A bioactive polypeptide and its use for treating cardiovascular and cerebrovascular diseases

Abstract

This invention belongs to the field of biomedical technology, specifically relating to a bioactive polypeptide and its use in treating cardiovascular and cerebrovascular diseases. This invention prepares the bioactive polypeptide from sea cucumber protein through an enzymatic hydrolysis reaction. The bioactive polypeptide can effectively inhibit cardiomyocyte apoptosis, inhibit cTnI secretion, and improve cardiac structure and function. Therefore, the polypeptide of this invention has excellent therapeutic effects on cardiovascular and cerebrovascular diseases, and is non-toxic and has no side effects. It also has the advantages of simple preparation, easy absorption, and ease of widespread application.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to a bioactive polypeptide and its use in treating cardiovascular and cerebrovascular diseases. Background Technology

[0002] Bioactive peptides typically consist of 2–20 amino acid residues and can exert beneficial biological activities exceeding the nutritional value of their parent proteins. They possess a range of advantages, including low toxicity and immunogenicity, good solubility, diverse tissue distribution patterns, and excellent pharmacokinetic performance. In recent years, the incidence of heart failure has been rising, making research on bioactive peptides for improving heart failure a hot topic. Animal-derived bioactive peptides refer to functional peptides obtained from animal proteins, either directly or indirectly. Due to their high safety and readily available raw materials, animal-derived bioactive peptides are currently receiving significant attention in the fields of nutrition and food science. Bioactive peptides derived from marine animals, such as sea cucumber polypeptides, show broad application prospects in improving heart failure. Proteins are both a source of essential amino acids and a source of bioactive peptides. Specific peptide segments with unique amino acid sequences present in proteins are called bioactive peptides, and once released from the parent protein, they possess corresponding biological effects. In recent years, various bioactive peptides prepared from marine animal proteins (such as sea cucumber, skipjack tuna, and oysters) have been reported to improve cardiovascular diseases.

[0003] Sea cucumber (Holothurian) belongs to the class Holothuroidea of ​​the phylum Echinodermata and is a marine animal that lives at depths of 8,000 meters. Sea cucumber is a precious food, considered on par with bird's nest and shark fin, and is hailed as one of the world's eight most precious delicacies. Modern scientific research has proven that sea cucumber has high nutritional value. Every 100 grams contains 15 grams of protein, 1 gram of fat, 0.4 grams of carbohydrates, 12 milligrams of phosphorus, 357 milligrams of calcium, 0.42 milligrams of iron, and more than 50 nutrients beneficial to human physiological activities, including vitamins B1, B2, and nicotinic acid. It contains 18 amino acids, taurine, chondroitin sulfate, and sea cucumber mucopolysaccharides, among other components. Taurine, lysine, and methionine are almost absent in plant-based foods. Chondroitin sulfate and sea cucumber mucopolysaccharides, found in sea cucumber, have been shown through pharmacological experiments to have special effects on human growth and development, anti-inflammatory bone formation, prevention of tissue aging, promotion of wound healing, and inhibition of several types of cancer cells. Sea cucumbers contain extremely low levels of cholesterol, and their high protein, low fat, and low cholesterol characteristics make them ideal for the elderly, children, and those with weak constitutions. However, current research on bioactive peptides in sea cucumbers primarily focuses on metabolic diseases. Studies have shown that some peptides in sea cucumbers can improve insulin resistance and kidney damage, and significantly lower blood sugar. Research on their role in cardiovascular diseases is limited, especially in the important area of ​​heart failure. The pathophysiological mechanisms of heart failure are complex, involving multiple processes such as cardiomyocyte hypertrophy, fibrosis, energy metabolism disorders, oxidative stress, and apoptosis. Existing treatments still have limitations and cannot fully meet clinical needs. Therefore, it is necessary to screen and identify novel bioactive peptides from sea cucumbers, systematically evaluate their protective effects on the cardiovascular system and their molecular mechanisms, and provide scientific evidence and candidate molecules for developing innovative drugs to treat cardiovascular diseases, especially improving heart failure. Summary of the Invention

[0004] In view of the current state of the technology, the purpose of this invention is to provide a bioactive polypeptide, specifically a sea cucumber bioactive polypeptide, which can effectively inhibit cardiomyocyte apoptosis, inhibit cTnI secretion, improve cardiac structure and function, and can be used to treat cardiovascular and cerebrovascular diseases such as heart failure. The protein extract of this invention not only has anti-apoptotic and cardiomyocyte damage-inhibiting effects, but is also non-toxic, has no side effects, and has the advantages of simple preparation and easy absorption.

