A polypeptide composition and its use for the treatment of male erectile dysfunction

Abstract

The present application provides a polypeptide composition and its use in treating male erectile dysfunction. Specifically, the polypeptide composition contains an erectile peptide screened and identified by the present application, which has good anti-oxidation and anti-fatigue properties, can effectively promote penile erection, increase testosterone level, effectively treat erectile dysfunction, and has a wide application prospect.

Description

Technical Field

[0001] This application relates to the biological field, and more specifically to a polypeptide composition and its use in the treatment of erectile dysfunction in men. Background Technology

[0002] Erectile dysfunction (ED), also known as impotence, refers to a man's inability to maintain an erection sufficient for satisfactory sexual intercourse. As a common condition affecting male sexual function, its incidence rate is significant. A meta-analysis in China concluded that the prevalence of ED among men aged 40-49 was 40.48%.

[0003] The main treatment for erectile dysfunction currently relies on Western medicine. A star drug is sildenafil, a type V phosphodiesterase (PDE5) inhibitor. After oral absorption, it binds to receptors in the smooth muscle of the corpus cavernosum. NO released from nerve endings binds to guanylate cyclase, stimulating guanosine triphosphate (GTP), converting GTP to cyclic guanosine monophosphate (cGMP). cGMP is then catalyzed by PDE5 to convert to guanosine monophosphate (CMP). cCMP is a vascular smooth muscle relaxant, increasing blood flow to the corpus cavernosum. Sildenafil binds to PDE5, inhibiting cCMP conversion and increasing blood flow to the corpus cavernosum, thus achieving an erection. Its citrate formulation (Viagra, manufactured by Pfzer in the US) was approved by the FDA in March 1998 and is considered the first safe and effective drug for treating erectile dysfunction. In a controlled study of 12 patients (36-63 years old) with mixed erectile dysfunction, who took different doses of valsildenafil orally, the duration of penile root erection (80%) was assessed as 1.3 minutes in the control group, while it was 3.5, 8.0, and 11.2 minutes in the drug groups (10, 25, and 50 mg), respectively. The duration of penile tip erection (80%) was assessed as 1.2 minutes in the control group, while it was 4 minutes in the 50 mg group.

[0004] In addition, there are other treatment drugs such as apomorphine. Apomorphine alkaloids were originally extracted by the Egyptians and Mayans from the tuber of a poplar tree for the treatment of mental illness. Now synthesized from morphine, it is used for emetics, sedation, and aphrodisiacs, and most recently for refractory Parkinson's disease. Apomorphine is a dopamine receptor agonist, having an erectile effect in both healthy individuals and those with erectile dysfunction. It lowers the erection and ejaculation threshold by reducing the activity of dopamine in the central nervous system, but this effect can be blocked by central dopamine receptors. Apomorphine is usually administered subcutaneously; 0.25-1.0 mg can induce erections in 60% of patients with psychogenic erectile dysfunction, but 50% experience nausea. Sublingual administration of 3-4 mg allows for complete absorption of the active ingredient, resulting in erections in 60%-80% of patients with erectile dysfunction with virtually no side effects. This drug has potential addictive properties and must be administered according to a prescription, with dosages kept as low as possible. Another treatment drug is naltrexone. Naltrexone is a long-acting sedative antagonist that amplifies the effects of endogenous gonadotropin-releasing hormone and inhibits the activity of sexual function antagonists, thereby inducing sexual arousal. Studies have shown that daily oral administration of 50 mg naltrexone can achieve full erection in 20% of patients, and all users experience morning erections.

[0005] In addition, there is a polypeptide drug called calcitonin peptide. Calcitonin peptide relaxes smooth muscle by activating potassium ion channels on the smooth muscle cell membrane and stimulating cyclic adenosine monophosphate (cAMP). Intracavernosal injection induces relaxation of the arterial walls, increasing blood flow; relaxation of the corpora cavernosa causes venous closure, resulting in erection. A mixture of 5 μg calcitonin peptide and 10 μg prostaglandin E1, used in patients with erectile dysfunction unresponsive to papaverine-phentolamine preparations or with incomplete penile venous closure, achieved erection in 70% of patients, demonstrating that the polypeptide drug calcitonin peptide has a good therapeutic effect on erectile dysfunction.

