Pharmaceutical use of (3-amino-5-ethyladamantan-1-yl) methyl nitrate and pharmaceutically acceptable salt thereof

Abstract

Provided is the pharmaceutical use of (3-amino-5-ethyladamantan-1-yl) methyl nitrate and a pharmaceutically acceptable salt thereof. In the present invention, provided is the use of (3-amino-5-ethyladamantan-1-yl) methyl nitrate and a pharmaceutically acceptable salt thereof in the prevention or treatment of a stroke and a sequela thereof, as well as the use in the preparation of a corresponding drug.

Description

Medical uses of (3-amino-5-ethyladamantan-1-yl)methyl nitrate and its pharmaceutically acceptable salts Technical Field

[0001] The present invention belongs to the field of biomedicine technology and relates to the medical use of (3-amino-5-ethyladamantan-1-yl)methyl nitrate, and specifically relates to the use of (3-amino-5-ethyladamantan-1-yl)methyl nitrate and pharmaceutically acceptable salts thereof in the preparation of drugs for preventing or treating stroke and its sequelae. Background Art

[0002] Stroke is a general term for brain diseases with sudden localized or diffuse neurological deficits caused by cerebral blood circulation disorders. Stroke is characterized by rapid onset and severe condition. In recent years, it has become the leading cause of death in my country. The results of the Global Burden of Disease (GBD) study showed that in 2019, there were 3.94 million new cases of stroke in my country, 28.76 million stroke patients, and 2.19 million stroke deaths. In addition, stroke is also the leading cause of disability-adjusted life years (DALYs) in my country. In 2019, DALYs caused by stroke reached 45.9 million (Wang Yongjun et al., China Stroke Report 2020, Chinese Journal of Stroke. 2022, 17(05):433). With the improvement of living standards and changes in lifestyles of Chinese residents, the incidence of stroke is still rising. According to the type of stroke, stroke is divided into ischemic stroke and hemorrhagic stroke. The World Health Organization report pointed out that ischemic stroke is the most common type of stroke, accounting for about 80% of all strokes (Hankey GJ. Stroke[J]. Lancet, 2017, 389(10069):641-654).

[0003] At present, the drugs used in clinical practice for ischemic stroke mainly include intravenous thrombolysis of fibrinolytic drugs, antiplatelet drugs, anticoagulants, etc. Intravenous thrombolysis is currently the most important measure to restore blood flow. Alteplase and urokinase are the main thrombolytic drugs currently used in my country. It is now believed that the time window for effectively saving penumbra tissue is within 4.5 hours or within 6 hours. Antiplatelet drugs can inhibit platelet aggregation and thus inhibit thrombosis in arteries. They are the main drugs for preventing ischemic stroke. Currently, commonly used antiplatelet drugs in clinical practice include thromboxane A2 inhibitors (aspirin), P2Y12 receptor inhibitors (clopidogrel, ticagrelor), glycoprotein IIb / IIIa receptor inhibitors (tirofiban), phosphodiesterase inhibitors (dipyridamole, cilostazol), etc. (Huo Yong, Wang Yongjun, Gu Yongquan, et al. Expert consensus on the diagnosis and treatment of people with intolerance and low responsiveness to commonly used oral antiplatelet drugs [J]. Chinese Journal of Cardiovascular Diseases: 2021(1):13). Anticoagulants prevent thrombosis by blocking blood clotting and are therefore very important clinically. Commonly used anticoagulants include heparin, which exerts its anticoagulant effect by indirectly inhibiting the activity of factors IIa, Xa, IXa, XIIa, and XIa through its interaction with antithrombin (ATIII); warfarin, which reduces the synthesis of prothrombin and factors VII, IX, and X by antagonizing vitamin K; direct thrombin inhibitors dabigatran and argatroban; and factor Xa inhibitors rivaroxaban and apixaban.Studies have found that the use of anticoagulants, antiplatelet and thrombolytic drugs, thrombocytopenia and abnormal coagulation factor function all increase the risk of bleeding after stroke (Pfeilschifter W, Spitzer D, Czech-Zechmeister B, et al. Increased risk of hemorrhagic transformation in ischemic stroke occurring during warfarin anticoagulation: an experimental study in mice[J]. Stroke, 2011, 42(4): 1116-1121; Hankey GJ. Dual antiplatelet therapy in acute transient ischemic attack and minor stroke[J]. N Engl J Med, 2013, 369(1): 82-83; Larrue V, von Kummer RR, Muller A, et al. Risk factors for severe hemorrhagic transformation in ischemic stroke patients treated with recombinant tissue plasminogen activator: a secondary analysis of the European-Australasian Acute Stroke Study (ECASS)). II)[J].Stroke,2001,32(2):438-441).

