Application of glabridin and pharmaceutically acceptable salt thereof in preparation of medicine for treating spinal cord injury

Abstract

The invention discloses application of glabridin and pharmaceutically acceptable salts thereof in preparation of drugs for treating spinal cord injury. The glabridin and the pharmaceutically acceptable salt thereof have an obvious effect of promoting spinal cord nerve repair, can improve nerve conduction disorder and motor function loss of a mouse with spinal cord injury, are helpful to recover normal physiological functions of an injured spinal cord area, and are expected to be developed into a new medicine for treating spinal cord injury.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical technology, specifically to the use of glycyrrhizin and its pharmaceutical compositions in the preparation of medicaments for treating spinal cord injury. More specifically, this invention relates to the use of glycyrrhizin and its pharmaceutically acceptable salts or pharmaceutical compositions thereof in the preparation of medicaments for treating spinal cord injury, which have the effects of promoting spinal cord nerve regeneration, improving nerve function, reducing inflammatory response and protecting spinal cord tissue. Background Technology

[0002] Spinal cord injury (SCI) refers to structural or functional damage to the spinal cord caused by various factors. It is a serious central nervous system disease that leads to irreversible motor, sensory, and autonomic dysfunction below the site of injury. It has a high disability rate and numerous complications, imposing a heavy psychological and economic burden on individuals, families, and society. Currently, there are over 3.7 million SCI patients in my country. Although some progress has been made in the treatment of SCI in recent years, to date, there is still a lack of effective treatment strategies for SCI in clinical practice, making it a major unsolved medical challenge recognized worldwide. Therefore, the discovery of drugs that can block the pathological progression of SCI has significant practical value.

[0003] Glycyrrhizin (CAS No.: 59870-68-7) is a naturally occurring flavonoid compound. It was first extracted from the legume *Glycyrrhiza glabra* in 1976. Glycyrrhizin (GLA) possesses antioxidant, anti-inflammatory, skin-whitening, and other bioactive properties. GLA is hailed as "skin-whitening gold" due to its powerful skin-whitening effects, capable of eliminating free radicals and melanin in the skin's basal layer. These properties make it a popular ingredient in skincare products such as creams, lotions, and serums, and it is considered a holy grail for skin whitening and anti-aging.

[0004] Currently, there are no reports on the therapeutic effects of glabridin in promoting spinal cord nerve regeneration, improving nerve function, reducing inflammation, and protecting spinal cord tissue. This invention, through experimental screening, has discovered that glabridin has the effect of protecting spinal cord neurons and promoting spinal cord injury repair; therefore, this invention further reveals its efficacy in treating new indications. Summary of the Invention

[0005] One object of this invention is to develop new pharmaceutical uses for glycyrrhizin and its pharmaceutically acceptable salts, specifically the use of glycyrrhizin or its pharmaceutically acceptable salts in the preparation of medicaments for treating spinal cord injuries.

[0006] The spinal cord injury mentioned includes, but is not limited to, spinal cord injuries caused by factors such as trauma, traffic accidents, falls, and sports injuries.

[0007] The use of glycyrrhizin and its pharmaceutically acceptable salts in the preparation of drugs for treating neuropathy after spinal cord injury or promoting nerve regeneration.

[0008] The use of glycyrrhizin and its pharmaceutically acceptable salts in the preparation of drugs for treating neurological dysfunctions associated with spinal cord injury and promoting nerve recovery.

[0009] The spinal cord injury-related neurological dysfunctions and the promotion of neurological recovery include paraplegia caused by spinal cord injury and motor conduction disorders after spinal cord injury.

[0010] A second object of the present invention is to provide the use of a pharmaceutical composition containing glycyrrhizin in the preparation of a medicament for treating spinal cord injury.

[0011] The pharmaceutical composition may also contain pharmaceutically acceptable excipients, such as stabilizers, antioxidants, colorants, etc., to improve the drug preparation process, enhance drug stability and bioavailability.

[0012] A third objective of this invention is to provide the use of pharmaceutical compositions containing glycyrrhizin in promoting spinal cord nerve regeneration, improving nerve function, reducing inflammatory responses, and protecting spinal cord tissue. This is for the treatment of conditions including paraplegia caused by spinal cord injury and motor conduction disorders following spinal cord injury.