[0006] While existing technologies offer several medications for treating erectile dysfunction, these drugs all have varying degrees of side effects. For example, sildenafil can lower blood pressure in both normal and abnormal individuals, and when used in combination with nitrates, it can cause fatal hypotension. However, this hasn't prevented men who haven't had sexual intercourse for years from abusing the drug in an attempt to regain their youth, leading to several deaths among men with cardiovascular disease. Therefore, the FDA has issued a warning, advising men with cardiovascular disease who are unable to engage in sexual activity not to use this drug. Common adverse reactions include headache, facial flushing, indigestion, nasal congestion, diarrhea, dizziness, and rash; less common side effects include blurred vision and photosensitivity, which are dose-related. Therefore, developing a drug with fewer side effects and better therapeutic efficacy is an important research direction. Summary of the Invention

[0007] This invention, through research, has discovered that antioxidants can help protect the body from damage caused by free radicals, which are a contributing factor to health problems such as erectile dysfunction. This invention, through peptide library screening, has identified erectile peptides that promote erection while also possessing antioxidant properties.

[0008] In one aspect, the present invention provides an erectile peptide, the amino acid sequence of which is shown in SEQ ID NO: 1.

[0009] In another aspect, the present invention provides a polypeptide composition characterized by containing the erectile peptide of the present invention, the amino acid sequence of which is shown in SEQ ID NO: 1. The polypeptide composition may be used to treat erectile dysfunction in men.

[0010] Furthermore, the polypeptide compositions of the present invention can be tablets, oral dosage forms, or injections. Preferably, they can be in the form of oral liquids. Orally usable pharmaceutical formulations include tablets, push-filled capsules made of gelatin, and sealed soft capsules made of gelatin and plasticizers such as glycerin or sorbitol. Tablets can be made by compression or molding, optionally with one or more excipients. Compressed tablets can be prepared by compressing a free-flowing active ingredient, such as powder or granules, in a suitable machine, optionally mixed with a binder, an inert diluent or lubricant, a surfactant, or a dispersant. Molded tablets can be prepared by molding a mixture of powdered compounds moistened with an inert liquid diluent in a suitable machine. Tablets can optionally be coated or scored and can be formulated to provide a slow or controlled release of the active ingredient therein. All oral dosage forms should be used at a dosage suitable for such administration. Push-filled capsules can contain the active ingredient mixed with a filler such as lactose, a binder such as starch, and / or a lubricant such as talc or magnesium stearate, and optionally a stabilizer. In soft capsules, the active compound can be dissolved or suspended in a suitable liquid, such as fatty oil, liquid paraffin, or liquid polyethylene glycol. Additionally, stabilizers can be added. The core of the sugar-coated pill has a suitable coating. For this purpose, a concentrated sugar solution can be used, which may optionally contain gum arabic, talc, polyvinylpyrrolidone, carbomer gel, polyethylene glycol and / or titanium dioxide, lacquer solution, and suitable organic solvents or solvent mixtures. Dyes or pigments can be added to the coating of the tablet or sugar-coated pill to identify or characterize different combinations of active compound dosages.

[0011] On the other hand, common excipients in peptide compositions include solvents, flavoring agents, taste enhancers, clarifying agents, and preservatives. These excipients can be added simultaneously or individually. Solvents are mandatory and can be water. Different combinations of excipients include sweeteners, flavoring agents, clarifying agents, or preservatives, or combinations of sweeteners and preservatives, with combinations of sweeteners and preservatives being preferred. Some excipients have both sweetening and flavoring effects; in these cases, only one excipient needs to be added.

