ALLERGEN PROTECTION AGAINST URUSHIOLS

Abstract

Allergenic substances, allergens such as urushiols, are captured by peptides that consist of 2-10 amino acids, at least one amino acid having one or more reactive side chains. This barrier effect of the peptides, in particular in topically applicable preparations, leads to a novel anti-allergic form of therapy.

Claims

1-15. (canceled)

16. A peptide, wherein the peptide is effective in the treatment of allergic contact dermatitis caused by urushiols and comprises 2 to 10 amino acids, at least one of these amino acids having one or more reactive side chains.

17. The peptide of claim 16, wherein at least one of the amino acids has one or more free thiol groups.

18. The peptide of claim 16, wherein at least one of the amino acids is histidine, cysteine, lysine, tyrosine, serine, selenocysteine, homocysteine, asparagine, aspartic acid, glutamine, glutamic acid, methionine, phenylalanine or pyrrolysine.

19. The peptide of claim 16, wherein the peptide is GSH, HHHHHH, Ac-RFAACAA, Ac-RFAALAA, RFAALAA, RFAACAA, Ac-RAACAA, RAACAA, Ac-RFACAA, RFACAA, Ac-RFACA or RFACA.

20. A preparation, wherein the preparation is topically applicable and comprises one or more peptides according to claim 16 and is capable of preventing or attenuating allergic reactions caused by urushiols in or on the skin.

21. The preparation of claim 20, wherein at least one of the one or more amino acids of the one or more peptides has one or more free thiol groups.

22. The preparation of claim 20, wherein at least one of the one or more amino acids of the one or more peptides is histidine, cysteine, lysine, tyrosine, serine, selenocysteine, asparagine, aspartic acid, glutamine, glutamic acid, methionine, phenylalanine or pyrrolysine.

23. The preparation of claim 20, wherein at least one of the one or more peptides is GSH, HHHHHH, Ac-RFAACAA, Ac-RFAALAA, RFAALAA, RFAACAA, Ac-RAACAA, RAACAA, Ac-RFACAA, RFACAA, Ac-RFACA or RFACA.

24. The preparation of claim 20, wherein the preparation comprises from 0.01% to 10% by weight of the one or more peptides, based on a total weight of the preparation.

25. The preparation of claim 24, wherein the preparation comprises from 0.1% to 5% by weight of the one or more peptides.

26. The preparation of claim 24, wherein the preparation comprises from 0.2% to 5% by weight of the one or more peptides.

27. The preparation of claim 23, wherein the preparation comprises from 0.01% to 10% by weight of the one or more peptides, based on a total weight of the preparation.

28. The preparation of claim 27, wherein the preparation comprises from 0.1% to 5% by weight of the one or more peptides.

29. The preparation of claim 27, wherein the preparation comprises from 0.2% to 5% by weight of the one or more peptides.

30. The preparation of claim 20, wherein the preparation is present in the form of at least one of an emulsion, a gel or a spray.

31. The preparation of claim 29, wherein the preparation is present in the form of at least one of an emulsion, a gel or a spray.

32. A method of forming a skin barrier against urushiols, wherein the method comprises applying onto the skin the preparation of claim 20.

33. A method of preventing or reducing the penetration and/or accumulation of urushiols on skin and/or in skin, wherein the method comprises applying onto the skin the preparation of claim 20.

34. A method of preventing or attenuating allergic reactions in skin or on skin, wherein the method comprises applying onto the skin the preparation of claim 20.

35. A method of preventing or attenuating allergic contact dermatitis caused by urushiols, wherein the method comprises applying onto skin the preparation of claim 20.

Description

[0091] Examples of preferred peptides are

[0092] Glutathione (GSH), also known as γ-L-glutamyl-L-cysteinylglycine, is a tripeptide having the sequence glutamic acid-cysteine-glycine. [0093] Hexahistidine (HHHHHH) [0094] Ac-RFAACAA - a peptide having the sequence acetyl-arginine-phenylalanine-alanine-alanine-cysteine-alanine-alanine

[0095] The peptide is shown by way of example in FIG. 1, in which the active amino acid side chain is marked with an arrow. [0096] Ac-RFAALAAA - a peptide having the sequence acetyl-arginine-phenylalanine-alanine-alanine-lysine-alanine-alanine [0097] Ac-RAACAA [0098] Ac-RFACAA [0099] Ac-RFACA [0100] RFAALAA [0101] RFAACAA [0102] RAACAA [0103] RFACAA [0104] RFACA

[0105] The peptide sequence listing of these peptides is given in the appendix.

