JP2013256473A - Trpa1 active inhibitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a TRPA1 active inhibitor effective for the reduction of pain caused by irritation.SOLUTION: A TRPA1 active inhibitor includes a compound expressed by formula (1) [wherein, Rto Rand Rdenote a hydrogen atom or a methyl group, independently; and Ror Rdenotes hydrogen atom, a hydroxyl group or a methyl group (provided that any one of Ror Ris a hydroxyl group)] as an active ingredient.

Description

  The present invention relates to a TRPA1 activity inhibitor that suppresses TRPA1 activity.

Sensory sensation occurs when externally received stimuli are converted into electrical signals and transmitted to the brain through nerve cells. In order to convert an external stimulus into an electrical signal, the presence of a receptor that senses the external stimulus is necessary.
TRPA1 is a non-selective cation channel belonging to the superfamily of transient receptor potential (TRP) ion channels, and was found as a cold receptor (17 ° C.) in nociceptive neurons (Non-patent Document 1). . TRPA1 is a chemical receptor that reacts to mustard oil and allyl isothiocyanate (AITC), cinnamon, garlic, methyl salicylate, eugenol, etc. contained in it, and also responds to low temperatures, mechanical and chemical stimuli. It has been reported that it is a pain receptor (Non-patent Documents 2 and 3).

  Recently, it has been reported that TRPA1 responds to parabens and alkaline agents, and that cells that have been transduced with TRPA1 can be used to screen for substances that suppress stimulation of parabens and alkaline agents (Patent Documents 1 and 2). ing.

  Thus, since TRPA1 is a nociceptor of skin and mucous membranes and is activated by various stimuli, suppressing the activity of TRPA1 is effective in reducing a sense of discomfort such as pain due to various stimuli. (Patent Document 3).

  On the other hand, compounds represented by the following formula (1) typified by isoborneol, fentyl alcohol, borneol and methylphenchol are known as synthetic fragrances, but they have a TRPA1 activity inhibitory action and a pain reducing action. It is not known that there is.

JP 2008-79528 A JP 2009-82053 A Special table 2009-528998

Story et al. 2003, Cell 112, 819-829 Kwan et al. 2006, Neuron 50, 277-289 Journal of Japanese Pharmacology, Vol. 124, pp. 219-227, 2004, published by The Japanese Pharmacological Society

  The present invention relates to providing a TRPA1 activity inhibitor effective in reducing pain caused by various stimuli.

  When the present inventors examined the material which suppresses the activity of TRPA1, it discovered that the compound represented by General formula (1) has the effect | action which suppresses the activation of TRPA1 effectively.

  That is, the present invention provides the following formula (1):

〔式中、Ｒ¹〜Ｒ⁵及びＲ⁸は独立して水素原子又はメチル基を示し、Ｒ⁶及びＲ⁷は水素原子、水酸基又はメチル基を示す（但し、Ｒ⁶及びＲ⁷のいずれか一方は水酸基である）。〕
で表される化合物を有効成分とするＴＲＰＡ１活性抑制剤に係るものである。

[Wherein, R ^{1 to} R ⁵ and R ⁸ independently represent a hydrogen atom or a methyl group, and R ⁶ and R ⁷ represent a hydrogen atom, a hydroxyl group or a methyl group (provided that any one of R ⁶ and R ⁷ One is a hydroxyl group). ]
This relates to a TRPA1 activity inhibitor comprising a compound represented by the formula:

  The TRPA1 activity inhibitor of the present invention has an effect of effectively suppressing the activation of TRPA1. Therefore, the TRPA1 activity inhibitor of the present invention is useful for alleviating irritation and pain caused by TRPA1. Specifically, by suppressing the irritation in the skin and nasal cavity, it is possible to suppress the tingling sensation that causes skin troubles and the irritating odor associated with the use of an ammonia preparation.

Of the compounds represented by the general formula (1) of the present invention (hereinafter also referred to as “the present compound”), those in which R ¹ , R ² and R ³ are all hydrogen atoms or both are methyl groups, R ³ , R ⁵ , R ⁷ and R ⁸ are all preferably methyl groups, R ¹ , R ² and R ³ are both hydrogen atoms and R ⁵ and R ⁶ are both methyl groups, R ¹ , R ^More preferably, ² and R ³ are both methyl groups and R ⁵ is a hydrogen atom, R ¹ and R ² are both hydrogen atoms, and R ³ , R ⁵ , R ⁷ and R ⁸ are all methyl groups preferable.
Furthermore, isoborneol (exo-1,7,7-trimethylbicyclo (2,2,1) heptan-2-ol) represented by the following formula, fentyl alcohol (1,3,3-trimethylbicyclo (2,2) , 1) heptan-2-ol), borneol (endo-1,7,7-trimethylbicyclo (2,2,1) heptan-2-ol), methylphenchol (endo-1,2,3,3- Tetramethylbicyclo (2,2,1) heptan-2-ol) is preferred.

