JP2007176944A - Nitric oxide decomposing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for efficient quenching of nitric oxide among the reactive oxygen species generated in a living body, and to cancel an excessive state of these reactive oxygen species in vivo. <P>SOLUTION: The invention relates to the decomposing agent of nitric oxide comprising fine powder of a transition metal such as platinum or platinum alloy. The decomposing agent is preferably provided as an aqueous solution containing transition metal colloid at a ratio of 1 mM or less per 1,000 ml. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a nitric oxide decomposing agent.

In vivo, particularly in mitochondria, microsomes, leukocytes, etc., O ₂ ⁻ (superoxide anion), H ₂ O ₂ (hydrogen peroxide), HO. (Hydroxy radical), and ¹ O ₂ (singlet) which is an excited molecular species Many active oxygen species (radicals) exhibiting high reactivity such as (oxygen) are generated and are said to be involved in biological control including ecological defense and biochemical reaction. Nitric oxide (NO) is a short-lived unstable radical species, and it has been clarified that this substance also has an important function in vivo as a kind of active oxygen (Modern Chemistry, 1994). April special issue).

  In normal cells, the amount of these reactive oxygen species produced is about 1% of the equivalent amount of the redox reaction, which is the main reaction, and is sequentially metabolized by degrading enzymes and the like. More than 95% of the oxygen that humans breathe into the body becomes water through normal metabolic processes, while the remaining few percent become active oxygen in the mitochondrial and microsomal electron transport systems, which are often -Eliminated by antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxide.

  However, not all active oxygens can be removed by these antioxidant enzymes, and some of the active oxygens oxidize proteins, lipids, nucleic acids and the like. Although these oxidized substances are partially repaired by another biological defense mechanism, gradually irreversibly oxidatively damaged substances are generated. As a result, it is said to lead to illness and aging.

  Furthermore, it is well known that the expression level of antioxidant enzymes such as superoxide desmutes decreases with age. If the metabolism of these oxides accumulates in time due to a decrease in reactive oxygen species metabolic capacity due to aging or excessive production of reactive oxygen species due to illness, cell components such as lipids are oxidized non-specifically, resulting in damage It can lead to cell death. This contributes to many diseases such as aging and Alzheimer's.

  Diseases involving active oxygen include cancer, diabetes, atopic dermatitis, Alzheimer, retinitis pigmentosa, etc., but over 90% of human illnesses involve excess oxygen in some way It is said. In particular, in the mitochondria in the living body, 90% or more of oxygen is metabolized, and active oxygen is generated most in the cell. If the balance between the active oxygen produced in mitochondria and the antioxidant system cannot be maintained due to genetic disease or aging, active oxygen that could not be processed from the mitochondria leaks and damages cells, resulting in aging and apoptosis. Cell death is caused.

As means for erasing active oxygen, water having electrolysis of water with an oxidation-reduction potential of -200 mV to -250 mV has been developed as reduced water, and alkaline ions having a pH of 9 to 11 by electrolysis are developed. Water has been developed (for example, Koji Tanikoshi, “Today's Mono-Knowing Series-A Book of Easy Water”, first edition, Nikkan Kogyo Shimbun, November 2001, p. 100-124). Highly active metal fine particles, such as platinum colloids, are known to decompose H ₂ O ₂ (hydrogen peroxide), which is a kind of active oxygen (for example, JP-A-10-68008, paragraph 0040). . However, there is no literature reporting that platinum colloids have a scavenging action on superoxide and nitric oxide in vivo.

  Various methods for producing highly active metal fine particles have been known for a long time (eg, Japanese Patent Publication No. 57-43125, Japanese Patent Publication No. 59-120249, and Japanese Patent Application Laid-Open No. 9-225317).

The inventors of the present invention provide a means for efficiently eliminating O ₂ ⁻ (superoxide anion) and nitric oxide among the active oxygens generated in the living body and eliminating the excess state of these active oxygens in the living body. We conducted earnest research to provide it. The present inventors have focused on transition metal fine powder, particularly platinum fine powder, which is a noble metal, and these fine powders can invade cells and can enter the inside of mitochondria. Was found to have the ability to dissipate superoxide anions and nitric oxide. The present invention has been completed based on the above findings.

