Use of rilpivirine in the preparation of a medicament for the prevention and treatment of trichinosis

Abstract

This invention discloses the application of rilpivirine (RPV) in the preparation of drugs for the prevention and treatment of trichinosis. This invention belongs to the field of biomedical technology. A mouse model of trichinosis was established by oral feeding. After oral administration of rilpivirine, the number of larval cysts, histopathological changes, and ultrastructural changes in the skeletal muscle tissue of the trichinella-infected mouse model were observed. The results showed that rilpivirine (as shown in Formula I) has a significant effect in killing trichinella larval cysts and can improve the degree of muscle tissue fibrosis caused by trichinosis. This invention provides a new technical means for the treatment of trichinosis and will also give rilpivirine broad application prospects in the treatment of fibrosis-related diseases caused by parasitic infections.

Description

Technical Field

[0001] This invention relates to a novel use of rilpivirine (4-[[(1R)-6,7-dimethoxy-2-methyl-3,4-dihydro-1H-isoquinolin-1-yl]methyl]-2-[[(1R)-1-[(4-hydroxyphenyl)methyl]-6-methoxy-2-methyl-3,4-dihydro-1H-isoquinolin-7-yl]oxy]phenol), particularly its use in the preparation of drugs for treating trichinosis. This invention belongs to the field of biomedical technology. Background Technology

[0002] Trichinella spiralis (T. spiralis), commonly known as the trichinella nematode, is a parasitic worm whose adult worms and larvae can simultaneously parasitize the small intestine and skeletal muscle cells in humans, causing trichinosis. Trichinella has extremely low host selectivity, infecting many mammals and even birds, making it a common foodborne zoonotic parasitic disease that seriously endangers human health and livestock production. When humans ingest meat containing trichinella larval cysts, the larvae escape from the small intestine, causing intestinal inflammation and gastrointestinal symptoms such as nausea and vomiting. Newly hatched trichinella larvae migrate into the bloodstream and to the host's skeletal muscle cells, forming larval cysts. This process leads to systemic symptoms such as fever, edema, muscle pain, and limited mobility. In severe cases, it can affect vital organs such as the heart and central nervous system, and even be life-threatening.

[0003] Studies have confirmed that after newborn Trichinella spiralis larvae invade muscle cells, the mechanical stimulation from the larvae and the chemical stimulation from their metabolic products damage muscle fibers, leading to extensive infiltration of inflammatory cells around the cells. The affected muscle cells are then covered by a layer of collagen derived from the host, forming a collagen cyst. Collagen synthesis begins on day 10 post-infection, and the collagen cyst continues to thicken until day 26 post-infection. During this process, the fibrous connective tissue directly connecting the muscle cells proliferates, eventually forming a fibrous layer outside the collagen cyst. As the pathological damage to the muscle cells continues to progress, patients will experience systemic myalgia, significant tenderness and pain upon palpation, and even paralysis.

[0004] Currently, the main drugs used to treat trichinosis are albendazole and mebendazole, but both are teratogenic and therefore contraindicated in pregnant women and children under 2 years of age. Pyrantel can be recommended for pregnant women and children under 2 years of age with trichinosis, but its efficacy is currently unclear. Therefore, developing more effective, harmless, and convenient anti-trichinosis drugs remains a problem that needs to be solved.

[0005] Rilpivirine (4-[[(1R)-6,7-dimethoxy-2-methyl-3,4-dihydro-1H-isoquinolin-1-yl]methyl]-2-[[(1R)-1-[(4-hydroxyphenyl)methyl]-6-methoxy-2-methyl-3,4-dihydro-1H-isoquinolin-7-yl]oxy]phenol) is a non-nucleotide HIV reverse transcriptase inhibitor widely used in the clinical treatment of acquired immune syndromes. Studies have shown that rilpivirine can reduce the degree of liver fibrosis caused by chronic liver injury by selectively regulating STAT1-mediated apoptosis of hepatic stellate cells. Other studies have shown that rilpivirine possesses antiplatelet and antitumor pharmacological properties. However, there are currently no reports on its use for trichinosis.