[0005] The present invention first provides a bioactive polypeptide, characterized in that the polypeptide is a sea cucumber bioactive polypeptide, and its amino acid sequence is shown in SEQ ID NO: 1.

[0006] Another aspect of the present invention provides a nucleic acid molecule encoding the bioactive polypeptide described herein.

[0007] Another aspect of the present invention provides a carrier comprising the nucleic acid molecule described herein.

[0008] Another aspect of the present invention provides an isolated host cell comprising the bioactive polypeptide, the nucleic acid molecule, or the carrier described in the present invention.

[0009] Another aspect of the present invention provides the use of the bioactive polypeptide in the preparation of a medicament for treating cardiovascular and cerebrovascular diseases.

[0010] In some embodiments, the cardiovascular disease is heart failure.

[0011] In some embodiments, the cardiovascular disease is chronic heart failure.

[0012] Another aspect of the present invention provides a pharmaceutical composition comprising an effective amount of the bioactive polypeptide of the present invention, the amino acid sequence of which is shown in SEQ ID NO: 1.

[0013] The bioactive polypeptides of the present invention, or pharmaceutical compositions containing the bioactive polypeptides of the present invention, are administered in the form of lyophilized powder.

[0014] In some embodiments, the bioactive polypeptides of the present invention or pharmaceutical compositions containing the bioactive polypeptides of the present invention may be used in combination with other anti-heart failure drugs.

[0015] In some embodiments, the anti-heart failure drug may be selected from angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), beta-blockers, aldosterone antagonists, digitalis and non-digitalis positive inotropic agents, diuretics, aspirin, allopurinol, statins, and anti-inflammatory agents.

[0016] Beneficial effects This invention extracts and prepares an active polypeptide from sea cucumber. This active polypeptide effectively inhibits cardiomyocyte apoptosis, suppresses cTnI secretion, and improves cardiac structure and function. Therefore, the polypeptide of this invention has excellent therapeutic effects on cardiovascular and cerebrovascular diseases and has certain clinical application value. The polypeptide H31 provided by this invention is easy to synthesize, low in cost, and easy to promote and apply. Attached Figure Description

[0017] Figure 1 The results shown are the cTnI content in the serum of rats in each group after different treatments. Detailed Implementation

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0019] Except as provided in the operational examples or otherwise indicated, all figures for the amount of expressed components or reaction conditions used herein should be understood to be modified by the term "about" in all cases. When used in conjunction with percentages, the term "about" may mean ±1%.

[0020] In some embodiments, the pharmaceutical compositions provided herein comprise about 1 pg to about 2000 mg of the active polypeptide described herein (e.g., a polypeptide component, which may be a single polypeptide in some embodiments), optionally wherein the pharmaceutical composition comprises about 1 pg to about 1000 mg, about 1 pg to about 500 mg, about 1 pg to about 400 mg, about 1 pg to about 300 mg, about 1 pg to about 200 mg, about 1 pg to about 100 mg, about 1 pg to about 50 mg, about 1 pg to about 25 mg, about 1 pg to about 20 mg, about 1 pg to about 15 mg, about 1 pg to about 10 mg, about 1 pg to about The active polypeptides described herein (e.g., polypeptide components, which in some embodiments may be a single polypeptide) of 5 mg, about 1 pg to about 1 mg, about 1 pg to about 500 pg, about 1 pg to about 250 pg, about 1 pg to about 200 pg, about 1 pg to about 150 pg, about 1 pg to about 100 pg, about 1 pg to about 50 pg, about 1 mg to about 1000 mg, about 1 mg to about 500 mg, about 1 mg to about 400 mg, about 1 mg to about 300 mg, about 1 mg to about 200 mg, about 1 mg to about 100 mg, about 1 mg to about 50 mg, about 1 mg to about 25 mg.

[0021] As used herein, the terms “treatment” or “improvement” are used interchangeably. These terms refer to the means of achieving a beneficial or desired outcome, including but not limited to therapeutic and / or preventative benefits.

