 is a graph comparing days of diarrhea index greater than 1 for a control group and a treatment group irradiated with X-rays according to an embodiment of the present invention.

Detailed description of the invention

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

According to one aspect of the invention, the invention provides the use of a SIRT1 inhibitor for the manufacture of a medicament for the prevention or treatment of radiation-induced intestinal damage.

Therefore, it can not only effectively solve the problem that intestinal radiation sickness has no ideal drug and therapeutic method, but also prevent or treat intestinal epithelial damage after radiation, reduce radiation-induced epithelial cell death, and improve intestinal crypt stem cell radiation. Survival rate, and promote the regeneration ability of epithelial cells after irradiation, significantly improve the survival rate of animals, and has broad market application prospects.

It should be noted that the term "prevention" refers to a reduction in the risk of acquiring a disease or disorder (ie, causing at least one clinical symptom of the disease to stop developing within the subject, the subject may face or predispose to face the disease) , but have not experienced or showed symptoms of the disease).

According to a particular embodiment of the invention, the SIRT1 inhibitor may be at least one selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin and niacinamide. The mammalian SIRT protein family consists of seven members and can be divided into four categories: SIRT1-3 belongs to the first category, SIRT4 belongs to the second category, SIRT5 belongs to the third category, and SIRT6/7 belongs to the fourth category, wherein SIRT1 is breast-feeding. An important amide adenine dinucleotide (NAD+)-dependent deacetylase in animals that interacts with chromatin, many important transcription factors (p53, p300, etc.) and transcriptional co-regulators, through deacetylation Regulate gene transcription, chromosomal stability and target protein activity, and then participate in a series of pathophysiological processes such as metabolism, aging, tumor development. The inventors have found that epithelial cells, as the main target of intestinal radiation damage, how to successfully protect epithelial cells, reduce epithelial cell death caused by radiation, or promote the ability of epithelial cells to regenerate after radiation is the key point and direction for the development of radiation-induced intestinal injury. When the SIRT1 inhibitor is selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin or niacinamide, it can effectively prevent or treat intestinal epithelial damage, successfully protect epithelial cells, reduce radiation-induced epithelial cell death, and promote epithelial cell radiation. The post-regeneration ability significantly increases the survival rate of the animals after irradiation. In addition, the above several SIRT1 inhibitors are small molecule compounds, which have low preparation, transportation and storage costs, are not only suitable for large-scale application in sudden nuclear accidents, but also effectively reduce the treatment cost of radiation-induced intestinal damage. .

According to a particular embodiment of the invention, the intestinal damage may be radiation enteritis and/or intestinal acute radiation sickness. Among them, radiation enteritis is an intestinal tract caused by radiotherapy in pelvic, abdominal and retroperitoneal malignant tumors. At present, radiation enteritis is generally treated with symptomatic treatment, which can only relieve the symptoms of patients, but can not fundamentally treat intestinal mucosal damage, mainly due to the lack of clinically effective drugs for the prevention and treatment of radiation enteritis. SIRT1 inhibitors have an effective preventive or therapeutic effect on radiation-induced intestinal epithelial damage, which can effectively reduce the intestinal epithelial cell death caused by radiation and promote the regeneration ability of epithelial cells after irradiation. Thus, in the present invention, by preparing a SIRT1 inhibitor into a drug, it can be effectively used for preventing or treating radiation-induced intestinal damage, and particularly has a significant therapeutic effect on various intestinal complications and intestinal necrosis caused by radiation. , thereby fundamentally improving the survival rate of animals after irradiation.

In addition, intestinal acute radiation sickness refers to a disease caused by large doses of radiation in a single or short time (several days), usually caused by a nuclear accident or a nuclear leak. Nuclear accidents or nuclear leaks often cause a large number of people to be injured. The time from radiation damage to the wounded and the treatment can be about 24 hours, so the National Nuclear Emergency Center or the hospital most hopes to develop drugs that can be given 24 hours after radiation damage. Medicine, and has a therapeutic effect. However, the use of the SIRT1 inhibitor proposed by the above embodiments of the present invention in the preparation of a medicament can be administered 24 hours after radiation injury and achieve an effective therapeutic effect, thereby effectively treating intestinal acute radiation sickness.

Thus, by using the pharmaceutical composition for preventing or treating radiation-induced intestinal damage according to the above-described embodiments of the present invention, it is possible to administer after irradiation, and to fundamentally protect and treat radiation-induced intestinal epithelial damage, thereby reducing Radiation-induced epithelial cell death, increased survival of small intestine crypt stem cells, especially for radiation enteritis and intestinal acute radiation sickness, and promotes regeneration of epithelial cells after radiation, significantly improving animals Survival rate. In addition, the pharmaceutical composition for preventing or treating radiation-induced intestinal damage of the above embodiments of the present invention is also suitable for large-scale application in a sudden nuclear accident, and has broad market application prospects.