[0013] The application can restore spinal cord function by acting directly on the site of spinal cord injury or by regulating secondary pathological changes after spinal cord injury.

[0014] Preferably, the pharmaceutically acceptable salts include, but are not limited to, inorganic acid salts and organic acid salts, such as sodium salts, potassium salts, malates, citrates, etc.

[0015] As a further preferred option, the pharmaceutical composition can be administered orally, by injection, externally, or by inhalation, in dosage forms such as tablets, capsules, granules, oral solutions, injections, suppositories, ointments, sprays, and aerosols.

[0016] The beneficial effects of this invention are as follows: This invention has found through extensive screening experiments that glycyrrhizin can significantly repair nerve structural damage: experimental data clearly show that glycyrrhizin can effectively promote significant reduction of tissue defect areas, significantly reduce demyelination rate, and greatly improve neuronal survival rate, thereby contributing to the comprehensive recovery of spinal cord function.

[0017] 2. Accelerating neurological function recovery: Experiments in this invention have shown that glycyrrhizin exhibits excellent neuroprotective capabilities, significantly improving motor, sensory, and autonomic nervous system function scores in animals after spinal cord injury, providing strong support for a significant improvement in patients' quality of life. Attached Figure Description

[0018] Figure 1 Glycyrrhizin did not cause significant toxic side effects on major organs (heart, liver, spleen, lungs, kidneys, brain, and spinal cord) (HE staining image).

[0019] Figure 2 Glycyrrhizin can significantly improve neural structural damage after spinal cord injury. One-way ANOVA.

[0020] Figure 3 The results show that glycyrrhizin significantly improves the number of neurons after spinal cord injury. One-way ANOVA.

[0021] Figure 4 The results show that glycyrrhizin significantly improved the demyelination area after spinal cord injury. One-way ANOVA.

[0022] Figure 5 Glycyrrhizin significantly improved motor dysfunction (BMS score / hindlimb flexion score) after spinal cord injury. One-way ANOVA. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments, but these embodiments should not be construed as limiting the present invention.

[0024] Example 1: Evaluation of the toxic side effects of glycyrrhizin on major organs

[0025] The present invention aims to evaluate the toxic side effects of glycyrrhizin on major organs. Experiments show that glycyrrhizin has no obvious toxic side effects on major organs.

[0026] 1. Experimental Principle This experiment is based on the fundamental principle of drug safety assessment, which states that while a drug exerts a therapeutic effect, it should not cause significant damage to the body's major organs. As a compound with potential medicinal value, the safety assessment of glycyrrhizin is particularly important. Therefore, this experiment administered a certain dose of glycyrrhizin to experimental animals and observed and recorded its effects on major organs (such as the heart, liver, spleen, lungs, kidneys, brain, and spinal cord) to evaluate the toxic side effects of glycyrrhizin.

[0027] 2. Experimental Materials and Methods Experimental animals and grouping: C57BL / 6 male mice (age: 8 weeks) were randomly divided into a control group and a glycyrrhizin (50 mg / kg) group.

[0028] Drugs and reagents: Glycyrrhiza glabra was purchased from Nanjing Chunqiu Biotechnology Co., Ltd., and physiological saline, DMSO, Tween-80 and other reagents were purchased from Solarbio Biotechnology Co., Ltd.

[0029] Administration: Animals in the experimental group were intraperitoneally injected with glycyrrhizin (50 mg / kg) for 7 consecutive days. Animals in the control group were given the same dose of solvent (4% DMSO + 4% Tween-80 + physiological saline).

[0030] Organ collection and testing: Seven days after administration, the experimental animals were euthanized, and their major organs were collected for pathological examination, etc., to assess the effects of glycyrrhizin on the organs.

[0031] 3. Experimental Results The results are as follows Figure 1 As shown, the major organs (heart, liver, spleen, lung, kidney, brain, and spinal cord) of the experimental animals in the glycyrrhizin (50 mg / kg) group showed no significant differences in morphology and structure compared to the control group. Therefore, glycyrrhizin has no obvious toxic side effects on the major organs. Example 2: Study on the improvement of neural structural damage after spinal cord injury by glycyrrhizin.