[0022] In this application, unless otherwise specifically stated, the use of the singular includes the plural. In this application, unless otherwise stated, the use of “or” means “and / or”. Furthermore, the use of the term “including” and other forms such as “includes” and “included” is not restrictive. Additionally, unless otherwise specifically stated, terms such as “element” or “component” cover elements and components that include one unit as well as elements and components that include more than one subunit. Additionally, the use of the term “part” can include a portion of a part or an entire portion. Throughout this specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising” will be understood to imply inclusion of the specified integer or group of integers, but not to exclude any other integer or group of integers.

[0023] The term "therapeuticly effective amount" refers to the amount that produces the desired effect of its administration. In some embodiments, the term refers to an amount sufficient to treat a disease, condition, and / or ailment when administered according to a therapeutic dosing regimen to a population suffering from or susceptible to such a disease, condition, and / or ailment. In some embodiments, a therapeutically effective amount is an amount that reduces the incidence and / or severity of one or more symptoms of a disease, condition, and / or ailment, and / or delays its onset. Those skilled in the art will understand that a therapeutically effective amount does not necessarily achieve successful treatment in every particular individual. Rather, a therapeutically effective amount can be an amount that provides a specific desired pharmacological response in a large number of subjects when administered to patients who require such treatment. In some embodiments, references to a therapeutically effective amount can be to an amount measured, such as in one or more specific tissues (e.g., tissues affected by a disease, condition, or ailment) or fluids (e.g., blood, saliva, serum, sweat, tears, urine, etc.). Those skilled in the art will understand that in some embodiments, a specific agent or therapy can be formulated and / or administered in a single dose. In some implementations, the therapeutic agent may be formulated and / or administered in multiple doses, for example, as part of a dosing regimen.

[0024] The pharmaceutical composition of the present invention further contains a pharmaceutically acceptable carrier.

[0025] Furthermore, the pharmaceutical compositions of the present invention can be oral dosage forms. Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In these solid dosage forms, the active polypeptide is mixed with at least one conventional inert excipient (or carrier), such as sodium citrate or dicalcium phosphate, or with the following components: (a) fillers or solubilizers, such as starch, lactose, sucrose, glucose, mannitol, and silica; (b) binders, such as hydroxymethyl cellulose, alginate, gelatin, polyvinylpyrrolidone, sucrose, and gum arabic; (c) humectants, such as glycerin; (d) disintegrants, such as agar, calcium carbonate, potato starch or cassava starch, alginate, certain complex silicates, and sodium carbonate; (e) slowing agents, such as paraffin wax; (f) absorption accelerators, such as quaternary ammonium compounds; (g) wetting agents, such as cetyl alcohol and glyceryl monostearate; (h) adsorbents, such as kaolin; (i) lubricants, such as talc, calcium stearate, magnesium stearate, solid polyethylene glycol, sodium dodecyl sulfate, or mixtures thereof. In capsules, tablets, and pills, the dosage form may also contain a buffer. Solid dosage forms, such as tablets, sugar pills, capsules, pellets, and granules, can be prepared using coatings and shells, such as casings and other materials known in the art. They may contain opaque agents, and the release of the active peptide or peptide in such compositions may be delayed at a site in the digestive tract. Examples of encapsulating components that may be used are polymeric substances and waxes. If necessary, the active peptide may also be formed into microcapsules with one or more of the excipients described above. Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, or tinctures. In addition to the active peptide, liquid dosage forms may contain inert diluents conventionally used in the art, such as water or other solvents, solubilizers and emulsifiers, such as ethanol, isopropanol, ethyl carbonate, ethyl acetate, propylene glycol, 1,3-butanediol, dimethylformamide, and oils, particularly cottonseed oil, peanut oil, corn germ oil, olive oil, castor oil, and sesame oil, or mixtures of these substances.

[0026] The provided formulation may include lyophilization protectants, such as those selected from sucrose, lactose, trehalose, dextran, erythritol, arabinitol, xylitol, sorbitol, maltose, lactulose, maltulose, glucol, maltitol, lactitol, isomaltulose, and mannitol; amino acids, such as arginine, histidine, proline, or glycine; lyotropic salts, such as magnesium sulfate; propylene glycol, glycerol, poly(ethylene glycol), or poly(propylene glycol); gelatin, dextrin, modified starch, carboxymethyl cellulose, and combinations thereof.

