Prevention and treatment of postoperative cognitive dysfunction (POCD)

Abstract

A method for preventing and / or treating postoperative cognitive impairment by administering to a human or other mammal an effective amount of one or more compounds selected from the group consisting of N-substituted 2(1H)pyridones, N-substituted 3(1H)pyridones, and any one or more pharma- ceutically acceptable salts thereof, optionally further substituted at various substitutable ring positions.

Description

[Background technology]

[0001] The term perioperative neurocognitive disorders refers to disturbances in behavior, affect, and cognitive function that can develop following anesthesia and surgery, including pre-existing cognitive impairment, postoperative delirium, and cognitive impairment (e.g., delayed neurocognitive recovery or postoperative cognitive dysfunction).

[0002] Postoperative cognitive dysfunction (POCD) is cognitive impairment resulting from surgery performed under general anesthesia and is diagnosed by comparing preoperative and postoperative neurocognitive domain testing. It is characterized by a decline in the patient's cognitive abilities and activities of daily living. Delayed recovery may last up to 30 days. Cognitive impairment may persist for more than 30 days and may last up to a year or more. POCD has been associated with worsening and onset of cognitive impairment. This can be seen up to 5 years after surgery. (Mahanna-Gabrielli, E. et al.) (All references cited herein are incorporated by reference in their entirety. Reference to these references does not imply general knowledge or state of the art.)

[0003] In an international study of POCD in elderly patients aged 60 years or older published in 1998 (Moller et al.), POCD was observed in 25.8% of patients 1 week after surgery. POCD persisted in 9.9% of patients 3 months after surgery. Furthermore, it was found that age, duration of anesthesia, low level of education, reoperation, postoperative infection, and respiratory problems increase the risk of early POCD. Only age was found to be a factor in late POCD (Moller JT et al.).

[0004] According to Kitsis et al., there is no specific treatment for POCD. Current treatment involves carefully selecting anesthesia, addressing mitigable risk factors, and utilizing intervention strategies such as pain management strategies, monitoring vital signs, providing adequate fluids and oxygen, and cognitive stimulation sessions daily for six days to minimize risk to the patient (Kitsis P et al.).

[0005] Since Moller et al.'s study, various researchers have supported the importance of POCD, and various cases have been reported depending on the type of surgery and neurocognitive testing performed. Unfortunately, to date, there is still an unmet need for a pharmacological approach leading to the prevention of POCD. Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to provide a method for preventing cognitive impairment resulting from surgery. It is a further object of the present invention to provide a method for preventing the onset of postoperative cognitive dysfunction in a postoperative patient. It is also an object of the present invention to ameliorate cognitive impairment resulting from surgery performed under anesthesia. It is a further object of the present invention to provide a method wherein an agent for preventing POCD is administered to a patient in an amount sufficient to prevent cognitive impairment in said patient. Another object of the present invention is to provide a method for pre-operatively administering to a patient an agent that ameliorates POCD in order to prevent post-operative cognitive impairment. It is a further object of the present invention to provide a method for administering drugs to a patient both pre- and post-operatively that affect post-operative cognitive impairment.

[0007] It is a further object of the present invention to administer pirfenidone or a pirfenidone analog or derivative to a patient pre-operatively in a dose that prevents the development of post-operative cognitive impairment. It is a further object of the present invention to administer pirfenidone or a pirfenidone analog or derivative to a patient pre-operatively in a dose that ameliorates post-operative cognitive dysfunction. It is a further object of the present invention to administer pirfenidone or a pirfenidone analog or derivative to a patient pre- and post-operatively in a dose that prevents the development of post-operative cognitive impairment. It is a further object of the invention to administer pirfenidone or a pirfenidone analog or derivative to a patient pre- and post-operatively in a dose that ameliorates post-operative cognitive dysfunction. A further object of the present invention is to provide a drug for preventing or alleviating cognitive decline in a patient, the drug being pirfenidone, a pirfenidone derivative, a pirfenidone analog, or a combination of two or more of pirfenidone, a pirfenidone derivative, or a pirfenidone analog. These and other objects described below are accomplished by a method for preventing and ameliorating postoperative cognitive impairment, which involves administering to a human patient one or more times an amount of pirfenidone, or a pirfenidone analog or derivative either preoperatively, intraoperatively, or postoperatively, or any combination thereof. Pirfenidone analogs and derivatives are described herein. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a bar graph showing the results of the contextual fear conditioning test in terms of freezing time on days 1 and 3 after surgery. [Diagram 2] FIG. 2 is a bar graph showing the overall percentage of time that mice were frozen during the fear conditioning cued test. [Diagram 3] FIG. 3 is a bar graph showing the duration of freezing during the fear conditioning cue test at pre-tone, during-tone, and post-tone time points. [Figure 4] FIG. 4 is a bar graph of novel object recognition exploration time during training and 1 and 24 hours after training for each treatment group. [Diagram 5] FIG. 5 is a bar graph comparing novel object recognition preferences for each treatment group during training and at 1 and 24 hours after training. [Figure 6] FIG. 6 is a bar graph showing the mean latency to reach the platform during the Morris Water Maze test, comparing Block 1 with Block 2 for each treatment group. [Figure 7] FIG. 7 is a bar graph showing the mean latency to reach the platform during the Morris Water Maze test, with each treatment group represented within a block. [Figure 8] FIG. 8 is a bar graph depicting the mean latency of the four-compartment probe test data in the Morris water maze. [Figure 9] FIG. 9 shows a non-parametric evaluation comparing the effects on morphological characteristics of hippocampal microglial cells in disease control animals and normal control animals. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Definition of Terms Cognitive impairment: Deficits related to attention, verbal and non-verbal learning, short-term and working memory, visual and auditory processing, problem solving and processing speed. Cytokine inflammatory cascade: Proinflammatory cytokines play a central role in inflammatory diseases of infectious or non-infectious origin. Examples include IL-1, IL-6, IL-8, IL-12, IL-18, and TNF. Gliosis: excessive glial development, especially in the interstitium. A nonspecific reactive change in glial cells to injury in the central nervous system, gliosis most often involves proliferation or hypertrophy of several different types of glial cells, including astrocytes, microglia, and oligodendrocytes (Wikipedia). Typically, it is accompanied by a change in cell phenotype, evidenced by changes in cell morphology. Neuroinflammation: Inflammation of a nerve or part of the nervous system, caused by excessive secretion of and / or activation of the presence of proinflammatory cytokines. Surgery: A surgical procedure performed on a patient. Surgery includes, but is not limited to, surgery performed in relation to the central nervous system, peripheral nervous system, endocrine organs and ectopic tumors, eyes, ears, respiratory system, cardiovascular system, lymphatic system, digestive system and mouth, urinary tract, male and female reproductive systems, bones, cartilage and joints, muscles and other soft tissues, breasts, skin and various other anatomical areas. Systemic inflammation: Systemic inflammation is defined as "a typical, multi-syndromic, stage-specific pathological process that develops from systemic injury." In the present invention, systemic inflammation refers to the body's general response to surgical trauma. TNF-a, IL-1b, IL-6: These cytokines play an important role in the inflammatory process.