  That is, according to the present invention, a superoxide anion decomposing agent containing a fine powder of a transition metal is provided. According to a preferred embodiment of the present invention, there is provided the above superoxide decomposition agent wherein the transition metal is a fine powder of a noble metal. This decomposing agent can decompose the superoxide anion in vivo.

  From another aspect, the present invention provides a nitric oxide decomposing agent comprising a fine powder of a transition metal. According to a preferred aspect of the present invention, there is provided the above-mentioned nitric oxide decomposing agent, wherein the transition metal is a fine powder of a noble metal.

  According to a preferred embodiment of these inventions, the above-mentioned decomposition agent in which the fine powder is a fine powder of platinum or a platinum alloy; the aqueous decomposition agent containing a transition metal colloid; An aqueous degradation agent comprising a colloid is provided.

  From still another aspect, there is provided a method for eliminating superoxide or nitric oxide in the living body of mammals including humans, the method comprising the step of administering a fine powder of transition metal to the living body. According to a preferred embodiment of the present invention, water containing a transition metal colloid can be administered.

  The kind of transition metal in the decomposition agent of the present invention is not particularly limited, and specific metals include metals such as gold, nickel, platinum, rhodium, paradium, iridium, ruthenium, osmium, and alloys thereof. The transition metal is preferably a noble metal. The type of the noble metal is not particularly limited, and any of gold, ruthenium, rhodium, palladium, osmium, iridium, or platinum may be used, but a preferable noble metal is ruthenium, rhodium, palladium, or platinum. A particularly preferred noble metal is platinum. The noble metal fine particles may contain two or more kinds of noble metals. Further, it is also possible to use fine particles of an alloy containing at least one kind of noble metal, or a mixture containing fine particles of one or more kinds of noble metals and fine particles of one or more kinds of metals other than noble metals. For example, an alloy made of gold and platinum may be used. Of these, platinum or an alloy containing platinum is preferable, and platinum is particularly preferable.

  As the noble metal fine particles, fine particles having a large specific surface area and capable of forming a colloidal state excellent in surface reactivity are preferable. The particle size of the fine particles is not particularly limited, but fine particles having an average particle size of 50 nm or less can be used, preferably the average particle size is 20 nm or less, more preferably the average particle size is 10 nm or less, and particularly preferably Fine particles having an average particle diameter of about 1 to 6 nm can be used. In particular, the average particle diameter is preferably about 1 to 6 nm for entry into the mitochondria. Finer fine particles can also be used, which is preferable in order to enhance the uptake into the living body. A decomposition agent containing these fine particles in a stable suspension in an aqueous medium is also preferred. As the aqueous medium, in addition to water, an organic solvent having low toxicity with respect to a living body and mixed with water at an arbitrary ratio, for example, ethanol, ethylene glycol, or the like can be used. Preferably, water can be used as the aqueous medium.

  Various methods for producing noble metal fine particles are known (for example, JP-B-57-43125, JP-B-59-120249, JP-A-9-225317, JP-A-10-176207, JP-A-2001). -79382, JP-A-2001-122723, etc.), those skilled in the art can easily prepare fine particles by referring to these methods. For example, as a method for producing noble metal fine particles, a chemical method called a precipitation method or a metal salt reduction reaction method, a physical method called a combustion method, or the like can be used. As the decomposing agent of the present invention, fine particles prepared by any method may be used, but it is preferable to use fine particles prepared by a metal salt reduction reaction method from the viewpoint of ease of production and quality.

  In the metal salt reduction reaction method, for example, an aqueous solution or an organic solvent solution of a water-soluble or organic solvent-soluble noble metal salt or noble metal complex is prepared, and after adding a water-soluble polymer to this solution, the pH of the solution is adjusted to 9 to 11. And fine particles can be obtained by reduction by heating to reflux in an inert atmosphere. The kind of the water-soluble or organic solvent-soluble salt of the noble metal is not particularly limited. For example, acetate, chloride, sulfate, nitrate, sulfonate, or phosphate can be used. It may be used.

  The type of water-soluble polymer used in the metal salt reduction reaction method is not particularly limited. For example, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, cyclodextrin, aminopectin, or methylcellulose can be used. A combination of the above may be used. Polyvinylpyrrolidone can be preferably used, and poly (1-vinyl-2-pyrrolidone) can be more preferably used. Moreover, it is also possible to use various surfactants, for example, anionic, nonionic, or fat-soluble surfactants in place of the water-soluble polymer or together with the water-soluble polymer. When the reduction is performed using alcohol, ethyl alcohol, n-propyl alcohol, n-butyl alcohol, n-amyl alcohol, ethylene glycol, or the like is used. However, the method for preparing the noble metal fine particles is not limited to the method described above.