According to a particular embodiment of the invention, the SIRT1 inhibitor may be at least one selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin and niacinamide. The inventors have found that epithelial cells, as the main target of intestinal radiation damage, how to successfully protect epithelial cells, reduce epithelial cell death caused by radiation, or promote the ability of epithelial cells to regenerate after radiation is the key point and direction for the development of radiation-induced intestinal injury. When the SIRT1 inhibitor is selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin or niacinamide, it can effectively prevent or treat intestinal epithelial damage, successfully protect epithelial cells, reduce radiation-induced epithelial cell death, and promote epithelial cell radiation. The post-regeneration ability significantly increases the survival rate of the animals after irradiation. In addition, the above several SIRT1 inhibitors are small molecule compounds, which have low preparation, transportation and storage costs, are not only suitable for large-scale application in sudden nuclear accidents, but also effectively reduce the treatment cost of radiation-induced intestinal damage. .

According to a specific embodiment of the present invention, the intestinal epithelial cells can be used as a target, and the intestinal stem cell culture technique can be fully utilized to study the anti-radiation of the SIRT1 inhibitors salermide, Sirtinol, EX527, Inauhzin or nicotinamide at the level of in vitro cultured organs. effect. Specifically, as shown in Figure 1, the small intestine crypt can be isolated from the mouse, planted in Matrigel plus conditioned medium, and inoculated 24 hours later with x-ray (RAD-320 X-ray machine (PXI, USA). At different doses (6Gy or 8Gy), various SIRT1 inhibitors (nicotinamide, EX527, Sirtinol, Salermide, Inauhzin) were added 24 hours after irradiation. After 5 days of culture, the survival rate and size difference of the treated group and the control group were observed. The optimal concentration of SIRT1 inhibitors effective in vitro was further validated and subsequently verified in vivo on mice.

According to a particular embodiment of the invention, the intestinal damage can be radiation enteritis. At present, radiation enteritis is generally treated with symptomatic treatment, which can only alleviate the symptoms of patients, but it does not effectively improve intestinal mucosal damage. There is still no effective prevention and treatment of radiation enteritis in clinical practice. SIRT1 inhibitors can effectively prevent or treat intestinal epithelial damage, reduce radiation-induced epithelial cell death, and promote the ability of epithelial cells to regenerate after irradiation. Thus, in the present invention, by using a SIRT1 inhibitor for the preparation of a medicament for preventing or treating intestinal damage caused by radiation, the incidence of various intestinal complications and intestinal necrosis due to radiation can be effectively reduced, thereby improving The survival rate of animals after irradiation.

According to a particular embodiment of the invention, the pharmaceutical composition may be in the form of an injection, a tablet, a capsule, an oral granule, or an enema. Thus, the pharmaceutical composition of the present invention for preventing or treating radiation-induced intestinal damage can be prepared into any pharmaceutical dosage form which is convenient for administration.

According to a specific embodiment of the present invention, the pharmaceutical composition for preventing or treating radiation-induced intestinal damage may further comprise a pharmaceutically acceptable excipient selected from the group consisting of a binder, a filler, and a film-coated polymer. At least one of a plasticizer, a glidant, a disintegrant, and a lubricant. Thus, the pharmaceutical composition of the present invention for preventing or treating radiation-induced intestinal damage can be prepared into any pharmaceutical dosage form which is convenient for administration.

According to a third aspect of the present invention, the present invention also provides a method for treating or preventing radiation-induced intestinal damage using the pharmaceutical composition for preventing or treating radiation-induced intestinal damage according to the above embodiment of the present invention. .

Therefore, it is possible to effectively treat intestinal damage caused by nuclear radiation, therapeutic radiation, etc., and to fundamentally protect and treat intestinal epithelial damage caused by radiation, thereby successfully protecting epithelial cells and reducing epithelial cell death caused by radiation. It also promotes the regeneration ability of epithelial cells after irradiation, and significantly improves the survival rate of animals. Further, the method of treating or preventing radiation-induced intestinal damage according to the above embodiment of the present invention is also suitable for large-scale application in a sudden nuclear accident.

According to a particular embodiment of the invention, the pharmaceutical composition provided to the animal after the animal has been irradiated. Thereby, the intestinal epithelial damage caused by radiation can be fundamentally protected and treated, thereby successfully protecting the epithelial cells, reducing the epithelial cell death caused by radiation, and promoting the regeneration ability of the epithelial cells after irradiation, and significantly improving the survival rate of the animals.

Example 1

(1) To study the protective effects of different doses of nicotinamide on intestinal damage caused by X-ray 6Gy irradiation:

The small intestine crypts were isolated from 8-12 weeks old C57BL mice, planted in Matrigel and conditioned medium, inoculated for 24 hours, and five groups of small intestine organs were taken and set as blank control group (no irradiation) and model control group. The administration group was administered 24 hours before, the administration group was administered 1 hour after the irradiation, and the administration group was administered 24 hours after the irradiation. X-ray 6Gy was used to irradiate the model control group, the 24-hour administration group, the 1-hour administration group, and the 24-hour administration group 24 hours after administration, and the model control group was not administered. In the first 24 hours, the administration group was administered with 10 mM of nicotinamide before the irradiation, and the administration group was administered 1 hour after the administration, and the administration group was administered with 10 mM of nicotinamide at 1 hour and 24 hours after the irradiation, respectively. The above five groups were cultured for 5 days, and the administration group (administered group 24 hours before administration, 1 hour after administration, and administered 24 hours after irradiation) and the control group (blank control group, model control group) were observed. Survival rate.