[0010] Surgical trauma can have serious effects on the body, especially the brain. One common but serious complication resulting from surgical trauma is postoperative cognitive decline. Although postoperative cognitive decline can occur at any age, the incidence and severity increases with age.

[0011] The complex process that causes POCD is not fully understood. However, some studies have hypothesized that neuroinflammation is a factor associated with postoperative cognitive decline (Safavynia SA et al., Berger M et al.). It has also been hypothesized that neuroinflammation is a factor associated with gliosis (e.g., microgliosis, astrogliosis, etc.) and that in combination with gliosis and neuroinflammation, it is involved in the pathogenesis of POCD, but this association (e.g., correlative or causative) and the putative mechanisms involved are unclear. These and other factors may be components of the pathological process that leads to postoperative cognitive decline, also known as postoperative cognitive dysfunction (POCD) (Wan Y et al., Terrando N et al.).

[0012] The applicant hypothesized that pirfenidone (5-methyl-1-phenyl-2(1H)-pyridone) would be useful in preventing the development or reducing the effects of POCD. Pirfenidone is an inhibitor of proinflammatory cytokines, particularly TNF-a, which may be involved in the development of POCD in various tissues (Cain WC et al., Oku H et al.). It is a nonsteroidal organic molecule (i.e., a nonbiological molecule) and a modified pyridone with a molecular weight of 185.22, making it a relatively small molecule compared to most biological molecules. Biological inhibitors of cytokines, such as antibodies and modified receptor fragments, can suppress inflammation throughout the body, but are too large to cross the blood-brain barrier. Thus, their effects on neuroinflammation are thought to be indirect. On the other hand, pirfenidone can cross the blood-brain barrier, and therefore may be able to suppress inflammation both throughout the body and in the brain (Macias-Barragan J et al.). To test this hypothesis, a series of experiments, described below, were designed and performed to investigate the use of pirfenidone for POCD in a mouse model.

[0013] The study also included experiments to investigate the therapeutic effects of pirfenidone administration in a mouse model of POCD. This model was developed in a pilot study conducted earlier in this study and was induced by laparotomy and manipulation of abdominal viscera and muscles for 5 min. The weight and physical condition of the animals were carefully monitored throughout the study period, and pirfenidone or saline was orally administered daily before and after surgery. Behavioral tests were performed to evaluate changes in learning and memory processes using the examples of fear conditioning, novel object recognition, and water maze. After euthanasia on the 8th day after surgery, hippocampal tissue was preserved and then evaluated for morphological features related to microglial cell activation.

[0014] The study protocol was reviewed and approved by the Atlantic Veterinary College Animal Ethics Committee. All animal care and experimental procedures conformed to the guidelines established by the Canadian Council on Animal Care (http: / / www.ccac.ca / en / standards / guidelines).

[0015] Upon arrival, mice were group-housed (4 mice per cage) in an SPF facility and allowed a minimum of 7 days to acclimate to the facility and researchers before starting treatment with test substances. During this acclimatization period, mice were handled in a way that minimized stress during study activities. All mice were housed on a standard 12-h day / night lighting schedule (6:00-18:00) and temperature and relative humidity were maintained at 22°C-23°C and 40%-60%, respectively. Standard rodent chow (Lab Diet 5001) and reverse osmosis water were provided ad libitum.

[0016] Mice were weighed 24 hours after arrival, weekly before the start of pirfenidone treatment, and daily thereafter for the duration of the study. After induction, animals were evaluated daily to monitor body condition, pain response, and general recovery parameters.

[0017] Experimental system: Male C57BI / 6 mice Number of animals / group: 12 per group (total 48) Age: Cohort 1: 12 weeks old upon arrival Cohort 2: 10 weeks of age on arrival Model induction: performed at 14 weeks of age Weight: 31.6±0.42 SEM g at surgery Allocation: Animals were pseudo-randomly assigned to treatment groups according to body weight. Health Examination: A health examination was performed by a clinical veterinarian prior to the start of the study.

[0018] Test substance The test article consisted of pirfenidone administered orally (i.e., by gavage) to adult mice at a dose of 400 mg / kg 10 min prior to model induction, followed by either 200 mg / kg (multiple doses) once daily for the remainder of the study, or 400 mg / kg (single dose) at a single time point (10 min prior) prior to model induction. To balance treatment groups and eliminate potential confounding factors, mice in the single dose group received saline only at all remaining time points corresponding to the dosing time points for mice in the multiple dose group.

[0019] Treatment Group: A. Laparotomy + pirfenidone (repeated dose group; 400 mg / kg initially; 200 mg / kg orally once daily for the remainder of the study) B. Laparotomy + pirfenidone (single dose group; 400 mg / kg administered as a single dose before surgery, followed by oral saline once daily for the remainder of the study) C. No surgery + saline (normal control group; saline was administered orally once a day during the study period) D. Laparotomy + saline (disease control group; saline was administered orally once a day during the study period)

[0020] Control group The study included both a normal control group (group C) and a disease control group (group D). For the normal control group of mice, no model induction was performed, but the same amount of saline used for the test substance was administered in the same manner.

[0021] Mice in the negative group (ie, disease control group) underwent surgery to induce the model, and were administered with the same amount of saline as the test substance in the same manner as the test substance.

[0022] TIFF2025515374000002.tif93170

[0023] Pirfenidone dosing and saline administration were prepared as follows: High dose information Identification: Pirfenidone Source: TCI America Appearance: White powder Storage conditions: Store at room temperature (20℃~25℃) in a dark place. High-dose formulations Vehicle: 0.9% saline Usage concentration: 66.67mg / mL Preparation: 1000 mg of pirfenidone in 15 mL of 0.9% saline. Stability in media: stable for at least 8 days High dose administration Method of administration: oral gavage Dose: 6mL / kg per mouse; equivalent to 400mg / kg Dosage frequency: 1 dose; 1 dose pre-surgery for treatment groups A and B Administration period: Started 10 minutes before model induction and continued until euthanasia. Low dose information Identification: Pirfenidone Source: TCI America Appearance: White powder Storage conditions: Store at room temperature (20℃~25℃) in a dark place. Low-dose preparations Vehicle: 0.9% saline Usage concentration: 33.33mg / mL Preparation: Add 12 mL of high-dose pirfenidone to 12 mL of 0.9% saline. Stability in media: stable for at least 8 days Low-dose administration Method of administration: oral gavage Dose: 6mL / kg per mouse, equivalent to 200mg / kg Dosing frequency: daily, treatment group B only Treatment period: 8 days

[0024] Preparing the model open surgery To induce POCD, mice were anesthetized with isoflurane and maintained at the same anesthesia level as for surgery (i.e., 2.0%–2.5%). The abdomen was shaved and cleaned / disinfected with both betadine and ethanol (70%). A 1.5 cm longitudinal incision was made along the midline of the abdomen, and the skin and abdominal cavity were perforated. A sterile blunt probe was inserted into the abdominal cavity, and the abdominal viscera and muscles were manipulated for 5 min. The abdominal muscles and skin were sutured, polysporine and topical lidocaine were applied to the incision site, and buprenorphine (0.1 mg / kg subcutaneous injection) was administered. Animals were placed in clean, pre-warmed home cages to recover and then housed individually.