  Since the metal fine powder prepared by the above method is usually obtained in a colloidal state using the solvent used as a medium, it can be used as it is as the superoxide anion decomposer or nitric oxide decomposer of the present invention. . When the organic solvent used is removed, the organic solvent is removed by heating, and the decomposition agent of the present invention can be prepared as a metal fine powder. The metal fine powder obtained by heating and drying does not lose its properties as a superoxide anion decomposer or nitric oxide decomposer.

  The decomposing agent of the present invention can be prepared in the form of reduced water. Reduced water is water having an action of reducing an oxidizing substance in vivo. According to the present invention, reduced water that decomposes the superoxide anion and / or nitric oxide can be prepared according to the amount of the added decomposition agent. For example, about 0.033 mM decomposition agent was added per 1000 ml of water. Even with reduced water, a sufficient reduction effect, that is, a decomposition effect of superoxide anion and / or nitric oxide can be obtained. For example, the reduced water of the present invention preferably contains the above decomposing agent at a ratio of 1 mM or less. By administering reduced water containing the above ratio to mammals including humans, most of the superoxide anion and / or nitric oxide in the body disappears.

  In a preferred embodiment of the decomposing agent of the present invention, a metal fine powder having a particle size of nanometer (nm) order is included, and the metal fine powder is taken into a cell after being administered into a living body, and further into the mitochondria. Invades the superoxide anion or nitric oxide generated in the mitochondria. Therefore, the degradation agent of the present invention is expected to be effective for the prevention or treatment of the above-mentioned diseases caused by active oxygen, particularly amyotrophic lateral sclerosis (FALS). In addition, the decomposition agent of the present invention provided as a form of reduced water can be used as drinking water or sports drink as health food, and can be used as a medicine or cosmetic, as well as production of health food and medicine. Or it can also be used for manufacture of cosmetics.

  Furthermore, by adding the nitric oxide decomposing agent of the present invention to a filter such as tobacco, it is possible to efficiently decompose nitric oxide contained in tobacco smoke. For example, fine particles of the decomposing agent of the present invention can be blended in a solid state together with activated carbon in a tobacco filter or in place of activated carbon. Alternatively, the nitric oxide contained in the tobacco smoke can be efficiently removed by filling the water pipe with the decomposing agent of the present invention in the form of an aqueous colloid and guiding the tobacco smoke into the water pipe.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, the scope of the present invention is not limited to the following Example.
Example 1
In a 100 ml two-necked eggplant bottom flask connected with an aryl condenser and a three-way cock, 0.1467 g of poly (1-vinyl-2-pyrrolidone), a reagent made by Wako Pure Chemical Industries, Ltd., is added and dissolved in 23 ml of distilled water. After stirring for 10 minutes with a stirrer chip, chloroplatinic acid crystals (H ₂ PtCl ₆ .6H ₂ O: Reagents manufactured by Wako Pure Chemical Industries, Ltd.) are dissolved in distilled water to a concentration of 1.66 × 10 ⁻² M 2 ml of the chloroplatinic acid aqueous solution adjusted to 1 was added, and the mixture was further stirred for 30 minutes. The reaction system was purged with nitrogen, 25 ml of special grade ethanol was added, and the mixture was refluxed at 100 ° C. for 2 hours while maintaining a nitrogen atmosphere. By measuring the UV of the reaction solution, the platinum ion peak disappeared, the saturation of the peak due to the scattering characteristic of the metal solid was confirmed, and the reduction reaction was completed. After removing the solvent with an evaporator, it was further lyophilized over 12 hours to obtain a fine platinum powder (decomposing agent of the present invention).

  The obtained decomposing agent was dissolved in a 0.1 M sodium phosphate buffer whose pH was adjusted to 7.8 in advance, and 0.66 mM, 0.495 mM, 0.330 mM, 0.165 mM, 0.083 mM, A dispersion containing colloidal degradation agent at a concentration of 0.033 mM was obtained. When observed under a microscope, the particle size of the platinum fine particles was 6 nanometers or less.

