New application of p-hydroxycinnamic acid

Abstract

The invention provides application of p-hydroxycinnamic acid in preparation of a medicine for preventing and treating noise-induced deafness. The invention has the advantages that the p-hydroxycinnamic acid has the advantages of strong pertinence, high safety, convenience in medication, good patient compliance and the like, not only effectively overcomes the defects of the existing noise-induced hearing loss treatment medicines, but also provides a brand-new preventive treatment thought; important clinical popularization significance and industrial application prospects are realized.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically the application of p-hydroxycinnamic acid in the preparation of drugs for the prevention and treatment of noise-induced hearing loss. Background Technology

[0002] p-Hydroxycinnamic acid is a naturally occurring phenolic acid widely found in plants. Belonging to the hydroxycinnamic acid derivative class, it is commonly found in various plants such as chili peppers, spinach, lavender, and blackthorn. It has demonstrated significant application value in multiple fields, including plant metabolism, food, medicine, and materials. In plant metabolism, it serves as an important intermediate product of secondary metabolism, participating in plant growth, development, and stress response regulation. In the food industry, due to its naturally occurring properties and good biocompatibility, it is often used as a natural antioxidant for food preservation and quality improvement. In the pharmaceutical field, studies have confirmed its significant antioxidant and anti-inflammatory activities. It exerts its physiological effects by regulating key signaling pathways and inhibiting the expression of pro-inflammatory mediators, making it a potential protective agent in research on oxidative stress-related damage. It has shown some application potential in anti-inflammatory, anti-tumor, and neuroprotective studies, but there are currently no reports of its application in the prevention or treatment of noise-induced hearing loss.

[0003] Noise-induced hearing loss is a common type of hearing loss in clinical practice. Statistics show that over 5% of the global population (more than 400 million people) suffer from noise-induced hearing loss due to occupational noise exposure, improper use of personal audio devices, and other reasons. This disease primarily damages the cochlea, clinically manifesting as tinnitus and progressive hearing loss. In severe cases, it can lead to permanent hearing loss and may also cause complications such as depression, significantly impacting the patient's quality of life. Current clinical interventions for noise-induced hearing loss have significant limitations and cannot meet clinical needs: primary prevention methods (such as wearing noise protection devices and controlling noise exposure limits) are highly dependent on individual compliance and cannot comprehensively cover various scenarios, including non-occupational exposure; in secondary interventions, hearing aids and cochlear implants can only compensate for hearing function and cannot reverse existing inner ear structural damage, and they also have high usage barriers and limited applicability; drug therapy, as an important intervention, currently focuses on antioxidant or anti-inflammatory symptomatic support, and there are no specific drugs that can repair inner ear damage and reverse hearing loss.

[0004] Existing drugs for treating noise-induced hearing loss mainly fall into two categories: one is antioxidant drugs, represented by N-acetylcysteine. As a precursor to reduced glutathione, this drug can reduce cochlear hair cell death by scavenging reactive oxygen species in the body, maintaining intracellular antioxidant enzyme levels, and thus providing some protection against noise-induced hearing loss. However, it has significant limitations in clinical application. Its target is singular, and its efficacy is limited, being effective only for early-stage, mild noise-induced hearing loss. Furthermore, the dosage is difficult to control; low doses cannot achieve effective cochlear protection, while high doses may cause systemic adverse reactions such as nausea, vomiting, rash, and bronchospasm. At the same time, the clinical efficacy of this drug remains controversial, with some clinical trials showing a lack of significant advantages in overall hearing recovery. Another category is anti-inflammatory drugs, represented by glucocorticoids (such as dexamethasone and prednisone). These drugs have been used to treat noise-induced hearing loss for more than 60 years. They can exert anti-inflammatory and anti-apoptotic effects by binding to relevant receptors in the ear. However, their mechanism of action is not fully understood, and there are many shortcomings in their clinical application. Not only are their targets limited and their efficacy restricted, but they can also cause a variety of serious systemic side effects, such as electrolyte imbalance, hypertension, hyperglycemia, osteoporosis, and increased susceptibility to infection. Furthermore, long-term use can interfere with the body's normal stress regulation mechanism, resulting in poor safety.

