JP2007093584A - Differentiation method for validity of antifungal agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for clarifying how much an antifungal agent given to a living body reaches a target tissue, how much it is trapped or inactivated in the target tissue, and how effective it works. <P>SOLUTION: A quantitative value obtained by giving the antifungal agent to a tissue of an animal, slicing the working and/or target portion of the antifungal agent in a fixed direction to the tissue, and measuring the concentration of the antifungal agent extracted from the resulting slice of the tissue with a solvent is compared with an antifungal activity value obtained by seeding the fungus on a slice of a tissue highly identical with the slice and differentiating the effect on growth of the fungus in the tissue slice to differentiate the dynamics of effective concentration of the antifungal agent given to the tissue. The tissue piece is preferably a nail, and the growth of the fungus is preferably determined based on whether the state of the fungus in the nail tissue piece is in hyphal formation or in conidial. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for differentiating an antifungal agent, and more particularly to a method for differentiating an antifungal agent useful for differentiating an antifungal action in a tissue.

  It is extremely difficult to distinguish whether an antifungal agent is effective in mycosis, in particular, ringworm. In general, antifungal activity against fungi is often evaluated by the minimum inhibitory concentration (MIC) value in an in vitro system. However, unlike such in vitro systems, it is known that some of the administered antifungal agents bind to proteins in the tissue and lose their effects in the actual therapeutic setting. It has become common knowledge that fungal growth is not inhibited as much as in vitro. It is not known at all how much the drug loses efficacy in such a process, and there is no means for identifying such properties. Such loss of efficacy is considered to be a kind of characteristic value that varies depending on the type of antifungal agent, and knowing this value is thought to greatly benefit the selection of drugs in the treatment of mycosis. As one of the attempts to obtain such characteristic values, a technique has been developed in which a drug is administered to the skin of a guinea pig, the skin is taken out, the section is cut in a horizontal direction, and the drug concentration in the section is measured by an activated label body. ing. (For example, see Non-Patent Document 1) However, in this paper, the medicinal effect is a general infection model, and the concentration is carried out in an uninfected animal and is not the same condition. In addition, there is a drawback that it is difficult, and in addition, is it inactivated by trapping proteins, etc., or is the antifungal agent inactivated without exhibiting antifungal action in the skin? It is unclear, and it is also unclear whether the antifungal action is bacteriostatic or bactericidal. In addition, no consideration can be given to how the antifungal agent administered to an actual living body is distributed to the tissue. Furthermore, it was not known at all that the antifungal activity of the antifungal agent varies depending on the tissue. It is not known that such differences in the appearance of antifungal activity depending on the target tissue cause the discrepancy between the actual clinical situation and the evaluation value such as MIC in the evaluation. There is no suggestion.

  As a method of evaluating and distinguishing antifungal agents, punching out parts such as nails with a punch, creating a continuous sliced piece, measuring the concentration of the administered antifungal agent in the slice, and determining the drug distribution Although already known (see, for example, Patent Document 1), although the distribution is known in this method, it is not known whether it is effective. Also known is a method of culturing fungi using only the nail as a nutrient source and distinguishing the effect of a drug passing through the nail under the condition. However, for example, a plurality of slices are cut out from a tissue piece collected from an animal administered with an antifungal agent, and then the concentration of the antifungal agent extracted from the slice of the tissue piece by a solvent is determined. Quantitative value obtained by the measurement and the antifungal activity value obtained by separately inoculating fungi on the same tissue piece, culturing, transplanting the cultured tissue piece to the medium, and distinguishing the effect on fungal growth There is no known method for distinguishing effective concentrations of antifungal agents to be contrasted. It was also not known at all that effective concentrations differed from tissue to tissue.

JP 2002-65695 A JP 2001-133449 A Tadashi Arika et. Al., Antimicrob. Agen. Chemotherap., 1993; 363-365

  The present invention has been made under such circumstances, to what extent the antifungal agent administered to the living body reaches the target tissue, how much is trapped or inactivated in the target tissue, and which It is an issue to provide technology for clarifying the degree of usefulness for each organization.