[0004] Stroke has a significant impact on cerebrovascular function. The brain requires a constant supply of blood to carry oxygen and nutrients to the neurons in the cerebral cortex to ensure their normal function. Numerous arteries work together to meet this requirement. Strokes occur in different arteries and / or their branches, causing lesions in a specific neuroanatomical location. Due to the complexity of the relevant neuronal networks in the cortex, damage to a specific vascular distribution and neuroanatomical location caused by a stroke usually impairs multiple functions, resulting in stroke sequelae. The most prominent damages recognized are post-stroke motor dysfunction and post-stroke cognitive dysfunction. In recent years, with the improvement of medical conditions and the advancement of clinical medical technology, the mortality rate of stroke has dropped significantly, but it has also led to a substantial increase in the prevalence of stroke sequelae, resulting in a greater disease burden.

[0005] Approximately 80% of stroke survivors experience motor dysfunction, which can lead to inability to eat, dress, or undress, limiting their daily activities and placing a significant burden on their families and society. Independence in daily activities largely depends on the recovery of motor function (Veerbeek JM, Kwakkel G, van Wegen EEH, et al. Early prediction of outcome of activities of daily living after stroke: a systematic review [J]. Stroke, 2011, 42(5): 1482-1488.). Studies have found that even with rehabilitation treatment, only 5% to 20% of stroke patients with motor dysfunction can recover (Kwakkel G, Kollen BJ, van der Grond J, et al. Probability of regaining dexterity in the flaccid upper limb: impact of severity of paresis and time since onset in acute stroke [J]. Stroke, 2003, 34(9): 2181-2186).

[0006] About one-third of stroke survivors experience post-stroke cognitive impairment. After a stroke, patients experience a rapid decline in cognition in the short term. After a certain degree of recovery, the long-term cognitive level is poor and difficult to recover. Domestic and international guidelines and current clinical practice ( MD, A, BRAININ M, et al. Post-stroke dementia - a comprehensive review[J]. BMC Med, 2017, 15(1): 11.; Chinese Stroke Society, Expert Committee on Management of Post-stroke Cognitive Impairment. Expert consensus on management of post-stroke cognitive impairment[J]. Chinese Journal of Stroke, 2017, 12(6): 519-531.; Chinese Stroke Society, Expert Committee on Management of Post-stroke Cognitive Impairment, Xu Jun. Outpatient management standards for patients with post-stroke cognitive impairment[J]. Chinese Journal of Stroke, 2019, 14(9): 909-922.; Expert Group of the Roundtable Meeting on Post-stroke Cognitive Impairment Research of the Chinese Stroke Society. Expert consensus on research on prevention and treatment of post-stroke cognitive impairment in China[J].) have clearly pointed out that the mortality rate of patients with post-stroke cognitive impairment is significantly higher than that of stroke patients without cognitive impairment.

[0007] Therefore, it is necessary to develop safe drugs to prevent or treat stroke and its sequelae.

[0008] Summary of the Invention

[0009] In order to solve the problems in the prior art, the object of the present invention is to provide the use of (3-amino-5-ethyladamantan-1-yl)methyl nitrate and pharmaceutically acceptable salts thereof in the preparation of drugs for preventing or treating stroke and its sequelae.

