Application of cycloglycine-proline in preparation of medicine for treating violent eating

Abstract

The invention discloses an application of cycloglycine-proline in preparation of a medicine for treating sudden eating diseases. The cycloglycine-proline disclosed by the invention is applied to the preparation of the medicine for treating the sudden eating disease. The cycloglycine-proline disclosed by the invention is applied to the preparation of active ingredients of medicines for treating the violent eating diseases (particularly violent eating diseases caused by emotional eating induced by social psychological stress), has the advantages of small molecular weight, strong lipophilicity, enzymatic stability, high bioavailability after oral administration and the like, and can be effectively absorbed by a central nervous system. The invention has a significant application value in treatment of overeating (especially overeating induced by emotional eating).

Description

Technical Field

[0001] The invention belongs to the field of application of drugs for treating bulimia, and relates to application of cycloglycine-proline in preparing drugs for treating bulimia. Background Art

[0002] Obesity has become a major public health problem worldwide. Obesity increases the risk of a variety of diseases, including type 2 diabetes, high blood pressure and high cholesterol, musculoskeletal problems, and several types of cancer. Binge eating disorder is often associated with obesity and physical and mental health complications. In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), Binge Eating Disorder (BED) is defined as "repeated episodes of eating significantly more food than most people would eat under similar circumstances over a short period of time, accompanied by a sense of lack of control." It is estimated that the global prevalence of binge eating disorder was 0.6% to 1.8% among adult women and 0.3% to 0.7% among adult men between 2018 and 2020. Existing research shows that emotion regulation disorders and emotional states affect eating behavior and play a critical role in the development and persistence of obesity.

[0003] Negative emotions and stress can trigger excessive eating, a pattern of eating known as emotional eating. Emotional eating is not a standalone eating disorder, but rather an eating behavior that is influenced by behaviors, stress, emotions, and personal feelings associated with eating. Emotional eating, or comfort eating, and stress-induced eating, all result in an individual’s tendency to eat when experiencing negative emotions. Emotional eating is positively associated with increased weight gain over time. This can be attributed to emotional eaters’ greater tendency to consume larger amounts of sugary and high-fat foods, eat in stressful situations, and snack more frequently than non-emotional eaters. These eating patterns serve as a coping mechanism to control and reduce negative emotions, such as low mood, anxiety, and stress. Furthermore, emotional eating is often considered a major contributing factor in models of eating disorders and pathological eating attitudes, such as overeating and binge eating, and can lead to significant psychological distress and health problems.

[0004] Insulin-like growth factor 1 (IGF-1) is produced in many organs and has biological effects on most cells. It stimulates amino acid transport, protein synthesis, and body growth. In patients with eating disorders, IGF-1 is closely associated with body mass index (BMI), body fat, and body muscle mass. Cyclic glycine-proline (cGP) is a naturally occurring substance produced by cyclization of the N-terminal tripeptide of IGF-1. cGP has the advantages of small molecular weight, strong lipophilicity, enzymatic stability, high bioavailability after oral administration, and can be effectively absorbed by the central nervous system. However, whether cGP has the therapeutic potential to improve long-term psychosocial stress-induced binge eating disorder has not been evaluated. Summary of the invention

[0005] The purpose of the present invention is to provide the use of cycloglycine-proline in preparing a medicine for treating bulimia.

[0006] The present invention targets the structurally stable cyclic dipeptide cycloglycine-proline (cGP) and evaluates its biological activity in drug treatment of binge eating disorder from the perspective of improving emotional eating, which has great application value for the treatment of binge eating disorder.

[0007] Use of cycloglycine-proline or a pharmaceutically acceptable salt thereof provided by the present invention in preparing a drug for treating bulimia; The structural formula of the cycloglycine-proline is shown in Formula I below: .

[0008] In the present invention, the cycloglycine-proline, English name Cyclic glycine-proline, English abbreviation cGP, molecular formula C7H 10 N2O2, molecular weight is 154.17.

[0009] The above application is characterized in that the bulimia is bulimia induced by emotional eating.

[0010] In the above application, the bulimia is bulimia caused by negative emotions induced by long-term social and psychological stress.