[0027] Alternatively or additionally, in some embodiments, the provided formulation may comprise a penetration enhancer, such as one selected from bile salts, such as sodium trihydroxycholate, sodium glycocholate, sodium taurocholate and dihydroxycholate, sodium deoxycholate, sodium glycodeoxycholate, sodium taurodeoxycholate; fatty acids, their salts and esters, such as oleic acid, lauric acid, cod liver oil extract, sodium lauryl laurate, sodium decanoate, glyceryl monostearate, diethylene glycol monoethyl ether and various sucrose fatty acid esters, medium-chain fatty acid glycerides, polycaprolactone eoma-3 fatty acids, lecithin (phosphatidylcholine), lysophosphatidylcholine; surfactants, such as sodium lauryl sulfate, polysorbate (polysorbate 80), lauryl ether, Brijs and benzalkonium chloride; complexing agents, such as cyclodextrin, dextran sulfate, ethylenediaminetetraacetic acid sodium salt; complexing agents, such as cyclodextrin, dextran sulfate, ethylenediaminetetraacetic acid sodium salt; Dextran, sodium EDTA, cosolvents such as ethanol and propylene glycol, a combination of 1% oleic acid and 5% / 10% polyethylene glycol 200, a combination of 2% glyceryl monolaurate and 40% alcohol, sodium decanoate and alcohol or propylene glycol, a combination of 10% lauric acid in propylene glycol, polyoxyethylene, 2,3-lauryl ether, menthol, sodium decanoate, sodium octanoate, sodium glycinate, ethylene glycol; polysaccharides such as chitosan and chitosan glutamate; and others It includes, for example, aprotinin, benzalkonium chloride, hexadecylpyridinium chloride, hexadecyltrimethylammonium bromide, sodium salicylate, lysophosphatidylcholine, methoxysalicylate, hydroxymethyl oleate, sodium EDTA, sulfoxide, various alkyl glycosides, ethylenediaminetetraacetic acid (EDTA), tartaric acid; lyotropic salts, such as magnesium sulfate; propylene glycol, glycerol, poly(ethylene glycol) or poly(propylene glycol); gelatin, dextrin, modified starch, carboxymethyl cellulose and combinations thereof.

[0028] Optionally or additionally, in some embodiments, the provided formulation may include an absorption enhancer, such as one selected from surfactants, cholesterol, glycerides, salicylates, bile salts, chelating agents, sodium decanoate, salts of decanoic acid, and others including N-(5-chlorosalicylic acid)-8-aminooctanoic acid (5-CNAC), 4-((4-chloro-2-hydroxybenzoyl))-amino)butyric acid (4-CNAB), and N-(8-(2-hydroxybenzoyl))-amino)octanoic acid, also known as sodium salicylate (SNAC, octanoic acid, C8, castor oil, medium chain, acylcarnitine, EDTA, glyceryl monolaurate, bovine P-casein, tocopheryl succinate glycol chitosan conjugate, lecithin, glyceryl monostearate (GMS), chitosan, and alginate. PLGA, silica, stearic acid, oleic acid, hydrogenated castor oil and trimyridine glyceryl, etoposide phosphate, enalapril maleate, ramipril, olmesartan medoxomil, valacyclovir, midodrine, gabapentin enalacarbide, sulfasalazine, or alternatively or additionally, in some embodiments, the provided formulation may contain a mucosal bioadhesive, such as selected from sucrose, lactose, trehalose, dextran, erythritol, arabinitol, xylitol, sorbitol, maltose, lactulose, maltulose, glucosyl alcohol, maltitol, lactitol, isomaltulose and mannitol; amino acids, such as arginine or histidine or proline or glycine; lyotropic salts, such as magnesium sulfate; propylene glycol, glycerol, poly(ethylene glycol) or poly(propylene glycol);Gelatin, dextrin, modified starch, carboxymethyl cellulose and combinations thereof; mucosal adhesion systems, such as those derived from natural sources, such as gelatin, agarose, chitosan, hyaluronic acid, and synthetic polymers, such as polyvinylpyrrolidone (PVP), polyacrylates, polyvinyl alcohol, sodium carboxymethyl cellulose (SCMC), and pectin; all anionic polymers, chitosan (cationic), and hydroxypropyl methyl cellulose (HPMC) as a nonionic polymer; polyacrylic acid (PAA) derivatives (CP934, CP940, PCP), 15% CMC and 35% CP; copolymers of acrylic acid and poly(ethylene glycol) monomethyl ether monomethacrylate (PEGMM); eudragitlNE40D is a neutral poly(ethyl acrylate methacrylate); hydrophilic polymers, such as methocel K4M, methocel K15M, SCMC 400, Cekol 700, Cekol 10000, CP934P, CP971P and CP974P, carboxyvinyl polymers and triethanolamine, HPC (hydroxypropyl cellulose), CP (Carbopol 934P), Carbopol (CP) Ex-55CMC (sodium carboxymethyl cellulose), HPMC (hydroxypropyl methyl cellulose), HEC (hydroxyethyl cellulose), PIP [poly(isoprene)], PIB [poly(isobutylene)], xanthan gum, locust bean gum, pectin, polycarbofil, benzyl ester, hydroxyethyl cellulose Formulations comprising: poly(acrylic acid), poly(acrylic acid-co-acrylamide), poly(acrylic acid-co-methyl methacrylate), poly(acrylic acid-co-butyl acrylate), (bioadhesive polymer blends of CP and PIB), composed of PVP, hexadecylpyridinium chloride (as stabilizer), chlorinated chitosan, polyethylene oxide, polymethyl vinyl ether / maleic anhydride (PME / MA) and tragacanth gum, polyethylene glycol monomethyl ether monomethyl acrylate, drum-dried waxy corn starch (DDWM), carbopol 974P and stearyl fumarate sodium, and cellulose derivatives; hydrogels of acrylic acid (polar) and butyl acrylate (non-polar) and combinations thereof.