[0006] This invention studies the effects of rilpivirine on Trichinella spiralis-infected mice. The results show that rilpivirine can effectively reduce the number of larval cysts in the skeletal muscle tissue of Trichinella spiralis-infected mice, alleviate the pathological and ultrastructural damage of skeletal muscle tissue, and improve the degree of muscle tissue fibrosis. Therefore, it can be used as a new type of drug for the prevention and treatment of trichinosis. Summary of the Invention

[0007] The purpose of this invention is to provide the use of rilpivirine (4-[[(1R)-6,7-dimethoxy-2-methyl-3,4-dihydro-1H-isoquinolin-1-yl]methyl]-2-[[(1R)-1-[(4-hydroxyphenyl)methyl]-6-methoxy-2-methyl-3,4-dihydro-1H-isoquinolin-7-yl]oxy]phenol) in the preparation of drugs for the prevention and treatment of trichinosis.

[0008] To achieve the above objectives, the present invention employs the following technical means:

[0009] This invention established a Trichinella infection mouse model by orally infecting mice with (100±5) Trichinella cysts per mouse. Mice were then administered rilpivirine (5 mg / kg / day) orally on day 10 post-infection for 14 consecutive days. Samples were collected on day 28 post-infection. Results showed that rilpivirine significantly reduced the number of larval cysts in the skeletal muscle tissue of infected mice, alleviated pathological and ultrastructural damage to skeletal muscle tissue, and improved the degree of muscle fibrosis. Therefore, this invention demonstrates that rilpivirine (RPV) has a therapeutic effect on trichinosis.

[0010] Therefore, based on the above research, this invention proposes the application of rilpivirine in the preparation of drugs for the prevention and treatment of trichinosis, wherein the chemical structural formula of rilpivirine is shown in Formula I:

[0011]

[0012] The preferred embodiment of rilpivirine achieves the purpose of treating trichinosis by reducing the number of larval cysts in the skeletal muscle tissue of mice infected with Trichinella spiralis, alleviating the pathological and ultrastructural damage of skeletal muscle tissue, and improving the degree of muscle tissue fibrosis.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] This invention proposes a novel drug for treating trichinosis—rilpivirine—which can be used for the prevention and treatment of trichinosis. Rilpivirine is an FDA-approved non-nucleoside HIV reverse transcriptase inhibitor, clinically used in the treatment of AIDS at a single daily oral dose of 25 mg. Therefore, at the recommended dosage, this drug is safe and suitable for long-term use. Following the principle of species-to-body-weight / body-surface-area conversion, this invention demonstrates that rilpivirine can treat trichinosis by reducing the number of larval cysts in the skeletal muscle tissue of trichinella-infected mice, alleviating pathological and ultrastructural damage to skeletal muscle tissue, and improving the degree of muscle fibrosis. Therefore, this invention provides a new technical means for the prevention and treatment of trichinosis and will also give rilpivirine broad application prospects in the treatment of fibrosis-related diseases caused by parasitic infections. Attached Figure Description

[0015] Figure 1 The infection status and counting results of trichinella larvae cysts in the diaphragmatic tissue of mice.

[0016] Among them, A: mouse diaphragm tissue (unstained 4×), TS is the Trichinella infection control group, and RPV is the group treated with rilpivirine after Trichinella infection; B: count of larval cysts in the diaphragm tissue of Trichinella-infected mice (*P<0.05); C: pathological observation of diaphragm tissue of Trichinella-infected mice, indicating that rilpivirine can reduce the number of larval cysts in Trichinella-infected mice.

[0017] Figure 2 The results of observation on the degree of fibrosis in the diaphragmatic tissue of mice infected with Trichinella spiralis;

[0018] Among them, A: Masson staining of diaphragmatic tissue of mice in the Trichinella infection control group; B: Masson staining of diaphragmatic tissue of mice in the Trichinella infection rilpivirine treatment group; C: Percentage of collagen area in Trichinella larval cysts (**P<0.01), indicating that rilpivirine can significantly alleviate the degree of muscle tissue fibrosis caused by Trichinella infection.

[0019] Figure 3 The results of ultrastructural observation of diaphragmatic tissue in mice infected with Trichinella spiralis;

[0020] Among them, A, C, and E are the ultrastructures of larval cysts in the Trichinella spiralis infection control group; B, D, and F are the ultrastructures of larval cysts in the rilpivirine treatment group, indicating that rilpivirine can reduce the proliferation of fibrous tissue outside the larval cysts, thereby hindering the development of larvae inside the cysts and destroying the morphological structure of the larvae. Detailed Implementation

[0021] The present invention will be further described below with reference to specific examples, and the advantages and features of the present invention will become clearer as a result. However, these examples are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0022] Example 1: Application of Rilpivirine in the Treatment of Trichinosis

[0023] 1. Animals and experimental reagents:

[0024] Mice (strain: purchased from Liaoning Changsheng Biotechnology Co., Ltd., Kunming).