[0025] Control animals Mice in the disease control (DC) group underwent laparotomy and were administered the same volume of saline as the animals treated with the test substances, whereas mice in the normal control (NC) group did not undergo any surgical procedures but were housed singly in the same manner as the test substance-treated groups for the remainder of the study to avoid breeding confounds, and were administered the same volume and in the same manner as the test substance-treated groups.

[0026] Physical evaluation body weight Mice were weighed 24 hours after arrival, once a week prior to the start of test substance administration, and daily thereafter for the duration of the study. At the time of surgery, there were no differences in body weight between groups (normal controls: 31.7 ± 0.62 g; disease controls: 31.5 ± 79 g; single pirfenidone group: 31.6 ± 1.1 g; multiple pirfenidone group: 31.8 ± 0.92 g). All mice had lost some weight 24 hours after surgery, but this loss did not differ between groups, and all mice gained or maintained their weight over the following week.

[0027] Pain and general health Pain and general health were assessed daily in all animals. Incision sites were inspected for signs of infection or suture failure. Animals that lost more than 1 g of body weight or appeared otherwise ill were fed a hydrated slurry diet to promote weight gain and reduce dehydration until physiology returned to normal.

[0028] Behavioral testing Behavioral tests were performed at various time points throughout the study, as outlined below by category and summarized in Table 2. All tests were recorded and analyzed by an experimenter blinded to treatment. TM Data were obtained through a combination of video tracking system evaluation.

[0029] TIFF2025515374000003.tif116170

[0030] Fear conditioning test Fear conditioning is a commonly used test of associative learning in which neural stimulation is paired with an aversive unconditioned stimulus, resulting in a quantifiable freezing response. Training was performed the day before surgery, and contextual tests were performed on PSD1 (i.e., 2 days after training) and PSD3 (i.e., 4 days after training), with a cued test on PSD3 3 h after the last contextual test. For training and contextual tests, mice were placed in operant chambers (Med Associates). For cued tests, mice were placed in a novel arena with a novel external environment and odor.

[0031] Fear conditioning: training Fear conditioning training was performed to establish an association between a neutral "conditioned" stimulus (a 80 dB tone) and an aversive "unconditioned" stimulus (a 0.4 mA shock). Prior to training, the system was tested to ensure that the shock and tone worked properly. During training, the testing environment was kept quiet and well-controlled. Temperature and humidity levels were kept constant, the operant chambers were hidden from view of the experimenter, and were cleaned between each change of animals. The training protocol was as follows: 1. Each mouse was allowed to acclimate to the testing room for 20 minutes. 2. Video recording was started and the animal's ID card was recorded. 3. Each mouse was placed in an operant chamber and the training protocol was carried out as follows: a. 120 s, no stimulation (habituation to the chamber); b. Sound presentation (80 dB) for 20 seconds; c. 20 s, no stimulus (trace delay period); d. 2-s foot shock (0.4 mA); e. 90 s, no stimulus (intertrial interval); f. Repeat steps a to d, with the last 30 seconds set as a no-stimulus period. 4. The mouse was returned to its home cage.

[0032] Fear conditioning: Contextual testing The purpose of the contextual test is to evaluate contextual memory for an aversive environment. The materials required for this process were an operant test chamber, a video recorder, a stopwatch, and a data recording sheet. During the test, the test environment was kept quiet, with constant temperature and humidity levels, and was properly controlled. The experimenter was not visible from the operant chamber. The chamber was cleaned after each change of animals. Contextual testing was performed as follows: 1. Mice were allowed to acclimate to the testing room for 15 min. 2. Video recording was started and the animal's ID card was recorded. 3. Mice were placed in the operant chamber and given 270 seconds to explore. 4. The mouse was returned to its home cage.

[0033] Fear conditioning: cued tests The purpose of the cued test was to assess cued memory for an aversive stimulus. The materials required for this process were a new chamber with a speaker, a dedicated computer and software, external cues and scented (vanilla) cotton balls, a video recorder, and data recording sheets. Prior to testing, the test system (computer, sound, etc.) was checked for proper operation. Visibility of external cues was checked and fresh scented cotton balls were placed inside the arena. The testing environment was kept quiet and well-controlled, with constant temperature and humidity levels maintained. Experimenters were not visible from the operant chambers, which were cleaned after each animal change. For this test, animals did not need to be habituated to the room. Cue testing was performed as follows: 1. Animals were placed in transfer cages and transported to the testing room. 2. Video recording was started and the animal's ID card was recorded. 3. The mouse was placed in a new chamber and the cued test protocol was initiated on the computer and conducted as follows: a. 135 seconds, no stimulation (pre-tone phase); b. Sound presentation (80 dB) for 135 seconds; c. 30 s, no stimulation (post-tone phase). 4. The mouse was returned to its home cage.

[0034] Consequences of fear conditioning Contextual fear conditioning testing was conducted on PSD1 and PSD3, with animals placed in the same arena used for training and in a contextual environment presented at the same times as the training period. On PSD3, the final contextual test was followed by a cued test phase. This test was conducted in a separate chamber from those used for training and context testing, with different chamber walls, floors, and odors, but the same tone presentation. The primary dependent measure for these test sessions was the time spent freezing.

[0035] The results of the fear conditioning contextual test are shown in the graph in Figure 1. The graph shows the freezing time in seconds for each test group. The test groups are designated as follows: normal control group: NC; disease control group: DC; single pirfenidone administration group: AC PFD; repeated pirfenidone administration group: CR PFD. Error bars indicate SEM. Normal control group (NC) n=11; disease control group (DC) n=11; single pirfenidone administration group (AC PFD) n=12; repeated pirfenidone administration group (CR PFD) n=12.

[0036] In the contextual test of PSD1 (i.e., 2 days after training), a significant main effect between groups was found during the 270-s test period (one-way ANOVA with Welch correction, p=0.042). Post-hoc tests with the LSD procedure revealed a trend towards differences between normal and disease controls (see # symbols; disease controls had shorter freezing times; p=0.078). On the other hand, both normal controls and single-dose pirfenidone-treated animals froze longer (i.e., indicating better contextual memory for the aversive environment) compared to animals in the repeated pirfenidone-treated group (p=0.037 and p=0.027, respectively).

