Application of cinacalcet and pharmaceutically acceptable salt thereof in preparation of antifungal drugs

Abstract

The invention provides application of cinacalcet and pharmaceutically acceptable salts thereof in preparation of antifungal drugs, discovers that the clinically marketed drug cinacalcet has a new antifungal application, realizes effective redevelopment of existing drugs, expands treatment indications of the drugs, and provides a new technical path and a potential chemical entity for drug reutilization. Experimental results show that cinacalcet has a good inhibition effect on various pathogenic fungi and has certain broad-spectrum antifungal activity. As the medicine is clinically applied for a long time, the safety is definite, the toxic and side effects are controllable, the safety evaluation and preparation development risks in the new medicine research and development process are remarkably reduced, and the feasibility and popularization value of industrial application are improved.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to the use of cinacalcet and its pharmaceutically acceptable salts in the preparation of antifungal drugs. Background Technology

[0002] Fungal infections, especially those caused by Candida albicans , Aspergillus fumigatus and Cryptococcus neoformans Invasive fungal infections caused by fungi are increasing in immunocompromised and critically ill patients. Current antifungal drugs mainly include polyenes (such as amphotericin B), azoles (such as fluconazole and voriconazole), and echinocandins (such as caspofungin). These drugs mostly exert their effects by inhibiting ergosterol synthesis in the fungal cell membrane or β-glucan synthesis in the cell wall. However, with the widespread use of antifungal drugs, drug-resistant fungal strains are constantly emerging; in addition, most currently used drugs have problems such as hepatotoxicity and nephrotoxicity, significant drug interactions, and narrow therapeutic windows, resulting in limited clinical treatment options [Vitiello et al., Biomedicines [2023, 11 (4), 1063.]. Therefore, finding new mechanisms of action or developing safe small molecule drugs with antifungal potential through the "drug repurposing" strategy has become an important direction in current antifungal drug research.

[0003] Previous studies have shown that calcium signaling plays a crucial regulatory role in fungal growth, differentiation, cell wall synthesis, and drug response. Disruption of calcium ion homeostasis can significantly affect fungal cellular physiological activities. Some studies have found that the intracellular calcium-calcineurin signaling pathway plays an important role in fungal survival, virulence formation, and drug resistance development [Liu et al., Eukaryotic Cell

[2015] . However, no studies have yet confirmed that the calcium receptor modulator Cinacalcet itself possesses direct antifungal activity, nor is there a systematic evaluation of its potential role in the prevention and treatment of fungal infections. This research gap provides a new possible direction for further exploring new uses of Cinacalcet in the field of antifungal drugs. Summary of the Invention

[0004] This invention addresses the shortcomings of existing antifungal drugs, such as their single mechanism of action, serious drug resistance problems, certain toxic side effects, and limitations in clinical use. It provides the use of cinacalcet and its pharmaceutically acceptable salts in the preparation of antifungal drugs, thereby making up for the deficiencies of the prior art.

[0005] This invention first provides a novel use of cinacalcet and / or its pharmaceutically acceptable salts as an active ingredient in the preparation of antifungal products; The aforementioned cinakas has the following structural formula: ; The pharmaceutically acceptable salt of cinacalcet, as a specific example, is cinacalcet hydrochloride, and a specific structural formula thereof is as follows: .

[0006] The fungi mentioned are yeast-like fungi or filamentous fungi; including but not limited to the genus Candida ( Candida spp.), Cryptococcus ( Cryptococcus spp.), Aspergillus ( Aspergillus spp.), Trichophyton genus ( Trichophyton spp.), Epidermophyton ( Epidermophyton spp.), Microsporum ( Microsporum spp.).

[0007] The present invention also provides an article having antifungal efficacy, comprising a pharmacologically effective concentration of cinacalcet and / or its pharmaceutically acceptable salt.

[0008] The product may be an oral preparation or a skin-contact ointment.