[0012] Furthermore, the compositions of the present invention also comprise excipients. Examples of such excipients may include: anti-adhesives (e.g., magnesium stearate, etc.); binders (e.g., sugars and their derivatives: disaccharides, sucrose, lactose; polysaccharides and their derivatives: starch, cellulose or modified cellulose, such as microcrystalline cellulose and cellulose derivatives, including cellulose ethers, such as hydroxypropyl cellulose; sugar alcohols, such as xylitol, sorbitol or mannitol; proteins: gelatin; synthetic polymers: polyvinylpyrrolidone or PVP, polyethylene glycol or PEG, polyvinylpyrrolidone, starch, sucrose and polyethylene glycol, methylcellulose); coating agents (e.g., cellulose ether hydroxypropyl methylcellulose, synthetic polymers, shellac, corn gluten, zein or other polysaccharides, gelatin); enteric solvents (fatty acids, waxes, shellac, etc.). Plastics and plant fibers); colorants (titanium oxide, azo dyes, etc.); disintegrants (e.g., cross-linked polymers: cross-linked polyvinylpyrrolidone such as crospovidone, cross-linked sodium carboxymethyl cellulose or crospovidone carboxymethyl cellulose, glycolates, etc.); fragrances (fruit extracts, etc.); flow aids (e.g., fumed silica, talc, and magnesium carbonate, etc.); lubricants (e.g., talc or silica, and fats such as vegetable stearin, magnesium stearate, or stearic acid, etc.); preservatives (e.g., antioxidants such as vitamin A, vitamin E, vitamin C, retinyl palmitate and selenium; cysteine, methionine; citric acid, sodium citrate; parabens: methylparaben and propylparaben); adsorbents; sweeteners. Flavoring agents (e.g., sugar); mediums (petrolatum, dimethyl sulfoxide, mineral oil, etc.); emollients / hardeners (carnauba wax, cetyl alcohol, cetyl ester wax, emulsifying wax, hydrous lanolin, lanolin, lanolin alcohol, microcrystalline wax, paraffin, petrolatum, polyethylene glycol, stearic acid, stearyl alcohol, white wax, yellow wax, etc.); emulsifiers / emulsifying agents / solvents (polysorbate 20, polysorbate 80, polysorbate 60, poloxamer, emulsifying wax, sorbitol monostearate, sorbitol monooleate, sodium lauryl sulfate, propylene glycol monostearate, diethylene glycol monoethyl ether, sodium docusate, etc.); humectants (e.g., glycerin, propylene glycol, polyethylene glycol, sorbitol solution, 1,2,6-hexanetriol, etc.); thickeners / gelling agents (carbomer, methyl methacrylate ... Ingredients include: cellulose, sodium carboxymethyl cellulose, carrageenan, colloidal silica, guar gum, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, gelatin, polyethylene oxide, alginate, sodium alginate, fumed silica, etc.; preservatives (benzoic acid, propylparaben, methylparaben, imidazoline, sorbic acid, potassium sorbate, benzalkonium chloride, phenylmercuric acetate, chlorobutanol, phenoxyethanol, etc.); penetration enhancers (propylene glycol, ethanol, isopropanol, oleic acid, polyethylene glycol, etc.); chelating agents (ethylenediaminetetraacetic acid, etc.); acidifying / alkalizing / buffering agents (citric acid, phosphoric acid, sodium hydroxide, sodium dihydrogen phosphate, trihydroxyamine, etc.); mediators / solvents (purified water, hexanediol, propylene glycol, oleyl alcohol, propylene carbonate, mineral oil, etc.).These examples can be numerous, and different excipients can be used for different reasons, and they can have dual or multiple functions.

[0013] Preferably, the sweetener in the composition is selected from one or more of protein sugar, xylitol, aspartame, and sucralose. Preferably, the preservative in the composition is selected from one or more of parabens, butylated hydroxyanisole, butylated hydroxytoluene, and sorbic acid.

[0014] The preservative may be parabens, butylated hydroxytoluene (BHT), or sorbic acid, with BHT being preferred. They may also be used in combination, such as a combination of parabens and BHT, or a combination of BHT and sorbic acid, or a combination of parabens and sorbic acid, or a combination of parabens, BHT, and sorbic acid. Preferably, the fragrance is a fruit flavoring.