[0011] In the above application, the bulimia is bulimia caused by cognitive dysfunction induced by long-term psychosocial stress.

[0012] In the above application, the dosage form of the drug is a dosage form for gastrointestinal administration or a dosage form for parenteral administration.

[0013] In the above applications, the intestinal tract dosage forms include powders, tablets, granules, capsules, solutions, emulsions or suspensions; and the parenteral dosage forms include injections.

[0014] In the above application, the treatment of binge eating disorder in the subject is manifested in improving emotional eating in mice, reducing negative emotions induced by long-term social and psychological stress, and enhancing the cognitive function of emotional eating mice.

[0015] In the above application, the pharmaceutically acceptable salt of cycloglycine-proline is selected from at least one of hydrochloride, nitrate, methanesulfonate, phosphate, citrate, fumarate, sulfate, succinate, tartrate, citrate, hydrobromide, hydroiodide, acetate, lactate, tosylate, cinnamate, salicylate, malonate, glutarate and malate.

[0016] The present invention also provides a pharmaceutical composition for treating bulimia, which comprises the cycloglycine-proline or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

[0017] In the above-mentioned pharmaceutical composition, the dosage form of the pharmaceutical composition includes powder, tablet, granule, capsule, solution, emulsion, suspension or injection.

[0018] The present invention has the following beneficial effects: The cycloglycine-proline (cGP) of the present invention is used in the preparation of an active ingredient for a drug for treating binge eating disorder (specifically, binge eating disorder caused by emotional eating induced by social and psychological stress). cGP has the advantages of small molecular weight, strong lipophilicity, enzymatic stability, high bioavailability after oral administration, and can be effectively absorbed by the central nervous system. The present invention has great application value for the treatment of binge eating disorder (especially binge eating disorder induced by emotional eating). BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram showing that long-term social and psychological stress induces eating disorders and negative emotions in mice. Figure 1 A in the middle represents the experimental flow chart of long-term social and psychological stress inducing eating disorders and negative emotions in mice, B represents daily food intake, C represents body weight changes, D represents the novel environment inhibition feeding experiment, E represents the elevated plus maze experiment, F represents the spontaneous activity test, G represents the social interaction behavior test, H represents the forced swimming test, I represents the tail suspension test, J represents the novel object recognition experiment - the time the mice stay on the novel object, and K represents the novel object recognition experiment - the recognition index of the mice for the novel object.

[0020] Figure 2This is a schematic diagram of the results of cycloglycine-proline improving emotional eating in mice. Figure 2 A in the figure represents the experimental flow chart of cycloglycine-proline improving emotional eating in mice, B represents daily food intake, and C represents body weight changes.

[0021] Figure 3 This is a schematic diagram of the results of cycloglycine-proline reducing anxiety-induced behaviors induced by long-term psychosocial stress. Figure 3 A in the figure represents the experimental flow chart of cycloglycine-proline reducing anxiety behavior induced by long-term psychosocial stress, B represents the novel environment inhibition feeding experiment, C represents the elevated plus maze experiment, and D represents the spontaneous activity test.

[0022] Figure 4 This is a schematic diagram of the results of cycloglycine-proline alleviating long-term psychosocial stress-induced depressive behavior. Figure 4 A in the figure represents the experimental flow chart of cycloglycine-proline alleviating depressive behavior induced by long-term psychosocial stress, B represents social interaction behavior test, C represents forced swimming test, and D represents tail suspension test.

[0023] Figure 5 This is a schematic diagram of the results of cycloglycine-proline enhancing the cognitive function of emotional eating mice. Figure 5 A in the figure represents the experimental flow chart of cycloglycine-proline enhancing the cognitive function of emotional eating mice, B represents the novel object recognition experiment - the time the mice stay on the novel object, and C represents the novel object recognition experiment - the recognition index of the mice for the novel object. DETAILED DESCRIPTION

[0024] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0025] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0026] In the following examples, cycloglycine-proline (cGP) was purchased from Bachem (G-1720). The preparation method of cGP was 3 mg dissolved in 20 ml of normal saline, the intragastric volume was 0.2 ml / 10 g body weight, and the intragastric dose for mice was 3 mg / kg.