Example 2
Superoxide of the resulting degradation agent using O ₂ ⁻ (superoxide anion) generated by the combination of hypoxanthine / xanthine oxidase and the combination of phenadiene methosulfate / NADH (reduced nicotinamide adenine dinucleotide), respectively Anion resolution was measured as follows.

(A) Hypoxanthine / xanthine oxidase system In a sample container, 20 μl of DMPO (5,5-dimethyl-1-pyrroline-N-oxide: spin trap agent manufactured by Labotech) at a concentration of 8.8 M and hypoxanthine (Sigma) at a concentration of 1 mM. 50 μl, MilliQ (purified water: manufactured by Millipore) 50 μl, and 50 μl of each of the above five samples having different concentrations were sequentially added and mixed, and then xanthine oxidase (Roche) at a concentration of 0.04 U / ml. 50 μl was added, and after 45 seconds, an ESR spectrum was measured using an ESR measuring apparatus (JES-FA200 manufactured by JEOL Ltd.). The amount of O ₂ ⁻ (superoxide anion) was measured in comparison with the standard substance (manganese). The results obtained are shown in Table 1. The numerical value in the parenthesis is a relative value when the value when the density is 0 is 100.

(B) Phenadiene methosulfate / NADH system For 4 types (concentrations 0.033 mM, 0.083 mM, 0.165 mM and 0.330 mM) of the above samples, 20 μl of DMPO with a concentration of 8.8 M, NADH (Funakoshi) Table 2 shows the results of measuring the ESR spectrum in the same manner as described above after 1 minute after sequentially adding and mixing 50 μl of the above sample and phenazine methosulfate (manufactured by Wako Pure Chemical Industries, Ltd.) and the above sample. The numerical value in the parenthesis is a relative value when the value when the density is 0 is 100.

Comparative Example 1
Using poly (1-vinyl-2-pyrrolidone) itself or cisplatin (PtCl ₂ (NH ₃ ) ₂ ), which is a platinum complex, the poly (1-vinyl-2-pyrrolidone) or platinum concentration is the same as in the examples. Then, the amount of O ₂ ⁻ (superoxide anion) was measured, but no difference was observed from the blank (platinum concentration = 0).

Example 2
NO ₂ / NO ₃ Assay Kit-C II (Dojindo Laboratories, Inc.) was used as an analysis kit to examine the ability to eliminate NO by platinum colloid. This kit measures NO ₂ produced by hydrolysis of NO. Using a microplate reader (Model 550 manufactured by BIO RAD), the detection wavelength was set to 570 nm, and each sample was measured three times. A 96-well microplate was used as the microplate. Moreover, NOC7 (Dojindo Laboratories Inc.) was used as the NO donor. The analysis was basically performed according to the manual that came with the kit, with some modifications. 8 μL of sample was added to each well of the microplate, 84 μL of buffer solution and 8 μL of NOC7 were mixed, and left for 30 minutes. Reagent A (50 μL) was mixed and allowed to stand for 5 minutes. Reagent B (50 μL) was further mixed and allowed to stand for 10 minutes, and then detected with a microplate reader at a detection wavelength of 570 nm. If NO ₂ generated from NO reacts with platinum nanocolloid, the elimination of NO cannot be observed. Therefore, NO ₂ and platinum nanocolloid were mixed and the absorbance analysis was performed. As a result, it was clarified that when platinum nanocolloid was contained, the absorbance slightly increased but NO ₂ decomposition did not occur. Each sample was analyzed for NO elimination ability. The results are shown in FIG. From this result, it was clarified that the platinum nanocolloid has NO elimination ability.

  The superoxide anion decomposing agent and nitric oxide decomposing agent of the present invention can decompose excessive superoxide anion and / or nitric oxide in the living body by being administered to the living body.

FIG. 1 is a diagram showing the action of the nitric oxide decomposing agent of the present invention.

Claims (5)

Decomposing agent for nitric oxide containing fine powder of transition metal. The decomposition agent according to claim 1, wherein the transition metal is a noble metal. The decomposition agent of Claim 1 containing the fine powder of a platinum fine powder or a platinum alloy. The decomposition agent according to any one of claims 1 to 3, comprising an aqueous transition metal colloid. The decomposition agent according to claim 4, comprising a transition metal at a ratio of 1 mM or less per 1000 ml.