[0009] This invention is the first to discover a novel antifungal use for the clinically marketed drug cinacalcet, achieving effective redevelopment of an existing drug, expanding its therapeutic indications, and providing a new technical pathway and potential chemical entity for drug reuse. Experimental results show that cinacalcet exhibits good inhibitory effects against a variety of pathogenic fungi, possessing a certain broad-spectrum antifungal activity. Because this drug has been used clinically for a long time, its safety is well-established and its toxic side effects are controllable, significantly reducing the risks of safety assessment and formulation development during new drug development, and improving the feasibility and promotional value of industrial application. Furthermore, the antifungal mechanism described in this invention may be related to the regulation of intracellular calcium signaling pathways or disruption of cell membrane homeostasis in fungal cells, suggesting that its mechanism of action differs from traditional antifungal drugs, providing a new theoretical basis and research direction for developing novel antifungal treatment strategies. Detailed Implementation

[0010] Cinacalcet (chemical name N-[(1R)-1-(1-naphthyl)ethyl]-3-[3-(trifluoromethyl)phenyl]propan-1-amine hydrochloride) is an oral small-molecule calcium-sensing receptor (CaSR) agonist. Originally developed by NPS Pharmaceuticals, it was approved by the U.S. Food and Drug Administration (FDA) in 2004 for the treatment of secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD) undergoing dialysis, and hypercalcemia caused by parathyroid cancer or inoperable primary hyperparathyroidism. Cinacalcet binds to the allosteric site of CaSR, enhancing the receptor's sensitivity to extracellular calcium ions, thereby reducing parathyroid hormone (PTH) secretion and regulating blood calcium and phosphorus balance.

[0011] This invention discovers and verifies the application potential of cinacalcet and its hydrochloride in antifungal applications. Through in vitro minimum inhibitory concentration (MIC) determination, it was discovered for the first time that cinacalcet and its hydrochloride exhibited inhibitory activity against a variety of pathogenic fungi, including Candida, Cryptococcus, Aspergillus, Trichophyton, Epidermophyton, and Microsporum. This provides a new mechanism of action and drug molecule source for existing antifungal drug systems, thus offering new technical solutions for the redevelopment of antifungal drugs and the research of new uses for existing drugs.

[0012] The meanings of some symbols in the example table are as follows: MIC: Minimum inhibitory concentration, which is the lowest concentration of a drug that can inhibit the growth of more than 99% of fungi.

[0013] MIC 50 The half-maximal inhibitory concentration (MCI) is the lowest drug concentration at which 50% of the tested bacterial strains are inhibited from growing.

[0014] MIC 90 90% inhibitory concentration, which is the lowest drug concentration at which 90% of the tested bacterial strains are inhibited from growing.

[0015] GMIC: Geometric mean of the MIC values ​​of all tested strains.

[0016] The present invention will now be described in detail with reference to the embodiments.

[0017] Example 1: Study on antifungal activity 1. Experimental Methods: The minimum inhibitory concentration (MIC) of vortioxetine and its hydrobromide against 275 pathogenic fungi was determined using the microbroth dilution method. The standardized methods for in vitro fungal susceptibility testing published by CLSI were followed. For yeast-phase fungi, the method was based on CLSI M27 (CLSI. Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts; Approved Standard—Third Edition. CLSI document M27-A3. Wayne, PA: Clinical and Laboratory Standards Institute; 2008.); for filamentous fungi, the method was based on CLSI M38 (CLSI. Reference Method for Broth Dilution Antifungal Susceptibility Testing of Filamentous Fungi. 3rd ed. CLSI standardM38. Wayne, PA: Clinical and Laboratory Standards Institute; 2017.).

[0018] 2. Strains Preparation: The quality control strains were *Candida parapsilosis* ATCC 22019 and *Candida krusei* ATCC 6258. Clinical strains were identified by ITS sequencing and MALDI-TOF MS and were stored in the Fungal Disease Control Laboratory of the Institute for Infectious Disease Control and Prevention, Chinese Center for Disease Control and Prevention. All test strains were subcultured and activated before use to ensure purity and viability.

[0019] 3. Preparation of culture medium: The culture medium is RPMI-1640 solution containing glutamine, free of bicarbonate, with phenol red as acid-base indicator, and trimorpholine propanesulfonic acid (MOPS) as buffer (pH 7.0).

[0020] 4. Operating Procedures: (1) Preparation of standardized drug sensitivity plates: Prepare stock solutions of cinacalcet and its hydrochloride (100×), serially dilute the stock solutions by 2 times with DMSO, and then dilute them 1:50 with RPMI-1640 medium and add them to 96-well plates (100 μL / well). The final concentrations of vortioxetine and its hydrobromide in the drug sensitivity plates are 0, 0.5, 1, 2, 4, 8, 16, 32, 64 and 128 μg / mL, respectively.

