Application of metformin in preparation of medicine for treating interstitial cystitis

Abstract

The invention discloses an application of metformin in preparation of a medicine for treating interstitial cystitis, and finds that the metformin can reduce the pain sensitivity of an interstitial cystitis (IC) rat, reduce the bladder edema degree of the IC rat, recover the bladder capacity of the IC rat, repair the bladder mucosa of the IC rat and reduce submucosal bleeding. Macrocyte infiltration is reduced, that is, the metformin has a remarkable curative effect on interstitial cystitis, and a new medicine can be provided for treating interstitial cystitis.

Description

Technical Field

[0001] The present invention relates to a new application of metformin, and in particular to an application of metformin in preparing a medicine for treating interstitial cystitis. Background Art

[0002] Interstitial cystitis / bladder pain syndrome (IC / BPS) is a multifactorial, chronic bladder disease characterized by bladder and pelvic pain, increased pain sensitivity, and lower urinary tract symptoms such as urinary frequency and urgency or nocturia, which significantly impair patients' quality of life. Existing studies of bladder wall morphology in BPS / IC have most commonly reported findings of reduced urothelial thickness, disrupted glycosaminoglycan (GAG) layers, abnormal smooth muscle structure, increased microvascular and nerve density, mast cell infiltration, and fibrosis. However, its pathogenesis, natural history, and pathological mechanisms remain incompletely understood.

[0003] Currently, the treatment of IC / BPS emphasizes individualized and comprehensive treatment strategies. Treatment methods include non-drug treatment, drug treatment, and surgical treatment. The drugs used in drug treatment are divided into oral drugs (α-receptor blockers, M-receptor blockers, antidepressants, and muscle relaxants, etc.) and intravesical instillation drugs (dimethyl sulfoxide, hyaluronic acid, heparin, pentosan polysulfate, lidocaine, etc.).

[0004] Metformin (Met) has been designated as one of the most important first-line treatments for type 2 diabetes. It primarily works by activating AMPK (adenosine monophosphate-activated protein kinase) in cells, thereby reducing hepatic glucose output. Metformin also regulates glucose and lipid metabolism in cardiomyocytes and reduces the production of advanced glycation end products and reactive oxygen species in endothelial cells, thereby minimizing cardiovascular risk. Studies have shown that it inhibits tumor cell proliferation and induces apoptosis, and has inhibitory effects on malignant tumors in organs such as the breast, kidney, brain, ovary, lung, and endometrium. Preclinical studies have also demonstrated the neuroprotective effects of metformin in Parkinson's disease, Alzheimer's disease, multiple sclerosis, and Huntington's disease. Currently, there are no reports of metformin being used to treat interstitial cystitis. Summary of the Invention

[0005] The present invention is based on the discovery that metformin can significantly improve the symptoms of interstitial cystitis, thereby inventing a use of metformin in the preparation of a drug for treating interstitial cystitis.

[0006] The technical solution of the present invention is: use of metformin in preparing a medicine for treating interstitial cystitis.

[0007] The present invention found that metformin can reduce the pain sensitivity of rats with interstitial cystitis (IC), reduce the degree of bladder edema in IC rats, restore the bladder capacity of IC rats, repair the bladder mucosa of IC rats and reduce submucosal bleeding, and reduce mast cell infiltration. In other words, metformin has a significant therapeutic effect in treating interstitial cystitis and can provide a new drug for the treatment of interstitial cystitis. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a diagram showing the effect of the Von Frey pain threshold experiment on rats in each experimental group of the present invention.

[0009] Figure 2 These are ultraviolet imaging images of rat urine spots in each experimental group of the present invention.

[0010] Figure 3 It is a statistical graph of urine spot area analysis of rats in each experimental group of the present invention.

[0011] Figure 4 1 is a comparative diagram of the wet weight of rat bladders in each experimental group of the present invention.

[0012] Figure 5 1 is a HE staining picture of rat bladder tissue in each experimental group of the present invention.

[0013] Figure 6 3. It is the toluidine blue staining picture of the rat bladder tissue of each experimental group of the present invention.

[0014] Figure 7 Schematic diagram of mast cell counts in rat bladder tissue of each experimental group of the present invention. DETAILED DESCRIPTION

[0015] 1. Source of Animal Materials and Experimental Methods Twelve SPF Sprague-Dawley rats (220-250 g) were housed in pathogen-free conditions (room temperature 22°C, humidity 50%) with free access to food and water and 12 hours of light per day. All rats were matched by weight and randomly assigned to a control group (control group), an inflammation group (IC group), an oral gavage treatment group (Met 100 mg / kg group), or an intravesical instillation group (Met 10 mg / ml group), with three rats per group. The inflammation, oral gavage, and intravesical instillation groups were administered 10 mg / ml protamine sulfate (PS) and 1 mg / ml lipopolysaccharide (LPS) intravesically on day 1 of the experiment to establish an interstitial cystitis model. The control group was also administered normal saline intravesically. After model establishment, the oral gavage group was administered metformin hydrochloride 100 mg / kg intravesically on days 2, 4, and 6 of the experiment. The intravesical instillation group was administered metformin hydrochloride 10 mg / ml intravesically on days 2, 4, and 6 of the experiment. The control group was also administered normal saline intravesically. Metformin was obtained from Merck & Co.

