Novel small peptides and their use in antagonizing metabolic disorder-related fatty liver

Abstract

To provide a novel small-molecule peptide and a use thereof against metabolic dysfunction-associated fatty liver disease (MAFLD).SOLUTION: The small-molecule peptide has a sequence including Tyr and Phe. The small-molecule peptide has activity in inhibiting fat build-up in the liver, controlling metabolizing enzymes in the liver, and controlling the blood glucose level. The small-molecule peptide can be used to treat or improve MAFLD and MAFLD-related diseases.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a peptide and its use, in particular to a novel low molecular weight peptide and its use in antagonizing fatty liver associated with metabolic disorders. [Background technology]

[0002] Since the liver is the main metabolic organ, once liver cells are damaged, the liver's metabolic function is impaired, leading to various metabolic diseases such as chronic hepatitis, cirrhosis, and hepatitis. Metabolic-associated fatty liver disease (MAFLD), also known as nonalcoholic fatty liver disease, is a disease in which excessive accumulation of fat in the liver causes liver damage. When a large amount of fat accumulates in the liver, it leads to lipotoxicity, which causes diseases such as hepatocyte ballooning and lobular inflammation. In addition, patients with metabolic-associated fatty liver often also suffer from other metabolic diseases such as obesity, hyperlipidemia, diabetes, and hypertension.

[0003] The incidence of metabolic disorder-related fatty liver is increasing, but currently there is no effective clinical treatment for metabolic disorder-related fatty liver, and patients can only improve the symptoms of fatty liver by increasing exercise, controlling diet and losing weight. However, since the majority of patients cannot continue to improve their lifestyle habits, developing a method to treat and improve metabolic disorder-related fatty liver is an important clinical issue. [Summary of the invention] [Problem to be solved by the invention]

[0004] The main object of the present invention is to provide a novel low molecular weight peptide and its use for antagonizing fatty liver associated with metabolic abnormality. That is, the low molecular weight peptide disclosed in the present invention has the activity of suppressing fat accumulation and controlling glucose metabolism, and therefore, by administering an effective amount of the low molecular weight peptide disclosed in the present invention to an individual, diseases caused by metabolic imbalance, particularly fatty liver and its related diseases, can be effectively treated or prevented. [Means for solving the problem]

[0005] To achieve the above-mentioned objectives, the present invention discloses a small peptide, the amino acid sequence of which comprises a sequence consisting of Tyr and Phe.

[0006] Specifically, the amino acid sequence of the small peptide disclosed in the present invention includes any one of the following sequences: the sequence shown in SEQ ID No.: 1, the sequence shown in SEQ ID No.: 2, Tyr-Phe, or Phe-Tyr.

[0007] In one embodiment of the invention, the small peptide is a dipeptide, the amino acid sequence of which is Tyr-Phe or Phe-Tyr.

[0008] In another embodiment of the invention, the small peptide is a tetrapeptide, the amino acid sequence of which is the sequence shown in SEQ ID No.:1 or the sequence shown in SEQ ID No.:2.

[0009] Furthermore, since the small molecular weight peptides disclosed in the present invention have the activity of suppressing fat accumulation and controlling glucose metabolism, the examples of the present invention disclose the use of the small molecular weight peptides for treating and / or preventing metabolic disorder-associated fatty liver and its associated symptoms, or for weight loss.

[0010] Among them, conditions related to metabolic disorder-related fatty liver are related to imbalances in blood sugar control, such as diabetes, hyperglycemia, and insulin dysfunction.

[0011] Among them, symptoms associated with metabolic abnormality-related fatty liver include hypertension, hyperlipidemia, cardiovascular disease, and obesity, which are related to fat accumulation and fat metabolic imbalance.