[0037] At PSD3, there were no statistically significant differences between groups (one-way ANOVA p=0.671). Interestingly, within-group evaluation revealed that both normal control and single pirfenidone-treated mice spent less time freezing in the context chamber during this second test run compared to freezing times at PSD1 (paired t-tests p=0.020 and p=0.009, respectively, indicating a trend toward shorter freezing times; disease controls p=0.063). Repeat pirfenidone-treated mice did not differ across test days (paired t-test p=0.942). It is important to note that repeated exposure to the same situation in the absence of an aversive stimulus often results in some extinction of the fear response, so a shorter freezing time would typically be expected during the second run. In this case, it is unclear why the extinction effect was not observed in the repeated pirfenidone-treated animals. However, it should be noted that mice treated with a single dose of pirfenidone again performed comparable to normal controls at PSD3.

[0038] To summarize the results of this experimental model, in which mice were trained 24 hours before surgery and tested on PSD1 and PSD3, the most striking results were obtained with PSD1, but a notable trend was still observed in the results with PSD3.

[0039] Figure 2 shows the results of the fear conditioning cue test (global measure) performed on PSD3 (i.e., 4 days after training). The fear conditioning cue test was assessed at three separate time points: before, during, and after the tone. Although no main effects were observed at any time point (p<0.05 by one-way ANOVA), the mean freezing time tended to be decreased in the disease control group (see # symbols) compared to the normal control group (p=0.075 by t-test), and the repeated pirfenidone-treated mice performed more similarly to the disease control group. The single pirfenidone-treated mice showed improved mean performance (i.e., longer freezing time) compared to both the repeated pirfenidone-treated and disease control mice. In Figure 2, error bars indicate SEM. Normal control group (NC), n=11; disease control group (DC), n=11; single pirfenidone administration group (AC PFD), n=12; repeated pirfenidone administration group (CR PFD), n=12.

[0040] Figure 3 shows the freezing times before, during, and after the tone. Within-group evaluations comparing freezing responses before and during tone, and during and after tone, were statistically significant in all groups (paired t-test p<0.01), indicating that all mice still had a strong aversive association with the tone.

[0041] The post-tone period corresponds closely to trace conditioning, since mice learn during training that a shock follows the tone. Thus, it is the period during which shock is most expected. Here, both disease control and repeated pirfenidone-treated mice showed a tendency to have a decreased freezing time (and therefore a decreased memory) compared to normal control animals (see # symbols - disease control vs normal control, p=0.098; repeated pirfenidone vs normal control, p=0.088). Single pirfenidone-treated mice showed improved mean performance (i.e., longer freezing time) compared to disease control mice. In Figure 3, error bars indicate SEM. Normal control (NC) n=11; disease control (DC) n=11; single pirfenidone (AC PFD) n=12; repeated pirfenidone (CR PFD) n=12.

[0042] Novel object recognition test Novel object recognition (NOR) is a tool used to assess the ability of mice to discriminate between familiar and novel objects (i.e., recognition memory). This example exploits the tendency of rodents to interact more with novel objects than familiar objects. In this task, animals were habituated to the testing arena the day before training (PSD4), and the first test trial (short-term recall) was conducted 1 h after training on PSD5, followed by a second test trial (long-term recall) 24 h later (PSD6). Object recognition can be determined by assessing the proportion of time spent exploring the novel object relative to the total time spent exploring both the novel and familiar objects. Normal animals spend more time exploring the novel object. If the exploration time for both objects is the same, this behavior may be a sign of recognition memory impairment.

[0043] Novel object recognition: Habituation The purpose of habituation was to allow the mice to explore and become accustomed to the test area. The following materials were used: 1. Arena (50cm x 50cm) 2. Webcam / Computer (software "AnyMaze TM ") 3. Stopwatch 4. Data recording sheet.

[0044] The following were general considerations: 1. Ensure that the testing room is quiet and well lit. 2. Clean the arena before acclimation of each animal. 3. Do not place any objects in the arena at this stage. The habituation process was carried out as follows: 1. Animals were placed in transfer cages and transported to the testing room. 2. Video recording was started and the animal's ID card was recorded. 3. The mouse was placed in the center of the arena and allowed to explore freely for 5 min. 4. The mouse was returned to its home cage.

[0045] Novel Object Recognition: Training The goal of novel object recognition training is to have the mice recognize two identical objects. The following materials were used: 1. Arena (50cm x 50cm) 2. Webcam / Computer (software "AnyMaze TM ") 3. Two objects (rectangular blue blocks) 4. Stopwatch 5. Data recording sheet.

[0046] The following were general considerations: 1. Ensure that the testing room is quiet and well lit. 2. Clean the arena before acclimation of each animal. 3. Place each object in the designated location in the arena. The training process for a pair of objects was carried out as follows: 1. Animals were placed in transfer cages and transported to the testing room. 2. Video recording was started and the animal's ID card was recorded. 3. The mouse was placed in the center of the arena and allowed to explore freely for 10 min. 4. The mouse was returned to its home cage.

[0047] Novel object recognition: Test 1 The purpose of this test was to assess short-term (1 hour) recognition memory. The following materials were used: 1. Arena (50cm x 50cm) 2. Webcam / Computer (software "AnyMaze TM ") 3. Familiar object (rectangular blue block) 4. Novel object (pink ball) 5. Stopwatch 6. Data recording sheet.

[0048] General considerations for this protocol were: 1. Ensure that the testing room is quiet and well lit. 2. Clean the arena before acclimation of each animal. 3. Test the animals one hour after training. 4. Rotate the object's location on each trial to eliminate the effects of place preference.

[0049] Novel object (1 hour) testing was conducted as follows: 1. The arena was prepared with one original object (a block) and one novel object (a ball). 2. Animals were placed in transfer cages and transported to the testing room. 3. Video recording was started and the animal's ID card was recorded. 4. The mouse was placed in the center of the arena and allowed to explore for 10 minutes. 5. The mouse was returned to its home cage.

[0050] Novel object recognition: Test 2 The purpose of this study was to assess long-term (24 h) recognition memory. The following materials were used: 1. Arena (50cm x 50cm) 2. Webcam / Computer (software "AnyMaze TM ") 3. Familiar object (rectangular blue block) 4. Novel object (metal dome) 5. Stopwatch 6. Data Recording Sheet

[0051] General considerations for this study were: 1. Ensure that the testing room is quiet and well lit. 2. Clean the arena and objects after each animal change. 3. Test each animal at the same time each day. 4. Rotate the object's location on each trial to eliminate the effects of place preference.

[0052] Novel object (24 h) testing was conducted as follows: 1. The arena was equipped with one original object (a block) and one novel object (a dome). 2. Animals were placed in transfer cages and transported to the testing room. 3. Video recording was started and the animal's ID card was recorded. 4. The mouse was placed in the center of the arena and allowed to explore for 10 minutes. 5. The mouse was returned to its home cage.

[0053] Novel Object Recognition Results In the novel object recognition test, all mice, regardless of treatment, showed similar overall exploration patterns (one-way ANOVA, training, p=0.823; 1-h test, p=0.603; 24-h test, p=0.767), spending the most time interacting with the same object during the training activity. In the novel object test 1 h after training, all groups showed an overall decrease in total time spent interacting with the object compared to training (within-group paired t-tests, normal control, p=0.06; disease control, p=0.03; single pirfenidone, p=0.01; repeated pirfenidone, p=0.04). Exploration time decreased again after 24 h (within-group paired t-tests, 24-h test vs. training, p<0.05), but the difference between exploration time in the 1-h and 24-h tests was not statistically significant in any group. Exploration time data are shown in Figure 4 , with training (T), 1 hour (1), and 24 hour (24) testing time points shown for each group.