The compound of the present invention includes optical isomers and stereoisomers, and in the present invention, any of them is included.
These may be used alone or in combination of two or more.

  The compound of the present invention can be chemically synthesized by a known method, or a commercially available product can be used. Commercial products include, for example, isoborneol (exo-1,7,7-trimethylbicyclo (2,2,1) heptan-2-ol) and borneol (endo-1,7,7-trimethylbicyclo (2,2,2)). 1) Heptan-2-ol) from Tokyo Kasei Kogyo Co., Ltd., Fentyl alcohol (1,3,3-trimethylbicyclo (2,2,1) heptan-2-ol) from SIGMA-AlDRICH (End-1,2,3,3-tetramethylbicyclo (2,2,1) heptan-2-ol) is available from Takasago International Corporation.

The compound of the present invention, as shown in the Examples below, shows that when allylic isothiocyanate, a TRPA1 stimulating substance, is contacted with a cell transduced with TRPA1 (TRPA1-expressing cell), the intracellular cation caused by allylisothiocyanate It has a TRPA1 activity inhibitory action of suppressing the inflow of the amount (Example).
Therefore, the compound of the present invention can be a TRPA1 activity inhibitor.

Here, “inhibition of TRPA1 activity” means that the activity of receptor TRPA1 is suppressed, specifically, for example, the activity expressed by binding of TRPA1 stimulating substance (agonist) to TRPA1, for example, ion flux It suppresses or inhibits the regulation ability (eg, ability to transport cations such as calcium ions and sodium ions from the outside of the cell into the cell) and the ability to regulate membrane potential (eg, ability to generate current). .
Here, as the TRPA1 stimulating substance, there is a chemical substance (referred to as “irritating causative substance”) that may cause irritation to the skin and mucous membranes. For example, allyl isothiocyanate (AITC), ammonia, bradykinin Cinnamaldehyde, 4-hydroxynonenal, allicin, acrolein, menthol, methyl salicylate, eugenol, parabens, phenoxyethanol, butyl carbamate propynyl iodide (IPBC), triclosan, benzyl alcohol and the like.

  The TRPA1 activity-suppressing effect by the compound of the present invention is, for example, the concentration of calcium ions in a TRPA1-expressing cell contacted with a TRPA1-stimulating substance (for example, AITC) in the presence of the compound, and It can be evaluated by comparing the difference with the calcium ion concentration in the TRPA1-expressing cells brought into contact with the TRPA1-stimulating substance in the absence.

  The TRPA1 activity inhibitor of the present invention includes, for example, a composition containing the above-mentioned irritation sensation causing substance (skin cleanser, hair cleanser, makeup agent, bath agent, permanent wave agent, hair dye, soaps, Such as kitchen detergents, laundry detergents, toothpaste cosmetics, quasi-drugs, pharmaceuticals, daily necessities, etc.) For example, prepared separately from the composition containing the substance that causes irritation It is used by combining at the same time or sequentially, whereby the sensory stimulation caused by the substance causing the irritation can be alleviated.

  The TRPA1 activity inhibitor may be the one using the compound of the present invention alone, or oil, pigment, fragrance, preservative, chelating agent, pigment, antioxidant, vitamin, mineral, sweetener, seasoning, storage Various preparations such as pharmaceuticals, cosmetics, quasi-drugs, daily necessities, such as additives, binders, extenders, disintegrants, surfactants, lubricants, dispersants, buffers, coating agents, carriers, diluents, etc. It may be a composition combined with additives, excipients and the like used in the above. Moreover, those forms are not particularly limited, and can be prepared in any form such as a solution, emulsion, suspension, gel, solid, powder, granule, aerosol, and the like.

  When the TRPA1 activity inhibitor of the present invention is used together with a composition containing a substance causing irritation, the amount of the TRPA1 activity inhibitor is not particularly limited as long as it has a TRPA1 activity inhibitory effect. The compound of the present invention is 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and 100 parts by mass or less, preferably 50 parts by mass or less, more preferably with respect to parts by mass. May be 10 parts by mass or less, and may be 0.01 to 100 parts by mass, preferably 0.1 to 10 parts by mass.

With respect to the above-described embodiment, the following aspects are disclosed in the present invention.
<1> The following formula (1):

[Wherein, R ^{1 to} R ⁵ and R ⁸ independently represent a hydrogen atom or a methyl group, and R ⁶ and R ⁷ represent a hydrogen atom, a hydroxyl group or a methyl group (provided that any one of R ⁶ and R ⁷ One is a hydroxyl group). ]
TRPA1 activity inhibitor which uses the compound represented by these as an active ingredient.