[0012] In another embodiment of the present invention, compositions such as food, dietary supplements, pharmaceuticals, functional foods, etc., are disclosed that contain an effective amount of any one of the small peptides described above or a combination thereof. [Brief description of the drawings]

[0013] [Figure 1] The results are shown in the analysis of the percentage of weight gain in mice in each group. [Diagram 2] 4 shows the results of fasting blood glucose measurement for mice in each group. [Diagram 3] The figures show the results of blood glucose level measurements taken 0, 30, 60, 90, and 120 minutes after glucose administration in an oral glucose tolerance test performed on each group of mice. [Figure 4] 4 shows the results of calculation of the area under the curve (AUC) in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention provides a novel low molecular weight peptide and its use for antagonizing metabolic disorder-related fatty liver. The low molecular weight peptide includes a sequence consisting of Tyr and Phe. Specifically, the low molecular weight peptide mainly includes the following amino acid sequences: Tyr-Phe (YF), Phe-Tyr (FY), the sequence shown in SEQ ID No.:1 (EWYF) and the sequence shown in SEQ ID No.:2 (EWFY). The low molecular weight peptide disclosed in the present invention has the activity of suppressing fat accumulation in the liver, controlling metabolic enzymes in the liver and controlling blood sugar, and therefore the low molecular weight peptide disclosed in the present invention can be used to treat or improve metabolic disorder-related fatty liver and its associated diseases. In other words, the low molecular weight peptide disclosed in the present invention can be used as an active ingredient of a composition for treating or improving metabolic disorder-related fatty liver and its associated diseases.

[0015] Diseases associated with metabolic abnormality-related fatty liver include hyperlipidemia, diabetes, hyperglycemia, obesity, cardiovascular disease, metabolic syndrome, and the like.

[0016] In one embodiment of the present invention, the small peptide is composed of two amino acids, the sequence of which may be Tyr-Phe (YF) or Phe-Tyr (FY).

[0017] In another embodiment of the present invention, the small peptide is composed of four amino acids, the sequence of which may be the sequence shown in SEQ ID No.:1 or the sequence shown in SEQ ID No.:2.

[0018] The small peptides disclosed in the present invention may be obtained by artificial synthesis, biosynthesis, or other peptide preparation methods known in the art, or may be obtained by extraction from natural products. Regardless of the method used, the effect of the small peptides and the scope of protection of the present invention are not affected.

[0019] The term "small peptide" refers to a molecule whose molecular weight is less than 5000 Da. The small peptide disclosed in the present invention is composed of 2 to 4 amino acids.

[0020] The term "composition" refers to a product such as a medicine, a dietary supplement, or a food product containing an effective amount of the small peptide disclosed in the present invention, and the effective amount can be adjusted according to the different subjects to be administered. The composition can be in the form of an injection, a powder, a tablet, a capsule, or other common dosage form.

[0021] The term "effective amount" refers to a dosage that can achieve a desired effect in an individual, and varies depending on parameters such as the method of use, the method of administration, the type of product, etc. In general, the effective amount of the low molecular weight peptide disclosed in the present invention in the composition accounts for 0.01 to 100% of the total weight of the composition.

[0022] The term "extraction" refers to the process of separating a target substance from a mixture, for example by the difference in solubility of each substance in the mixture in various solvents. In addition, the extraction process can be followed by further steps such as concentration and purification to increase the purity of the target substance.

[0023] The term "artificial synthesis" refers to a method of synthesizing peptides by linking multiple amino acids together into a peptide chain.

[0024] The term "biosynthetic method" refers to a method in which a nucleotide sequence capable of expressing a target peptide is introduced into a host by genetic engineering, the host is cultured to obtain metabolites containing the target peptide, and the target peptide is then obtained through further steps such as separation and purification.

[0025] In the following, in order to explain the technical features and effects of the present invention, several experimental examples will be described in detail with reference to the drawings.

[0026] The amino acid sequences of the four peptides used in the following examples are Tyr-Phe (YF), Phe-Tyr (FY), the sequence shown in SEQ ID No.:1, and the sequence shown in SEQ ID No.:2, respectively. Each peptide was artificially synthesized, and it was confirmed that there were no errors in the amino acid composition of each peptide.

[0027] The dosages used in the following examples are calculated according to experimental animals, but the dosages do not limit the scope of the present invention. That is, a person skilled in the art of the present invention can adjust the dosage for various administration subjects or dosage forms based on ordinary knowledge.

