JP2006213629A - Suppressant of toxicity attributable to quinone compound or precursor of quinone compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical agent effective to toxicity originated from a quinone compound or a precursor of quinone compound produced by oxidation of an exotic medical agent, or endogenous amines, amino acids or proteins, and specifically effective to cranial neuropathy and/or cytopathy. <P>SOLUTION: The invention relates to the suppressant of toxicity due to the quinone compound or precursor of the quinone compound comprising a compound selected from a group comprising dopamine receptor agonist (dopamine agonist). Dopamine receptor agonist such as bromocriptine mesilate, pergolide mesilate, talipexole hydrochloride, ropinirole hydrochloride, pramipexole hydrochloride, etc., has activities directly bonding to dopamine quinone compound or dopa quinone compound itself, and capturing and erasing. The suppressant exerts an excellent suppressing effect in a group administered with levodopa on cranial neuropathy caused by production of intracerebral quinone compounds. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toxicity inhibitor characterized by suppressing toxicity caused by a quinone or quinone precursor and preventing or treating a disease caused by the quinone or quinone precursor or adverse effects on a living body. Specifically, the present invention relates to a preventive / therapeutic agent for cranial nerve damage and / or cell damage caused by a quinone body or a quinone body precursor. Furthermore, it is related with the screening method of this preventive-therapeutic agent.

  It has been known that brain neuropathy is caused by quinone, particularly dopamine quinone or dopaquinone produced by oxidation of dopamine or dopa (levodopa) (Non-patent Document 1), but the treatment method is unknown. .

  It has been reported that dopamine quinone or dopaquinone impairs the function of the protein by binding to a cysteine residue of an intracellular functional protein (Non-patent Documents 2 to 4).

  In the dopamine cultured neurons, the present inventors have reported that dopamine, dopamine quinone produced from dopa or dopaquinone induces p53 cells, decreases mitochondrial membrane potential, activates caspase-3, and induces DNA fragmentation. In addition, it was found that catalase without quinone scavenging ability is ineffective, although it can be blocked by dopamine quinone or glutathione that eliminates dopaquinone, superoxide dismutase. Patent Document 5). From this result, it is shown that cranial nerve damage caused by dopamine quinone or dopaquinone production can be suppressed / blocked by a substance having the ability to eliminate quinone.

  Substances that bind directly to quinone itself such as dopamine quinone or dopaquinone and eliminate its toxicity include endogenous glutathione (Non-patent document 6), superoxide dismutase (Non-patent document 5), α-synuclein ( Non-patent document 7) is known, and it is suggested that N-acetylcysteine, dithiothreitol and ascorbic acid may also eliminate dopamine toxicity (non-patent document 8). It has been reported that when dopamine is administered in the brain together with glutathione or ascorbic acid, quinone production in the brain by dopamine can be suppressed (Non-patent Document 9). However, at the experimental animal level, there is no report that peripheral administration of these substances showed an inhibitory effect on the production or toxicity of dopamine quinone or dopaquinone in the brain.

  In addition to dopamine quinone and dopaquinone, quinone is also produced by oxidation of exogenous drugs having a dihydroxyphenyl skeleton or endogenous amines, amino acids and proteins. It acts as a transcription factor that induces the expression of quinone-eliminating enzymes such as NAPDH quinone oxidoreductase (DT-diaphrase), glutathione S-transferase, superoxide dismutase, etc. As reagents that enhance the activity of the enzyme, butylated hydroxyanisole (BHA), dimethyl fumarate (DMF), tert-butylhydroquinone (tBHQ) and the like have been reported at the level of cultured cells (Non-patent Documents 10 and 11). It does not bind to and eliminate dopaquinone itself, and its peripheral toxicity and transferability into the brain are unknown. It is not clear whether peripheral administration can provide a sufficient inhibitory effect on quinone toxicity. Moreover, no compound is known that suppresses the production and toxicity of dopamine quinone or dopaquinone in the brain by peripheral administration to experimental animals.