[0027] In the following examples, the high-fat feed was purchased from Biopac Biotechnology Co., Ltd., and the food ingredients included corn starch (115.5 g / kg), casein (200 g / kg), sucrose (100 g / kg), dextrin starch (132 g / kg), lard (312 g / kg), soybean oil (40 g / kg), cellulose (50 g / kg), minerals (35 g / kg), vitamins (10 g / kg), L-cysteine ​​(3 g / kg), and choline (2.5 g / kg), wherein 60% of the calories came from fat.

[0028] In the following examples, the experimental animals were 3-week-old C57BL / 6J female mice (weight 7-9 g) purchased from Beijing Huafukang Biotechnology Co., Ltd., license number: SCXK (Beijing) 2019-0008. The animals were kept in an SPF animal room, maintaining temperature (22±2°C), humidity (50±10%) and 12h circadian rhythm cycle (8:00-20:00 as light cycle). Animals can drink water and eat freely, and behavioral evaluation is performed during the dark cycle. All operations on animals are in compliance with the requirements of experimental animal ethics and follow the regulations promulgated by the National and Peking University Health Science Center Animal Use and Protection Committee.

[0029] Establishment of animal model of long-term social psychological stress: In the process of biological evolution, social interaction has become a basic need for social animals, just like eating, drinking, and sleeping. Therefore, lack of social interaction or even social isolation is a kind of social psychological stress, which will generally have a negative impact on mental health at all ages and even increase the risk of multiple mental disorders. This experiment used social isolation of mice to establish a long-term social psychological stress model based on previous studies. Starting from the 21st day after birth, female C57BL / 6J mice were kept in single cages (Isolation) or group-housed (Control) for 8 consecutive weeks, and both groups of mice were given a regular amount of high-fat food at the same time. Before and during the experiment, the food intake and weight of each group of animals were recorded daily. After 8 weeks, social behavior experiments, spontaneous activity tests, novel environment inhibition feeding experiments, elevated plus maze tests, forced swimming experiments, tail suspension experiments, and novel object recognition were used to detect the behavioral performance of mice, and the effects of long-term social psychological stress on the feeding situation, weight, negative emotions, and cognitive functions of mice were analyzed.

[0030] Social behavior test: The social behavior experiment was divided into two stages, each lasting 2.5 min, with a 30 s interval between the two stages. The experiment was conducted in a 42 cm × 42 cm × 25 cm open field. In the first stage, the C57BL / 6J test mice were randomly placed in the far corner of the interaction area. A 3 cm × 6 cm × 25 cm plastic transparent box covered with small holes was placed in the interaction area. No mice were placed in the box. The C57BL / 6J test mice were allowed to move freely in the open field, and the time the C57BL / 6 test mice stayed in the interaction area was recorded. In the second stage, a mouse was placed in the transparent box, and the C57BL / 6 test mouse was placed back in the corner of the open field. The interaction between the C57BL / 6J test mouse and the mouse was observed, and the time (seconds) that the C57BL / 6 test mouse was in the interaction area was recorded.

[0031] Spontaneous activity test: An open field test was conducted in a 42 cm × 42 cm × 25 cm open field. The mice were placed in the center of the open field and the distance they moved within 5 min was recorded as the evaluation standard for the spontaneous activity level of the animals.

[0032] Novel environment inhibited feeding experiment: mice were fasted for 24 h before the test. The test was conducted in an opaque acrylic box with an open top of 42 cm × 42 cm × 42 cm. Four food pellets of similar size were placed in the center of the test box. The mice were gently placed in the test box from the corner. The time from the start of the test to the mice's food intake was the latency to feed, which was used as an indicator to evaluate anxiety-like behavior. During the test, the mice were allowed to explore freely in the test box for 10 min, with the longest latency of 600 s. After the test, the mice were returned to their original living cages. The excrement left in the test box was cleaned between the tests of every two mice, and the test box was wiped with 75% alcohol to remove residual odors.