RESULTS: Figure 2 shows the topographical images of the blank control group (no irradiation), the model control group, and the 24 hour post-administration group under the microscope. Fig. 3 shows the survival rate of intestinal organs in the model control group, the administration group 24 hours before the irradiation, the administration group 1 hour after the irradiation, and the administration group 24 hours after the irradiation. Figure 4 shows the size of viable organs in the model control group and the 24 hour post-administration group. In Fig. 3, the survival rate of the administration group was 31.28±2.85% 24 hours before irradiation, the survival rate of the administration group was 38.42±5.04% at 1 hour after irradiation, and the survival rate of the administration group was 63.27±2.25% at 24 hours after irradiation. The survival rate of the model control group was 52.27±1.75%. (Mean±SD) In Figure 4, the size of the surviving organs in the drug-administered group was 3.81±1.23×10 ⁴ pixels at 24 hours after irradiation. 2.34 ± 1.10 × 10 ⁴ pixels, expressed as area under a 200X microscope; Mean ± SD, p < 0.0001).

Conclusion: The survival rate of the drug-administered group at 24 hours before irradiation and 1 hour after irradiation was lower than that of the model control group, indicating that radiation sensitization occurred in the administration 24 hours before irradiation and 1 hour after irradiation. The rate was lower than that of the unadministered model control group. The radiation protection effect is obvious only when administered 24 hours after irradiation. Therefore, the inventors have found that the administration time significantly affects the radiation protection effect, and it is found by the above-mentioned several administration time points that administration is the optimum administration time point 24 hours after the irradiation.

(2) Enhance the irradiation to X-ray 8Gy, and give 10 mM nicotinamide to the intestinal tract injury 24 hours after the optimal administration time point:

The small intestine crypts were isolated from 8-12 weeks old C57BL mice, planted in Matrigel and conditioned medium, inoculated for 24 hours, and two groups of small intestine organs were taken and set as model control group and 24 hours after administration. . The small intestine organs of the model control group and the 24-hour administration group were irradiated with X-ray 8Gy. Among them, the model control group was not administered, and the administration group received 10 mM of nicotinamide 24 hours after the irradiation. The organ size and survival rate of the model control group and the 24-hour administration group were observed after the above two groups were cultured for 5 days.

RESULTS: X-rays were cultured for 5 days after 8 Gy irradiation. The morphology of the small intestine organs in the model control group and the 24-hour administration group was as shown in Fig. 5; the model control group and the 24-hour administration group. The survival rate of intestinal organs was as shown in Fig. 6. The survival rate of the administration group was 19.65±2.67% after 24 hours, and the survival rate of the model control group was 3.46±0.74% (Mean±SD, p<0.0001). The size of the small intestine organ in the model control group and the 24-hour administration group is shown in Fig. 7. The size of the viable organ in the administration group was 1.64 ± 0.57 × 10 ⁴ pixels 24 hours after the irradiation, and the model control group survived the organ. The size was 0.90 ± 0.57 × 10 ⁴ pixels, expressed as area under a 200X microscope; Mean ± SD, p < 0.0001.

Conclusion: It can be seen from the results of the above two studies, Fig. 2 and Fig. 5, that the small intestine organ injury is severe after X-ray irradiation, and the small intestine organ injury in the administration group administered with nicotinamide 24 hours after irradiation is more serious. light. It can be seen from Fig. 3 and Fig. 6 that after the X-ray irradiation for 24 hours, the SIRT1 inhibitor nicotinamide was added, and the survival rate of the small intestine organs was significantly better than that of the model control group. As can be seen from Fig. 4 and Fig. 7, after the X-ray irradiation for 24 hours, the area of the small intestine organ administered to the nicotinamide-treated administration group was relatively large relative to the model control group. In summary, it is indicated that the small intestine organ is treated with the SIRT1 inhibitor nicotinamide after 24 hours of irradiation, and has a therapeutic effect on the intestinal organ damage of the mouse.

In addition, by studying the protective effects of administration of nicotinamide at different times on intestinal damage caused by X-ray 6Gy irradiation, it was found that the survival rate of the small intestinal organs administered 24 hours after irradiation was significantly higher than that of the administration 24 hours before the irradiation and 1 hour after the irradiation. Administration (associated with the previous administration time data (Fig. 3). Further, the treatment mode of administration 24 hours after the irradiation was verified, and by irradiation, X-ray 8 Gy was used, and 10 mM of nicotinamide was administered 24 hours after the irradiation. The protective effect on intestinal damage was observed. The survival rate (19.65±2.67%) was significantly higher than that of the model control group (3.46±0.74%). It can be determined that the optimal administration time should be 24 after irradiation. Dosage in hours.