[0015] Preferably, the clarifying agent is one or a mixture of chitosan and gelatin.

[0016] Preferably, the diluent is one or more of cellulose and inorganic salts. Examples include microcrystalline cellulose, calcium sulfate, calcium hydrogen phosphate, pharmaceutical-grade calcium carbonate, and mannitol, which increase the volume of the raw material to aid in its molding.

[0017] Preferably, the adhesive is one or more of water, ethanol, sodium carboxymethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose, gelatin, and polyvinylpyrrolidone.

[0018] Preferably, the lubricant is one or more of magnesium stearate, micronized silica gel, talc, hydrogenated vegetable oil, polyethylene glycol, and magnesium lauryl sulfate.

[0019] Preferably, the disintegrant is one or more of low-substituted hydroxypropyl, croscarmellose, and croscarmellose sodium carboxymethyl cellulose.

[0020] Furthermore, the composition of the present invention can also be in the form of granules. These granules can be swallowed directly or dissolved in warm water for drinking, making them convenient to use and carry, and allowing for rapid dissolution and absorption. The pharmaceutical excipients used in the granules are similar to those used in tablets, involving one or more of fillers, binders, wetting agents, disintegrants, lubricants, and film coating materials.

[0021] For granules, preferably, the filler is one or more of cellulose and inorganic salts. Examples include microcrystalline cellulose, calcium sulfate, calcium hydrogen phosphate, pharmaceutical-grade calcium carbonate, and mannitol, which increase the volume of the raw material to aid in its formation.

[0022] For granules, preferably, the binder is one or more of water, ethanol, sodium carboxymethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose, gelatin, and polyvinylpyrrolidone.

[0023] For granules, preferably, the wetting agent is water, ethanol, or a mixture of both. Examples include one or more of magnesium stearate, micronized silica gel, talc, hydrogenated vegetable oil, polyethylene glycol, and magnesium lauryl sulfate.

[0024] For granules, preferably, the disintegrant is one or more of low-substituted hydroxypropyl, croscarmellose, and croscarmellose sodium carboxymethyl cellulose.

[0025] For granules, preferably, the film coating material is one or more of hydroxypropyl methylcellulose, polyethylene glycol, cellulose acetate phthalate, and polyvinyl acetal diethylamine acetate.

[0026] Beneficial effects

[0027] This invention provides a polypeptide composition and its use in treating male erectile dysfunction. Specifically, the polypeptide composition contains an erectile peptide screened and identified by this invention. This erectile peptide has good anti-oxidative fatigue properties and can effectively promote penile erection, increase testosterone levels, and effectively treat erectile dysfunction, showing broad application prospects. Attached Figure Description

[0028] Figure 1 Figure 1 shows the effect of erectile peptide on serum testosterone levels in rats.

[0029] Figure 2 Figure showing the effect of erectile peptides on penile ICPmax in rats. Detailed Implementation

[0030] Those skilled in the art can refer to the content of this document and appropriately improve the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention. Unless otherwise specified, the methods, equipment, and materials in the following embodiments are all conventional methods, equipment, and materials in the art and are commercially available.

[0031] Example 1: Anti-fatigue experiment of erectile peptides

[0032] The erectile peptide identified by the inventors based on peptide library screening of SEQ ID NO: 1 was artificially synthesized by Qiangyao Biotechnology with a purity of 98.5% and a concentration of 10 mg / mL for later use.

[0033] SPF-grade male mice (weighing 18-20g, Beijing Vital River Laboratory Animal Technology Co., Ltd.) were used. After one week of acclimatization, the mice were randomly divided into four groups (n=10): a blank control group (administered by gavage with the same dose of 0.9% saline), a low-dose group (10mg / kg), a medium-dose group (50mg / kg), and a high-dose group (100mg / kg). Each group was administered the drug by gavage once daily for four consecutive weeks. During the gavage period, the mice had free access to food and water. Thirty minutes after the last gavage, the mice were placed in a 45cm×52cm×45cm swimming tank (water depth 30cm, water temperature 25℃) with a lead weight of 5% of their body weight attached to the base of their tails. They were then encouraged to swim using a glass rod. The time from the start of swimming until exhaustion and complete submersion in the water for 10 seconds was recorded as the exhaustion time. The results are shown in Table 1.

