Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Having -c- – wherein x is chalcogen – bonded directly to...
Reexamination Certificate
1999-09-29
2001-06-12
Jarvis, William R. A. (Department: 1614)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Having -c-, wherein x is chalcogen, bonded directly to...
C514S471000, C514S563000
Reexamination Certificate
active
06245795
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a melanogenesis inhibitor, a skin cosmetic composition and a bath preparation, which are superior in effect of preventing pigmentation caused by inflammation of the skin due to ultraviolet rays or the like.
More particularly, the present invention relates to a melanogenesis inhibitor, a skin cosmetic composition and a bath preparation, which are used for the purpose of effectively inhibiting specific melanogenesis caused by stimulation of histamine released on inflammation of the skin, using histamine H
2
receptor antagonist antagonists.
BACKGROUND ART
Ultraviolet rays cause inflammation of the skin, resulting in the release of various factors, thereby stimulating melanocytes. Tyrosinase is activated in the stimulated melanocytes to produce melanin. This melanin is delivered to epidermal cells through dendrites extended by melanocytes due to stimulation, thereby melanizing the skin, while the melanin plays a role of absorbing ultraviolet rays to protect the body. However, excess accumulation of melanin causes pigmentation of the skin, such as stains, freckles or the like.
Heretofore, compounds capable of inhibiting a tyrosinase activity of melanocytes have exclusively been developed to inhibit pigmentation of the skin. Known examples thereof include ascorbic acid or derivatives thereof, placental extract, glycyrrhiza extract, hydroquinone or derivatives thereof, kojic acid and the like. Although these ingredients have an action of inhibiting the tyrosinase activity and inhibiting melanogenesis, almost all of them can not exert a sufficient effect because of low activity or causes a problem in safety. Therefore, there has been required the development of an effective and selective melanogenesis inhibitor having an action different from that of tyrosinase activity inhibition.
A method of blocking stimulation to melanocytes has been hitherto known as a technology of inhibiting melanogenesis by an action other than that of tyrosinase activity inhibition. A principal substance that stimulates melanocytes to accelerate melanogenesis in the skin inflamed by ultraviolet rays includes, for example, melanocyte stimulating hormone (MSH), endothelin-1 (ET-1), histamine or the like (see Journal of Cell Science, Vol. 107, page 205, 1994; The Journal of Investigative Dermatology, Vol. 105, page 32, 1995; and Journal of Dermatological Science, Vol. 6, page 146, 1993). Among them, MSH and ET-1 are known to stimulate melanocytes via specific receptors. In particular, inhibition of melanogenesis by means of a method of inhibiting binding to the receptors has been reported for ET-1 (see Pigment Cell Research, Vol. 7, page 373, 1994).
Of course ET-1 is an effective ingredient, however, it is considered to be important to prevent stimulation due to histamine which particularly closely relates to the inflammatory reaction, considering the prevention of pigmentation after inflammation of the skin.
It has commonly been known that histamine is a substance, which is released from mast cells due to various stimulations and has various physiological activities, and includes three specific receptors (H
1
, H
2
and H
3
). It is considered that an H
1
receptor mainly relates an immediate anaphylactic reaction (allergic reaction), an H
2
receptor mainly relates to secretion of gastric acid, and an H
3
receptor relates to a release or synthesis of histamine in mast cells.
With regard to melanogenesis due to histamine stimulation in melanocytes, however, there was no established theory about the fact whether or not melanogenesis is caused by the reaction via a receptor specific for histamine. Therefore, histamine-mediated melanogenesis has never been made clear. Furthermore, there has hitherto been submitted a report disclosing a whitening effect of an anti-histaminic agent, particularly histamine H
1
receptor antagonist (Japanese Published Unexamined Patent Application No.17115/1990), but the histamine H
1
receptor antagonists do not have an effect of inhibiting melanogenesis as described hereinafter.
DISCLOSURE OF THE INVENTION
Under these circumstances, we have intensively studied to selectively inhibit a melanogenesis acceleration action of histamine. As a result, surprisingly, we have found a new fact that histamine stimulates melanocytes via its specific receptor to accelerate melanogenesis and, moreover, the melanogenesis is accelerated only via H
2
receptors without being concerned with H
1
and H
3
receptors. Thus, the present invention has been completed. It is an object of the present invention to provide a melanogenesis inhibitor, a skin cosmetic composition and a bath preparation, which are superior in the effect of preventing pigmentation due to inflammation by selectively inhibiting stimulation of histamine to melanocytes.
The above-mentioned object can be attained by a melanogenesis inhibitor comprising a histamine H
2
receptor antagonist capable of selectively inhibiting a histamine H
2
receptor, and a skin cosmetic composition and a bath preparation, comprising a histamine H
2
receptor antagonist; or a melanogenesis inhibitor comprising a histamine H
2
receptor antagonist, and at least one of histamine release inhibitors and histamine H
3
receptor agonists, and a skin cosmetic composition and a bath preparation, comprising a histamine H
2
receptor antagonist, and at least one of histamine release inhibitors and histamine H
3
receptor agonists.
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention will be described in detail hereinafter.
The histamine H
2
receptor antagonist used in the present invention includes, for example, cimetidine, famotidine, ranitidine hydrochloride, tiotidine, zolantidine, metiamide, burimamide, nizatidine, etc.; inorganic acid salts thereof, such as hydrochloride, hydrobromide, sulfate, etc.; organic acid salts thereof, such as fumarate, maleate, etc.; and a mixture thereof.
The histamine H
2
receptor antagonist used in the present invention may be alone, or two or more kinds of them can be appropriately selected.
In order to supplement the action of the histamine H
2
receptor antagonist or to make it effective, a release inhibitor of histamine to be released from mast cells (antiallergic drug) and a histamine H
3
receptor agonist for inhibiting synthesis or release of histamine of mast cells can also be used, simultaneously.
The histamine release inhibitor used in the present invention includes, for example, emedastine hydrochloride, emedastine fumarate, tranilast, sodium cromoglicate, azelastine hydrochloride, terfenadine, and plant extracts, such as a solvent extract of a plant belonging to the genus Rosaceae Pyracantha.
The histamine H
3
receptor agonist used in the present invention includes, for example, R-(&agr;)-methylhistamine or the like.
The melanogenesis inhibitor of the present invention may be one of the above-mentioned substances, and may also contain solvents such as water or vehicles.
For example, the melanogenesis inhibitor of the present invention can be incorporated into skin cosmetic compositions such as cosmetics and quasi-drugs, and bath preparations, because of its excellent melanogenesis inhibition effect. In addition, the melanogenesis inhibitor can also be used as pharmaceuticals, and reagents for studying and testing to be added in the cultured cell system.
The amount of the melanogenesis inhibitor of the present invention to be incorporated into the skin cosmetic composition or bath preparation varies depending on the subjects to which it is to be applied and is not defined unconditionally, but the amount on a dry basis of each substance is preferably from 0.0001 to 10% by weight, more preferably from 0.001 to 5% by weight, based on the total amount of the composition to be applied.
If necessary, fats and oils, humectants, pigments, dyes, surfactants, antioxidants, UV absorbers, antiseptics, water-soluble polymers and resins, which are conventionally incorporated into pharmaceuticals, quasi-drugs, skin external preparations such as cosmetics, and bath preparat
Inoue Shintaro
Takahashi Yoshito
Yoshida Masaki
Flynn ,Thiel, Boutell & Tanis, P.C.
Jarvis William R. A.
Kanebo Limited
Kim Vickie
LandOfFree
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