In view of such circumstances, the present inventors have determined how much the antifungal agent administered to the living body reaches the target tissue, how much is trapped or inactivated in the target tissue, and how much is As a result of diligent research efforts to find a technique to clarify whether it works usefully, antifungal agents are administered to animal tissues, and then the action and / or target site of the antifungal agents are assigned to the tissues. On the other hand, if the tissue is a body surface tissue, for example, a section is cut out horizontally with respect to the body surface, and then the concentration of the antifungal agent extracted by the solvent from the tissue slice can be measured. This distinction can be achieved by contrasting the quantitative value with the antifungal activity value obtained by seeding fungus on a separate slice of tissue with high identity and discriminating the effect on fungal growth in the slice of tissue. Find what you can do and complete the invention It led to the cell. Here, a section having high identity means a highly probable section that exists in the immediate vicinity of the section, such as a section cut out before and after the section. As a specific technique, it can be exemplified that serial sections are alternately used for quantitative determination of an antifungal agent and for differentiation of action on fungal growth. That is, the present invention is as follows.
(1) An antifungal agent is administered to an animal tissue, and then the action and / or target site of the antifungal agent is cut out in a certain direction with respect to the tissue, and then the tissue slice is removed with a solvent. Obtained by differentiating the quantitative value obtained by measuring the concentration of the extracted antifungal agent and the effect of the tissue slice on the growth of the fungus by separately inoculating the slice of tissue highly identical to the slice. A method for differentiating the kinetics of an effective concentration of an antifungal agent administered to a tissue, characterized by contrasting with an antifungal activity.
(2) The differentiation method according to (1), wherein the tissue piece is a nail or skin.
(3) The fungal growth is determined based on whether the fungal properties in the nail tissue pieces or skin tissue pieces form hyphae or in a conidial state, (1) or (2) The differentiation method described in.
(4) Furthermore, when fungal growth suppression is observed in the tissue piece seeded with the fungus, the tissue piece transplanted to the medium is treated with phospholipid and polyoxyethylene sorbitan fatty acid ester after determining the growth status of the fungus. Transplanted again to the medium containing it, examined whether the fungus grows from the tissue piece, if it grows, the effective concentration is identified as a bacteriostatic effective concentration, and if it does not grow, bactericidal effective concentration The discrimination method according to any one of (1) to (3), wherein the discrimination method is characterized as follows.

  It is possible to provide a technique for clarifying how much an antifungal agent administered to a living body reaches a target tissue, how much is trapped or inactivated in the target tissue, and how much is useful.

  The method of distinguishing the kinetics of the effective concentration of an antifungal agent administered to the tissue of the present invention is to administer the antifungal agent to an animal tissue, and then determine the action and / or target site of the antifungal agent on the tissue. In a certain direction, for example, a body surface tissue, a section was cut out in a horizontal direction with respect to the body surface, and then the concentration of the antifungal agent extracted from the tissue slice by a solvent was measured. It is characterized by contrasting the quantitative value and the antifungal activity value obtained by separately inoculating fungi on a slice of tissue having a high identity with the slice and distinguishing the effect on the growth of the fungus in the slice of tissue. Here, a section having high identity means a highly probable section that exists in the immediate vicinity of the section, such as a section cut out before and after the section. As a specific technique, it can be exemplified that serial sections are alternately used for quantitative determination of an antifungal agent and for differentiation of action on fungal growth.

  Here, the administration of the antifungal agent to the tissue can be performed to a tissue previously taken out from the living body of the animal, or can be administered to a tissue that belongs to the living body. Human tissue can be used as long as the removal of the tissue does not violate morality, but in the latter case, tissue of animals other than humans is used. The tissue can be used without any particular limitation, and may be a body tissue such as an internal organ or a body surface tissue, but is preferably a body surface tissue. Specifically, skin, nails, hair and the like can be suitably exemplified. In these tissues, even if the concentration is the same in the tissue, the effectiveness may be different depending on the tissue. Therefore, it is necessary to distinguish effectiveness for each organization. A nail is particularly preferable as such a target tissue. This is because drug penetration, fungal persistence, recurrence, etc. are particularly serious problems with nails. That is, there is a high probability that there is a discrepancy between the index of antifungal activity such as MIC in vitro and the effective concentration in the tissue.

  Administration of the drug to the tissue may be oral administration, injection, infusion, and for external use, an open system or an occlusive system such as a closed patch. If the tissue is extracted in advance, it can be administered using a device such as a Franz-type cell. The drug may be administered once or several times. The preferred form is administered continuously for about one week. This is because reproducibility can be improved.