[0034] ;

[0035] Improved exercise endurance is the most direct manifestation of enhanced anti-fatigue ability, and the length of swimming time can reflect the degree of exercise fatigue in animals. Table 1 shows that compared with the blank control group, the exhaustion swimming time of mice in different dosage groups was significantly increased (P<0.05), and this showed a good dose-dependent effect. However, the increase in the high-dose group was not significant, and the medium-dose group offered the best cost-effectiveness and could be effectively used in subsequent experiments. This indicates that erectile peptides themselves have a good anti-fatigue effect.

[0036] Mice in each group were removed from the swimming tank, their fur was dried, and then they were decapitated to collect blood. Serum was separated, and relevant biochemical indicators such as BLA and BUN were measured according to the kit method. The results are shown in Table 2:

[0037] ;

[0038] During strenuous exercise, the body's tissues and organs function through the lactic acid system. As the intensity of exercise increases, the higher the BLA content, the more easily the body becomes fatigued. The higher the BUN content, the worse the body's adaptability to high loads. As shown in Table 2, with increasing dosage, both BLA and BUN in the treatment group were significantly lower than in the blank control group. This fully demonstrates that erectile peptides can effectively reduce BLA and BUN levels and have a good anti-fatigue effect.

[0039] Example 2: Verification of the efficacy of erectile peptides on mating function in rats

[0040] Nine-week-old healthy SD rats (weighing 250-280g) were used and fed normally for one week. Female rats underwent bilateral ovariectomy. Experiments were conducted two weeks post-surgery. Four hundred and eighty hours before the experiment, each rat was subcutaneously injected with 20 μg of estradiol benzoate, and four hours prior, it was injected subcutaneously with 500 μg of progesterone. Male rats were randomly divided into four groups of ten each. The blank control group received 5 mL / kg of distilled water. -1 Low-dose erectile peptide group: 10 mg / kg -1 Erectile peptide medium-dose group: 50 mg / kg -1 Positive control group: Sildenafil group 10 mg / kg -1 All patients were given gavage once daily for 20 consecutive days.

[0041] Each male rat was placed alone in a cage for 10 minutes to allow it to adapt to the new environment. Then, one female rat was added to each cage. The following indicators were recorded: the time from when the female rat was introduced to when the male rat first captured her (capture latency); the time from when the female rat was introduced to when the male rat first ejaculated (ejaculation latency). The results are shown in Table 3.

[0042] ;

[0043] As can be seen from the results in Table 3, compared with the blank control group, all three treatment groups significantly reduced the capture latency and ejaculation latency, indicating that erectile peptides can significantly improve the sexual function of rats.

[0044] Example 3: Effect of erectile peptide on serum testosterone levels in rats

[0045] Nine-week-old healthy male SD rats (weighing 250-280g) were collected and fed normally for one week. The male rats were then randomly divided into four groups of 10 rats each, based on their body weight. The blank control group received 5 mL / kg of distilled water. -1 Low-dose erectile peptide group: 10 mg / kg -1 Erectile peptide medium-dose group: 50 mg / kg -1 Positive control group: Sildenafil group 10 mg / kg -1 All patients were administered the medication by gavage once daily for 60 consecutive days. Serum testosterone levels were measured before the experiment. Twenty-four hours after the last administration, blood was collected from the tail artery, and serum testosterone levels were measured again. Results are as follows: Figure 1 As shown.