On the other hand, as an effect on dopamine metabolism (conversion to inactive form) and antioxidant action of dopamine receptor agonists (dopamine agonists), the present inventors have reported that bromocriptine mesylate, pergolide mesylate and cabergoline are Parkinson's disease model animals. It has the ability to suppress dopamine metabolism in the striatum in the brain, the ability to eliminate free radicals such as hydroxyl radicals and nitric oxide radicals, and the ability to inhibit lipid peroxidation, and the administration of cabergoline and ropironil hydrochloride It has been reported that the glutathione concentration increases (Non-Patent Documents 12 to 17). Furthermore, it has also been reported that pramipexole hydrochloride, a dopamine agonist, has hydroxyl radical scavenging ability, lipid peroxidation inhibiting ability, glutathione, and catalase increasing ability (Non-Patent Documents 18 to 20).
However, a prophylactic / therapeutic agent for the formation of quinone bodies such as dopamine quinone or dopaquinone induced in the levodopa administration group in Parkinson's disease and cerebral neuropathy caused thereby is unknown.

Neurotoxicity Research, 5 (3), 165-176, 2003 Molecular Pharmacology, 14, 633-643, 1978 Biochemical Pharmacology, 31 (18), 2887-2889, 1982 Neuropharmacology, 25, 451-454, 1986 Biochemica et Biophysica Acta, 1619 (1), 39-52, 2003 Journal of Neurochemistry, 73, 2546-2554, 1999 Science, 294, 1346-1349, 2001 Biochemical Pharmacology, 53 (3), 363-372, 1997 Proc. Natl. Acad. Sci. USA., 93, 1956-61, 1996 Journal of Neurochemistry, 86, 143-152, 2003 Journal of Biological Chemistry, 278 (7), 4536-4541, 2003 Brain Research, 657, 207-213, 1994 Archives internationales de Pharmacodynamie et de Therapie, 329 (2), 221-230, 1995 Journal of Neurochemistry, 67, 2208-2211, 1996 Brain Research, 790, 202-208, 1998 Neuroscience Research, 43, 259-267, 2002 Brain Research, 838, 51-59, 1999 Brain Research, 883, 216-223, 2000 Neuroscience Letters, 281, 167-170, 2000 Journal of Neural Transmission, 107, 1165-1173, 2000

  The present invention is effective for toxicity caused by quinone or quinone precursor produced by oxidation of exogenous drugs or endogenous amines, amino acids, or proteins, specifically cranial nerve damage and / or cell damage. It is an object to provide a novel toxicity inhibitor.

  As a result of intensive studies to solve the above problems, the present inventors have found that a compound selected from the dopamine receptor agonist group has an action of directly binding to, capturing and eliminating dopamine quinone or dopaquinone itself. For example, it was confirmed that the compound exhibits an excellent inhibitory effect against cranial nerve damage due to quinone formation in the brain in the levodopa administration group, and the present invention has been completed.

That is, this invention consists of the following.
1. A toxicity inhibitor comprising as an active ingredient a compound selected from the group of dopamine receptor agonists, which suppresses toxicity caused by a quinone or a quinone precursor.
2. 2. The toxicity inhibitor according to item 1 above, which suppresses the binding between a quinone or quinone precursor and a functional protein, and suppresses toxicity caused by the quinone or quinone precursor.
3. 3. The toxicity inhibitor according to 1 or 2 above, wherein the toxicity caused by the quinone body or the quinone body precursor is cranial nerve disorder and / or cell disorder.
4). 4. The toxicity inhibitor according to any one of items 1 to 3, wherein the compound selected from the dopamine receptor agonist group is any one of bromocriptine mesylate, pergolide mesylate, talipexol hydrochloride, ropinirole hydrochloride, and pramipexole hydrochloride.
5. 5. The toxicity inhibitor according to any one of the preceding items 1 to 4, wherein the quinone or quinone precursor is produced by oxidation of an exogenous drug or endogenous amines, amino acids, or proteins.
6). 6. The toxicity inhibitor according to 5 above, wherein the exogenous drug is levodopa.
7). A screening method for a prophylactic / therapeutic agent for cranial neuropathy and / or cell damage using the interaction of a quinone or quinone precursor and a dopamine receptor agonist as a marker.
8). 8. The screening method according to item 7 above, wherein the interaction between the quinone or quinone precursor and the dopamine receptor agonist is a bond between the dopamine receptor agonist and the quinone or quinone precursor.
9. A screening method for a prophylactic / therapeutic agent for cranial neuropathy and / or cell damage, which uses as a marker a function that controls the production of a quinone or quinone precursor.
10. 10. The screening method according to item 9 above, wherein the functional marker that controls the production of a quinone body or a quinone body precursor is the amount of quinoprotein in the striatum of an animal brain.