  The extracted tissue to which the drug has been administered can be cut out according to a conventional method. That is, the tissue is cut out by a section cutting device such as a microtome, a cold tome, or a cryotome and used as a specimen. If the tissue is soft tissue, it can be cut out in a frozen state. The thickness of the section may be such that it can carry an antifungal agent and does not leak the seeded fungal solution. Specifically, it is preferably 1 to 20 μm, and preferably 3 to 10 μm. Is more preferable.

  The slices thus cut are partly used for quantification of antifungal agents and partly used for differentiation of antifungal action. Measurement of the content of the drug in the tissue section can be performed according to a conventional method, for example, extraction with a solvent such as tetrahydrofuran, acetonitrile, methanol, water, and then gas chromatography, high performance liquid chromatography, LC / Mass. It can be quantified by means such as / Mass. From the recovery rate in such measurement, the amount of the antifungal agent trapped in the tissue and insolubilized can be calculated backward. Moreover, the concentration of the antifungal agent working effectively in the tissue can be identified from the dose dependency of the growth inhibitory action identified by the following procedure. The differentiation of the fungal growth inhibitory action may be performed according to the method described in Patent Document 2.

The effect on fungi can be identified as a growth inhibitory effect on fungi by seeding the fungus on a tissue piece, culturing under conditions according to the type of fungus, and observing the effect on fungal growth on the tissue piece. I can do it. Examples of the culture conditions include conditions for culturing at a temperature of 30 to 40 ° C. and a humidity of 80 to 100% for 1 to 10 days. The seeding of the fungus on the tissue piece may be carried out in accordance with a conventional method. For example, seeding with a conidia number of 10 ³ to 10 ¹⁰ / ml is preferable. After the completion of the culture, the fungus on the tissue piece and / or the entire tissue is stained and observed under a microscope. When formation of mycelium is observed, it is identified that the growth inhibitory effect on the fungus does not exist. If only the offspring are observed, it is discriminated that the growth inhibitory effect existed. The dyeing method can be applied without particular limitation as long as it is a dyeing method capable of distinguishing such a growth situation. For example, Grocott dyeing, dyeing with Fungiflora Y, dyeing with FUN-1, dyeing with crystal violet, neutral Examples include red staining and PAS staining, and PAS staining is more preferable. PAS staining consists of seven steps: (1) Fixing the sample (2) Washing with running water (3) Periodic acid treatment (4) Washing with distilled water (4) Schiff reagent treatment (6) Sulfurous acid solution treatment (7) Washing with running water After that. At this time, it is particularly preferable to measure the antifungal activity value by culturing only the tissue piece as a nutrient source.

  In the differentiation of growth inhibition, when growth inhibition is observed, a tissue section is collected, transplanted to a medium containing phospholipid and polyoxyethylene sorbitan fatty acid ester, and cultured again for 12 to 72 hours, Observe whether the fungus grows from the tissue section. As the phospholipid, lecithin, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidic acid, phosphatidylserine and the like can be used, and its content is preferably 0.1 to 5% by mass in the medium, and polyoxyethylene sorbitan fatty acid ester POE (20) sorbitan monooleate, POE (20) sorbitan sesquioleate, POE (20) sorbitan trioleate and the like can be suitably exemplified, and the content thereof is preferably 0.1 to 5% by mass in the medium. In this case, when the fungus does not grow, the growth inhibitory action is identified as a bactericidal action, and when the fungus grows, the growth inhibitory action is identified as a bacteriostatic action. Further, differentiation of growth inhibition can be confirmed by a method using PCR. There are commercially available fungal culture media containing such phospholipids and polyoxyethylene sorbitan fatty acid esters, and such commercial products can be purchased and used. Examples of such commercially available media include “SCDLP medium“ Digo ”” and “SCDLP agar medium“ Digo ”” sold by Wako Pure Chemical Industries, Ltd. Usually, it is clear that antifungal agents have a growth inhibitory effect on fungi. Therefore, when focusing only on the effectiveness, the above-mentioned “Sabouraud dextrose medium” can be omitted.

  As such a fungus that can be differentiated, it can be applied without particular limitation as long as it is a fungus known as a pathogen, such as Trichophyton Mentagrophytes, Trichophyton rubrum, Aspergillus niger, Preferred examples include Candida albicans, Malassezia furfur, Malassezia globosa, Malassezia restrictor and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples, but it goes without saying that the present invention is not limited to such examples.