Example 2

Study the protective effect of EX527 on radiation-induced intestinal damage:

The small intestine crypts were isolated from 8-12 weeks old C57BL mice, planted in Matrigel and conditioned medium, and inoculated for 24 hours to take three groups of small intestine organs, which were set as model control group and given to the nicotinamide group 24 hours after irradiation. The EX527 group was given 24 hours after the photo. X-ray (RAD-320 X-ray machine (PXI, USA) 8Gy pair model control group, 24 hours after irradiation to the nicotinamide group, and 24 hours after irradiation to the EX527 group three groups of small intestine organs were irradiated, of which model control The group was not administered, and the nicotinamide group was administered with 10 mM of nicotinamide 24 hours after irradiation, and the EX527 group was given EX527 (100 μM) 24 hours after the irradiation 24 hours after the irradiation. The above three groups were cultured for 5 days respectively. The differences in organ survival rate and size between the drug-administered group (to the niacinamide group at 24 hours after irradiation and the EX527 group at 24 hours after irradiation) and the model control group were observed.

Results: Figure 8 shows a topographical view of the model control group and the 24 hour post-administration group under the microscope. Figure 9 shows the survival rate of the small intestine organs in the model control group, the 24-hour nicotinamide group, and the EX527 group 24 hours after the irradiation.

The morphology of the treatment group treated with EX527 (100 μM) 24 hours after irradiation with X-ray 8 Gy was as shown in Fig. 8 . After 5 days of culture, the survival rate of the organs treated with EX527 and the control group 24 hours after irradiation was as shown in Fig. 9. The survival rate of the treatment group treated with EX527 24 hours after irradiation was 19.32±1.67%. The survival rate of the group was 19.65±2.67%, and the survival rate of the control group was 6.81±0.33% (Mean±SD, EX527vs control p<0.0001).

Conclusion: It can be seen from Fig. 8 that after X-ray irradiation, the small intestine organ injury is severe, and the small bowel organ injury in the treatment group treated with EX527 24 hours after irradiation is effectively recovered. As can be seen from Fig. 9, after 24 hours of X-ray 8Gy irradiation, the survival rate of the organs treated with EX527 was significantly higher than that of the control group, and the effect was equivalent to that of niacinamide (10 mM). In summary, it is indicated that the small intestine organ is treated with the SIRT1 inhibitor EX527 after 24 hours of irradiation, and has a therapeutic effect on the intestinal organ damage of the mouse.

Example 3

To study the protective effect of Sirtinol on radiation-induced intestinal damage:

The small intestine crypts were isolated from 8-12 weeks old C57BL mice, planted in Matrigel and conditioned medium, inoculated for 24 hours, and five groups of small intestine organs were taken and designated as model control group, and Sirtinol was given 24 hours after irradiation. The group of 10 μM) was given to the Sirtinol (50 μM) group 24 hours after the irradiation, the Sirtinol (100 μM) group was administered 24 hours after the irradiation, and the nicotinamide (10 mM) was administered 24 hours after the irradiation. After irradiation with x-ray (RAD-320 X-ray machine (PXI, USA) 8Gy, different concentrations of SIRT1 inhibitor Sirtinol (10μM, 50μM, 100μM) were added 24 hours after irradiation, and DMSO control and nicotinamide control were set up. The difference in survival rate between the treated group and the control group was observed after 5 days.

RESULTS: Figure 10 shows the model control group, the Sirtinol (10 μM) group 24 hours after the irradiation, the Sirtinol (50 μM) group 24 hours after the irradiation, the Sirtinol (100 μM) group 24 hours after the irradiation, and the administration of the tobacco 24 hours after the irradiation. Small intestinal organ survival rate of amide (10 mM).

Among them, after 5 days of culture, the survival rate of the organ treated with Sirtinol and the control group 24 hours after the irradiation was as shown in Fig. 10, and the survival rate of the treatment group treated with Sirtinol (100 μM) 24 hours after the irradiation was 10.52 ± 0.88. %, the survival rate of the niacinamide group was 21.92±0.72%, and the survival rate of the control group was 4.00±0.70% (Mean±SD, Sirtinol vs control p<0.001).

Conclusion: After 24 hours of X-ray 8Gy irradiation, the survival rate of the organs in the control group treated with Sirtinol was significantly higher than that in the control group, indicating that the small intestines were treated with the SIRT1 inhibitor Sirtinol after 24 hours of irradiation. Organ damage has a therapeutic effect.

Example 4

Study the protective effect of Salermide on radiation-induced intestinal damage:

The small intestine crypts were isolated from 8-12 weeks old C57BL mice, planted in Matrigel and conditioned medium, inoculated for 24 hours, and five groups of small intestine organs were taken and designated as model control group, and Salequide was given 24 hours after irradiation. The group of 10 μM) was given to the Salermide (50 μM) group 24 hours after the irradiation, the Salermide (100 μM) group was administered 24 hours after the irradiation, and the nicotinamide (10 mM) was administered 24 hours after the irradiation. After irradiation with x-ray (RAD-320 X-ray machine (PXI, USA) 8 Gy, different concentrations of SIRT1 inhibitor Salermide (10 μM, 50 μM, 100 μM) were added 24 hours after irradiation, and DMSO control and nicotinamide control were set up. The difference in survival rate between the treated group and the control group was observed after 5 days.