[0054] In Figure 4, trends of differences compared to training in the normal control group are indicated with a # symbol, and statistically significant differences in test times compared to training times within groups are indicated with an asterisk. Error bars indicate SEM. Normal control group (NC) n=12, disease control group (DC) n=11, single pirfenidone treatment group (AC PFD) n=12, repeated pirfenidone treatment group (CR PFD) n=12.

[0055] Mice that did not meet the minimum exploration time criteria for the assessment of object preference were excluded from the analysis because they were not expected to have spent sufficient exploration time for learning or discrimination.

[0056] No main effect of treatment was observed at the 1-h (short-term) test (one-way ANOVA p=0.376), but a treatment effect was observed at the 24-h (long-term) test (p=0.054). In post-hoc (LSD) tests, both single- and repeated-pirfenidone-treated mice showed a trend toward increased preference (i.e., increased memory) compared with disease control mice (single-dose vs disease control, p=0.08; repeated-dose vs disease control, p=0.09).

[0057] To further evaluate these trends, memory performance within groups was assessed. These analyses revealed that all groups except disease control mice (paired t-test, p=0.017) retained memory for the familiar object as indicated by statistically equivalent preference indices between test time points (paired t-test, normal control, p=0.477; single pirfenidone, p=0.762; repeated pirfenidone, p=0.828). Graphs of the data at 1 and 24 hours are shown in Figure 5. This figure confirms that disease control mice overall showed a statistically decreased recognition memory between the 1 and 24 hour test periods (indicated by asterisks). This difference was not seen in any of the other groups. Error bars indicate SEM. Normal control group (NC) n=9, disease control group (DC) n=11, single pirfenidone administration group (AC PFD) n=10, repeated pirfenidone administration group (CR PFD) n=12.

[0058] Morris Water Maze The Morris water maze test is a well-established method to assess spatial learning and memory. To navigate the maze, mice must use extramaze cues to find a hidden platform and escape from the water. The test was performed on PSD7. Mice were subjected to two blocks of four 60-s trials, and the latency to reach the platform between blocks was compared as an index of learning and memory processes. Swimming speed was assessed to evaluate motor ability. On PSD8 (i.e., 24 h later), mice were re-introduced to the platform-free maze and a 1-min probe trial was performed to assess reference memory.

[0059] For the Morris Water Maze testing, the following materials were used: 1. Water maze arena (diameter 96 cm, depth 43 cm) 2. White non-toxic paint (to make the water opaque) 3. Escape Platform 4. Webcam / Computer (software "AnyMaze TM ") 5. Stopwatch 6. Data Recording Sheet

[0060] General considerations for this protocol were: 1. Fill the pool with water each day and drain it each day. 2. Maintain the water temperature at 22±1℃. 3. Purify and agitate the water between each change of animals to eliminate odor cues. 4. Submerge the platform 1cm below the water surface and check that it is in the correct position.

[0061] The test protocol was carried out as follows: 1. Animals were brought into the testing room in their transfer cages. 2. Video recording was started and the animal's ID card was recorded. 3. The mouse was gently placed (i.e., without being dropped) into the water in the appropriate starting position (north, south, east, or west) facing the wall of the pool. 4. Mice were given 60 seconds to find and climb onto the underwater platform. If the mouse did not find the platform within the allotted time, it was gently guided away and scored as 61 seconds. 5. Mice were given 60 seconds to recover on the platform and observe extra-maze cues; if they jumped into the water they were immediately searched for and returned to the platform for the remainder of the intertrial interval. 6. Steps 3 to 5 were repeated for a total of four trials (Block 1). 7. The mouse was returned to its travel cage lined with a dry towel and allowed to rest for 5 minutes. 8. Steps 3 to 5 were repeated for a total of four trials (Block 2). 9. Mice were gently dried and returned to their home cages.

[0062] For the Morris Water Maze Probe Test, the following materials were used: 1. Water maze arena (diameter 96 cm, depth 43 cm) 2. White non-toxic paint (to make the water opaque) 3. Webcam / Computer (software "AnyMaze TM ") 4. Stopwatch 5. Data recording sheet.

[0063] General considerations for probe testing were: 1. Fill the pool with water each day and drain it each day. 2. Maintain the water temperature at 22±1℃. 3. Purify and agitate the water between each change of animals to eliminate odor cues. 4. Don’t use platforms.

[0064] A probe session was conducted as follows: 1. Animals were placed in transfer cages and transported to the testing room. 2. Video recording was started and the animal's ID card was recorded. 3. The mouse was gently placed (i.e., without being dropped) into the water in the appropriate starting position (north, south, east, or west) facing the wall of the pool. 4. The mouse was allowed to swim freely for 60 seconds. 5. Mice were gently dried and returned to their home cages.

[0065] The results of latency to reach the platform in the Morris water maze test are shown graphically in Figure 6 (mean latency to reach the platform in the Morris water maze), with error bars indicating SEM. Block 1 = B1, Block 2 = B2, normal control group (NC) n = 11, disease control group (DC) n = 11, single pirfenidone administration group (AC PFD) n = 11, repeated pirfenidone administration group (CD PFD) n = 12.

[0066] During the water maze test, assessment of the early learning process showed an overall main effect of treatment (repeated measures ANOVA [block × treatment], p = 0.016), and post hoc analyses revealed statistically significant decreases in latency to reach the platform in both single- and repeated-pirfenidone-treated groups compared with disease controls (single-dose vs. disease controls, p = 0.028; repeated-dose vs. disease controls, p = 0.052).

[0067] To better understand the initial learning improvements observed in pirfenidone-treated mice in this task, we assessed the latency in each block (see Figure 7). A main effect was observed during Block 1 trials (one-way ANOVA, p = 0.004). Post-hoc analysis showed that mice in the repeated pirfenidone group had a statistically significant reduction in latency to reach the platform compared to both disease and normal controls (Tukey's HSD range test, p = 0.02 and p = 0.03, respectively). Meanwhile, mice in the single pirfenidone group found the platform faster compared to disease controls only (p = 0.04; Tukey's HSD range test). In Block 2, no main effect between groups was observed (one-way ANOVA, p = 0.117; see Figure 7). No differences were observed between pirfenidone treatment groups, and no differences were observed between normal and disease control groups within blocks (p>0.05).

[0068] To evaluate memory function in this study, a paired t-test was used. The decrease in latency between blocks is an indicator of spatial memory for the location of the platform. Here, no statistically significant differences were obtained, but the normal control group showed a decrease in the time to reach the platform between blocks (paired t-test, p=0.12; block 1: 52.3±2.1 SEM, block 2: 45.5±5.1 SEM). This difference was not observed in the other groups (paired t-test, disease control, p=0.81; single pirfenidone group, p=0.61; repeated pirfenidone group, p=0.54).