[0106] For use, one or more peptides of the invention comprising one or more active amino acids are applied to the surface of the skin.

[0107] The invention therefore also encompasses preparations for topical application, in particular cosmetic or dermatological preparations, comprising one or more of the peptides of the invention.

[0108] Topical application can take place in many different ways, for example in the form of a cosmetic formulation. Application to the skin results in the creation of a protective mechanism, a barrier effect.

[0109] Simple aqueous or lipid-containing formulations up to preparation forms with a complex make-up are possible, depending on the field of use.

[0110] The skin is in constant contact with foreign substances from the environment, or allergens such as urushiols. The protective mechanism means that foreign substances from the environment now come up against this barrier first. Potential allergens encounter the peptides contained in the applied formulation and are thus able to directly react with or be bound or at least hindered by the active amino acids of these peptides. The allergens are thus intercepted and are no longer able to cause a biological reaction in the body.

[0111] The allergen reaction with effector (skin’s own peptide or protein) is prevented before an allergy to the allergen can develop.

[0112] Likewise, the allergens are intercepted and the triggering of the allergy by the specific allergen (elicitation) thus prevented.

[0113] The barrier effect of the peptides of the invention and their prevention or attenuation of allergic reactions has been impressively demonstrated in the investigations elucidated below.

[0114] One operating principle in the experiments carried out here is based primarily on the scavenging of allergens through the formation of covalent bonds to the reactive group, for example the amino acid cysteine, according to the mechanism of a nucleophilic addition, also termed SN1 and SN2.

[0115] The following investigations were carried out to demonstrate the barrier effect.

[0116] FIG. 2 shows investigations into the reactivity of peptides of the invention with urushiol allergens after 24 h. The absorbance is plotted on the y-axis. The peptide-allergen reactions were realized according to a direct peptide reactivity assay. The test is referred to as the in-chemico method, that is to say no cells are used, but a chemical reaction is carried out.

[0117] The direct peptide reaction assay (DPRA) is an OECD-validated test method.

[0118] The native, still-unbound peptide is detected by reaction with Ellman’s reagent and corresponding absorbance measurement. The direct peptide reactivity assay (DPRA) is a chemical method for predicting epidermal protein binding. DPRA uses for example HPLC to measure the depletion of peptides in solution after exposure to test chemicals.

[0119] RFAACAA was selected as an example of a peptide of the invention.

[0120] In the DPRA method, the absorbance at 415 nm is determined as the measured variable.

[0121] The allergen concentration is in the investigations carried out a standard 5 mM and thus 10 times the concentration of the peptide used (0.5 mM).

[0122] The reaction courses shown were determined colorimetrically through the reaction of the peptide with Ellmann’s reagent in a photometer. In this reaction, DTNB ((5,5′-dithiobis-2-nitrobenzoic acid, Ellmann’s reagent) is cleaved and attached to the SH residue of the amino acid cysteine of the peptides of the invention (RFAACAA).

[0123] The SH radical is at the same time the reactive binding site of the peptide with the allergens. The color reaction with DTNB (color change from colorless to yellow) competes with the allergen reaction. This means that the better the allergen reacts with the peptide, the less peptide remains available for the reaction with the detection reagent, i.e. the less the resulting yellow coloration.

[0124] FIG. 2 shows the allergen reduction (urushiols and model allergen eugenol) in the direct peptide reaction assay (DPRA) after a 24 h reaction, n = 3.

[0125] FIG. 2 shows the fall in peptide against eugenol and against various urushiol derivatives. The control is the peptide in the buffer system without allergen, i.e. instead of allergen only its solvent (ethanol) is added.

[0126] Urushiols of the structure below were used.

