Peptides with ACE inhibitory activity and compositions thereof

Abstract

The objective of the present invention is to provide a peptide having ACE inhibitory activity and a composition thereof. [Solution] The present invention discloses a peptide with ACE inhibitory activity and a composition thereof. The peptide is composed of three amino acids and has the ability to inhibit ACE activity. Therefore, by administering an effective amount of the peptide disclosed in the present invention or a composition containing the peptide to an individual, the individual's blood pressure can be effectively adjusted to approach normal values, thereby achieving the effect of preventing and / or treating hypertension and its related diseases.

Description

[Technical Field]

[0001] The present invention relates to small molecule peptides and uses thereof, and in particular to peptides having ACE inhibitory activity and compositions thereof. [Background technology]

[0002] According to information released by the World Health Organization, approximately one-third of the world's population suffers from health problems caused by high blood pressure. High blood pressure is a risk factor for stroke, diabetes, dementia, kidney disease, and cardiovascular disease. Statistics from Taiwan's Ministry of Health and Welfare show that heart disease, cerebrovascular disease, and hypertension caused by high blood pressure are among the top 10 causes of death. This shows that high blood pressure has become one of the health issues receiving attention worldwide.

[0003] Because the development of hypertension is related to genetic factors as well as lifestyle and dietary habits, current clinical treatment of hypertension begins with administering antihypertensive drugs and encouraging hypertensive patients or those at risk of developing hypertension to improve their lifestyles. Although antihypertensive drugs can effectively control blood pressure, long-term use can cause side effects such as edema and renal failure, and they cannot be administered to patients with prehypertension, so they cannot completely prevent the onset of hypertension and its related diseases. Summary of the Invention [Problem to be solved by the invention]

[0004] The main object of the present invention is to provide a peptide and composition thereof having ACE inhibitory activity, which effectively regulates blood pressure and brings it closer to normal levels, thereby preventing and / or treating hypertension and its related diseases. [Means for solving the problem]

[0005] Therefore, in order to achieve the above-mentioned effects, the present invention discloses a peptide having ACE inhibitory activity, which is composed of three amino acids having the sequence A1-A2-phenylalanine, where A1 is leucine, valine, or tyrosine, and A2 is serine or threonine.

[0006] Specifically, the peptides with ACE inhibitory activity are LSF (Leu-Ser-Phe), VTF (Val-Thr-Phe), LTF (Leu-Thr-Phe) or YVF (Tyr-Val-Phe), and by being able to inhibit the activity of ACE in the body, they have the effect of bringing blood pressure closer to normal, and peptides with ACE inhibitory activity can maintain blood pressure within the normal range.

[0007] Furthermore, since peptides with ACE inhibitory activity can be used as angiotensin-converting enzyme inhibitors, administering an effective amount of the peptides with ACE inhibitory activity disclosed in the present invention to an individual can effectively improve the symptoms of hypertension in the individual, thereby achieving the effects of preventing and / or treating hypertension and its related diseases.

[0008] The individual is a patient with high blood pressure or a patient who has been diagnosed as prehypertensive.

[0009] The peptide having ACE inhibitory activity can be prepared as a peptide composition. Preferably, the active ingredients of the peptide composition are LSF, VTF, LTF, and YVF, and the amounts of the active ingredients (LSF, VTF, LTF, and YVF) in the peptide composition are 9.0 to 54.0 ng / mg. [Brief explanation of the drawings]

[0010] [Figure 1] LC-MS / MS graphs of YVF, VTF, LSF and LTF. [Figure 2] FIG. 1 shows the difference in systolic blood pressure between each group of rats and the negative control group at each week. [Figure 3]FIG. 1 shows the difference in diastolic blood pressure between each group of rats and the negative control group at each week. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention discloses a peptide having ACE inhibitory activity and a composition thereof. Specifically, the peptide is composed of three amino acids having the sequence A1-A2-phenylalanine, where A1 is leucine, valine, or tyrosine, and A2 is serine or threonine. Since the peptide disclosed in the present invention has the ability to inhibit ACE activity, administering an effective amount of the peptide disclosed in the present invention or a composition containing the peptide to an individual can effectively regulate the individual's blood pressure to approach normal levels, thereby achieving the effects of preventing and / or treating hypertension or related diseases.

[0012] In an embodiment of the present invention, the amino acid sequence of the peptide is LSF (Leu-Ser-Phe), VTF (Val-Thr-Phe), LTF (Leu-Thr-Phe), or YVF (Tyr-Val-Phe). The molecular weights of the peptides disclosed in the present invention are shown in Table 1 below.