[0016] 2. Validation Methods and Results for Interstitial Cystitis Treatment On the 7th day of the group experiment, the following experiments were conducted and the corresponding results were obtained.

[0017] 1. Von Frey pain threshold test Experimental Method: Each group is placed on a wire mesh and their hind paw is tested. Using a Von Frey filament of a specific gauge (e.g., a starting gauge of 0.6 g), gently touch the plantar surface of the animal's hind paw from the underside of the mesh, maintaining contact for 1-2 seconds. Adjust the filament gauge based on the rat's response. If no withdrawal response (e.g., paw withdrawal or licking) is observed, increase the filament gauge; if a response is observed, decrease the filament gauge until a filament that elicits a withdrawal reflex is found. Repeat this process multiple times (e.g., 5 times), with at least 2 minutes between each session to ensure the rat has returned to its baseline state.

[0018] The results are as follows Figure 1 As shown, Figure 1 *: p < 0.05, **: p < 0.01. The results showed that compared with the control group, the pain threshold of rats in the IC group was significantly lower (p < 0.05), indicating a more pronounced pain perception. The pain thresholds of rats in both groups treated with metformin were significantly elevated (p < 0.05), and after the third treatment, they were no different from those in the control group, indicating that metformin restored pain sensitivity to normal in rats with interstitial cystitis.

[0019] 2. Urine spot test During the experiment, a single SD rat was placed in an experimental cage and on filter paper. The experimental cage containing the rat was placed in a quiet environment to allow the rat to urinate. The test time was 4 hours. No drinking water was provided during the test, only feed was provided. After 4 hours, the urine spot filter paper was collected, imaged by ultraviolet light, and analyzed with Image J software to measure the size of the urine spot.

[0020] UV imaging Figure 2 The statistical results were analyzed using Image J software as shown in Figure 3 As shown, Figure 3 **: p < 0.01. Results showed that compared with the control group, the urine spot area in rats in the IC group was significantly reduced (p < 0.05), indicating decreased urine volume, i.e., decreased bladder capacity, and impaired bladder function. After metformin treatment, the urine spot area in rats significantly increased (p < 0.05), with the increase being particularly pronounced in rats treated with intravesical instillation. This demonstrates that metformin treatment increases bladder capacity and restores bladder function in rats with interstitial cystitis.

[0021] 3. Bladder wet weight The bladder of rats was collected and rinsed with PBS buffer on ice. After rinsing, the surface moisture was absorbed with filter paper and then weighed.

[0022] The results are as follows Figure 4 As shown, Figure 4 *: p<0.05. The results showed that compared with the control group, the wet weight of the bladder of IC rats increased significantly, indicating that the degree of bladder edema was obvious. After treatment with metformin, the wet weight of the bladder of rats with interstitial cystitis model decreased significantly, especially for rats treated with intravesical instillation. The decrease in wet weight was more obvious, indicating that the degree of bladder edema in rats with interstitial cystitis model was reduced after metformin treatment.

[0023] 4. HE staining Bladder tissue was fixed in 4% paraformaldehyde and embedded in paraffin. 5 μm thick sections were cut using a rotor microtome, dewaxed, rehydrated, and cleared before staining with hematoxylin and eosin.

[0024] HE staining results Figure 5 Results showed that the bladders of control rats displayed normal histological morphology, with intact bladder mucosa and no edema or hemorrhage. However, in IC rats, the bladder mucosa showed significant exfoliation, edema, and hemorrhage. Metformin treatment restored the bladder mucosa of rats with interstitial cystitis to its integrity, without edema or hemorrhage, with the effect being more pronounced in the intravesical instillation group.

[0025] 5. Toluidine Blue Staining Bladder tissue was fixed in 4% paraformaldehyde and embedded in paraffin. 5-μm-thick sections were cut using a rotor microtome, dewaxed, rehydrated, and cleared before staining with toluidine blue and counting mast cells.

[0026] The results of bladder histamine blue staining were as follows Figure 6 The mast cell count diagram is shown in Figure 7 As shown, Figure 7 *: p < 0.05, **: p < 0.01. The results showed that compared with the control group, the number of mast cells in the IC group was significantly increased (p < 0.05), and the number of mast cells in rats with interstitial cystitis treated with metformin was significantly reduced (p < 0.05), with the reduction in mast cell number in the intravesical instillation group being particularly significant.

[0027] The above experimental results demonstrate that metformin has significant efficacy in treating interstitial cystitis and can be used in the preparation of a drug for the treatment of interstitial cystitis. The drug can be administered orally, intravenously, intraperitoneally, or intravesically.

Claims

1. Use of metformin in the preparation of a medicament for treating interstitial cystitis.

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