[0028] Example 1: Animal testing

[0029] One hundred five-week-old male C57BL / 6JNarl mice were housed in an environment with a temperature of 22-25°C, 12 hours of light and 12 hours of darkness, and a humidity of 45-60%. They were then given regular food and water for three weeks, after which they were randomly divided into 10 groups and treated under the following conditions:

[0030] Group 1: blank group, given normal animal feed and distilled water.

[0031] Group 2: Control group, fed a 60% kcal fat diet + 30% v / v isomerized sugar (and 0.5% carboxymethylcellulose (CMC) solution) to induce metabolic disorder-associated fatty liver model mice.

[0032] Group 3: Low dose YF dipeptide group, fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 10 mg / kg / day of Tyr-Phe dipeptide.

[0033] Group 4: High dose YF dipeptide group, fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 50 mg / kg / day of Tyr-Phe dipeptide.

[0034] Group 5: FY dipeptide low dose group, fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 10 mg / kg / day of Phe-Tyr dipeptide.

[0035] Group 6: FY50 dipeptide high dose group, fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 50 mg / kg / day of Phe-Tyr dipeptide.

[0036] Group 7: EWYF tetrapeptide low dose group, fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 10 mg / kg / day of Glu-Trp-Tyr-Phe tetrapeptide (peptide shown in SEQ ID No.:1).

[0037] Group 8: EWYF tetrapeptide high dose group, fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 50 mg / kg / day of Glu-Trp-Tyr-Phe tetrapeptide (peptide shown in SEQ ID No.:1).

[0038] Group 9: EWFY tetrapeptide low dose group: fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 10 mg / kg / day of Glu-Trp-Phe-Tyr tetrapeptide (peptide shown in SEQ ID No.: 2).

[0039] Group 10: EWFY tetrapeptide high dose group: fed a 60% kcal fat diet + 30% v / v isomerized sugar and a dose of 50 mg / kg / day of Glu-Trp-Phe-Tyr tetrapeptide (peptide shown in SEQ ID No.:2).

[0040] Each peptide was mixed with 0.5% carboxymethylcellulose to prepare a peptide solution, which was then intragastrically injected into mice using a syringe.

[0041] The experimental period was 8 weeks in total, and the weight and food intake of each group of mice were measured every week. Furthermore, after the experiment, each group of mice was sacrificed and the weight of the liver, spleen, and white fat in the viscera was measured. The results are shown in Table 1, Table 2, and Figure 1.

[0042] JPEG0007623645000001.jpg110130

[0043] JPEG0007623645000002.jpg110138

[0044] From the results of FIG. 1, Table 1 and Table 2, it can be seen that the body weight, liver weight, spleen weight and visceral white fat weight of the mice of Group 2 were all significantly increased compared to the mice of Group 1, and it is certainly understood that the construction of a metabolic abnormality-associated fatty liver model mouse was successful. Furthermore, compared to the mice of Group 2, the body weight, liver weight, spleen weight and visceral white fat weight of the mice of Groups 3 to 10 were each significantly decreased. This result shows that each peptide disclosed in the present invention, regardless of whether it is a low dose or a high dose, can effectively suppress the body weight gain, the increase in liver and spleen weight caused by a high sugar and high fat diet, and can also suppress fat accumulation in the viscera.

[0045] Example 2: Analysis results of blood biochemistry test values

[0046] After the experiment of Example 1 was completed, blood samples were taken from each group of mice, and the serum alanine aminotransferase (sALT), triglyceride (sTG), total cholesterol (sTC), free fatty acid (sFFA) and very low density lipoprotein (sVLDL) contents of each group of mice were measured. The results are shown in Table 3.

[0047] JPEG0007623645000003.jpg126147

[0048] From the results in Table 3, it can be seen that each blood lipid index in the serum of the mice of Group 2 was significantly higher than that of the mice of Group 1, indicating that the mice of Group 2 had dyslipidemia. In addition, compared to the mice of Group 2, the contents of alanine aminotransferase and each blood lipid index in the serum of the mice of Groups 3 to 10 were significantly lower.