[0010] To achieve the above object, the technical solution of the present invention is:

[0011] Application of (3-amino-5-ethyladamantan-1-yl)methyl nitrate and pharmaceutically acceptable salts thereof in the preparation of drugs for preventing or treating stroke and its sequelae.

[0012] The (3-amino-5-ethyladamantan-1-yl)methyl nitrate has the chemical structure shown in MN08:

[0013] On the other hand, the present invention provides a method for using (3-amino-5-ethyladamantan-1-yl)methyl nitrate or a pharmaceutically acceptable salt thereof to prevent and / or treat stroke and its sequelae, characterized in that it comprises administering a therapeutically effective amount of (3-amino-5-ethyladamantan-1-yl)methyl nitrate or a pharmaceutically acceptable salt thereof.

[0014] According to one embodiment of the present invention, (3-amino-5-ethyladamantan-1-yl)methyl nitrate and pharmaceutically acceptable salts thereof are used in the preparation of a drug for preventing or treating stroke and its sequelae, wherein the stroke is a stroke confirmed to have no bleeding risk.

[0015] According to one embodiment of the present invention, the stroke is a stroke without hemorrhagic transformation. The basis for determining whether there is a risk of hemorrhage after a stroke is a head imaging examination.

[0016] According to one embodiment of the present invention, the method of confirming stroke without hemorrhagic risk is imaging means, such as CT or MRI.

[0017] According to one embodiment of the present invention, stroke without hemorrhagic risk is confirmed by imaging methods such as MRI (Magnetic Resonance Imaging), CTA (CT angiography), and CTP (CT perfusion imaging).

[0018] A cranial CT scan (CT of the brain) is a well-known method for examining the brain using CT. It can clearly demonstrate the anatomical relationships and specific brain tissue structures across different cross-sectional views. Cranial CT is important for diagnosing most conditions within the brain, skull, and scalp, and is often used to examine patients with symptoms such as stroke and craniocerebral injury.

[0019] Magnetic resonance imaging (MRI) is an imaging technique based on the principle that atomic nuclei with magnetic moments can undergo energy level transitions under the influence of a magnetic field. MRI utilizes an external high-frequency magnetic field, which generates signals from internal substances radiating energy to the surrounding environment. The imaging process is similar to image reconstruction and CT, but MRI does not rely on external radiation, absorption, or reflection, nor on gamma radiation from radioactive substances within the body. Instead, it utilizes the interaction between an external magnetic field and the object to create images. High-energy magnetic fields are harmless to the human body. Cranial MRI can be used to examine patients with stroke, craniocerebral injury, and multiple cerebral infarctions.

[0020] According to one embodiment of the present invention, (3-amino-5-ethyladamantan-1-yl)methyl nitrate and its pharmaceutically acceptable salts are used in the preparation of a drug for preventing or improving stroke sequelae, wherein the stroke sequelae are post-stroke motor dysfunction, post-stroke memory impairment, and / or post-stroke cognitive impairment.

[0021] The establishment of stroke sequelae described in the present invention can be established in accordance with the commonly used clinical diagnosis methods, for example, three factors are required at the same time: a clear stroke diagnosis, the presence of sequelae functional impairment (motor dysfunction, memory impairment, cognitive impairment, etc.), and the temporal relationship between stroke and sequelae functional impairment (occurring after the stroke event).

[0022] According to one embodiment of the present invention, the above-mentioned (3-amino-5-ethyladamantan-1-yl) methyl nitrate or its pharmaceutically acceptable salt is used in the preparation of a drug for preventing or treating executive dysfunction after stroke; or in the preparation of a drug for preventing or treating attention disorder after stroke; or in the preparation of a drug for preventing or treating memory disorder after stroke; or in the preparation of a drug for preventing or treating visual-spatial disorder after stroke; or in the preparation of a drug for preventing or treating reasoning and abstract thinking ability disorder after stroke.

