Use of nitrate preparations for the manufacture of a medicament for the treatment of diabetic ulcers

Abstract

The present application discloses the use of a nitrate salt selected from the group consisting of sodium nitrate, potassium nitrate, lithium nitrate, zinc nitrate, magnesium nitrate, iron nitrate, calcium nitrate and copper nitrate in the manufacture of a medicament for the treatment of diabetic ulcers.

Description

Technical Field

[0001] This invention provides the use of nitrate compounds in the preparation of drugs for treating diabetic ulcers. Background Technology

[0002] Diabetic ulcers are a common and highly disabling complication of diabetes, and have always been a challenge in clinical treatment. The mortality rate after amputation in patients with diabetic ulcers increases significantly with the progression of the disease (1. Armstrong DG, Tan TW, Boulton AJM, Bus SA. Diabetic Foot Ulcers: A Review. Jama. 2023; 330(1):62-75.). The persistently high rates of disability and death from diabetic ulcers have a serious negative impact on patients and society, placing a heavy burden on patients and global public health. Therefore, therapies that minimize amputation and promote wound healing are of great significance.

[0003] Peripheral nerve and lower extremity vascular lesions caused by long-term hyperglycemia, as well as delayed wound healing caused by a combination of factors such as chronic inflammation, ischemia-hypoxia, oxidative stress and repeated infection, are typical characteristics of tissue damage in diabetic ulcers. The wound healing process, such as inflammation reduction and tissue regeneration, is disordered or stalled in diabetic ulcers, ultimately manifesting as long-term local chronic inflammation and persistent wound healing (2. Jeffcoate W, Boyko EJ, Game F, Cowled P, Senneville E, Fitridge R. Causes, prevention, and management of diabetes-related footulcers. Lancet Diabetes Endocrinol. 2024; 12(7):472-82.).

[0004] Traditional treatments for diabetic foot ulcers mainly focus on wound management, infection control, and blood glucose management. New drugs and dressings, such as Xianglei Tang Foot Ointment and hydrocolloids, have shown certain effects in the treatment of diabetic foot ulcers (3. Chinese Society of Endocrinology, Chinese Alliance of Endocrinology and Metabolic Diseases. Expert consensus on the treatment of diabetic foot ulcers (2024). Chinese Journal of Endocrinology and Metabolism, 2024; 40(7):565-569.). Literature reports that silver ion salts (including silver nitrate) can also treat diabetic ulcers (although meta-analysis studies show that the clinical evidence for the treatment of diabetic ulcers with silver nanoparticles is not conclusive (4. Hosseini RS, Hasanpour K, Khoshnevis M, Fakhr MS, Derin E, Ghaffarian A, Kement C. Therapeutic Effect of Silver Nanoparticles in the Management of Diabetic Ulcers: A Systematic Review and Meta-Analysis on RCTs. Int J Low ExtremWounds. 2024:15347346241241836.)), but current evidence suggests that the mechanism of silver ion salts in treating ulcer-like diseases is mainly based on the antibacterial and proliferative effects of silver ions (5. Lansdown AB. Silver in healthcare: antimicrobial effects and safety in use. Curr Probl Dermatol. 2006; 33:17-34; 9. Tian J, Wong KK, Ho CM, Lok CN, Yu WY, Che CM, Chiu JF, Tam PK. Topical delivery of silver nanoparticles promotes wound healing. Chem Med Chem. 2007; 2(1):129-36.). Summary of the Invention

[0005] The inventors have surprisingly discovered that nitrates such as potassium nitrate and zinc nitrate, despite not containing silver ions, can still exert a therapeutic effect on diabetic ulcers based on the activity of nitrate ions. Therefore, they propose that nitrates, as a single active ingredient, can effectively treat diabetic ulcers, thus completing this invention. The nitrates of this invention can also be used in combination with other therapeutic agents.

[0006] The purpose of this application is to provide the use of nitrates in the preparation of medicaments for treating diabetic ulcers.

[0007] According to some embodiments of this application, the nitrates in this application are selected from sodium nitrate, potassium nitrate, lithium nitrate, zinc nitrate, magnesium nitrate, ferric nitrate, calcium nitrate, or copper nitrate, etc.

[0008] According to some embodiments of this application, the nitrates used in this application are preferably potassium nitrate or zinc nitrate, and more preferably zinc nitrate.

[0009] According to some embodiments of this application, the nitrates of this application are used to treat diabetic ulcers. The nitrates of this application can promote the healing of diabetic ulcer wounds.

[0010] According to some embodiments of this application, nitrates can be administered topically or systemically, with an effective dose range of 0.1 mg / kg body weight to 50 mg / kg body weight.

[0011] The diabetic ulcers in this application include infections, ulcers, and / or deep tissue damage on the skin, feet, and other parts of the body caused by distal nerve abnormalities and varying degrees of vascular lesions in diabetic patients.

[0012] The nitrates in this application refer to salts formed by the reaction of nitric acid (HNO3) with metals, which are composed of metal ions and nitrate ions. They include sodium nitrate, potassium nitrate, lithium nitrate, zinc nitrate, magnesium nitrate, iron nitrate, calcium nitrate, or copper nitrate, with zinc nitrate being preferred.

[0013] The beneficial effects of this invention are: nitrates have a therapeutic effect on diabetic ulcers, can improve the wound healing rate of diabetic ulcers, reduce the size of the wound, and increase the thickness of the newly formed tissue in the wound. Attached Figure Description

[0014] Figure 1 Representative images and statistical results of the effects of potassium nitrate and zinc nitrate on wound healing in diabetic ulcer mice are shown. Mean ± standard deviation is presented. One-way ANOVA was used, and Dunnett's test was used for comparisons between groups. * p<0.05, ** P<0.01, compared with the STZ group.