[0013] JPEG0007769052000002.jpg45138

[0014] The peptides disclosed in the present invention can be prepared by chemical synthesis, artificial synthesis, or biosynthesis. For example, solid-phase synthesis is one of the most commonly used synthesis methods, in which amino acids are linked one by one via a solid-phase support such as a resin that serves as the base of the reactants to form a target peptide, and then the target peptide is cleaved from the solid-phase support. Biosynthesis involves constructing a recombinant vector that expresses the target peptide using recombinant technology, then introducing the recombinant vector into host cells for expression, and then obtaining the target peptide through purification and isolation techniques.

[0015] The peptides disclosed in the present invention can also be isolated from vegetable protein hydrolysates. For example, rice protein is first mixed with water at a ratio of 7.4% (w / v) and then hydrolyzed with a hydrolase to obtain rice protein hydrolysates. The hydrolase can be Alcalase, Bromelain, Flavorzyme, or Papain, with alkaline hydrolase exhibiting the most effective hydrolysis. The hydrolysis conditions are a hydrolysis time of at least 60-120 minutes and a pH of 5.5-7.5. The peptides disclosed in the present invention (molecular weights ranging from 360-430 Da) are then isolated and purified from the rice protein hydrolysates.

[0016] The capital letters used in the peptide sequences disclosed in the present invention are abbreviations for amino acids, and unless otherwise specified, are understood based on common knowledge in the technical field to which the present invention pertains. For example, the peptide sequence "LSF" disclosed in the present invention is Leu-Ser-Phe, the peptide sequence "VTF" is Val-Thr-Phe, and the peptide sequence "LSF" is Leu-Ser-Phe.

[0017] The peptide disclosed in the present invention has ACE inhibitory activity and is therefore an angiotensin-converting enzyme inhibitor (ACE inhibitor, abbreviated as "ACEI"), and can be prepared as a peptide composition for preventing and / or treating hypertension and its related diseases.

[0018] In one embodiment of the present invention, the peptide composition contains LSF, LTF, VTF, and YVF, and the total amount of LSF, LTF, VTF, and YVF is approximately 9.0 to 54.0 nanograms (ng) per 1 mg of the peptide composition.

[0019] The weight ratio of LSF, LTF, VTF and YVF in the peptide composition is 6:1.5 to 2:1:3.

[0020] The peptide composition may contain other components such as other peptides, flavoring agents, excipients, etc. depending on the use, dosage form, administration target, etc.

[0021] The composition may be a food product, a supplement, or a pharmaceutical product.

[0022] The term "hypertension" refers to an individual's blood pressure being consistently too high and exceeding the values ​​defined as hypertension by clinical blood pressure standards, such as a resting systolic blood pressure of 130 mmHg or higher and a diastolic blood pressure of 80 mmHg or higher, according to the latest treatment guidelines for hypertension published by the American Heart Association on November 13, 2017.

[0023] The term "prehypertension" refers to blood pressure levels between normal and hypertension. When an individual is diagnosed with prehypertension, they are considered at high risk for developing hypertension.

[0024] The term "hypertension-related disease" refers to diseases for which hypertension is a risk factor, such as angiogenic diseases, stroke, kidney disease, dementia, and diabetes.

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

[0026] The peptides used in the following experimental examples were either artificially synthesized or isolated from vegetable protein hydrolysates, and the sequences were identified by liquid chromatography tandem mass spectrometry. The results are shown in FIG.

[0027] The peptide composition used in the following experimental examples contains at least the following three peptides as active ingredients: LSF, LTF, VTF, and YVF, and may be combined with other ingredients. Each mg of peptide composition contains a total of approximately 9.0 to 54.0 nanograms (ng) of LSF, LTF, VTF, and YVF, and the LSF, LTF, VTF, and YVF are prepared in a weight ratio of 6:1.5 to 2:1:3. For example, the weight ratio of LSF, LTF, VTF, and YVF in the peptide composition was 54:14:9:27.

[0028] All animal experiments in the following experimental examples complied with ethical regulations for animal experiments.

[0029] The doses of the peptide compositions disclosed in the following experimental examples are doses used in animal experiments, and the doses actually used in different living organisms are converted based on common knowledge or conversion standards in the technical field to which the present invention pertains.

[0030] (Experimental Example 1: Cell Test) The IC of ACE inhibitory activity of the peptides LSF, LTF, VTF, and YVF was determined using methods well known to those skilled in the art. 50 The results of the measurements are shown in Table 2 below.