[0023] According to one embodiment of the present invention, the stroke is a transient ischemic attack, hemorrhagic stroke, or ischemic stroke. Furthermore, the stroke is multiple cerebral infarctions. Multiple cerebral infarctions (also known as multiple lacunar infarctions) are a special type of stroke that often occurs in the basal ganglia.

[0024] According to one embodiment of the present invention, the pharmaceutically acceptable salt of the present invention is a salt formed by an adamantane nitrate compound and an acid, such as a salt formed with the following acids: hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, trifluoroacetic acid, propionic acid, hexanoic acid, heptanoic acid, cyclopentanepropionic acid, glycolic acid, pyruvic acid, lactic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethanedisulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, p-chlorobenzenesulfonic acid, p-toluenesulfonic acid, 3-phenylpropionic acid, trimethylacetic acid, tert-butylacetic acid, dodecylsulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoic acid, salicylic acid or stearic acid.

[0025] The term "inhibit" in the present invention means to prevent or delay the progression to an adverse condition.

[0026] In addition, "improvement" in the present invention refers to improvement of symptoms or diseases, prevention or delay of worsening of symptoms or diseases, reversal, prevention or delay of progression of symptoms or diseases, or treatment of symptoms or diseases. "Improvement" in the present invention also includes the meaning of prevention.

[0027] The term "prevention" in the present invention refers to preventing or delaying the onset of a symptom or disease of the target of application, or reducing the risk of onset of a symptom or disease of the target of application.

[0028] As used herein, the term "therapeutically effective amount" means an amount of a compound or composition that, when administered to a subject for treating cognitive impairment and / or memory loss, is sufficient to effect such treatment of cognitive impairment and / or memory loss.

[0029] The present invention provides the use of (3-amino-5-ethyladamantan-1-yl) methyl nitrate and its pharmaceutically acceptable salts in the preparation of drugs for preventing or treating stroke and its sequelae. In a rat right middle cerebral artery transient occlusion (t-MCAO) stroke model, it was found that administration of the (3-amino-5-ethyladamantan-1-yl) methyl nitrate compound of the present invention in the early stages of stroke increased the risk of cerebral hemorrhage. Surprisingly, for stroke animals confirmed to have no risk of bleeding, administration of a therapeutically effective amount of (3-amino-5-ethyladamantan-1-yl) methyl nitrate or its pharmaceutically acceptable salt significantly improved the experimental animals' post-stroke motor ability and memory ability without increasing the risk of bleeding. In a rat model that had already developed stroke sequelae, administration of the (3-amino-5-ethyladamantan-1-yl) methyl nitrate compound effectively improved the rats' stroke sequelae without increasing the risk of cerebral hemorrhage. In summary, the (3-amino-5-ethyladamantan-1-yl)methyl nitrate of the present invention can improve stroke and stroke sequelae, and the improvement effect is better than that of memantine, which is of great significance for the treatment and prevention of stroke and its sequelae. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 shows the effect of MN08 on post-stroke cerebral hemorrhage in t-MCAO rats;

[0031] FIG2 is a graph showing weight changes in t-MCAO mice after stroke;

[0032] Figure 3 is a summary of the pole climbing data of t-MCAO mice after stroke, ****P<0.0001, ***P<0.001, **P<0.01, *P<0.05 vs. model group;

[0033] Figure 4 is a summary of the rotarod data of t-MCAO mice after stroke, ****P<0.0001, ***P<0.001, **P<0.01, *P<0.05 vs. model group;

[0034] Figure 5 is a summary of the wire-hanging data of t-MCAO mice after stroke, ****P<0.0001, ***P<0.001, **P<0.01, *P<0.05 vs. model group;

[0035] Figure 6 shows the combined data from the latency study of t-MCAO mice during navigation in the water maze test. ***P<0.001, **P<0.01, *P<0.05 vs. model group.

[0036] Figure 7 shows the number of platform crossings in the spatial exploration phase of t-MCAO mice. ***P<0.001, **P<0.01, *P<0.05 vs. model group.

[0037] Figure 8 shows the summary of the time t-MCAO mice spent in the target quadrant. ***P<0.001, **P<0.01, *P<0.05 vs. model group.