RESULTS: Figure 11 shows the model control group, the Salermide (10 μM) group 24 hours after the irradiation, the Salermide (50 μM) group 24 hours after the irradiation, the Salermide (100 μM) group 24 hours after the irradiation, and the administration of the tobacco 24 hours after the irradiation. Small intestinal organ survival rate of amide (10 mM).

Among them, after 5 days of culture, the survival rate of the treatment group treated with Salermide and the control group 24 hours after the irradiation was as shown in Fig. 11, and the survival rate of the treatment group treated with Salermide (100 μM) 24 hours after the irradiation was 23.77 ± 0.80. %, the survival rate of the nicotinamide (10 mM) group was 21.92 ± 0.72%, and the survival rate of the control group was 4.00 ± 0.70% (Mean ± SD, Salermide vs control p < 0.001).

Conclusion: After 24 hours of X-ray 8Gy irradiation, the treatment group treated with Salermide (100μM) showed a significant increase in the survival rate of the organs compared with the control group, and the effect was equivalent to nicotinamide (10 mM), indicating that the small intestine organs were given after 24 hours of irradiation. Treatment with the SIRT1 inhibitor Salermide has a therapeutic effect on intestinal organ damage in mice.

Example 5

To study the protective effect of Inauhzin on radiation-induced intestinal damage:

The small intestine crypts were isolated from 8-12 weeks old C57BL mice, planted in Matrigel and conditioned medium, inoculated for 24 hours, and three groups of small intestine organs were taken and set as model control group, and niacinamide was given 24 hours after irradiation. The group was given to the Inauhzin group 24 hours after the photo. X-ray (RAD-320 X-ray machine (PXI, USA) 8Gy pair model control group, 24 hours after irradiation to the niacinamide group, and 24 hours after irradiation to the Inauhzin group, three groups of small intestine organs were irradiated, of which model control The group was not administered, and the niacinamide group was administered with 10 mM of nicotinamide 24 hours after the irradiation, and the Inauhzin group was administered to Inauhzin (10 μM) 24 hours after the irradiation 24 hours after the irradiation. The above three groups were cultured for 5 days, respectively. The difference in organ viability between the drug-administered group (administered to the niacinamide group 24 hours after irradiation and the Inauhzin group 24 hours after irradiation) and the model control group was observed.

Results: Figure 12 shows the survival rate of the small intestine organs in the model control group, the 24-hour nicotinamide group, and the Inauhzin (10 μM) group 24 hours after the irradiation.

Among them, after 5 days of culture, the survival rate of the treatment group treated with Inauhzin (10 μM) and the control group 24 hours after the irradiation was as shown in Fig. 12, and the survival rate of the treatment group treated with Inauhzin (10 μM) 24 hours after the irradiation. 13.50 ± 0.59%, the survival rate of the nicotinamide group was 17.40 ± 0.50%, and the survival rate of the control group was 1.60 ± 0.26% (Mean ± SD, Inauhzin vs control p < 0.001).

Conclusion: After 24 hours of X-ray 8Gy irradiation, the survival rate of the organs in the treatment group treated with Inauhzin was significantly higher than that in the control group, indicating that the small intestines were treated with SIRT1 inhibitor Inauhzin after 24 hours of irradiation. Organ damage has a therapeutic effect.

Comparative example 1

To study the protective effects of SIRT2 inhibitors (Splitomicin, Thiomyristoyl, SirReal2, AGK2) on radiation-induced intestinal damage:

The small intestine crypts were isolated from 8-12 weeks old C57BL mice, planted in Matrigel plus conditioned medium, and inoculated 24 hours after x-ray (RAD-320 X-ray machine (PXI, USA) 8 Gy, after irradiation 24 Different concentrations of SIRT2 inhibitors Splitoticin ((10μM, 50μM, 100μM), Thiomyristoyl (100nM, 1μM, 10μM), SirReal2 (200nM, 1μM, 10μM), AGK2 (5μM, 10μM, 50μM) were added in the hour, and DMSO control was added. And nicotinamide control. After 5 days of culture, the survival rate and size difference of the treated group and the control group were observed.

Results: Figure 13 shows the model control group and the 24 hour post-administration group: Splitinicin ((10 μM, 50 μM, 100 μM), Thiomyristoyl (100 nM, 1 μM, 10 μM), SirReal 2 (200 nM, 1 μM, 10 μM), AGK2 ( 5μM, 10μM, 50μM) intestinal organ survival rate.

Among them, after 5 days of culture, the survival rate of the treatment group treated with the SIRT2 inhibitor (Splitomicin, Thiomyristoyl, SirReal 2, AGK2) and the control group 24 hours after the irradiation was as shown in Fig. 13, and 24 times after the irradiation, Splitomicin (100 μM) was administered. The survival rate of treatment was 3.57±0.73%, the survival rate of treatment with Thiomyristoyl (10 μM) was 6.30±0.53%, the survival rate treated with SirReal2 (10 μM) was 4.69±0.40%, and the survival rate of treatment with AGK2 (50 μM). It is 3.12±0.80%.