<2> Use of a compound represented by the above formula (1) for producing a TRPA1 activity inhibitor.
<3> A compound represented by the above formula (1) for use in inhibiting TRPA1 activity.
<4> A method for alleviating sensory irritation caused by a substance causing irritation using the compound represented by the formula (1) together with a composition containing the substance causing irritation.

Example 1 TRPA1 activity inhibitory action (1) Production of stable expression strain of human TRPA1 The human TRPA1 gene was purchased from Open Biosystems in a state where it was inserted into pENTR223.1. The TRPA1 gene was subcloned from the purchased entry vector into the expression vector pcDNA3.2-V5 / DEST (Invitrogen) and transduced into HEK293 cells with Lipofectamine 2000 (Invitrogen). Transduced cells were selected by growing in DMEM medium containing G-418 (450 μg / ml; Promega). Since HEK293 cells do not express endogenous TRPA1, they can be used as a control (control) for the TRPA1 transduced strain.

(2) Calcium imaging TRPA1 activity transduced into HEK293 cells was measured using a fluorescent calcium imaging method. First, cultured TRPA1-expressing cells were seeded (30000 cells / well) in a 96-well plate (BD Falcon) coated with poly-D-lysine, incubated at 37 ° C. overnight, and then the culture solution was removed. Fluo4-AM (2 μg / ml; Dojindo) dissolved in the solution was added and incubated at 37 ° C. for 60 minutes. Thereafter, the Fluo4-AM solution was removed, the Ringer solution was added to the wells, and the plate was set on a fluorescent plate reader (FDSS3000; Hamamatsu Photonics). A fluorescence image was detected with a CCD camera at a detection wavelength of 520 nm when excited at an excitation wavelength of 480 nm with the apparatus internal temperature set at 24 ° C. Measurement is performed for 4 minutes every second, and 15 seconds after the start of measurement, TRPA1 stimulating substance allyl isothiocyanate and the compound of the present invention are added at final concentrations of 5.0 μM and 0.01%, respectively, using a dispenser with a built-in FDSS 3000. TRPA1 activity was evaluated by the change in fluorescence intensity thereafter. The TRPA1 activity was expressed as a fluorescence intensity ratio (Ratio; F _peak / F ₀ ) obtained by dividing the fluorescence intensity peak (F _peak ) after addition of the stimulating substance by the fluorescence intensity (F ₀ ) before adding the stimulating substance. As a control, the same substance was added to HEK293 cells not transduced with TRPA1, the fluorescence intensity ratio (Ratio ₂₉₃ ) was calculated, and it was confirmed that the peak of activity due to the stimulating substance was derived from TRPA1 activation. .
As the compounds of the present invention, “(+) / (−)-isobornol” (Tokyo Kasei Kogyo), “(−)-bornol” (Tokyo Kasei Kogyo), “fenchyl alcohol” (SIGMA-AlDRICH), “methyl fenchol” ( Takasago International Corporation) was used.

(3) TRPA1 activity inhibition evaluation TRPA1 activity when allyl isothiocyanate (5.0 μM) and ethanol (0.01%; solvent control) were added to verify the effect of each compound on TRPA1 activation by allyl isothiocyanate The inhibitory action (activity inhibition rate;%) of each compound with respect to was evaluated. The TRPA1 activity inhibitory action by mixing and adding allyl isothiocyanate (stimulant) (5.0 μM) and compound (0.01%) was calculated by the following formula.
[Equation 1]
TRPA1 activity inhibition rate (%) = (1-((stimulating substance + ratio by adding compound) − (stimulating substance + ratio by adding compound ₂₉₃ ))) / ((stimulating substance + ratio by adding ethanol) − (stimulating substance + ethanol Ratio ₂₉₃ by addition))) x 100

(4) TRPA1 activation inhibitory action Table 1 shows the effect (activity inhibition ratio) of the compound of the present invention on TRPA1 activation by allyl isothiocyanate 5.0 μM. The compound of the present invention was shown to be a TRPA1 activity-suppressing material that is more effective than d-camphor, which is a known TRPA1 activity-suppressing material.

Claims (1)

Following formula (1):

[Wherein, R ^{1 to} R ⁵ and R ⁸ independently represent a hydrogen atom or a methyl group, and R ⁶ and R ⁷ represent a hydrogen atom, a hydroxyl group or a methyl group (provided that any one of R ⁶ and R ⁷ One is a hydroxyl group). ]
TRPA1 activity inhibitor which uses the compound represented by these as an active ingredient.