[0038] Figure 9 shows the summary of the time t-MCAO mice spent outside the pool, ***P<0.001, **P<0.01, *P<0.05 vs. model group.

[0039] FIG10 is a representative image of coronal sections (including the hippocampal region) in ASL and T2W1 sequences.

[0040] Figure 11 Summary of research data on rats in positioning navigation; **** P<0.0001,***P<0.001,**P<0.01,*P<0.05vs.model group.Memantine:MEM..

[0041] Figure 12: Latency of rats in the spatial exploration phase; **** P<0.0001,***P<0.001,**P<0.01,*P<0.05vs.model group.Memantine:MEM..

[0042] Figure 13 Summary of research data on the number of times rats crossed the platform. **** P<0.0001,***P<0.001,**P<0.01,*P<0.05vs.model group.Memantine:MEM.. DETAILED DESCRIPTION

[0043] In order to have a better understanding of technical solution of the present invention, below in conjunction with accompanying drawing, specific embodiment of the present invention or embodiment are described in more detail, obviously, embodiment described herein only includes a part of the present invention rather than whole embodiment. It should be understood by those skilled in the art that specific embodiment of the present invention or embodiment are modified or some technical features are replaced equally, and without departing from the spirit of technical solution of the present invention, all should be encompassed in the scope of protection of the present invention. Reagents used in the present invention are all commercially available products.

[0044] Unless otherwise specified, all parts described in the present invention are parts by weight and all percentages described are mass percentages.

[0045] Example 1: Evaluation of the therapeutic effect of MN08 in the early stage of rat t-MCAO stroke model

[0046] Male SD rats were selected for the experiment, and a stroke model was established using transient occlusion of the right middle cerebral artery (t-MCAO). After transient occlusion of the right middle cerebral artery, the rats were randomly divided into a model group, an MN08 group, and a memantine group. Behavioral evaluation of the grouped animals was normal after modeling, with no evidence of cerebral hemorrhage. The rats were given MN08 or the positive control drug memantine once starting 20 minutes after grouping, followed by oral administration at 9:00 AM and 3:00 PM the following day. MN08 was administered at a dose of 6 mg / kg per dose, and memantine was administered at a dose of 5 mg / kg per dose, an equimolar dose to MN08 (6 mg / kg). These were administered by gavage.

[0047] The results showed that 24 hours after administration, some animals in the MN08 group experienced cerebral vascular rupture (as shown in Figure 1), while none of the animals in the model group or the positive control group experienced cerebral vascular rupture. This phenomenon was also observed in subsequent repeated experiments.

[0048] Imaging methods have shown that in animal stroke experiments, the risk of bleeding usually occurs within 24 hours.

[0049] Example 2: Study on the prevention of sequelae of stroke in mice by MN08

[0050] 1. Model preparation and grouping

[0051] The experiment involved SPF mice, using transient occlusion of the right middle cerebral artery (t-MCAO) to establish a stroke model. Three days after the t-MCAO procedure, the mice were evaluated for neurological impairment scores. Mice with unsuccessful modeling were removed. The remaining mice (confirmed to be free of bleeding risk) were randomly divided into groups and given varying doses of MN08 or the positive control drug memantine by gavage daily at 9:00 AM for 28 consecutive days.

[0052] A 7-point neurological scoring system was used as the scoring standard. The neurological function score of each mouse (or rat) was recorded 1 day, 3 days, and 7 days after surgery, as well as 0-4 weeks after administration. The scoring details are shown in Table 1 below:

[0053] Table 1 Scoring criteria for neurological impairment

[0054] The doses of MN08 administered each time were 6 mg / kg, 12 mg / kg, and 24 mg / kg; the dose of Memantine administered each time was 10 mg / kg, which was an equimolar dose to MN08 (12 mg / kg) (the specific groups are shown in Table 2).