CONCLUSIONS: After 24 hours of X-ray 8Gy irradiation, the survival rate of SIRT2 inhibitors (Splitomicin, Thiomyristoyl, SirReal2, AGK2) was higher than that of the control group.

Example 6

Study the effect of nicotinamide on the regeneration of crypts:

Twelve C57BL/6 mice, aged 8-12 weeks, were given 14Gy abdominal X-rays. After irradiation, the mice were randomly divided into two groups: control group and treatment group, with 6 rats in each group. In the treatment group, mice in the treatment group were given intraperitoneal injection of nicotinamide (1000 mg/Kg) 24 hours after irradiation, and the control group was intraperitoneally injected with the corresponding solvent PBS. The mice were sacrificed for 3.5 days, and the small intestine was taken for pathological section HE staining to observe the number of regenerating crypts in the small intestine.

RESULTS: Figure 14 shows a comparison of the morphology of the small intestine cross section under microscope for 3.5 days after irradiation in the model control group and the treatment group. Figure 15 shows the comparison of the number of regenerative crypts in the model control group and the treatment group after 3.5 days of irradiation.

Among them, after 14 days of 14Gy abdominal X-ray irradiation, the morphology of the small intestine cross section under the microscope in the control group and the treatment group is shown in Fig. 14. The number of mouse crypts in the control group and the treatment group is shown in Fig. 15. The number of mouse crypts was 25.59±11.31, and the number of mouse crypts in the control group was 11.36±6.71 (Mean±SD, p<0.0001).

From Fig. 14 and Fig. 15, the following conclusions can be drawn: after treatment with nicotinamide (1000 mg/Kg) 24 hours after irradiation, the number of crypts in the mice was significantly higher than that in the control group, indicating that nicotinamide treatment was given after X-ray irradiation. Can promote crypt regeneration.

Example 7

To study the effect of nicotinamide on improving the survival rate of mice after irradiation:

(1) Animal experiment, 32 C57BL/6 mice of 8-12 weeks old were given 14Gy abdominal X-ray irradiation. After irradiation, the mice were randomly divided into two groups: control group and treatment group, with 16 rats in each group. The mice in the treatment group were given intraperitoneal injection of nicotinamide (1000 mg/Kg) 24 hours after the irradiation, and the control group was intraperitoneally injected with the corresponding solvent PBS. Observe the survival situation.

RESULTS AND CONCLUSION: Figure 16 shows the difference in survival rate between the model control group and the treatment group (single dose). The survival of the treated group and the control group after X-ray irradiation is shown in Fig. 16. The results showed that 15 mice in the irradiation control group died in 5-9 days, and only 1 mouse survived. Seven mice in the treatment group died in 5-9 days, and 9 mice survived. The survival rates of the treatment group and the control group were 56.25% and 6.25%, respectively.

(2) Twelve C57BL/6 mice, aged 8-12 weeks, were given 15Gy abdominal X-rays. After irradiation, the mice were randomly divided into two groups: control group and treatment group, with 6 rats in each group. The treatment group received intraperitoneal injection of nicotinamide (1000 mg/Kg) in the treatment group 24 hours and 72 hours after irradiation. The control group was given intraperitoneal injection of the corresponding solvent PBS. Observe the survival situation.

RESULTS AND CONCLUSION: Figure 17 shows the difference in survival rate between the model control group and the treatment group (two doses) after irradiation. The survival of the treated group and the control group after X-ray irradiation is shown in Fig. 17. The results showed that the control mice died in 5-9 days; only 2 mice died in the treatment group, and the remaining 4 mice survived for more than 90 days. The survival rates of the treatment group and the control group were 66.67% and 0, respectively.

In summary, it can be concluded that the administration of nicotinamide to mice after 24 hours of X-ray irradiation can significantly improve the survival rate of mice. After X-ray irradiation for 24 hours, the administration of nicotinamide for 72 hours after X-ray irradiation can further improve the survival rate of the mice.

Example 8

To study whether the target of nicotinamide is SIRT1:

The small intestine crypts were isolated from 5 weeks old C57BL SIRT1 knockout homozygous mice, planted in Matrigel plus conditioned medium, inoculated for 24 hours, and 10 groups of small intestine organs were taken and set as blank control group (no irradiation), 4 Group model control group, blank drug administration group (no irradiation) and group 4 group 24 hours after administration group, 4 groups of model control groups were irradiated with X-rays to 2Gy, 4Gy, 6Gy, 8Gy, respectively. PBS solution (10 mM) was added to the blank control group (no irradiation) and the four model control groups; the four groups were irradiated with X-rays to 2Gy, 4Gy, 6Gy, and 8Gy 24 hours after irradiation, respectively. Nicotinamide (10 mM) was added to the blank administration group (no irradiation) and the 24 hour administration group after 4 groups. After the drug treatment for 24 hours, the fresh medium was changed. After 5 days of culture, the blank control group (no irradiation), the blank administration group (no irradiation), the 4 model control group, and the 4 groups of the 24 hours after administration were observed. Rate difference.