[0021] (2) Preparation of pathogenic fungal suspension: Taking Candida as an example, take freshly cultured pathogenic fungi, adjust the concentration of the suspension to 0.5 McFarland concentration, dilute 1:1000 with RPMI-1640 medium (1:50 for filamentous fungi), and add it to the prepared antifungal susceptibility plate (100 μL / well). The final concentration of the suspension should be controlled at 0.5 × 10⁻⁶. 3 –2.5×10 3 CFU / mL.

[0022] (3) After incubating the bacterial suspension plate at 35°C for 24 hours, observe the results and record the minimum inhibitory concentration (MIC).

[0023] (4) Result interpretation: The MIC value is interpreted by comparing it with the drug-free control well after the same culture time, and the lowest drug concentration that achieves 100% inhibition.

[0024] The experiment used the microbroth dilution method (CLSI M27-A3, M38 standards) to test a total of 275 clinical and standard strains, including Candida, Cryptococcus, Aspergillus, Trichophyton, Epidermophyton, and Microsporum. The results showed that cinacalcet and its hydrochloride exhibited measurable minimum inhibitory concentrations (MICs) and strong inhibitory activity against some fungi, particularly Trichophyton, Epidermophyton, and Microsporum. The geometric mean of the MIC values ​​for all tested strains ranged from 8.00 to 16.00 (Tables 1-6).

[0025] Table 1: MIC values ​​of cinacarcin and its hydrochloride against Candida spp.

[0026] Table 2: MIC values ​​of cinacarcin and its hydrochloride against Cryptococcus spp.

[0027] Table 3: MIC values ​​of cinacarase and its hydrochloride against Aspergillus species.

[0028] Table 4: MIC values ​​of cinacarcin and its hydrochloride against Trichophyton spp.

[0029] Table 5: MIC values ​​of cinacarcin and its hydrochloride against *Epidermophyton* spp.

[0030] Table 6: MIC values ​​of cinacarase and its hydrochloride against Microsporum spp.

[0031] In summary, the experimental results demonstrate the potential application value of cinacalcet and its pharmaceutically acceptable salts in the field of antifungal treatment. This compound exhibits measurable antifungal activity against multiple pathogenic fungi in vitro, suggesting a novel pharmacological mechanism of action. Compared with traditional antifungal drugs, cinacalcet possesses the following advantages: 1) As a clinically marketed drug, it has clear pharmacokinetic characteristics, high safety, short development cycle, and low conversion cost; 2) It may exert its effects by regulating fungal cell calcium signaling or membrane homeostasis pathways, providing new insights into overcoming existing antifungal resistance mechanisms; 3) With its good oral absorption and systemic distribution characteristics, this drug has the potential to be used in the prevention and treatment of systemic fungal infections, dermatophytes, and immunosuppression-related fungal infections.

[0032] Therefore, this invention not only provides a new paradigm for the research of new uses for old drugs, but also opens up new chemical and pharmacological directions for the development of antifungal drugs, and has significant scientific research value and industrial application prospects.

Claims

1. Use of cinacaict and / or its pharmaceutically acceptable salt as an active ingredient in the preparation of an antifungal preparation.

2. Use according to claim 1, wherein The structure of the said cinacaict is as follows: 。 3. The use according to claim 1, wherein The pharmaceutically acceptable salt of the said cinacaict is cinacaict hydrochloride.

4. Use according to claim 3, wherein the compound is ###0002### The structure of the said cinacaict hydrochloride is as follows: 。 5. The use according to claim 1, wherein The said fungus is a yeast phase fungus or a filamentous fungus.

6. The use according to claim 5, wherein the compound is ###0002### The fungus mentioned is Candida genus ( Candida spp.), Cryptococcus ( Cryptococcus spp.), Aspergillus ( Aspergillus spp.), Trichophyton genus ( Trichophyton spp.), Epidermophyton ( Epidermophyton spp.) or Microsporum genus ( Microsporum spp.).

7. An article having antifungal efficacy, characterized by, The said preparation contains a pharmacologically effective concentration of cinacaict and / or its pharmaceutically acceptable salt.

8. The article of claim 7, wherein, The said preparation further contains a pharmaceutically acceptable adjuvant.

9. The article of claim 7, wherein, The said preparation is an oral preparation or a cream for dermal contact absorption.

10. The article of claim 7, wherein, The said fungus is a yeast phase fungus or a filamentous fungus.

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