[0033] Elevated plus maze test: The mouse elevated plus maze test apparatus consists of two open arms (30 cm × 5 cm), two closed arms (30 cm × 5 cm, 23 cm high) and a central area (5 cm × 5 cm). The open arms are 75 cm above the ground. At the beginning of the test, the mouse is gently placed in the central area with its head facing the open arm. The mouse freely explores the elevated plus maze for 6 min. The time (s) that the mouse stays in the open arm is recorded as an indicator for evaluating anxiety-like behavior. The excrement left in the test box is cleaned between the tests of every two mice, and the test box is wiped with 75% alcohol to remove residual odor.

[0034] Forced swimming test: The forced swimming test was conducted in a 20 cm diameter, 30 cm high organic glass tank, with a water depth of 15 cm and a water temperature of 23 ± 1°C. When the mouse is swimming, it is ensured that it cannot rely on its limbs or tail for support, and that the tip of its nose can be above the water surface for breathing. The swimming time is 6 min, and after 2 min of adaptation, the floating immobility time (seconds) of the mouse is recorded as an indicator of despair behavior.

[0035] Tail suspension test: In the mouse tail suspension test device, use white tape to fix the mouse upside down on the suspension rod of the tail suspension test device 1 cm from the tip of its tail. Hang it for 6 minutes and record the immobility time (seconds) of the mouse in the last 5 minutes.

[0036] Novel object recognition test: The mouse novel object recognition test is divided into two stages, each stage lasts 3 minutes, and the two stages are separated by 15 minutes. The experiment was conducted in a 40 cm × 27 cm × 18 cm open field. In the first stage, two identical objects A were placed in the center of the open field, and the test mice were placed from the corners to allow the test mice to freely explore the two identical objects A. In the second stage, familiar objects A and novel objects B were placed in the center of the open field. Objects B and A were different in properties, materials, and colors. The test mice were allowed to explore freely in the open field. The time the mice explored objects A and B was recorded respectively. The cognitive ability of the mice was evaluated using the novel object recognition index as an indicator. The novel object recognition index = time to explore object B / (time to explore object A + time to explore object B).

[0037] Statistics: Data were analyzed using GraphPad Prism8 software (GraphPad Software Inc.). All results are expressed as mean ± standard error (mean ± SEM). Two-way ANOVA Bonferronis multiple analysis was used for the two-factor experimental results. The differences between the two groups were analyzed using the two-tailed unpaired t-test. p <0.05 was used as the standard for significant difference.

[0038] Example 1: Long-term psychosocial stress induces eating disorders and negative emotions in mice The experiment used 18 3-week-old C57BL / 6J female mice and randomly divided them into two groups: a normal group-raising (Control) group and a social isolation (Isolation) group, with 9 mice in each group. Before the experiment began, the daily food intake and body weight of the two groups of mice were measured, which was the baseline value (Baseline). Subsequently, the mice in the social isolation (Isolation) group were housed in single cages (that is, 1 mouse was placed in each standard cage), and 4-5 mice were placed in each standard cage in the normal group-raising (Control) group. The whole process lasted for 8 weeks. During this process, both groups of mice were given a regular amount of high-fat feed. After the end of the 8th week, the mice's eating habits and body weight (recorded as Week-8), as well as negative emotions of anxiety and depression and cognitive functions were tested. All experiments were completed within one week. During this process, each group of mice still maintained their original handling mode and eating habits. The experimental process is as follows Figure 1 As shown in A, the specific results are as follows: Mice that underwent eight weeks of social isolation showed an increase in their intake of high-fat food compared to baseline values. p <0.001, e.g. Figure 1 However, the food intake of mice in normal group housing (Control) did not differ significantly from the baseline value at Week 8 (Week-8). The food intake of the Isolation group increased significantly compared with the Control group at Week 8 ( p <0.001, e.g. Figure 1 This indicates that the psychosocial stress caused by long-term social isolation increases the intake of high-fat food in mice. In addition, the data of animal weight monitoring showed that compared with the baseline value (Baseline), both the Isolation group and the Control group mice showed a trend of weight gain; however, in Week 8 (Week-8), the weight gain of the Isolation group mice was more obvious than that of the Control group ( p <0.001, e.g. Figure 1 (shown in middle C), indicating that long-term psychosocial stress increases the food intake and body weight of mice.