RESULTS: After 5 days of X-ray irradiation, the survival rates of small intestinal organs in the blank control group (no irradiation), model control group, blank administration group (no irradiation) and 24 hours after irradiation were as follows. 18, wherein, after 5 days of culture, the survival rate of the small intestine organs in the blank control group (no irradiation), X-rays irradiated with 2Gy, 4Gy, 6Gy, 8Gy was: 99.03±0.33%, 87.88± 1.06%, 68.34±2.19%, 23.26±2.47%, 1.65±0.42%, small intestines in the blank administration group (no irradiation) and 24 hours after irradiation with X-rays to 2Gy, 4Gy, 6Gy, and 8Gy The organ survival rates were 99.16±0.40%, 86.83±1.31%, 66.25±2.59%, 26.35±2.52%, 3.05±0.70% (Mean±SD, p>0.05 for each dose group).

Conclusion: SIRT1 knockout homozygous mice have no protective effect on nicotinamide administered 24 hours after irradiation with different X-ray doses, indicating that nicotinamide exerts intestinal protection through SIRT1, ie the target of nicotinamide is SIRT1. .

Example 9

To investigate whether SIRT1 inhibitors regulate P53 acetylation by inhibiting SIRT1 activity:

The small intestine crypt was isolated from 8 weeks old C57BL mice, and conditioned medium was added to Matrigel. After 8 days of inoculation, 9 groups of small intestine crypts were taken and set as blank control group (no irradiation) and blank nicotinamide administration group. (No irradiation), 5 sets of X-ray 6Gy irradiation group, 24 hours after X-ray 6Gy irradiation, nicotinamide administration group, and EX527 administration group 24 hours after X-ray 6Gy irradiation. Intestinal crypt cell protein at 2 hours, 6 hours, 12 hours, 24 hours, and 30 hours after X-ray 6Gy irradiation, and blank control group (no irradiation) and blank niacinamide administration group after 6 hours of administration (no irradiation) Intestinal crypt cell protein of the IM527 administration group (i.e., 30 hours after irradiation) 24 hours after the X-ray 6Gy irradiation, the nicotinamide administration group (i.e., 30 hours after the irradiation) and the X-ray 6Gy irradiation 24 hours. The collected 9 groups of proteins were subjected to Western blot analysis to detect the amount of acetylated P53 (379 lysine) and total P53.

RESULTS: Changes in acetylated P53 and total P53 at different time points after irradiation and after treatment with SIRT1 inhibitor are shown in FIG.

Conclusion: Administration of SIRT1 inhibitors such as nicotinamide and EX527 after 24 hours of intestinal crypt exposure can increase P53 acetylation, ie, SIRT1 inhibitors regulate P53 acetylation by inhibiting SIRT1 activity.

Example 10

To investigate whether nicotinamide regulates P53 acetylation by inhibiting SIRT1 activity, thereby regulating the survival of intestinal epithelial organ radiation:

The small intestine crypt was isolated from 8 weeks old C57BL P53 knockout homozygous mice, planted in Matrigel and conditioned medium, inoculated for 24 hours, and 10 groups of small intestine organs were taken and set as blank control group (no irradiation), 4 Group model control group, blank drug administration group (no irradiation) and group 4 group 24 hours after administration group, 4 groups of model control groups were irradiated with X-rays to 2Gy, 4Gy, 6Gy, 8Gy, respectively. PBS solution (10 mM) was added to the blank control group (no irradiation) and the four model control groups; the four groups were irradiated with X-rays to 2Gy, 4Gy, 6Gy, and 8Gy 24 hours after irradiation, respectively. Nicotinamide (10 mM) was added to the blank administration group (no irradiation) and the 24 hour administration group after 4 groups. After the drug treatment for 24 hours, the fresh medium was changed. After 5 days of culture, the blank control group (no irradiation), the blank administration group (no irradiation), the 4 model control group, and the 4 groups of the 24 hours after administration were observed. Rate difference.

RESULTS: After 5 days of X-ray irradiation, the survival rates of small intestinal organs in the blank control group (no irradiation), model control group, blank administration group (no irradiation) and 24 hours after irradiation were as follows. 20, wherein, after 5 days of culture, the survival rate of the small intestine organs in the blank control group (without irradiation) and the X-rays irradiated with 2Gy, 4Gy, 6Gy, and 8Gy was: 99.76±0.24, 83.03±1.97. %, 65.41±2.85%, 47.61±1.71%, 30.23±1.74%; blank administration group (no irradiation) and small intestine organ in the group administered 24 hours after irradiation with X-rays to 2Gy, 4Gy, 6Gy, 8Gy The survival rates were 99.87±0.13%, 86.07±1.50%, 68.12±0.817%, 43.63±0.81%, 28.86±0.99% (Mean±SD, p>0.05 for each dose group).