[0005] Furthermore, most currently used drugs for treating noise-induced hearing loss are Western medicines, which inevitably suffer from significant side effects and insufficient safety profiles. Plant-derived small molecule compounds, with their advantages of natural origin, good biocompatibility, and low risk of side effects, are increasingly demonstrating their value in clinical drug development and application. Therefore, finding a naturally sourced active ingredient for the preventative treatment of noise-induced hearing loss—one that can alleviate symptoms, protect inner ear structures, and avoid the various side effects associated with Western medicines—has become a pressing technical challenge in clinical practice and provides a new direction for drug development in this field. Summary of the Invention

[0006] To overcome the above shortcomings, the purpose of this invention is to provide a novel application of p-hydroxycinnamic acid in the preparation of noise-induced hearing loss. P-hydroxycinnamic acid reduces noise-induced hair cell damage by reducing cellular oxidative stress, thereby solving the problem of hearing loss caused by noise in daily life.

[0007] Furthermore, p-hydroxycinnamic acid can reduce the loss of cochlear hair cells.

[0008] Furthermore, when p-hydroxycinnamic acid is used to prepare drugs for the prevention and treatment of noise-induced hearing loss, it also includes a drug carrier adapted to it.

[0009] Furthermore, the dosage of p-hydroxycinnamic acid is 25-100 mg / kg.

[0010] By employing the above-mentioned technical solution, this invention applies p-hydroxycinnamic acid to the intervention and treatment of noise-induced hearing loss, achieving significant technological progress and clinical application value. Specific beneficial effects are as follows: First, it effectively breaks through the current technical bottleneck in the clinical treatment of noise-induced hearing loss, changing the situation where there is a lack of targeted treatment drugs for this disease in the existing technology. It innovatively changes the treatment mode from the traditional passive relief of hearing damage to a brand-new mode of preventing hearing loss in advance and actively protecting the inner ear structure. It can reduce the damage of noise to cochlear hair cells from the source, significantly improve the intervention effect of noise-induced hearing loss, and fill the technical gap of using natural active ingredients for the preventive treatment of this disease.

[0011] Secondly, it boasts high safety and excellent patient compliance. Experimental studies have verified that p-hydroxycinnamic acid has no toxic effects on cochlear tissue, and its side effects are significantly reduced compared to currently used Western medicine treatments. Furthermore, as a natural small molecule compound and an endogenous metabolite, p-hydroxycinnamic acid exhibits good biocompatibility and is naturally derived, eliminating the need for patients to bear complex medication burdens. This leads to higher patient acceptance and effectively improves medication compliance, ensuring the smooth implementation of the treatment plan and enabling patients to achieve stable and effective intervention without affecting their normal quality of life.

[0012] Third, it is convenient to administer and has precise effects, with a wide range of applications. p-Hydroxycinnamic acid can be administered orally, a simple and easy route that facilitates long-term adherence to medication. Simultaneously, this compound can successfully cross the blood-labyrinth barrier, directly reaching the inner ear target organ, precisely protecting the cochlear hair cells and effectively reducing hair cell damage caused by factors such as noise, thereby lowering the risk of hearing loss. Furthermore, it can mitigate the impact of chemotherapy on hearing, further expanding its clinical application scenarios and demonstrating greater practical value.

[0013] In summary, the p-hydroxycinnamic acid used in this invention has advantages such as strong targeting, high safety, convenient administration, and good patient compliance. It not only effectively solves many defects of existing drugs for the treatment of noise-induced hearing loss, but also provides a brand-new preventive treatment approach, which has important clinical promotion significance and industrial application prospects. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of p-hydroxycinnamic acid of the present invention.

[0015] Figure 2 This is a schematic diagram of the process of administering p-hydroxycinnamic acid and creating a noise model in 8-week-old C57BL / 6 mice according to the present invention.