[0069] The assessment of swimming speed showed no differences between groups (one-way ANOVA, p=0.273). Probe trial testing in the water maze task did not reveal any statistically significant differences between groups in terms of time spent in the target compartment and swimming speed (one-way ANOVA, p>0.05). However, it should be noted that here too, animals in the disease control group showed a reduced mean performance, while treated mice behaved similarly to normal controls. Data on time in the compartment probe test are graphed in Figure 8.

[0070] Assessment of hippocampal microglial cell morphology immunohistological staining A subset of mice was evaluated (n=8 / pirfenidone-treated group) to compare tissues from single and repeated pirfenidone treatments with normal and disease control groups. As an indicator of the level of inflammatory response, the neuroinflammatory marker ionized calcium-binding adaptor molecule 1 (Iba1) was examined in the hippocampus, which is particularly vulnerable to acute and chronic stressors, including those induced by physical trauma.

[0071] end Immediately after the final behavioral test, mice were deeply anesthetized with isoflurane, cardiac blood was collected, and mice were exsanguinated via transcardial perfusion with normal PBS solution, and brain tissue was harvested.

[0072] Brain tissue collection After saline perfusion, the brains were harvested and divided into hemispheres, and the right hemisphere was prepared for immunohistochemical staining. Protocol: Purpose: Materials: For the purpose of providing tissue for subsequent analysis Dissection Kit, Cryovials / Tubes Saline Liquid nitrogen Optimal Cutting Temperature (OCT) medium: 10% neutral buffered formalin plus 30% sucrose

[0073] Cryopreservation of the right hemisphere 1. After dissection, the brain is separated into two hemispheres using a razor blade. 2. Place the right hemisphere in 10% neutral buffered formalin containing 30% sucrose. 3. Store at room temperature for 2 to 3 days to allow complete fixation. 4. Turn the brain so that the cerebellum is facing down and freeze in OCT. 5. Store at -80℃.

[0074] organizational structure To investigate the effects of laparotomy and drug intervention on inflammatory mechanisms in the hippocampus, a section of the right hemisphere of the study mice was evaluated by fluorescent IHC analysis. Iba1 was evaluated as a marker of neuroinflammation, as it indicates inflammatory responses in the central nervous system.

[0075] Tissue preparation Cryoprotected hemispheres were blocked with OCT compound (Thermofisher) and stored at -80°C until sectioning. Three 30 μm thick coronal sections from the rostral, intermediate and caudal regions of the hippocampus were cut using a Leica cryostat (chamber temperature -21°C) into well plates containing Millonig's buffer and stored at +4°C until used for IHC analysis.

[0076] immunohistological staining Heat-induced epitope retrieval (HIER) Scintillation vials containing sodium citrate buffer (10 mM trisodium citrate dihydrate, 0.05% Tween 20, pH adjusted to 6.0) were heated to 80°C in a water bath. All tissues were individually incubated for 10 min and then cooled in buffer for 10 min before proceeding with the remaining steps of the immunohistochemical staining protocol.

[0077] Immunohistochemistry: 2-day protocol After HIER, tissues were permeabilized and blocked for 2 hours at room temperature, then incubated with the appropriate primary antibody cocktail overnight at 4° C. The next day, sections were washed and incubated with the appropriate secondary antibody cocktail for 2 hours at room temperature, then washed again, mounted, and sealed with a coverslip.

[0078] Procedure: Objective: Materials: Protocol: Day 1: immunohistological staining Assessment of Iba1 in brain tissue Iba1 (Abcam ab178846: 1 / 2000) Donkey anti-rabbit donkey 594 (Invitrogen A21207: 1:2000) PBS solution containing 0.3% Triton X-100 (PBS-T) 1× PBS (blocking buffer) containing 2% donkey serum, 0.5% Triton X-100, and 0.1% sodium azide, Fluoromount G, coverslips, and sealant were prepared. Wash tissues 3 times for 10 min with 1.1x PBS. 2. Place the tissue in 100°C sodium citrate buffer for 10 minutes and then cool for an additional 10 minutes. 3. Incubate in blocking buffer for 2 hours at room temperature. 4. Incubate in primary antibody solution / blocking buffer overnight at 4°C and protect from light.

[0079] Day 2 1. Wash sections three times with 1x PBS for 10 min each. 2. Incubate in secondary antibody solution / blocking buffer for 4 hours at room temperature and protected from light. 3. Wash sections three times for 5 min each with 1x PBS to remove secondary antibody. 4. Mount the tissue on a slide, apply Fluoromount G, cover with a coverslip and seal the slide.

[0080] Image Generation Fluorescence microscopy Purpose: Material: procedure: Taking micrographs for quantification Fluorescence microscope (Zeiss Axio Observer Z1); Imaging system: ApoTome.2 Zeiss Imaging Software (Zen2 Blue Edition)

[0081] Settings were manually selected to ensure that the signal was visible for all sections (low intensity sections should have the signal visible, but high intensity sections should not be overexposed). Images were taken using a 20x objective, with the tissue positioned to fully view the CA3 / lateral hippocampal region.

[0082] Quantification of Iba1 Ionized calcium-binding adaptor molecule 1 (Iba1) is a microglia-specific calcium-binding protein that is involved in phagocytosis in activated microglia. It is specifically expressed in macrophages / microglia and its expression is upregulated during activation of these cells. Therefore, Iba1 is a sensitive marker of inflammation and can be quantified by measuring the intensity of Iba1-positive signals.

[0083] The morphology of Iba1-stained microglia can be a sensitive indicator of the cell's response to disease and therefore function. Ramified microglia have elongated, branched processes with small cell bodies and are associated with homeostasis. Activated microglia, on the other hand, have shorter, sometimes thicker processes and a larger cell body. Amoeboid Iba1-stained microglia have large, rounded cell bodies and no processes. Both activated and amoeboid microglia are associated with phagocytic processes and immune responses.

[0084] Right hemisphere hippocampal tissue was non-parametrically ranked and assessed for functional cellular morphology as follows: 0 = normal morphology (branched, nearly branched) 1 = moderate morphology (branching-activation) 2 = Activated form (active, activated amoeboid, amoeboid)

[0085] Morphological results of Iba1 stained tissues 8 days after surgery are shown in Figure 9. Non-parametric evaluation of Iba1 positive cell morphology showed a statistically significant increase in the expression of microglial cells exhibiting activated characteristics in disease control mice compared to normal control mice (post-hoc analysis of Dunn's multiple comparison test, p<0.05). Single and repeated administration of pirfenidone reduced this microglial activation. Asterisks indicate statistically significant differences from normal controls, error bars show SEM. All groups, n=8.