Conclusion: P53 knockout homozygous mice have no protective effect on nicotinamide administered 24 hours after irradiation with different X-ray doses. Combined with Example 8 and Example 9, it is indicated that nicotinamide inhibits SIRT1 and increases P53 acetylation. The horizontal action exerts intestinal protection, that is, nicotinamide regulates P53 acetylation by inhibiting SIRT1 activity, thereby regulating the survival of intestinal epithelial organs.

Example 11

To study the protective effect of nicotinamide on the intestinal tract of low-dose segmentation in mice:

Animal experiments, 12 C57BL/6 mice at 8 weeks of age were randomly divided into two groups: control group and treatment group, with 6 rats in each group, respectively, given abdominal X-ray segmentation irradiation, 2Gy/time, 1 time/day, each 5 times a week, the total dose of 50Gy was 25 times, completed in 5 weeks. Nicotinamide (200 mg/Kg) was intraperitoneally injected into the treatment group 12 hours after each irradiation, and the control mice were intraperitoneally injected with the corresponding solvent PBS. 5 times a week for a total of 6 weeks. The daily weight changes, fecal occult blood, and diarrhea of the mice were observed. Among them, the occult blood index is 0-4, 0 is no occult blood. The larger the value, the more severe the occult blood. The mouse feces are classified into 0-3 grades according to color, softness and water content. The larger the value, the more severe the diarrhea.

RESULTS: (1) The difference in body weight of mice in the control group and the treatment group was shown in Fig. 21. As can be seen from the figure, the body weight was 100% before X-ray irradiation, and the treatment group was small during and after irradiation. The weight of the rats remained stable, did not decrease significantly, and some mice gained weight. The mice in the control group lost weight after exposure and decreased significantly two weeks after irradiation. At the end of the irradiation (Day 35), the control body weight percentage was 89.72±0.854%, and the treatment group weight percentage was 98.72±2.529% (Mean±SD, p<0.01). At 4 weeks after the end of irradiation (day 63), the control body weight percentage was 76.88±1.464%, and the treatment group weight percentage was 94.63±5.079% (Mean±SD, p<0.01).

(2) The difference of fecal occult blood in the control group and the treatment group with time is shown in Fig. 22 and Fig. 23, respectively. As can be seen from Fig. 22, in the X-ray irradiation and after the irradiation, the intestinal bleeding in the treatment group was obvious. It is better than the control group; and as can be seen from Fig. 23, the fecal occult blood index of the mice in the treatment group is 5.3±1.5 days, and the fecal occult blood index of the control group is greater than 1 day, which is 27.0±1.7 days (Mean±SD, p<0.0001).

(3) The difference in diarrhea of mice in the control group and the treatment group with time is shown in Fig. 24 and Fig. 25. As can be seen from Fig. 24, the mice developed obvious diarrhea after X-ray irradiation, and the number of diarrhea days in the treated group. It was significantly better than the control group, and it can be seen from Fig. 25 that the diarrhea index of the treatment group was greater than 1 day 9.7 ± 2.0 days, and the control group diarrhea index was greater than 1 day 25.0 ± 1.3 days (Mean ± SD, p < 0.0001).

Conclusion: Abdominal X-ray segmentation of the mice and the administration of nicotinamide to the mice 12 hours after each irradiation can significantly reduce the intestinal damage of the mice and improve the quality of life of the mice after irradiation.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material or feature is included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification and features of various embodiments or examples may be combined and combined without departing from the scope of the invention.

Although the embodiments of the present invention have been shown and described, it is understood that the above-described embodiments are illustrative and are not to be construed as limiting the scope of the invention. The embodiments are subject to variations, modifications, substitutions and variations.

Claims

Use of a SIRT1 inhibitor for the preparation of a medicament for the prevention or treatment of radiation-induced intestinal damage.
The use according to claim 1, wherein the SIRT1 inhibitor is at least one selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin and niacinamide.
The use according to claim 1 or 2, characterized in that the intestinal damage is radiation enteritis and/or intestinal acute radiation sickness.
A pharmaceutical composition for preventing or treating radiation-induced intestinal damage, characterized in that the pharmaceutical composition comprises a SIRT1 inhibitor.
The pharmaceutical composition according to claim 4, wherein the SIRT1 inhibitor is at least one selected from the group consisting of salermide, Sirtinol, EX527, Inauhzin, and niacinamide.
The pharmaceutical composition according to claim 4 or 5, wherein the intestinal damage is radiation enteritis.
The pharmaceutical composition according to any one of claims 4 to 6, wherein the pharmaceutical composition is in the form of an injection, a tablet, a capsule, an oral granule, and an enema.
The pharmaceutical composition according to any one of claims 4 to 7, which further comprises a pharmaceutically acceptable excipient selected from the group consisting of a binder, a filler, a coating film polymer, At least one of a plasticizer, a glidant, a disintegrant, and a lubricant.
A method of treating or preventing radiation-induced intestinal damage, characterized in that the animal is provided with the pharmaceutical composition according to any one of claims 4-8.
The method of claim 9 wherein said animal is provided with said pharmaceutical composition after said animal is irradiated.