[0031] JPEG0007769052000003.jpg45142

[0032] (Experiment 2: Animal Experiment (1)) The peptide composition disclosed in the present invention was administered to spontaneously hypertensive rats (SHR) at doses of 50 mg / kg body weight and 100 mg / kg body weight, respectively, and blood pressure and changes therein were measured at the time of administration (time 0) and 2, 4, 6, and 8 hours after administration. The results are shown in Tables 3 and 4 below.

[0033] JPEG0007769052000004.jpg46154

[0034] JPEG0007769052000005.jpg46154

[0035] The results in Table 3 show that 4, 6, and 8 hours after administration of a 50 mg / kg dose of the peptide composition, systolic blood pressure was reduced by 9.5, 15.3, and 16.1 mmHg from time 0. The results in Table 4 show that 4, 6, and 8 hours after administration of a 100 mg / kg dose of the peptide composition, systolic blood pressure was reduced by 37.36, 43.8, and 46.3 mmHg from time 0, all of which were reductions of more than 20 mmHg. These results demonstrate that the peptide composition disclosed in the present invention can effectively reduce blood pressure, and that the reduction increases with increasing dose and / or time.

[0036] (Experimental Example 3: Animal Experiment (2)) Six-week-old spontaneously hypertensive rats (SHR) were divided into five groups and treated according to the conditions of each group. Negative control group (NC group): water supply, Positive control group (PC group): 1 mg / kg of Captopril, a drug for treating hypertension, was fed. Low-dose treatment group (Group L): fed with the peptide composition disclosed in the present invention at a dose of 50 mg / kg; Medium dose treatment group (Group M): fed with the peptide composition disclosed in the present invention at a dose of 100 mg / kg; High-dose treatment group (Group H): The peptide composition disclosed in the present invention was fed at a dose of 200 mg / kg.

[0037] In addition, Wistar Kyoto rats (WKY group) were used as a control group, and the treatment conditions for this group were as follows: the peptide composition disclosed in the present invention was fed at a dose of 100 mg / kg.

[0038] The experiment continued for 8 weeks, and the diastolic and systolic blood pressures of the rats in each group were measured weekly. The results are shown in Tables 5 and 6. The differences between each group and the negative control group were analyzed, and the results are shown in Figures 2 and 3.

[0039] JPEG0007769052000006.jpg131163

[0040] JPEG0007769052000007.jpg131153

[0041] The results in Tables 5 and 6 show that the systolic blood pressure of rats in groups L, M, and H, which were administered with the peptide composition disclosed herein from week 1 of the experiment, was significantly different from that of groups PC and NC, and the difference in systolic blood pressure of rats in group L from the NC group was more than 20 mmHg by week 3, and the difference in systolic blood pressure of rats in groups M, H, and PC from the NC group was more than 20 mmHg from week 2. After 8 weeks of the experiment, the systolic blood pressure of rats in groups L, M, and H, which were administered with the peptide composition disclosed herein, was significantly different from that of rats in groups PC and NC, and the differences in systolic blood pressure between rats in groups L, M, and H and those in the NC group were 56.8, 67.4, 73.1, and 81.6 mmHg, respectively.

[0042] The above results show that the peptide composition disclosed in the present invention was able to reduce systolic blood pressure by more than 20 mmHg at low, medium, and high doses. According to the criteria set forth in the evaluation method for the blood pressure regulation assisting function of health foods, where a test substance is judged to have a blood pressure regulating effect if systolic blood pressure is reduced by 20 mmHg or more before and after the experiment, it can be demonstrated that the peptide composition disclosed in the present invention reliably regulates blood pressure and has the effect of treating or preventing hypertension and its related diseases.

[0043] Furthermore, there was no significant difference in blood pressure in the WKY group of rats during the 8-week continuous feeding period of the peptide composition disclosed in the present invention, indicating that the peptide composition disclosed in the present invention did not cause hypotension in normotensive rats.

Claims

1. A composition for preventing and / or treating hypertension and its related diseases, comprising a peptide having ACE inhibitory activity, wherein the peptide having ACE inhibitory activity is LSF (Leu-Ser-Phe), VTF (Val-Thr-Phe), LTF (Leu-Thr-Phe) or YVF (Tyr-Val-Phe), and the composition contains the following peptides: LSF, VTF, LTF and YVF.

2. 2. The composition of claim 1, wherein the amount of LSF, VTF, LTF, and YVF in the composition is 9.0 to 54.0 ng / mg.

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