[0032] This invention aims to evaluate the ameliorative effect of glycyrrhizin on nerve structural damage using HE staining, LFB staining, Nissl staining, and related quantitative analyses. Experimental results show that glycyrrhizin can significantly improve nerve structural damage following spinal cord injury.

[0033] 1. Experimental Principle Neural structural damage is a key pathological feature of many neurological diseases, including neuronal death, axonal breakage, and demyelination. Hematoxylin-Eosin staining (HE staining) can observe the overall morphology and structure of neural tissue; Luxol Fast Blue (LFB) staining is mainly used to display the integrity of the myelin sheath; and Nissl staining reflects the state of Nissl bodies in neurons, thereby assessing neuronal activity. In this experiment, glycyrrhizin was administered to damaged neural tissue, and the recovery of neural structure was observed using the above staining methods. Further quantitative analysis was conducted to verify the ameliorative effect of glycyrrhizin.

[0034] 2. Experimental Materials and Methods Experimental animals and grouping: Eight-week-old male C57BL / 6 mice were purchased from Jiangsu Huachuang Xinno Pharmaceutical Technology Co., Ltd. and were randomly divided into control group, SCI model group, model + glycyrrhizin (25 mg / kg), and model + glycyrrhizin (50 mg / kg).

[0035] Methods for establishing the SCI model: Mice were anesthetized with ketamine / toluidine via intraperitoneal injection. The T10 segment and surrounding area were disinfected with povidone-iodine. A longitudinal incision of approximately 1 cm was made in the midline of the mouse's back. Subcutaneous tissue and paravertebral muscles were separated, and a T10 laminectomy was performed to fully expose the spinal cord. Then, a precision impactor was used to simulate clinical SCI injury at the T10 segment with a strike velocity of 1 m / s, a depth of 0.5 mm, and a dwell time of 0.5 s. Successful model establishment was indicated by the presence of a hematoma or ecchymosis in the center of the spinal cord after the strike. The wound was sutured after disinfection with povidone-iodine. Artificial urination assistance was provided once daily until the mice regained spontaneous urination.

[0036] Drug treatment: The experimental animals were given a certain dose of glycyrrhizin or an equal volume of solvent by intraperitoneal injection.

[0037] Staining steps: ① HE staining: Spinal cord tissue sections from each group of mice were stained according to the routine HE staining procedure, including dewaxing, hydration, staining, dehydration, clearing and mounting.

[0038] ②LFB staining: Slides are stained with LFB to observe the integrity of the myelin sheath. The staining steps include slide pretreatment, LFB staining, differentiation, clearing, and mounting.

[0039] ③ Nissl staining: Nissl staining is performed on the slides to observe the Nissl body state of neurons. The staining steps include slide pretreatment, toluidine blue staining, dehydration, clearing, and mounting.

[0040] Quantitative analysis: The staining results were quantitatively analyzed using a microscope and image processing software, including the measurement of indicators such as tissue defect area, demyelination rate, number of neurons, and Nissl body density.

[0041] 3. Experimental Results The results are as follows Figure 2-4 As shown, compared with the control group, the model group exhibited significant damage to neural structures, including larger tissue loss areas, higher demyelination rates, reduced neuronal numbers, and decreased Nissl body density. However, in the glycyrrhizin treatment group, these pathological changes were significantly improved.

[0042] In summary, this experiment, through HE staining, LFB staining, Nissl staining, and related quantitative analyses, demonstrated that glycyrrhizin can significantly improve neural structural damage. This finding provides important evidence for the application of glycyrrhizin in the treatment of nervous system diseases. Example 3: Study on the improvement of motor dysfunction after spinal cord injury by glycyrrhizin

[0043] This invention aims to investigate the effect of glycyrrhizin on motor dysfunction. Through quantitative analysis of the BassoMouse Scale (BMS) score and hindlimb flexion score, the efficacy of glycyrrhizin on a model animal of motor dysfunction was systematically evaluated. Experimental results show that glycyrrhizin can significantly improve motor dysfunction following spinal cord injury.