[0025] 2. Establishment of an animal model of trichinosis:

[0026] Twenty-four healthy male Kunming mice (weighing 22-25 grams) were used to establish a trichinosis mouse model. Eight mice served as the negative control group (NC group), while the remaining 16 mice were orally infected with Trichinella spiralis cysts, with an inoculation rate of (100±5) cysts per mouse. The infected mice were randomly divided into two groups based on body weight: the positive control group (TS group) received saline orally via gavage on day 10 of infection for 14 consecutive days; the rilpivirine treatment group (RPV group) received rilpivirine (5 mg / kg / day) orally via gavage on day 10 of infection for 14 consecutive days. On day 28 of infection, diaphragmatic tissue was aseptically collected from each group for various assays.

[0027] 3. Results

[0028] 3.1 Rilpivirine can reduce the number of Trichinella spiralis larval cysts in mice.

[0029] Twenty-eight days after mice were infected with Trichinella spiralis, diaphragmatic tissue was aseptically collected from each group of mice, and larval cysts were counted under a microscope. The results are as follows: Figure 1 As shown in A and 1B, the results indicate that the number of sacs in the diaphragm of mice in the RPV group was significantly reduced; HE staining of the diaphragm tissue yielded the following results. Figure 1 As shown in Figure C, the results indicate that in the TS group, the Trichinella spiralis larval cysts were intact, with significant surrounding inflammatory cell infiltration, intact worm morphology, and extensive fibrosis within the cysts. In contrast, the RPV group showed a significant reduction in the pathological damage to the Trichinella spiralis cysts, with incomplete worm morphology, thinner cyst walls, and a smaller fibrotic area. This suggests that rilpivirine can significantly reduce the number of Trichinella spiralis larval cysts in infected mice.

[0030] 3.2 Rilpivirine can significantly alleviate the degree of muscle tissue fibrosis caused by Trichinella spiralis infection.

[0031] To further evaluate the effect of rilpivirine on muscle tissue fibrosis in Trichinella spiralis-infected mice, Masson staining was used to detect the content of collagen fibers around the cysts in the diaphragm of mice (muscle tissue and Trichinella spiralis were stained orange-red, while collagen fibers were stained blue). The results are as follows: Figure 2 As shown, extensive proliferation of collagen fibers around the capsule was found in the diaphragm of TS group mice. Figure 2 A); The cyst walls of larval cysts in the RPV group were significantly thinner, the staining was lighter, and the collagen fiber area was significantly reduced. Figure 2 B); Calculate the percentage of collagen fiber area outside the capsule, and the results are as follows: Figure 2 As shown in Figure C, the results indicate that the degree of muscle tissue fibrosis was significantly reduced in the RPV group (P = 0.0022).

[0032] 3.3 Rilpivirine can disrupt the ultrastructure of Trichinella spiralis larval cysts and hinder larval development.

[0033] To further observe changes in host muscle cells, Trichinella spiralis larval cysts, and the worm body, diaphragmatic tissue was fixed in 2.5% glutaraldehyde to prepare electron microscopy specimens. Its ultrastructure was observed under a transmission electron microscope, and the results are as follows: Figure 3 As shown, the results indicate that the TS group mice formed complete cysts with thick walls, and a large number of collagen fibers formed around the cysts. Figure 3 A); In the RPV group, cysts were incompletely formed and had thinner walls, and the larval structures within the cysts showed signs of fusion. Figure 3 B) At the same magnification, only part of the worm structure could be observed in the TS group, while the complete worm could be seen in the RPV group, indicating that the worm in the RPV group was significantly smaller than that in the TS group.

[0034] The results of observation of the larval structure inside the cyst are as follows: Figure 3 As shown in CE, the results indicate that there were obvious gaps within the cysts of mice in the TS group, and the epidermal layer and subcutaneous muscles of the parasites were neatly arranged. Figure 3 C) The mitochondrial structure inside the worm is intact and well-formed. Figure 3 E (indicated by the red arrow); the mitochondria inside the RPV group were swollen and accompanied by obvious vacuolation (as shown by the red arrow). Figure 3 D).

Claims

1. The application of rilpivirine as the sole active ingredient in the preparation of drugs for the prevention and treatment of trichinosis, wherein the chemical structural formula of rilpivirine is shown in Formula I: 。

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