[0086] Summary of Experimental Results Overall, the results of the experiments described herein show that pirfenidone treatment exerts a protective effect against many memory-related behavioral changes in postoperative cognitive dysfunction. During behavioral testing, animals treated with pirfenidone once consistently responded as well as or better than normal controls, and animals treated with repeated pirfenidone also appeared to benefit, especially with respect to recognition memory. At the cellular level, pirfenidone reduced microglial activation in the hippocampus. Pirfenidone is a promising solution to postoperative cognitive dysfunction, a condition that has long lacked adequate treatment and represents an unmet need.

[0087] Pharmaceutical Compositions, Administration and Dosages It is envisaged that the medicament of the present invention can comprise pirfenidone alone, or one or more (i.e. combination) of pirfenidone, its analogue, and / or its derivative.The analogue and derivative of pirfenidone used in the present invention can be any of those disclosed in, for example, U.S. Patent No. 6,090,822; U.S. Patent No. 6,300,349; U.S. Patent No. 6,956,044.Each and all of these patents are incorporated herein by reference in their entirety.

[0088] In addition to pirfenidone (5-methyl-1-phenyl-2-1H-pyridin-2-one), related molecules such as fluorophenidone (1-(3-fluorophenyl)-5-methylpyridin-2-one), mefnidone [1-(4-((3-(4-methylpiperazin-1-yl)propyl)amino)benzyl)-5-(trifluoromethyl)pyridin-2(1H)-one], and other pirfenidone-related analogs and derivatives are contemplated for use in the present invention. These include N-substituted 2(1H)pyridones and N-substituted 3(1H)pyridines, which have been found to be useful in the treatment of disorders caused by the overproduction of inflammatory cytokines.

[0089] The general structural formula of N-substituted 2(1H)pyridones and N-substituted 3(1H)pyridones having the following structures are shown: [ka] [ka] In the 2(1H)pyridone, R2 is an alkyl group and R3 is hydrogen. Alternatively, R3 may be an alkyl group and R2 is hydrogen. R1 and R4 are hydrogen. In the 3(1H)pyridine, R2 is an alkyl group and R3 is hydrogen, or alternatively, R3 may be an alkyl group and R1 is hydrogen.

[0090] In either structure, A is typically an aryl group such as phenyl, thienyl, and the like. It is contemplated that the agents of the present invention have ionizable groups, such as, for example, -COOH and / or -CONH2, each of which can be attached to one or more of the R groups of, for example, two N-substituted pyridones. These two ionizable groups are presented for illustrative purposes and are not limiting in any way. Molecules that have ionizable groups may also have counterions, which makes the molecule a pharma-ceutically acceptable salt. Common counter ions include, but are not limited to, hydrochloride, sodium, sulfate, acetate, phosphate or diphosphate, chloride, potassium, maleate, calcium, citrate, mesylate, nitrate, tartrate, aluminum, gluconate, etc. Pharmaceutical salt preparations can be expected to have certain effects, such as improved solubility, improved gastrointestinal absorption, and changes in drug half-life and metabolism.

[0091] The following are illustrative, but not necessarily limiting, examples of 2 and 3 pyridones: 5-methyl-1-(3-nitrophenyl-2)-(1H)pyridine, 5-methyl-1-(4'-methoxyphenyl)-2-(1H)pyridine, 5-methyl-1-p-tolyl-2-(1H)pyridine, 5-methyl-1-(3'-trifluoromethylphenyl)-2-(1H)pyridone, 1-(4'-chlorophenyl)-5-methyl-2)-(1H)pyridone, 5-methyl-1-(2'-naphthyl)-2-(1H)pyridone, 5-methyl-1-(1'-naphthyl)-2-(1H)pyridone, 3-methyl-1-phenyl-2-(1H)pyridone, 3-ethyl-1-phenyl-2-(1H)pyridone, 6-methyl-1-phenyl-2-(1H)pyridone, 3,6-dimethyl-1-phenyl-2-(1H)pyridone, 5-methyl-1-(2'-thienyl)-2-(1H)pyridone, 1-(2'-furyl)-5-methyl-2-(1H)pyridone, 5-methyl-1-(5'-quinolyl)-2-(1H)pyridone, 5-methyl-1-(4'-pyridyl)-2-(1H)pyridone, 5-methyl-1-(3'-pyridyl)-2-(1H)pyridone, 5-methyl-1-(2'-pyridyl)-2-(1H)pyridone, 5-methyl-1-(2'-quinolyl)-2-(1H)pyridone, 5-methyl-1-(4'-quinolyl)-2-(1H)pyridone, 5-methyl-1-(2'-thiazolyl)-2-(1H)pyridone, 1-(2-imidazolyl)-5-methyl-2-(1H)pyridone, 5-ethyl-1-phenyl-2-(1H)pyridone, 1-phenyl-2-(1H)pyridone, 1-(4'-nitrophenyl)-2-(1H)pyridone, 1,3-diphenyl-2-(1H)pyridone, 1-phenyl-3-(4'-chlorophenyl)-2-(1H)pyridone, 1,3-diphenyl-5-methyl-2-(1H)pyridone, 3-(4'-chlorophenyl-5-methyl-1-phenyl-2-(1H)pyridone, 5-methyl-3-phenyl-1-(2-thienyl)-2-(1H)pyridone, 5-methyl-1-phenyl-3-(1H)pyridone, 5-methyl-1-(4'-methoxyphenyl-3-(1H)pyridone, 5-methyl-1-p-toyl-3-(1H)pyridone, 1-(4'-chlorophenyl)-5-methyl-3-(1H)pyridone, 5-methyl-1-(2'-naphthyl)-2-(1H)pyridone, 4-methyl-1-phenyl-3-(1H)pyridone, 6-methyl-1-phenyl-3-(1H)pyridone, 5-methyl-1-(2'-thienyl)-3-(1H)pyridone, 1-(2'-furyl)-5-methyl-3-(1H)pyridone, 5-methyl-1-(5'-quinolyl)-3-(1H)pyridone, 5-methyl-1-(3'-pyridyl)-3-(1H)pyridone, 5-methyl-1-(2'-pyridyl)-3-(1H)pyridone, 5-methyl-1-(2'-quinolyl)-3-(1H)pyridone, 5-ethyl-1-phenyl-3-(1H)pyridone, 1-Phenyl-3-(1H)pyridone.

[0092] The agents of the invention can be administered before, during, and / or immediately after surgery, and can be administered parenterally, intravenously, intraarterially, intraperitoneally, intrahepatically, intraventricularly, intrathoracically, intracranially, intramuscularly, transdermally, topically, subcutaneously, or by infusion.

[0093] The preparation of drugs for the above-listed administration methods is well known to those skilled in the art of sterile pharmaceutical compounding and dosage formulations. For example, such a person would know of excipients, vehicles, buffers, salts and / or other additional substances that may be used to formulate the drugs of the invention and to facilitate administration to a patient.

[0094] The agent of the present invention can be administered to a patient, most typically by a surgeon or anesthesiologist, with the appropriate formulation, at a time and dose that is consistent with the pharmacokinetics of the agent. The mean terminal half-life of pirfenidone is about 3 hours in healthy subjects. (https: / / www.accessdata.fda.gov / drugsatfda_docs / label / 2017 / 208780s000IbI.pdf). For this reason, during prolonged surgery lasting several hours, it may be necessary to administer the agent multiple times, or administer the agent in a sustained release formulation or continuous infusion.