  The drug containing a compound selected from the dopamine receptor agonist group of the present invention as an active ingredient is a quinone or quinone precursor produced by oxidation of an exogenous drug or endogenous amines, amino acids, or proteins. Inhibits toxicity caused by. Specific examples of toxicity caused by quinone or quinone precursor include cranial nerve damage and / or cell damage. For example, against cranial neuropathy caused by quinone formation in the brain in patients administered with levodopa known as a therapeutic agent for Parkinson's disease, the drug of the present invention can reach the brain even by peripheral administration, such as dopamine quinone or dopaquinone It exhibits an excellent inhibitory effect by directly binding to the quinone body itself. Further, it is effective not only for the production of exogenous quinone, but also for toxicity caused by the quinone produced endogenously, such as cell damage.

Treatment of cranial nerve disorders such as neurotoxicity caused by quinone or quinone precursor with levodopa administration in Parkinson's disease has been started after the symptoms of the problem have occurred. It is difficult to take preventive measures immediately afterward. There is a need for a strategy that can prevent cranial nerve damage due to quinone formation in the brain by peripheral administration in advance in combination with levodopa administration and the like.
In addition, a treatment method that can prevent progression of cranial nerve damage due to quinone formation by starting combination immediately after the onset of problem symptoms is also desired.
Furthermore, in neurological diseases / disorders in which oxidative stress is involved in the pathological condition, quinone forms are produced by oxidation of endogenous amines, amino acids, and proteins, which promotes the disorder and can prevent and / or treat such disorder. The law is also desired.

  Therefore, the present invention is not limited to exogenous drugs such as levodopa administration in Parkinson's disease, but also quinone or quinone precursor produced in vivo by oxidation of endogenous amines, amino acids, or proteins due to oxidative stress or the like. Toxicity suppressors for the treatment or prevention of the resulting toxicity, such as cranial nerve damage and / or cell damage, are provided.

  In the present invention, the quinone body or quinone body precursor refers to a quinone body or quinone body precursor produced in vivo by oxidation of an exogenous drug or endogenous amines, amino acids, or proteins. Examples of the quinone produced by an exogenous drug include a quinone produced by administration of a drug having a dihydrophenyl skeleton, specifically, dopamine quinone and dopaquinone produced by administration of a levodopa preparation known as a therapeutic drug for Parkinson's disease. In addition, a quinone is transiently generated in the oxidation process of endogenous amines, amino acids, or proteins due to oxidative stress.

  In the present invention, specific examples of intracellular functional proteins that bind to quinone or quinone precursor include α-synuclein and tyrosine hydroxylase (TH). Aggregation and degeneration of α-synuclein are said to be related to Parkinson's disease and other neurological diseases. Tyrosine hydroxylase is an enzyme that generates dopa from phenylalanine or tyrosine, and dopa becomes dopamine by the action of dopa decarboxylase.

In the present invention, cerebral neuropathy and cell damage are mentioned as the toxicity caused by the quinone or quinone precursor.
Examples of the damage caused by administration of an exogenous drug having a dihydrophenyl skeleton such as levodopa and dopamine quinone and dopaquinone are as follows.
Symptoms such as Wearing-off and dyskinesia appear with long-term administration of levodopa for Parkinson's disease. The Wearing-off phenomenon means that the effective time of a drug is shortened to 1 to 3 hours and the drug effect is reduced. The cause is that dopamine neurons fall off due to degeneration, and levodopa in the brain is not retained by dopamine neurons, but is metabolized to dopamine by dopa decarboxylase of other cells (glia cells and serotonin cells) in a short time. It is thought to be done. Since levodopa becomes a large amount of dopamine in a short time and acts on the dopamine receptor, an involuntary movement (dyskinesia) occurs due to excessive dopamine action. One of the causes of the appearance of problem symptoms associated with such long-term administration of levodopa is considered to be toxicity due to the formation of quinone or quinone precursor by levodopa administration. In the present invention, levodopa, which is an exogenous drug, may be a single levodopa agent or may be included in a combination with carbidopa.