[0044] 1. Experimental Principle Motor dysfunction is usually caused by neurological damage or disease, manifesting as symptoms such as muscle weakness and gait abnormalities. The BMS score and hindlimb flexion score are important indicators for assessing the recovery of motor function after spinal cord injury, while gait analysis and quantitative analysis of stride length and width can more meticulously reflect the dynamic characteristics of an animal's walking. This embodiment evaluates the effect of glycyrrhizin on improving motor dysfunction by treating animals with a motor dysfunction model with glycyrrhizin and observing and recording changes in their BMS score and hindlimb flexion score.

[0045] 2. Experimental Materials and Methods Experimental animals and grouping: Eight-week-old male C57BL / 6 mice were purchased from Jiangsu Huachuang Xinno Pharmaceutical Technology Co., Ltd. and were randomly divided into control group, SCI model group, model + glycyrrhizin (25 mg / kg), and model + glycyrrhizin (50 mg / kg).

[0046] Methods for establishing the SCI model: Mice were anesthetized with ketamine / toluidine via intraperitoneal injection. The T10 segment and surrounding area were disinfected with povidone-iodine. A longitudinal incision of approximately 1 cm was made in the midline of the mouse's back. Subcutaneous tissue and paravertebral muscles were separated, and a T10 laminectomy was performed to fully expose the spinal cord. Then, a precision impactor was used to simulate clinical SCI injury at the T10 segment with a strike velocity of 1 m / s, a depth of 0.5 mm, and a dwell time of 0.5 s. Successful model establishment was indicated by the presence of a hematoma or ecchymosis in the center of the spinal cord after the strike. The wound was sutured after disinfection with povidone-iodine. Artificial urination assistance was provided once daily until the mice regained spontaneous urination.

[0047] Experimental procedure: During the treatment period, the BMS score and hindlimb flexion score of the animals were recorded regularly (1 day, 3 days, 7 days, 14 days, 21 days and 28 days after spinal cord injury) to assess the recovery of their motor function.

[0048] 3. Experimental Results The results are as follows Figure 5 As shown, the BMS score and hindlimb flexion score of the animals in the glycyrrhizin treatment group were significantly higher than those in the SCI model group, indicating that glycyrrhizin can significantly improve the motor function of the model animals.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. The use of glycyrrhizin and its pharmaceutically acceptable salts in the preparation of drugs for treating spinal cord injury.

2. The use of glycyrrhizin and its pharmaceutically acceptable salts in the preparation of drugs for treating neuropathy after spinal cord injury or promoting nerve regeneration.

3. According to claim 1, glycyrrhizin and its pharmaceutically acceptable salts promote spinal cord nerve repair to treat spinal cord injury.

4. Application of glycyrrhizin and its pharmaceutically acceptable salts in the preparation of drugs for treating neurological dysfunctions related to spinal cord injury and promoting nerve recovery.

5. The application according to claim 4, wherein the spinal cord injury-related neurological dysfunction and the promotion of neurological recovery include paraplegia caused by spinal cord injury and motor conduction disorders after spinal cord injury.

6. The use of a pharmaceutical composition in the preparation of a medicament for treating neurological dysfunction following spinal cord injury, said pharmaceutical composition comprising glycyrrhizin or a pharmaceutically acceptable salt thereof and pharmaceutically acceptable excipients.

7. The use of pharmaceutical compositions containing glycyrrhizin or pharmaceutically acceptable salts thereof in the preparation of medicaments for treating neuropathy associated with spinal cord injury and promoting nerve regeneration.

8. The application according to claim 7, wherein the spinal cord injury-related neuropathy and the promotion of nerve regeneration include paraplegia caused by spinal cord injury and motor conduction disorders after spinal cord injury.

9. The application according to any one of claims 1 to 8, wherein the pharmaceutically acceptable salt comprises an organic acid salt or an inorganic acid salt.

10. The application according to any one of claims 1 to 8, wherein glycyrrhizin and its pharmaceutically acceptable salts or with a pharmaceutically acceptable carrier are prepared into tablets, capsules, granules, oral solutions, injections, suppositories, ointments, sprays or aerosols.

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