[0046] from Figure 1As shown, compared with the blank control group, the low-dose and high-dose erectile peptide groups significantly increased testosterone levels, and the testosterone level in the medium-dose group reached (12.92±0.13) nmol / L. In contrast, there was no significant difference in testosterone levels before and after sildenafil administration in the positive control group, nor was there a significant difference compared with the blank control group, indicating that sildenafil cannot significantly improve testosterone levels. This result suggests that erectile peptide can significantly increase testosterone levels, thereby improving sexual function in rats.

[0047] Example 4: Effects of erectile peptides on erectile function in rats

[0048] Nine-week-old healthy male SD rats (weighing 250-280g) were used and fed normally for one week. A vascular ED rat model was established by bilateral internal iliac artery ligation. In the sham-operated group, the rats were fixed on the operating table, and a midline incision was made in the lower abdomen. After opening the abdominal cavity, the bilateral internal iliac arteries were located and exposed without ligation. Then, the abdominal organs were repositioned, and the peritoneum, muscles, subcutaneous fat, and skin were sutured in sequence.

[0049] Rats with vascular erectile dysfunction were randomly divided into three groups (model group, positive control group, and experimental group), with 10 rats in each group. Rats in the positive control group were administered 10 mg / kg via gavage daily. -1 The experimental group received 10 mg / kg of erectile peptide via gavage daily. -1 Rats in the model group and sham-operated group received no intervention, but were given an equal volume of physiological saline by gavage daily. After four weeks of continuous gavage, penile erection was induced by stimulation of the corpus cavernosum nerves. The maximum intracavernosal pressure (ICPmax) was measured using an RM-6280XC multichannel physiological signal acquisition and processing system to assess the rats' erectile function. The corpus cavernosum nerves were stimulated twice consecutively using the same method, with a 10-minute interval between the two stimulations. The ICPmax measured after the second stimulation was taken as the penile ICPmax data for that rat. The results were averaged. The results are as follows: Figure 2 As shown.

[0050] from Figure 2 It can be seen that the ICPmax of the positive control group and the model group was significantly higher than that of the model group (P<0.01). The ICPmax of the experimental group (54.31±2.12 mmHg) was also higher than that of the positive control group (45.82±1.85 mmHg), and closer to that of the sham-operated group; this proves that erectile peptides can improve the erectile function of model mice and have a good therapeutic effect.

[0051] Although various illustrative embodiments have been described above, any of the various modifications to these embodiments may be made without departing from the scope of the invention as described in the claims. For example, in alternative embodiments, the order in which the various method steps described are performed may often be changed, while in other alternative embodiments, one or more method steps may be skipped. Optional features of various device and system embodiments may be included in some embodiments, while they may not be included in others. Therefore, the foregoing description is provided primarily for illustrative purposes and should not be construed as limiting the scope of the invention as set forth in the claims.

[0052] The embodiments and illustrations included herein are shown in an illustrative and not limiting manner to illustrate specific implementations of the subject matter of the invention. As mentioned, other embodiments can be used and derived therefrom, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure. For convenience only, the term "invention" may be used herein, individually or collectively, to refer to these embodiments of the subject matter of the invention, without intending to limit the scope of this application to any single invention or inventive concept (if the invention does disclose multiple). Therefore, although specific embodiments have been illustrated and described herein, any solution calculated to achieve the same purpose may replace the specific embodiments shown. This disclosure is intended to cover any and all modifications or variations of the various embodiments. Combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art upon reading the above description.

Claims

1. An erectile peptide, characterized in that... The amino acid sequence of the erectile peptide is shown in SEQ ID NO:

1.

2. A polypeptide composition, characterized in that... It contains an erectile peptide, the amino acid sequence of which is shown in SEQ ID NO:

1.

3. Use of the erectile peptide in the preparation of a polypeptide composition for treating erectile dysfunction in men, the amino acid sequence of said erectile peptide being shown in SEQ ID NO:

1.

4. The use as described in claim 3, characterized in that... The polypeptide composition is in tablet form.

5. The use as described in claim 3, characterized in that... The polypeptide composition is in oral dosage form.

6. The use as described in claim 4 or 5, characterized in that... The polypeptide composition also contains a pharmaceutically acceptable carrier.

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