[0039] The results of the novel environment inhibition feeding experiment showed that after 8 weeks of social isolation, mice showed a longer latency to feed compared with the control group ( p <0.001, e.g. Figure 1 In the elevated plus maze test, the socially isolated mice (Isolation) spent less time in the open arm compared to the control group (Control). p <0.001, e.g. Figure 1The two groups of mice showed no significant difference in spontaneous activity test ( p >0.05, e.g. Figure 1 The results of the social behavior test showed that the mice isolated for 8 weeks showed obvious social avoidance behavior, that is, the interaction ratio in the interaction area decreased significantly ( p <0.01, e.g. Figure 1 In the forced swimming test, social isolation mice showed a significant increase in immobility time ( p <0.001, e.g. Figure 1 In the tail suspension test, social isolation mice also showed a significant increase in immobility time ( p <0.001, e.g. Figure 1 In the novel object recognition experiment to evaluate cognitive ability, social isolation mice showed a decrease in the time they spent on the novel object ( p <0.001, e.g. Figure 1 J in the figure), and has a lower recognition index ( p <0.001, e.g. Figure 1 K), indicating that the cognitive abilities of mice were impaired.

[0040] The above results show that the psychological stress caused by long-term social isolation not only causes eating disorders and weight gain in mice, but also increases negative emotions such as anxiety and depression, and is also accompanied by a decline in cognitive function. This further confirms that emotional regulation disorders and emotional states do affect eating behavior, and reducing emotional eating by enhancing cognitive abilities is expected to improve eating disorders and the binge eating behavior caused by them.

[0041] Example 2: Cycloglycine-proline improves emotional eating in mice The experimental process is as follows Figure 2 As shown in A. After 8 weeks of social isolation and high-fat diet intervention, the mice were randomly divided into 2 groups, with 9 mice in each group. Starting from the 9th week, the two groups of animals were given saline and cycloglycine-proline (cGP, 3 mg / kg) by oral gavage once a day for 4 consecutive weeks. The animals' eating habits and weight changes were tested in the 12th week. The experimental results showed that compared with the saline group, the food intake of mice treated with cGP for 4 weeks was significantly reduced ( p <0.001, e.g. Figure 2 Similarly, the body weight of mice treated with cGP also decreased significantly ( p<0.001, e.g. Figure 2 These results indicate that cGP treatment can significantly improve emotional eating behavior and weight gain in mice induced by long-term psychosocial stress.

[0042] Example 3: Cyclic Glycine-Proline Reduces Negative Emotions Induced by Long-term Social Psychological Stress This example first evaluates the effect of cycloglycine-proline (cGP) on anxiety behavior in mice induced by long-term social and psychological stress. Figure 3 As shown in A. After 8 weeks of social isolation and high-fat diet intervention, the mice were randomly divided into 2 groups, with 9 mice in each group. Starting from the 9th week, the two groups of animals were given saline and cycloglycine-proline (cGP, 3 mg / kg) by oral gavage once a day for 4 consecutive weeks. At the 12th week, the anxiety behavior of the mice was detected by novel environment inhibition of food intake, elevated plus maze and spontaneous activity tests. The experimental results showed that compared with the saline group (saline), the latency of mice to eat in the novel environment inhibition of food intake experiment was significantly shortened in the mice that had been intervened with cGP for 4 weeks ( p <0.001, e.g. Figure 3 Mice in the cGP-treated group also spent more time in the open arms in the elevated plus maze test than mice in the saline group (Fig. p <0.001, e.g. Figure 3 C), indicating that the anxiety behavior of mice was alleviated; however, cGP intervention for 4 weeks did not affect the normal spontaneous activity ability of mice ( p >0.05, e.g. Figure 3 The above results suggest that cGP treatment can significantly improve the anxiety of mice caused by long-term social and psychological stress.