  Toxicity caused by the oxidation of endogenous amines, amino acids, or proteins, resulting from quinone or quinone precursors, may cause cell damage by binding to α-synuclein and tyrosine hydroxylase. It is done.

  In the present invention, the ergot alkaloid derivative and the non-ergot alkaloid derivative are exemplified as the compound selected from the dopamine receptor agonist group. Examples of ergot alkaloid derivatives include pergolide mesylate and bromocriptine mesylate, and examples of non-ergot alkaloid derivatives include talipexol hydrochloride, ropinirole hydrochloride, pramipexole hydrochloride, and the like.

  As a therapeutic agent for Parkinson's disease, a compound selected from the group of dopamine receptor agonists is used.For example, pergolide mesylate has a daily dose of 50 μg and a maintenance dose of 750 days a day in consideration of efficacy and safety. It is described in the package insert of the drug to be ˜1250 μg. Similarly, in the case of bromocriptine mesylate, it is described that the daily dose is 2.5 mg and gradually increases from 15.0 to 22.5 mg a day while seeing the effect. Similarly, in the case of pramipexole hydrochloride, it is described that the daily dose starts from 0.25 mg and gradually increases from 1.5 to 4.5 mg while observing the effect.

The elimination of toxicity based on the quinone form of a compound selected from the dopamine receptor agonist group of the present invention has a mechanism of action different from the agonist activity for the dopamine receptor, that is, it acts directly on the quinone form or quinone form precursor. By doing.
In the case of levodopa administration as a therapeutic agent for Parkinson's disease, it has been conventionally performed in combination with a dopamine receptor agonist. In this case, the dose of dopamine receptor agonist was determined with a focus on agonist activity at the dopamine receptor, and was insufficient to improve cranial nerve damage when used in combination with levodopa. .
In the present invention, the dose of the compound selected from the dopamine receptor agonist group depends on the level of quinone or quinone precursor that can be produced or the degree of toxicity caused by the quinone or quinone precursor. Can be determined as appropriate.

Furthermore, the present invention extends to a screening method for a toxicity inhibitor comprising as an active ingredient a compound selected from the group of dopamine receptor agonists that suppresses toxicity caused by a quinone or quinone precursor. Toxicity inhibitors can be screened using the interaction of a quinone or quinone precursor and a dopamine receptor agonist as a marker. Specifically, it is based on a screening method using as a marker the binding between a dopamine receptor agonist and a quinone or quinone precursor. A method known per se can be applied to detect the binding between the quinone or quinone precursor and the compound.
Moreover, the said toxicity inhibitor can be screened using the function which controls the production | generation of a quinone body or a quinone body precursor as a marker. Specifically, the screening method uses the amount of quinoprotein in the striatum of an animal's brain as a marker. A method known per se can be applied to detect the amount of quinoprotein produced in the striatum of an animal's brain.

  Toxicity inhibitors containing as an active ingredient a compound selected from the dopamine receptor agonist group of the present invention can contain one or more pharmaceutically acceptable excipients, and are quinone or quinone precursors. It can be set as the pharmaceutical composition as a therapeutic / prophylactic agent for cranial nerve damage and / or cell damage caused by the body.

  EXAMPLES The present invention will be described below with reference to examples, but it is obvious that the present invention is not limited to these examples.

Example 1
Effects of dopamine receptor agonists on dopamine quinone or dopamine semiquinone production systems

  According to the method of Haque et al. (Non-Patent Document 5), dopamine receptor action on a quinone (semiquinone) generating system that generates dopamine quinone or dopamine semiquinone from dopamine under conditions of pH 7-8 with sodium hydroxide added to dopamine. The effect of drug addition was examined.

  Dopamine was dissolved and suspended in 10 mM sodium phosphate buffer (pH 7.4) or 0.5% methylcellulose to 10 mM (final concentration 2.5 mM) immediately before use. As dopamine receptor agonists, ergot alkaloid dopamine agonists bromocriptine mesylate, pergolide mesylate, cabergoline, non-ergot dopamine agonists rovinirole hydrochloride or pramipexole hydrochloride are used immediately before use. It was suspended in 0.5% methylcellulose so as to have a final concentration of 25 μM to 1 mM and added to a dopamine quinone or dopamine semiquinone production system.