[0055] Table 2 Experimental dosage design

[0056] 2. Effect of MN08 on the body weight of stroke mice

[0057] The mice were weighed before modeling, on the first, third, and seventh days after modeling, and at weeks 2, 3, and 4. The experimental results showed that the mice lost weight sharply on days 1 to 3 after modeling, but began to gain weight gradually on day 7 after modeling, indicating that the body of the mice with successful modeling gradually recovered (as shown in Figure 2).

[0058] The results of the effect of MN08 on the body weight of stroke mice showed that the body weight of mice in the MN08 (12 mg / kg) group increased significantly on the 7th day compared with the model group, indicating that MN08 can improve the recovery of consciousness in stroke mice.

[0059] 3. Sports behavior indicators

[0060] (1) Pole climbing experiment

[0061] The climbing pole test was used to detect the limb movement ability and muscle strength of mice. A homemade climbing pole device was made using an iron stand, and the iron bars of the iron stand were wrapped with medical tape to increase the friction between the mouse and the iron stand. During the experiment, the mouse's tail was grasped so that the mouse's head was facing down. The timer started after the tail was released. The time when the forelimbs touched the ground was used as the standard. The time it took for the mouse to climb to the bottom of the pole without external force was recorded. The test time was 15s as the maximum value. If it exceeded 15s, it was counted as 15s. Pole climbing training was performed 3 days before administration, twice a day. Mice that did not meet the standards were eliminated. Behavioral tests were performed once a week, and each mouse was tested three times to obtain the average value.

[0062] Experimental cycles: 1 day before surgery, 2 days, 7 days, 14 days, 21 days, and 28 days after surgery.

[0063] The experimental results are shown in Figure 3. On the second day after modeling (i.e., one day before medication), the model mice spent significantly more time climbing the pole than the sham-operated mice, indicating that the modeling was successful. On the seventh day after modeling (i.e., the fourth day after medication), the time spent by the mice in the MN08 (12 mg / kg) group on climbing the pole began to decrease, showing a significant difference from the model group. On the 21st day after modeling, the time spent by all medication groups on climbing the pole showed a significant difference from the model group, and the differences between the three groups of mice administered with MN08 were more obvious.

[0064] (2) Rotating rod fatigue test

[0065] Pre-experimental preparation: Mice used for the first experiment should be trained three times daily for three days before the experiment. The rotarod speed should be slowly increased from 5 to 30 rpm over 5 minutes. The rotarod should be stopped when the time the mice spend on the accelerating rotarod remains constant at a stable baseline. Mice meeting the experimental requirements should be screened. The day before model establishment, screened mice should undergo three rotarod tests. The third test should be recorded and averaged.

[0066] Rotarod test: Mice were placed on a rotating rod, and the speed of the rod was slowly increased from 5 to 30 rpm over 5 minutes. The experiment was stopped when the mouse fell off the rod, and the time the mouse spent on the rod was recorded. Each mouse rested for 15 minutes, and the first, second, and third rounds of the experiment were repeated. The average time of the third round was recorded and used as the average time for the mouse on the rod that day.

[0067] Experimental period: 1 day before surgery, 7 days, 14 days, and 21 days after surgery.

[0068] The experimental results are shown in Figure 4: From the statistical results, starting from the 7th day after modeling, all groups of MN08-treated mice showed varying degrees of improvement in the forepaw grip and overall motor ability of stroke mice.

[0069] (3) Line suspension experiment

[0070] A homemade hanging experiment apparatus (2 mm diameter, 50 mm long center wire; 35 cm high platforms at each end) was used to suspend mice by placing their forepaws between the wires. The number of times the mouse fell and reached the platforms within 90 seconds was recorded. The baseline score for the mouse was set at 10 points, with 1 point subtracted for each fall and 1 point added for each platform reach. If the mouse fell or reached a platform, it was resuspended until the 90-second count was reached.

[0071] Experimental period: 1 day before surgery, 7 days, 14 days, and 21 days after surgery.