[0016] Figure 3The image shows the ABR hearing test results of C57BL / 6 mice after drug administration; among them, compared with the noise-only treatment group, #### indicates p<0.0001, ## indicates p<0.01; compared with the noise-only treatment group, the protective groups with different doses of p-hydroxycinnamic acid pretreatment, This indicates that p < 0.01. This indicates that p < 0.05.

[0017] Figure 4 The image shows the DPOAE hearing test results in C57BL / 6 mice after drug administration; among them, the 100 mg / kg p-hydroxycinnamic acid pretreatment group compared with the noise-only treatment group... This means p < 0.0001. This indicates that p < 0.05.

[0018] Figure 5 This is a schematic diagram of noise detection by Myo7a staining and hair cell damage after treatment with p-hydroxycinnamic acid, wherein hair cells are labeled green by Myosin7a and cilia are labeled red by phalloidin.

[0019] Figure 6 This invention presents a schematic diagram of Myo7a staining detection of noise and hair cell damage after treatment with p-hydroxycinnamic acid, as well as a statistical graph of hair cell counts in the apical, middle, and basal gyri of the basement membrane; compared with the noise group, the blank control group, the p-hydroxycinnamic acid treatment group, and the noise group... This indicates that p < 0.05. This means p < 0.0001.

[0020] Figure 7 This is a schematic diagram illustrating the noise detection of Myo7a and 3-NT co-staining and the oxidative stress damage of hair cells after treatment with p-hydroxycinnamic acid. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0022] Example 1: A novel application of p-hydroxycinnamic acid provided by the present invention. The chemical structural formula of p-hydroxycinnamic acid is shown below. Figure 1 As shown, this invention discovers that p-hydroxycinnamic acid can be used to prepare drugs for the prevention and treatment of noise-induced hearing loss. The following is animal validation using a mouse model: (1) Noise-induced hearing loss model mice (referred to as Noise group): 8-week-old C57BL / 6 mice were exposed to a 110 dB noise environment for 2 hours.

[0023] (2) Constructing mice treated with p-hydroxycinnamic acid (referred to as PCA group): 8-week-old C57BL / 6 mice were treated with 100 mg / kg p-hydroxycinnamic acid by gavage for 14 days. The p-hydroxycinnamic acid solution was prepared using the same dissolution method as the control group described in (4).

[0024] (3) Construct a mouse model of noise-induced hearing loss treated with p-hydroxycinnamic acid (referred to as the PCA+Noise group) (procedure as follows) Figure 2 (As shown): Eight-week-old C57BL / 6 mice were pretreated with p-hydroxycinnamic acid by gavage for 14 days, followed by 2 hours of noise at 110 dB. The concentrations of p-hydroxycinnamic acid used were 25 mg / kg, 50 mg / kg, and 100 mg / kg. The solution form of p-hydroxycinnamic acid was the same as that of the control group in (4).

[0025] (4) Control group: After dissolving p-hydroxycinnamic acid in DMSO, the p-hydroxycinnamic acid-DMSO mixture was dissolved in corn oil at a mass ratio of 1:9.

[0026] (5) Verification method: ABR testing: ABR testing was performed before and the day after administration in each group. Mice were anesthetized by intraperitoneal injection of 1% pentobarbital (10 ml / kg). Mice were placed in a soundproof box, and recording electrodes were inserted subcutaneously along the midline of the brain. A reference electrode was inserted into the postauricular region of the test ear, and a ground electrode was inserted subcutaneously on the back. Short pure tone stimulation was administered to the mice using an auditory evoked potential recording system. Tests were performed at frequencies of 4, 8, 12, 16, 24, and 32 kHz, with rise and fall times of 5 ms and a duration of 10 ms. Critical thresholds were recorded for subsequent analysis.

[0027] There was no significant difference in ABR thresholds between the control group and the p-hydroxycinnamic acid treatment group, indicating that p-hydroxycinnamic acid has no side effects on mice. Mice in the noise treatment group showed significantly increased threshold shifts at all frequencies, while mice co-treated with p-hydroxycinnamic acid (25-100 mg / kg) and noise showed significantly lower thresholds at 12, 16, 24, and 32 kHz than the noise-only treatment group. Figure 3 ).