[0029] In addition to these inert diluents, the composition may also contain auxiliaries such as wetting agents, emulsifiers and suspending agents, sweeteners, flavoring agents and fragrances.

[0030] In addition to active peptides, suspensions may contain suspending agents such as ethoxylated isooctadecyl alcohol, polyoxyethylene sorbitol and dehydrated sorbitol esters, microcrystalline cellulose, aluminum methoxide and agar, or mixtures of these substances.

[0031] Compositions for parenteral injection may comprise physiologically acceptable sterile aqueous or anhydrous solutions, dispersions, suspensions, or emulsions, and sterile powders for reconstitution into sterile injectable solutions or dispersions. Suitable aqueous and non-aqueous carriers, diluents, solvents, or excipients include water, ethanol, polyols, and suitable mixtures thereof.

[0032] Dosage forms of the polypeptides of the present invention for topical administration include ointments, powders, patches, sprays, and inhalers. The active ingredient is mixed under sterile conditions with a physiologically acceptable carrier and any preservatives, buffers, or, if necessary, propellants.

[0033] The pharmaceutical compositions of the present invention are formulated to a pH of 5.5 to 7.5. In one embodiment, the pH of the aqueous medium can be adjusted by low concentrations of suitable biocompatible buffering agents, non-limiting examples of which are glycerol, sodium carbonate and sodium bicarbonate, and sodium dihydrogen phosphate and disodium hydrogen phosphate.

[0034] The compositions of the present invention can be administered daily or intermittently, with a frequency of once daily or two to three times daily. If each of the two active ingredients is a single formulation, their administration frequencies can be the same or different. Furthermore, the compositions of the present invention can be used alone or in combination with other cardiovascular disease treatments. Considering all the foregoing factors, it is important to administer the lowest possible dose to achieve optimal efficacy without side effects, which can be readily determined by those skilled in the art. In some embodiments, the dosing regimen is repeated, for example, once, twice, three times, or more; for example, repeated over the remaining lifespan of the individual in need.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but this does not limit the present invention in any way. Any modifications or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0036] Example 1: Screening of bioactive peptides from sea cucumber 1.1 Preparation of sea cucumber polypeptides Fresh dried sea cucumber body walls were rinsed with deionized water and then flash-frozen at -70°C. The sea cucumber body walls were then dried and pulverized to obtain powder. The powder was added to a neutral protease solution containing PBS and 1% of the sea cucumber's body weight. The solution was then hydrolyzed at 50°C and pH 7 for 6 hours. The solution was boiled at 90°C for 10 minutes to stop the enzymatic reaction. Subsequently, the solution was added to 3 times its volume of 95% ethanol, allowed to stand for 12 hours, and then centrifuged at 4500 rpm for 25 minutes. The supernatant was collected. The supernatant was purified by G10 gel chromatography, filtered for sterilization, and then freeze-dried to obtain crude sea cucumber peptides.