[0072] The experimental results are shown in Figure 5: On the second day after modeling (i.e., one day before drug administration), the wire hanging test results of the mice were significantly different from those of the sham-operated group, indicating that the modeling was successful; starting from the 14th day after modeling, all groups treated with MN08 showed varying degrees of improvement in the forepaw grip and overall motor ability of stroke mice.

[0073] The motor ability of mice was comprehensively evaluated by testing the limb muscle strength, forelimb grasping endurance and overall movement conditions through pole climbing test, wire hanging test and rotarod test. It can be seen that MN08 can improve the motor ability of stroke mice.

[0074] 4. Cognitive ability indicators

[0075] (1) Water maze test to measure the effect of learning and memory on stroke mice

[0076] The water maze experiment consists of two phases: positioning navigation and spatial exploration. The mice were given the positioning navigation experiment 24-28 days after drug administration: the mice were placed in the pool facing the pool wall from any of the four starting points on the pool wall. The free video recording system recorded the time it took for the mice to find the platform. The mice explored freely for 60 seconds. If the platform was not found within the specified time, the latency was recorded as 60 seconds. The experiment lasted for a total of 5 days. 24 hours after the positioning navigation experiment, the platform was removed and a spatial exploration experiment was conducted: the pool wall farthest from the platform was selected as the entry point for the test phase, and the mice were placed in the water. The swimming path of the mice within 60 seconds was recorded, as well as the swimming speed of the mice, the number of times they crossed the original platform, and the time they stayed in the target quadrant and the periphery of the pool.

[0077] The experimental results show that during the navigation phase, the latency of mice to find the platform gradually decreased after daily training. However, the latency of the model group decreased significantly less than that of the sham group, and on day 5, the latency of the MN08 (12 mg / kg) group was statistically different from that of the model group (Figure 6). During the spatial exploration phase, the model group crossed the original platform significantly less frequently than the sham group, and showed statistical differences from the MN08 (6 mg / kg) and MN08 (12 mg / kg) groups (Figure 7). The model group spent significantly less time in the target quadrant than the MN08 (12 mg / kg) group (Figure 8), while spending significantly more time outside the pool than the MN08 (12 mg / kg) group (Figure 9), indicating that MN08 (12 mg / kg) improved the memory ability of stroke-induced mice for the hidden platform.

[0078] Example 3: Evaluation of the therapeutic effect of MN08 in a rat model with established post-stroke cognitive impairment

[0079] 1. Model building and grouping

[0080] A multiple cerebral infarction model was established in SD male rats using microsphere injection (Takeo, S., et al., Sustained damage to energy metabolism of brain regions after microsphere embolism in rats. Stroke, 1992, 23(1): p. 62-8).

[0081] Neurological function injury score: The severity of cerebral ischemia in rats was assessed using the Zea-Longa criteria (Table 3). Longa scores were performed and recorded in each group of rats one day after surgery.

[0082] Table 3 Zea Longa Standard

[0083] Animals were divided into six groups: a sham group (normal saline), a model group (normal saline), a low-dose (3 mg / kg), a medium-dose (6 mg / kg), and a high-dose (12 mg / kg) MN08 group, and a positive control group (Memantine hydrochloride, 5 mg / kg). On day one after the multiple stroke model was established, rats were screened for successful stroke modeling using the Zea Longa five-point scoring system. One week after surgery, these selected rats gradually exhibited cognitive impairment. On day 10 after surgery, rats that developed cognitive impairment were screened (to confirm the absence of bleeding risk). Dosing began on day 12 after surgery (oral gavage) twice daily at 9:00-10:00 AM and 4:00-5:00 PM for 28 consecutive days. Rats were weighed before modeling and on days 1, 3, 7, 14, 21, and 28 after dosing.

[0084] 2. Weight changes

[0085] The rats were weighed before modeling and on days 1, 3, 7, 14, 21 and 28 after administration. The body weights of the rats in each group decreased after surgery.

[0086] 3. Infarction volume

[0087] One month after modeling, the rats' brains were scanned using MRI ASL and T2WI sequences to observe changes in brain infarct volume. The T2WI results (Figure 10) showed that MN08 treatment reduced brain infarct volume.