  In a light-shielded test tube, (1) 10 mM sodium phosphate buffer (pH 7.4), (2) 10 mM (final concentration 2.5 mM) dopamine, (3) 100 μM to 4 mM (final concentration 25 μM to 1 mM) 100 μM to 4 mM (final concentration 25 μM to 1 mM) dopamine receptor agonist (bromocriptine mesylate, pergolide mesylate, cabergoline, ropinirole hydrochloride, pramipexole hydrochloride) or 0.5% methylcellulose as a control, (4) 10 mM sodium hydroxide Were added in an amount of 50 μl, and reacted at 37 ° C. for 1 minute.

  Immediately after the reaction, dopamine quinone or dopamine semiquinone in the reaction solution was detected and measured by an electron spin resonance method as a unique spectrum with a free radical measurement device (nuclear timing resonance device: JES-FR30 manufactured by JEOL). . The measurement conditions of the nuclear magnetic resonance apparatus are magneticfield, 335 ± 5mT; power, 4 mW; modulation frequency, 9.41GHz; modulation amplitude, 125μT; response time, 0.1sec; temperature, 25 ℃; amplitude, 1 × 1000; sweep time , 1 min. The ratio of the integrated value of the second spin adduct of the maximum amplitude among the four spins representing dopamine semiquinone to the integrated value of the spin adduct of internal standard manganese oxide was calculated as the amount of dopamine semiquinone, and a dopamine receptor agonist The percentage with respect to the value when no was added (0.5% methylcellulose added group for control) was calculated. Three experiments were performed for each concentration, and the average value was evaluated.

Table 1 shows the experimental results regarding the action of dopamine receptor agonists on dopamine quinone or dopamine semiquinone production systems.

  As shown in Table 1, among the dopamine receptor agonists, pergolide mesylate and pramipexole hydrochloride had an action of directly binding to, capturing and eliminating dopamine quinone or dopamine semiquinone. In addition, ropinirole hydrochloride and bromocriptine mesylate were weak, but had binding and scavenging ability (erasing ability) to dopamine quinone or dopamine semiquinone. However, the ergot alkaloid dopamine agonist cabergoline did not show any ability to eliminate dopamine quinone or dopamine semiquinone. Therefore, it was confirmed that the ability of these dopamine receptor agonists to directly bind / capture (eliminate) to dopamine quinone or dopamine semiquinone itself is not based on agonist activity with respect to the dopamine receptor.

(Example 2)
Mesylic acid for the increase of quinoprotein (quinone-binding protein as an indicator of quinone formation) in the lateral striatum in the brain by administration of levodopa (L-dopa (levodopa): carbidopa) to unilateral Parkinson's disease model animals Effect of pergolide administration

  According to the method of Kaneko et al. (Science, 289, 633-637, 2000), the dopamine neurotoxin 6-hydroxydopamine (6-OHDA) was added to the right striatum in 8 weeks old male CD-1 (ICR) mice. ) A total of 60 μg was injected under deep anesthesia using a stereotaxic device and a microsyringe to produce a unilateral Parkinson's disease model mouse. 14 days after 6-OHDA injection, apomorphine 0.5 mg / kg was administered subcutaneously, and rotation to the non-affected side (left side) was observed. One-sided parkinson with the dopamine nerve in the right nigrostriatal tract shed A disease model mouse was used for subsequent drug administration experiments.

  From 2 weeks after the apomorphine rotation test, pergolide mesylate (0.125 mg / ml, final dose concentration 0.5 mg / kg), levodopa combination (L-dopa (levodopa): carbidopa = 12.5: 1.25 mg / ml, (Final dose concentration 50: 5 mg / kg) or pergolide mesylate + levodopa (pergolide: L-dopa: carbidopa = 0.125: 12.5: 1.25 mg / ml, final dose concentration 0.5: 50: 5 mg / kg) Was administered intraperitoneally once daily for 7 days (total 7 times). All drugs were prepared by suspending in 0.5% methylcellulose immediately before use. The same volume of 0.5% methylcellulose was administered to the control group.