[0049] The above results show that each peptide disclosed in the present invention, regardless of whether it is a low dose or a high dose, has the activity of lowering the lipid content in serum and inhibiting liver-related enzymes. Therefore, by administering an effective amount of each peptide or a composition containing each peptide to an individual, it is possible to effectively improve or prevent related metabolic diseases such as liver-related diseases, hyperlipidemia, and other cardiovascular diseases caused by a high-sugar and high-fat diet.

[0050] Example 3: Blood Glucose Testing

[0051] On the final day of the experiment in Example 1, each group of mice was fasted, and the isomerized sugar bottle was replaced with distilled water. After 12 hours of fasting, 5 μL of blood samples were taken from the tail vein of each group of mice, and the measured blood glucose level was taken as fasting blood glucose. The results are shown in Figure 2.

[0052] Fasting blood glucose was defined as the blood glucose at 0 minutes in the oral glucose tolerance test (OGTT). Then, 2g / kg of D-glucose was administered into the stomach of each mouse, and the blood glucose of each mouse was measured and analyzed 30, 60, 90, and 120 minutes after glucose administration. The results are shown in Figures 3 and 4.

[0053] The results in Figures 2 to 4 show that the fasting blood glucose and OGTT areas under the curve of the mice in groups 3 to 10 were significantly lower than those of the mice in group 2, indicating that each peptide disclosed in the present invention has blood glucose control activity.

[0054] In other words, when an effective amount of each peptide or a composition containing each peptide is administered to an individual under a high-fat, high-sugar diet, the individual's blood sugar can be stabilized, thereby achieving glycemic control and preventing or treating the occurrence of diabetes and diseases related to glycemic imbalance.

[0055] Example 4: Analysis of liver lipid content

[0056] After the experiment of Example 1 was completed, each group of mice was sacrificed and their livers were taken to measure the liver lipid content, including hepatic triglyceride (hTG), hepatic total cholesterol (hTC), hepatic free fatty acid (hFFA) and hepatic very low density lipoprotein (hVLDL) in the liver of each mouse by enzymatic colorimetric method. Among them, the hepatic very low density lipoprotein was calculated as 1 / 5 of the hepatic triglyceride. The measurement analysis results are shown in Table 4.

[0057] JPEG0007623645000004.jpg110134

[0058] From the results in Table 4, the liver triglyceride, total cholesterol, free fatty acid and very low density lipoprotein contents of the mice in Group 2 were all significantly higher than those of the mice in Group 1, indicating that a high-fat, high-sugar diet indeed increases the lipid content in the liver and causes the occurrence of fatty liver and related metabolic diseases. Meanwhile, compared to the mice in Group 2, the liver triglyceride, total cholesterol, free fatty acid and very low density lipoprotein contents of the mice in Groups 3 to 10 were all significantly lower, indicating that each peptide disclosed in the present invention has the effect of suppressing fat accumulation in the liver and reducing the occurrence of a state of steatosis.

[0059] From the above results, it can be seen that each peptide disclosed in the present invention has the activity of reducing fat content in the liver, and therefore, by administering an effective amount of each peptide or a composition containing each peptide to an individual, it is possible to achieve the effect of improving or preventing metabolic disorder-related fatty liver and its associated symptoms.

Claims

1. A low molecular weight peptide comprising an amino acid sequence consisting of Tyr and Phe; A low molecular weight peptide, wherein the amino acid sequence of the low molecular weight peptide is the sequence shown in SEQ ID No.: 1, or the amino acid sequence of the low molecular weight peptide is the sequence shown in SEQ ID No.:

2.

2. The short peptide according to claim 1, wherein the amino acid sequence of the short peptide is the sequence shown in SEQ ID No.:

1.

3. The short peptide according to claim 1, wherein the amino acid sequence of the short peptide is the sequence shown in SEQ ID No.:

2.

4. A low molecular weight peptide according to any one of claims 1 to 3 for treating and / or preventing metabolic disorder-related fatty liver.

5. A low molecular weight peptide described in claim 4, having activity to control glucose metabolism.

6. A low molecular weight peptide described in claim 4, having activity to inhibit fat accumulation.

7. The small peptide of claim 4 for reducing body weight.

8. A composition containing at least an effective amount of a low molecular weight peptide described in any one of claims 1 to 3, accounting for 0.01 to 100% of the total weight.

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