  The free margins of fingers provided by healthy volunteers were set in Franz cells (nail thickness was 270-490 μm, average 390 μm). The cell on the nail plate side was opened and “Penlac” (Cyclopirox preparation; manufactured by Aventis Pharmaceuticals Co., Ltd.) was administered at 5 μL per day. The cell on the nail bed side was filled with 0.9% NaCl-containing agarose and sealed. This was left still in a constant temperature and humidity machine at 28 ° C. and a humidity of 50%. The administration was carried out every 24 hours for 5 days, after removing the film before the next administration, and then wiped off twice with water. After the administration was completed, the nail was punched out with a φ2 mm biopsy punch and sliced continuously to a thickness of 10 μm in the horizontal direction using a cold tome. Half of the sliced nails (hereinafter referred to as nail slices) were subjected to LC / MS / MS quantification of the drug amount, and half were subjected to measurement of antifungal activity. LC / MS / MS high performance liquid chromatography conditions were as follows: Column used: SUPELCO Discovery HS C18 f2.1 mm × 150 mm, column temperature: 45 ° C., moving bed: acetonitrile / water = 45/55, flow rate: 0.3 mL / min Injection amount: 5 uL, detection wavelength: 300 nm. Trichophyton mentagrophytes was used as the fungus. Seeding was performed by dropping 1 μL of a solution of 105 conidia / ml onto a nail slice placed on a slide glass. Cultivation was performed under conditions of humidity 100%, 35 ° C., 7 days, PAS staining after culturing, and the growth state was observed under a microscope. The results are shown in FIG. From this, it can be seen that the antifungal activity is observed up to a depth of 100 to 160 μm, and the drug concentration at that time is approximately 1000 μg / cm 3.

  Animal skin was examined in the same manner as in Example 1. That is, 10 μL of “Mycospoor” was applied to the sole of the hind limb of a guinea pig (Hartley, male, 8 weeks old). 24 hours after application, the application site was wiped off with water, and then the entire sole was cut out and the center of the application site was punched out with a biopsy punch of φ4 mm. Using a cold tome, it was sliced continuously to a thickness of 10 μm in the horizontal direction. Half of the sliced skin (hereinafter referred to as skin slice) was subjected to LC / MS / MS for quantification of the drug amount, and half was subjected to measurement of antifungal activity. LC / MS / MS high performance liquid chromatography conditions were as follows: Column used: SUPELCO Discovery HS C18 f2.1 mm × 150 mm, column temperature: 45 ° C., moving bed: methanol / 5 mM formic acid aqueous solution = 80/20, flow rate: 1.0 mL / Min (split ratio; 2: 8), injection amount: 5 uL. Trichophyton mentagrophytes was used as the fungus. For seeding, 2 μL of 5 × 10 5 conidia / mL solution was dropped onto a skin slice placed on a slide glass. Cultivation was performed under conditions of humidity 100%, 35 ° C., 7 days, PAS staining after culturing, and the growth state was observed under a microscope. The results are shown in FIG. From this, it can be seen that the antifungal activity is observed up to a depth of 40 to 80 μm, and the drug concentration at that time is approximately 1 to 10 μg / cm 3.

  The present invention can be applied to distinguish the action of antifungal agents.

FIG. 3 is a diagram showing the action of the antifungal agent of Example 1. It is a figure which shows the effect | action of the antifungal agent of Example 2.

Claims (4)

An antifungal agent is administered to the tissue of an animal, and then the action and / or target site of the antifungal agent is cut out in a certain direction with respect to the tissue, and then extracted from the tissue slice with a solvent. Quantitative value obtained by measuring the concentration of the antifungal agent and antifungal activity obtained by separately inoculating fungi on a slice of tissue with high identity to the slice and distinguishing the effect on fungal growth in the slice of tissue The differentiation method according to claim 1, wherein the tissue piece is a nail or skin. The differentiation method according to claim 1 or 2, wherein the growth of the fungus is determined based on whether the fungal properties in the nail tissue piece or the skin tissue piece form hyphae or in a conidial state. . Furthermore, when fungal growth suppression is observed in a tissue piece seeded with fungus, the tissue piece transplanted to the medium is determined in a medium containing phospholipids and polyoxyethylene sorbitan fatty acid ester after determining the growth status of the fungus. Transplanted again, examined whether the fungus grows from the tissue piece, if it grows, the effective concentration is identified as a bacteriostatic effective concentration, and if it does not grow, it is a bactericidal effective concentration The discrimination method according to any one of claims 1 to 3, wherein discrimination is performed.

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