One-sided Parkinson's disease model mice were divided into 3 to 4 mice per group, and divided into the following groups.
(1) Control (0.5% methylcellulose) administration group,
(2) Pergolide mesylate administration group,
(3) Levodopa mixture (L-dopa (levodopa): carbidopa) administration group (4) Pergolide mesylate + levodopa combination (L-dopa (levodopa): carbidopa) administration group

  Twenty-four hours after the final administration of the drug, transperitoneally perfused with ice-cold saline under deep anesthesia, sacrificed, and the damaged (right) and non-impaired (left) striatal tissues were removed, Protein was extracted from the solution by treatment with trichloroacetic acid. The concentration of quinoprotein (quinone-binding protein), which serves as an index of quinone formation, in the tissue is determined by the Paz et al. NBT-glycinate method (J. Biological Chemistry, 266 (2), 689-692, 1991 and Non-Patent Document 10). It was measured by. The amount of quinoprotein (quinone binding protein) was expressed as the absorbance (530 nm) in 1 mg protein based on the total protein concentration in the tissue.

Table 2 shows the experimental results regarding changes in the amount of quinoprotein in the striatum of the brain by daily administration of pergolide mesilate and levodopa alone or combined daily administration to unilateral Parkinson's disease model mice.

  As shown in Table 2, quinoprotein (quinone-binding protein) is an indicator of quinone formation only in the striatum on the damaged side by administration of levodopa (L-dopa (levodopa): carbidopa) to unilateral Parkinson's disease model mice. A significant increase in quantity was observed. In contrast, among the dopamine receptor agonists, pergolide mesylate was administered together with levodopa (L-dopa (levodopa): carbidopa) every day in combination with levodopa (L-dopa (levodopa): carbidopa: ) When administered alone, the increase in the amount of quinoprotein observed in the damaged striatum of Parkinson's disease model animals was almost completely suppressed. The ratio of pergolide mesylate to the levodopa mixture at this time was about 5 times higher than the ratio in the case of combined maintenance administration to Parkinson's disease patients.

  The prophylactic / therapeutic agent comprising a compound selected from the dopamine receptor agonist group of the present invention as an active ingredient is a cerebral nerve produced by quinone neurotoxicity or quinone precursors in the brain, including quinone neurotoxicity by levodopa administration in Parkinson's disease. In addition to disorders, it can be used as an agent for preventing and / or treating cranial nerve disorders and / or cell disorders caused by quinone or quinone precursors that are also produced by participation of endogenous amines, amino acids, and proteins.

Claims (10)

A toxicity inhibitor comprising as an active ingredient a compound selected from the group of dopamine receptor agonists, which suppresses toxicity caused by a quinone or a quinone precursor. The toxicity inhibitor according to claim 1, wherein binding of the quinone body or quinone body precursor and the functional protein is suppressed, and toxicity caused by the quinone body or quinone body precursor is suppressed. The toxicity inhibitor according to claim 1 or 2, wherein the toxicity caused by the quinone or quinone precursor is a cranial nerve disorder and / or a cell disorder. The toxicity inhibitor according to any one of claims 1 to 3, wherein the compound selected from the dopamine receptor agonist group is any one of bromocriptine mesylate, pergolide mesylate, talipexol hydrochloride, ropinirole hydrochloride, and pramipexole hydrochloride. The toxicity inhibitor according to any one of claims 1 to 4, wherein the quinone body or the quinone body precursor is produced by oxidation of an exogenous drug or endogenous amines, amino acids, or proteins. The toxicity inhibitor according to claim 5, wherein the exogenous drug is levodopa. A screening method for a prophylactic / therapeutic agent for cranial neuropathy and / or cell damage using the interaction of a quinone or quinone precursor and a dopamine receptor agonist as a marker. The screening method according to claim 7, wherein the interaction between the quinone or quinone precursor and the dopamine receptor agonist is a bond between the dopamine receptor agonist and the quinone or quinone precursor. A screening method for a prophylactic / therapeutic agent for cranial nerve damage and / or cell damage, which uses as a marker a function that controls the production of a quinone or quinone precursor. The screening method according to claim 9, wherein the functional marker that controls the production of a quinone body or a quinone body precursor is the amount of quinoprotein in the striatum of an animal brain.