[0028] DPOAE testing: DPOAE testing was performed before and the day after administration in each group. Mice were anesthetized by intraperitoneal injection of 1% pentobarbital (10 ml / kg). The external auditory canal of the mice was cleaned with sterile cotton swabs, and the tympanic membrane was examined with an otoscope to rule out damage or obstruction by secretions. The probe was ensured to have a good seal. The mouse's head was fixed to the ear rod, and the body position was adjusted so that the external auditory canal was aligned with the probe axis to reduce sound reflection loss. A mouse-specific ear cover was installed, and the DPM1 probe was slowly inserted into the external auditory canal, gently pushed until a slight resistance was felt (to avoid damaging the tympanic membrane). The probe was ensured to be airtight. Tests were performed at frequencies of 8, 12, 16, 24, and 32 kHz, and the critical thresholds were recorded for subsequent analysis.

[0029] The DPOAE thresholds of mice were compared between the control group and the p-hydroxycinnamic acid monotherapy group (p-hydroxycinnamic acid concentration of 100 mg / kg), showing no significant difference between the two. This indicates that p-hydroxycinnamic acid has no side effects on mice. Mice in the noise treatment group showed significantly increased threshold shifts at all frequencies, while mice co-treated with p-hydroxycinnamic acid and noise (p-hydroxycinnamic acid dose of 100 mg / kg) had significantly lower thresholds at 12 kHz and 16 kHz than the noise-only treatment group. Figure 4 At this concentration, p-hydroxycinnamic acid has a good protective effect against noise-induced hearing loss.

[0030] Cochlear dissection and immunofluorescence staining: Mice were euthanized by cervical dislocation, and the temporal bone was separated by decapitation and placed in pre-chilled phosphate-buffered saline (PBS). Excess tissue was removed under a microscope. A small hole was punctured at the apex of the cochlea, and a small amount of pre-chilled 4% paraformaldehyde (4% PFA, Beyotime) was injected through the round and oval windows of the cochlea using a syringe. The mouse cochlea was placed in a 2 ml EP tube containing pre-chilled 4% paraformaldehyde and fixed overnight at 4°C on a shaker. Then, it was decalcified in 10% EDTA for 4-5 hours. The decalcified cochlea was placed in a dissecting dish containing PBS, and the Apex, Middle, and Base gyri of the cochlea were dissected under a microscope. Excess tissue such as the tectorial membrane and vestibular membrane was removed.

[0031] Immunofluorescence staining of the basement membrane of mice in the control group, noise group, p-hydroxycinnamic acid single treatment group, and noise and p-hydroxycinnamic acid co-treatment group (p-hydroxycinnamic acid concentration of 100 mg / kg) with the hair cell marker antibody Myosin7a was performed and observed under a laser confocal microscope. It was found that mice in the prophylactic p-hydroxycinnamic acid group showed significantly reduced hair cell loss after noise treatment. Figure 5 and Figure 6 ).

[0032] Immunofluorescence staining of the basement membrane of mice in the control group, noise group, p-hydroxycinnamic acid single treatment group, and noise and p-hydroxycinnamic acid co-treatment group (p-hydroxycinnamic acid concentration of 100 mg / kg) with hair cell marker antibody Myosin7a and lipid peroxidation marker 3-NT was performed and observed under a laser confocal microscope. The results showed that mice in the prophylactic p-hydroxycinnamic acid group had significantly reduced hair cell oxidative stress damage after noise treatment. Figure 7 ).

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A novel application of p-hydroxycinnamic acid, characterized in that, Application of p-hydroxycinnamic acid in the preparation of drugs for the prevention and treatment of noise-induced hearing loss.

2. The new application according to claim 1, characterized in that, p-hydroxycinnamic acid can reduce the loss of cochlear hair cells.

3. The new application according to claim 1, characterized in that, When p-hydroxycinnamic acid is used to prepare drugs for the prevention and treatment of noise-induced hearing loss, it also includes a drug carrier adapted to it.

4. The new application according to claim 1, characterized in that, The dosage of p-hydroxycinnamic acid is 25-100 mg / kg.

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