[0015] Figure 2 This study investigated the effects of potassium nitrate and zinc nitrate on the histopathological effects of wounds in diabetic ulcer mice. Methods included local tissue sampling for HE staining, microscopic imaging of each group, and statistical analysis of unhealed wound length and thickness. Mean ± standard deviation was analyzed using one-way ANOVA, and Dunnett's test was used for intergroup comparisons. * p<0.05, ** P<0.01, *** P<0.001, compared with the STZ group. Detailed Implementation

[0016] To make the objectives, technical solutions, and features of this invention clearer, the technical solutions of this application will be described below through embodiments of this invention. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0017] Example 1: The therapeutic effect of nitrates on diabetic ulcers

[0018] (1) Animal preparation. Six male C57BL / 6J mice, aged 6-8 weeks, were acclimatized for one week and then fasted for at least 12 hours to establish a diabetic model. Streptozocin (STZ), the modeling drug, was dissolved in citrate-sodium citrate buffer (pH 4.2) and injected intraperitoneally at a dose of 150 mg / kg body weight. The streptozocin solution was kept at low temperature and protected from light; the solution was prepared fresh and injected within 30 minutes. Mice were then allowed free access to food. Blood glucose levels were measured via tail vein sampling 72 hours later. A blood glucose level of 16.67 mmol / L was considered a successful establishment of the diabetic model.

[0019] (2) Wound preparation. Prepare the skin on the mouse's back (by shaving the back hair). Using an 8mm diameter punch, prepare two full-thickness skin wounds on both sides of the mouse's back, with a distance of more than 1cm between the wounds. If no bleeding is observed and the wounds are of roughly the same size after preparation, the wound preparation is considered successful.

[0020] (3) The therapeutic effect of nitrates on diabetic ulcers. Potassium nitrate solution (40 mM) and zinc nitrate solution (8 mM) were prepared using deionized water. Mice were divided into a blank control group, a diabetic ulcer group, a diabetic ulcer + potassium nitrate group, and a diabetic ulcer + zinc nitrate group. The drugs were applied to the ulcer sites once daily, and the wounds were bandaged after application. The experimental period was 12 days. After full-thickness skin removal, the drugs were applied to the wounds once daily, and photographs were taken on days 0, 6, and 12.

[0021] (4) Results presentation. Figures 1 to 2 In the study, Control was the normal control group, STZ was the diabetic ulcer group, STZ+PN was the diabetic ulcer + potassium nitrate administration group, and STZ+ZN was the diabetic ulcer + zinc nitrate administration group.

[0022] Figure 1 Representative images of wounds at 0, 6, and 12 days, and statistical results of wound healing rate at 12 days. Figure 1 A shows representative images of the wound at 0, 6, and 12 days. Figure 1B represents the statistical results of the wound healing rate at 12 days. The method was to analyze and measure the wound area using the Image ProPlus 6.0 image analysis system and calculate the healing rate using the formula: Wound healing rate = (Wound area at 0 days - Wound area at 12 days) / Wound area at 0 days × 100%.

[0023] Figure 2 Representative HE-stained images of the wound area (semicircular) and statistical results of wound size and new tissue thickness under the microscope. Figure 2 A represents the images of each group obtained under a microscope at 1× after fixation, dehydration, embedding, sectioning, and HE staining. Figure 2 B represents a quantitative analysis of the unhealed portion of the wound, indicating the size of the wound. Figure 2 C represents the quantitative analysis of the thickest point of newly formed epidermal tissue at the wound site, indicating the thickness of the newly formed tissue. Figure 2 B and Figure 2 The unit of C is millimeters (mm).

[0024] (5) Results Analysis

[0025] Figure 1 and Figure 2 This is the result of the efficacy of nitrates in treating diabetic ulcers. Figure 1 The results showed that both nitrates had a higher wound healing rate at 12 days compared to the diabetic ulcer group, suggesting that nitrates have a therapeutic effect on diabetic ulcers. Figure 2 This indicates that, compared with the diabetic ulcer group, both nitrates can reduce the size of the wound and increase the thickness of the newly formed tissue, suggesting that nitrates can improve the severity of wounds in diabetic ulcer mice.

Claims

1. Use of nitrates in the preparation of medicaments for treating diabetic ulcers, wherein the nitrates are selected from sodium nitrate, potassium nitrate, lithium nitrate, zinc nitrate, magnesium nitrate, ferric nitrate, calcium nitrate, and copper nitrate.

2. The use according to claim 1, wherein the nitrate is selected from sodium nitrate.

3. The use according to claim 1, wherein the nitrate is selected from potassium nitrate.

4. The use according to claim 1, wherein the nitrate is selected from lithium nitrate.

5. The use according to claim 1, wherein the nitrate is selected from zinc nitrate.

6. The use according to claim 1, wherein the nitrate is selected from magnesium nitrate.

7. The use according to claim 1, wherein the nitrate is selected from ferric nitrate.

8. The use according to claim 1, wherein the nitrate is selected from calcium nitrate.

9. The use according to claim 1, wherein the nitrate is selected from copper nitrate.

10. The use according to any one of claims 1-9, wherein the diabetic ulcer refers to skin and foot infections, ulcers and / or deep tissue damage in a diabetic patient.

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