[0037] The crude sea cucumber peptide was prepared into a 1.5% solution and placed in the feed tank of an ultrafiltration system. Ultrafiltration was performed using a spiral wound ultrafiltration membrane module with a molecular weight cutoff of 1000 Da, with the pressure controlled at 0.1–0.3 MPa. The filtrate and retentate were collected, and their molecular weight distribution range was determined by high performance liquid chromatography. The filtrate and retentate were concentrated to an appropriate amount and then freeze-dried to prepare a dry powder, which was stored at 4°C for subsequent experimental research.

[0038] 1.2 Effects of sea cucumber polypeptides on inhibiting cardiomyocyte apoptosis The sea cucumber polypeptide filtrate and retentates A1, A2, A3, and A4 were prepared to the same concentration (1 mg / ml). H9c2 rat cardiomyocytes were cultured at 5 × 10⁻⁶ mg / ml. 4 Cells were seeded per well in 96-well plates and cultured for 24 hours until adherence and confluence. After treatment with sea cucumber peptides for 2 hours, a heart failure myocardial injury model was constructed using the hypoxia / reoxygenation (H / R) method (4 hours of hypoxia, 24 hours of reoxygenation). Specifically, all groups except the control group were placed in a hypoxic incubator (1% O2, 5% CO2, 94% N2) for 4 hours. After removal, the cells were replaced with fresh culture medium containing the corresponding drug / solvent and placed in a normal incubator (21% O2) for 24 hours of reoxygenation. The control group was cultured normally throughout the process without hypoxia / reoxygenation. Cardiomyocyte viability was assessed using a CCK-8 assay kit. After 24 hours of reoxygenation, 10 μL of CCK-8 solution (Beyotime, Cat: C0042) was added to each well and incubated at 37°C for 1.5 hours. The absorbance (OD value) at 450 nm was measured using a microplate reader to calculate cell viability.

[0039] The results showed that the A4 component exhibited the highest cardiomyocyte viability at a concentration of 1 mg / ml, suggesting that the A4 component can inhibit cardiomyocyte apoptosis caused by hypoxia and ischemia, and can be further studied as a potential active component for the treatment of heart failure.

[0040] The A4 component was subjected to liquid chromatography-tandem mass spectrometry (LC-MS / MS) for peptidomics analysis to obtain a series of peptide fragment sequences. Through further screening and verification of its anti-apoptotic activity against cardiomyocytes, the peptide with the best activity was identified as H31, whose amino acid sequence is shown in SEQ ID NO: 1.

[0041] Example 2. Effects of peptide H31 on chronic heart failure Twenty-four healthy, clean-grade male SD rats (purchased from Vital River), weighing 200-220g, were randomly divided into a control group, a heart failure model group, a losartan group, and an H31 group, with six rats in each group.

[0042] (1) Control group: Intraperitoneal injection of 5 mL / kg of normal saline twice a day for 10 weeks; (2) Model group: On days 1 and 3 of the experiment, Adr 1 mg / kg was injected intraperitoneally; on days 5 and 7, Adr 2 mg / kg was injected intraperitoneally; on days 9 and 11, Adr 3 mg / kg was injected intraperitoneally; on days 13 and 15, Adr 4 mg / kg was injected intraperitoneally. The cumulative dosage over 15 days was 20 mg / kg. At other times, an equal volume of physiological saline was injected intraperitoneally twice a day for 10 weeks.

[0043] (3) Losartan group: The dosage and administration of Adr were the same as those of the model group. At the start of Ard administration, losartan potassium (Chongqing Kerui Pharmaceutical Co., Ltd.) 6 mg / kg was administered by gavage once a day for 10 weeks. (4) H31 group: The dosage and administration of Adr were the same as those of the model group. Starting from the administration of Ard, H31 80µg / kg was administered intraperitoneally twice a day for 10 weeks.