[0088] 4. Water maze test to evaluate the impact of cognitive impairment

[0089] The rats were given the drug for 24-28 days and then underwent a water maze experiment. The experiment consisted of two phases: positioning navigation and spatial exploration. Positioning navigation phase: The rat was placed into the pool facing the pool wall from any of the four starting points on the pool wall. The free video recording system recorded the time it took for the rat to find the platform. The rat explored freely for 60 seconds. If the platform was not found within the specified time, the latency period was recorded as 60 seconds. The experiment lasted for a total of 4 days. 24 hours after the positioning navigation experiment, the platform was removed and a spatial exploration experiment was carried out: the pool wall farthest from the platform was selected as the entry point for the test phase, and the rat was placed in the water. The swimming path of the rat within 60 seconds, as well as the time the rat stayed in the target quadrant and the number of times it crossed the original platform were recorded.

[0090] Statistical analysis: Graphpad Prism 9.0 software was used for statistical analysis of the experimental data. The data were expressed as Mean ± SEM. The t-test was used for comparison between two groups, and the one-way ANOVA or two-way ANOVA was used for comparison between multiple groups. The Pearson correlation analysis was used for correlation analysis. A p value < 0.05 was considered to indicate a statistically significant difference.

[0091] Experimental results showed that during the navigation phase, the latency for rats to find the platform gradually decreased with daily training, but the decrease in latency in the model group was significantly smaller than that in the sham-operated group (Figure 11). During the spatial exploration phase, the latency in the model group was significantly higher than that in the sham-operated group (Figure 12), while the number of crossings of the original platform was significantly lower than that in the sham-operated group (Figure 13). Different doses of MN08 significantly reduced the latency and increased the number of crossings, with MN08 (6 mg / kg) showing the greatest efficacy and outperforming an equimolar dose of memantine.

[0092] The experimental results showed that in the rat model of stroke cognitive impairment, low, medium and high doses of MN08 can significantly improve the learning and memory ability, cognitive recognition ability and autonomous movement ability of stroke rats, and the efficacy of the medium dose (6 mg / kg) is better than that of memantine.

Claims

1. Use of (3-amino-5-ethyladamantan-1-yl) methyl nitrate and pharmaceutically acceptable salts thereof in the preparation of drugs for preventing or treating stroke and its sequelae; wherein the (3-amino-5-ethyladamantan-1-yl) methyl nitrate has the chemical structure shown in MN08:

2. The use according to claim 1, characterized in that The stroke was confirmed to be without bleeding risk.

3. The use according to claim 2, characterized in that The method for confirming a stroke without bleeding risk is imaging means.

4. The use according to claim 3, characterized in that The imaging method is cranial CT or MRI.

5. The use according to any one of claims 1 to 4, characterized in that: The stroke sequelae are post-stroke motor dysfunction, post-stroke memory impairment, and / or post-stroke cognitive impairment.

6. The use according to any one of claims 1 to 4, characterized in that: The stroke sequelae are post-stroke executive dysfunction, post-stroke attention disorder, post-stroke visual-spatial disorder, and / or post-stroke reasoning and abstract thinking ability disorder.

7. The use according to claims 1-4, characterized in that The stroke is transient ischemic attack, hemorrhagic stroke or ischemic stroke.

8. The use according to claim 7, characterized in that The stroke is multiple cerebral infarction.

9. The use according to claims 1-4, characterized in that: The pharmaceutically acceptable salt is a salt of (3-amino-5-ethyladamantan-1-yl)methyl nitrate and an acid, wherein the acid is selected from hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, trifluoroacetic acid, propionic acid, hexanoic acid, heptanoic acid, cyclopentanepropionic acid, glycolic acid, pyruvic acid, lactic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethanedisulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, p-chlorobenzenesulfonic acid, p-toluenesulfonic acid, 3-phenylpropionic acid, trimethylacetic acid, tert-butylacetic acid, dodecyl sulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoic acid, salicylic acid or stearic acid.

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