[0043] In addition, this example also evaluates the effect of cycloglycine-proline (cGP) on long-term social and psychological stress-induced depressive behavior in mice. Figure 4 As shown in A. After 8 weeks of social isolation and high-fat diet intervention, the mice were randomly divided into 2 groups, with 9 mice in each group. Starting from the 9th week, the two groups of animals were given saline and cycloglycine-proline (cGP, 3 mg / kg) by oral gavage once a day for 4 consecutive weeks. At the 12th week, social behavior, forced swimming test and tail suspension test were performed to detect the depressive behavior of mice. The results of the social behavior test showed that compared with the saline group, the mice that had been intervened by cGP for 4 weeks had a significantly increased interaction ratio in the interaction area ( p <0.0001, e.g. Figure 4(B), indicating that cGP improved the social avoidance behavior of mice with long-term social and psychological stress. The results of the forced swimming test showed that compared with the saline group, the immobility time of mice treated with cGP for 4 weeks was significantly reduced ( p <0.0001, e.g. Figure 4 The tail suspension test also showed that the immobility time of mice treated with cGP for 4 weeks was significantly reduced compared with the saline group ( p <0.001, e.g. Figure 4 The above results suggest that cycloglycine-proline (cGP) can reduce negative emotions induced by long-term psychosocial stress and has potential therapeutic value for binge eating disorder caused by emotional eating.

[0044] Example 4: Cycloglycine-proline enhances cognitive function in emotional eating mice The experimental process is as follows Figure 5 As shown in A. After 8 weeks of social isolation and high-fat diet intervention, the mice were randomly divided into 2 groups, with 9 mice in each group. Starting from the 9th week, the two groups of animals were given saline and cycloglycine-proline (cGP, 3 mg / kg) by oral gavage once a day for 4 consecutive weeks. At the 12th week, a new object recognition experiment was used to detect the cognitive function of the mice. The experimental test results showed that compared with the saline group, the mice that had been intervened by cGP for 4 weeks had a stronger ability to explore new objects, that is, they stayed at the new objects for a longer time ( p <0.0001, e.g. Figure 5 B), and also showed a higher recognition index ( p <0.01, e.g. Figure 5 This result suggests that cycloglycine-proline (cGP) can improve the cognitive ability of mice subjected to long-term psychosocial stress.

Claims

1. Use of cycloglycine-proline or a pharmaceutically acceptable salt thereof in the preparation of a drug for treating bulimia; The structural formula of the cycloglycine-proline is shown in Formula I below: 。 2. The use according to claim 1, characterized in that: The binge eating disorder is binge eating disorder induced by emotional eating.

3. The use according to claim 1 or 2, characterized in that: The bulimia nervosa is bulimia nervosa caused by negative emotions induced by long-term social and psychological stress.

4. The use according to claim 1 or 2, characterized in that: The bulimia nervosa is bulimia nervosa caused by cognitive dysfunction induced by long-term psychosocial stress.

5. The use according to claim 1 or 2, characterized in that: The dosage form of the drug is a dosage form for gastrointestinal administration or a dosage form for parenteral administration.

6. The use according to claim 5, characterized in that: The dosage forms for administration via the gastrointestinal tract include powders, tablets, granules, capsules, solutions, emulsions or suspensions; The parenteral dosage form includes injection.

7. The use according to claim 1 or 2, characterized in that: The treatment of binge eating disorder in the subject is manifested in improving the emotional eating of mice, reducing the negative emotions induced by long-term social and psychological stress, and enhancing the cognitive function of emotional eating mice.

8. The use according to claim 1 or 2, characterized in that: The pharmaceutically acceptable salt of cycloglycine-proline is selected from at least one of hydrochloride, nitrate, methanesulfonate, phosphate, citrate, fumarate, sulfate, succinate, tartrate, citrate, hydrobromide, hydroiodide, acetate, lactate, tosylate, cinnamate, salicylate, malonate, glutarate and malate.

9. A pharmaceutical composition for treating binge eating disorder, characterized in that: The pharmaceutical composition comprises the cycloglycine-proline or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

10. The pharmaceutical composition according to claim 9, characterized in that The dosage form of the pharmaceutical composition includes powder, tablet, granule, capsule, solution, emulsion, suspension or injection.

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