[0044] 2.1 Effects of H31 on cardiac function in rats with heart failure Rats were treated with the drug for 10 weeks. Cardiac function of all surviving rats was assessed using a Vivid7 high-frequency color Doppler ultrasound diagnostic instrument; the I13L probe had a frequency of 12–14 MHz and an image depth of 2.0 cm. 1. After accurately weighing the rats, they were anesthetized via intraperitoneal injection of 10% chloral hydrate at a dose of 300 mg / kg; 2. The anesthetized rats were fixed supine on a specialized small animal operating table, tilted to the left at approximately 30°, and the hair in the precordial region was shaved; 3. After applying coupling gel to the precordial region of the rats, the probe was placed on the left side of the chest wall, and a long-axis section of the left ventricle was taken. The M-mode ultrasound sampling line was placed at the level of the mitral valve chordae tendineae, perpendicular to the interventricular septum and the posterior wall of the left ventricle. The left ventricular end-diastolic dimension (LVDD), left ventricular end-systolic diameter (LVSD), left ventricular posterior wall thickness (LVPWD), left ventricular posterior wall thickness (LVPWS), and left atrial diameter (LA) were measured using M-mode ultrasound. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and stroke volume were also calculated. Volume (SV), ejection fraction (EF), and fraction shortening (FS).

[0045] The results are shown in Table 1. Compared with the control group, the model group showed a significant increase in LVDD, LVSD, and LA (p<0.01), and a significant decrease in LVPWd and LVPWs (p<0.01). Compared with the model group, the losartan group and H31 group showed a significant decrease in LVDD, LVSD, and LA (p<0.05), and a significant increase in LVPWD and LVPWS (p<0.05).

[0046] Table 1. Cardiac morphology in rats with chronic heart failure Note: Compared with the control group, **p<0.01; compared with the model group, #p<0.05, ##p<0.01 The results are shown in Table 2. Compared with the control group, the model group showed significantly increased LVEDV and LVESV (p<0.01), and significantly decreased SV, LVEF, and LVFS (p<0.05). Compared with the model group, the losartan group and H31 group showed significantly decreased LVEDV and LVESV (p<0.05), and significantly increased SV, LVEF, and LVFS (p<0.05).

[0047] Table 2 Cardiac systolic function in rats with chronic heart failure Note: Compared with the control group, *p<0.05, **p<0.01; compared with the model group, #p<0.05, ##p<0.01 2.2 Chemiluminescence assay for plasma troponin I content After cardiac function measurements were completed, rats were euthanized, and whole blood samples were collected. After centrifugation at 3500 rpm for 10 min, plasma was collected in EP tubes. The cTnI concentration in the prepared serum samples was detected using a cTnI kit (Solarbio, Cat: SEKR-0048). The chemiluminescence signal was detected using the Abbott ARCHITECT i2000SR automated chemiluminescence system.

[0048] The results are as follows: Figure 1 The results showed that the cTnI content in the plasma of rats in the model group was significantly higher than that in the control group (p<0.01), while the cTnI content in the H31-treated group was significantly lower than that in the model group.

Claims

1. A biologically active polypeptide, characterized in that, The polypeptide is a sea cucumber active polypeptide, and its amino acid sequence is shown in SEQ ID NO:

1.

2. A nucleic acid molecule encoding the bioactive polypeptide as described in claim 1.

3. A vector comprising the nucleic acid molecule as described in claim 2.

4. An isolated host cell comprising the bioactive polypeptide of claim 1, the nucleic acid molecule of claim 2, or the carrier of claim 3.

5. The use of the bioactive polypeptide according to claim 1 in the preparation of a medicament for treating cardiovascular and cerebrovascular diseases.

6. The use according to claim 5, wherein the cardiovascular disease is heart failure.

7. The use according to claim 6, wherein the heart failure is chronic heart failure.

8. A pharmaceutical composition comprising an effective amount of the bioactive polypeptide as claimed in claim 1.

9. The pharmaceutical composition according to claim 8 may further be used in combination with other anti-heart failure drugs.

10. The pharmaceutical composition according to claim 9, wherein the anti-heart failure drug may be selected from angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), beta-blockers, aldosterone antagonists, digitalis and non-digitalis positive inotropic agents, diuretics, aspirin, allopurinol, statins, and anti-inflammatory agents.

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