[0095] For mammals, a daily dose of about 10 mg / kg to about 500 mg / kg of body weight is preferably used. For human patients, a daily dose of about 20 mg / kg to about 150 mg / kg is most preferred. However, for human patients, a single dose of about 200 mg to 3,000 mg is generally used.

[0096] For example, counter anions such as potassium, sodium, calcium, zinc can be used with the -COOH group, and hydrochloride can be used with the -CONH2 group.

[0097] The beneficial results demonstrated in this application are believed to be evidence of similar activity for all compounds disclosed herein and their pharma- ceutically acceptable salts.

Claims

1. A method for preventing and / or treating postoperative cognitive impairment by administering to a human or other mammal an effective amount of one or more compounds selected from the group consisting of N-substituted 2(1H)pyridones, N-substituted 3(1H)pyridones, and any one or more pharma- ceutically acceptable salts thereof, optionally further substituted at various substitutable ring positions.

2. 2. The method of claim 1, wherein in the N-substituted 2(1H)pyridone, R1 and R4 are hydrogen, R2 is a C1-C10 substituted alkyl group, and R3 is hydrogen, or R2 is hydrogen and R3 is a C1-C10 substituted alkyl group.

3. 2. The method of claim 1, wherein in the N-substituted 3(1H)pyridone, R2 is a C1-C10 substituted alkyl group and R3 is hydrogen, or R3 is a C1-C10 substituted alkyl group and R1 is hydrogen.

4. The method according to claim 2, wherein the C1-C10 group of at least one of R2 and R3 is substituted with a fluoro group.

5. The method according to claim 3, wherein the C1 to C10 group of at least one of R2 and R3 is substituted with a fluoro group.

6. 10. The method of claim 1, wherein one or more of said compounds are administered in a total amount of from about 10 mg to about 500 mg / kg of body weight per day.

7. 7. The method of claim 6, wherein one or more of said compounds are administered in a total amount of about 20 mg to about 150 mg / kg of body weight per day.

8. 10. The method of claim 1, wherein the amount administered to a human is from about 200 mg to about 3,000 mg per dose.

9. 10. The method of claim 1, wherein the one or more compounds and / or salts thereof are administered pre-operatively, intra-operatively, post-operatively, or a combination thereof.

10. 10. The method of claim 9, wherein the one or more compounds and salts thereof are administered as a sustained release formulation prior to surgery or by continuous infusion during surgery.

11. 10. The method of claim 1, wherein the one or more compounds administered is pirfenidone or a pharma- ceutically acceptable salt thereof.

12. The pharma- ceutically acceptable salt of the one or more compounds is selected from the group —COOH or —CONH ２ The method of claim 10 comprising an inorganic salt of the group.

13. The method of claim 11, wherein the salt of the -COOH group has a pharma- ceutically acceptable counterion comprising any of potassium, sodium, calcium, and zinc cations.

14. Said-CONH ２ 12. The method of claim 11, wherein the salt of the group is protonated to comprise a hydrochloride salt with a pharma- ceutically acceptable counterion.

15. 10. The method of claim 1, wherein the one or more compounds and / or pharma- ceutically acceptable salts thereof are administered in a form selected from the group including capsules, tablets, powders, granules, syrups, aerosols, injections, intravenous injections, pills, creams, ointments, inhalants, eye drops, and suppositories.

16. 2. The method of claim 1, wherein the one or more compounds or pharma- ceutically acceptable salts thereof reduce microglial activation in the hippocampus.

17. The method of claim 1, wherein the N-substituted 2(1H) and 3(1H) pyridones are comprised of any one or combination of the following: 5-methyl-1-(3-nitrophenyl-2)-(1H)pyridine, 5-methyl-1-(4'-methoxyphenyl)-2-(1H)pyridine, 5-methyl-1-p-tolyl-2-(1H)pyridine, 5-methyl-1-(3'-trifluoromethylphenyl)-2-(1H)pyridone, 1-(4'-chlorophenyl)-5-methyl-2)-(1H)pyridone, 5-methyl-1-(2'-naphthyl)-2-(1H)pyridone, 5-methyl-1-(1'-naphthyl)-2-(1H)pyridone, 3-methyl-1-phenyl-2-(1H)pyridone, 3-ethyl-1-phenyl-2-(1H)pyridone, 6-methyl-1-phenyl-2-(1H)pyridone, 3,6-dimethyl-1-phenyl-2-(1H)pyridone, 5-methyl-1-(2'-thienyl)-2-(1H)pyridone, 1-(2'-furyl)-5-methyl-2-(1H)pyridone, 5-methyl-1-(5'-quinolyl)-2-(1H)pyridone, 5-methyl-1-(4'-pyridyl)-2-(1H)pyridone, 5-methyl-1-(3'-pyridyl)-2-(1H)pyridone, 5-methyl-1-(2'-pyridyl)-2-(1H)pyridone, 5-methyl-1-(2'-quinolyl)-2-(1H)pyridone, 5-methyl-1-(4'-quinolyl)-2-(1H)pyridone, 5-methyl-1-(2'-thiazolyl)-2-(1H)pyridone, 1-(2-imidazolyl)-5-methyl-2-(1H)pyridone, 5-ethyl-1-phenyl-2-(1H)pyridone, 1-phenyl-2-(1H)pyridone, 1-(4'-nitrophenyl)-2-(1H)pyridone, 1,3-diphenyl-2-(1H)pyridone, 1-phenyl-3-(4'-chlorophenyl)-2-(1H)pyridone, 1,3-diphenyl-5-methyl-2-(1H)pyridone, 3-(4'-chlorophenyl-5-methyl-1-phenyl-2-(1H)pyridone, 5-methyl-3-phenyl-1-(2-thienyl)-2-(1H)pyridone, 5-methyl-1-phenyl-3-(1H)pyridone, 5-methyl-1-(4'-methoxyphenyl-3-(1H)pyridone, 5-methyl-1-p-toyl-3-(1H)pyridone, 1-(4'-chlorophenyl)-5-methyl-3-(1H)pyridone, 5-methyl-1-(2'-naphthyl)-2-(1H)pyridone, 4-methyl-1-phenyl-3-(1H)pyridone, 6-methyl-1-phenyl-3-(1H)pyridone, 5-methyl-1-(2'-thienyl)-3-(1H)pyridone, 1-(2'-furyl)-5-methyl-3-(1H)pyridone, 5-methyl-1-(5'-quinolyl)-3-(1H)pyridone, 5-methyl-1-(3'-pyridyl)-3-(1H)pyridone, 5-methyl-1-(2'-pyridyl)-3-(1H)pyridone, 5-methyl-1-(2'-quinolyl)-3-(1H)pyridone, 5-ethyl-1-phenyl-3-(1H)pyridone, 1-Phenyl-3-(1H)pyridone.

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