TABLE-US-00008 Urushiol I [00001] —(CH.sub.2).sub.14CH.sub.3 Urushiol II —(CH.sub.2).sub.7CH═CH(CH.sub.2).sub.5CH.sub.3 Urushiol III —(CH.sub.2).sub.7CH═CHCH.sub.2CH═CH(CH.sub.2).sub.2CH.sub.3 Urushiol IV —(CH.sub.2).sub.7CH═CHCH.sub.2CH═CHCH═CHCH.sub.3 Urushiol V —(CH.sub.2).sub.7CH═CHCH.sub.2CH═CHCH.sub.2CH═CH.sub.2

[0127] The investigated urushiols differ in the saturation in the side chain R.

[0128] Urushiols where R = C15 singly (C15:1), doubly (C15:2) or triply (C15:3) unsaturated were investigated.

[0129] The results demonstrate very high reactivity and thus protective activity of the peptides of the invention against urushiols too. The peptides, especially Ac-RFAACAA and RFAACAA, show very high reactivity and thus protective activity against urushiol structures I-V in particular.

[0130] Urushiols are the strongest naturally occurring allergen, which is in addition responsible for many sensitizations, as explained above. Urushiols are the main sensitizing constituent of the sumac plants, such as poison sumac (Toxicodendron quercifolium), including, in particular, in the various Rhus species such as poison ivy (Toxicodendron radicans), poison oak (Toxicodendron diversilobum), and lacquer tree (Rhus verniciflua), and also in Toxicodendron rydbergii, Toxicodendron toxicarium, and Toxicodendron vernix.

[0131] Allergy to urushiols, which requires prior sensitization, can be triggered in approx. 50-75% of all Americans. This contact dermatitis affects 10-50 million Americans every year.

[0132] Contact allergy to urushiols is a serious occupational disease, for example in agricultural and forestry workers and firefighters, but also in all recreation seekers who move around in nature. In the USA they are responsible for 7.1 million doctor visits and 430000 hospital inpatient stays. For example, this contact allergy is the cause of 10% of all work time lost to injury at US Forest Services, and approximately one-third of forestry workers in California, Oregon, and Washington are unfit for work during the wildfire season because of these reactions.

[0133] The invention now provides a possible remedy here.

[0134] The preparations of the invention comprising the short-chain peptides of the invention result in alleviation of the allergic skin reaction to constituents of poison ivy.

[0135] All investigations impressively demonstrate the allergen barrier effect of the peptides of the invention in preventing or reducing the penetration and/or accumulation of urushiols on and/or in the skin.

[0136] The numerous investigations of the various peptides demonstrate by way of example the barrier effect and the prevention or attenuation of allergic reactions for all peptides of the invention having a total of 2 to 10 amino acids, wherein at least one amino acid has one or more reactive side chains.

[0137] The peptides of the invention can advantageously be incorporated into typical cosmetic and dermatological preparations, which can take different forms. For instance, examples of preferred preparation forms are a solution, a water-in-oil (W/O) type emulsion or an oil-in-water (O/W) type emulsion, or multiple emulsions, for example a water-in-oil-in-water (W/O/W) type or oil-in-water-in-oil (O/W/O) type, a hydrodispersion or lipodispersion, a gel, a solid stick or even an aerosol.

[0138] The content of one or more peptides of the invention in preparations for topical application is advantageously chosen within a range from 0.01% to 10% by weight, especially within a range from 0.1% to 5% by weight, more preferably within a range from 0.2% to 5% by weight, based on the total mass of the preparation.

[0139] Preferred application forms of the peptides of the invention are emulsion preparations, gels, and spray formulations.

[0140] Emulsions produced according to the invention, for example in the form of a cream, a lotion or a cosmetic milk, are advantageous and comprise, for example, fats, oils, waxes, and/or other fatty substances, and also water and one or more emulsifiers as are customarily used for formulations of this type.

[0141] The preparations of the invention advantageously comprise one or more film formers.

[0142] In addition, the peptides can be chemically modified to improve the physicochemical properties. For example, derivatization with fatty acid residues (for example acetyl, caproyl, undecenoyl, or palmitoyl) increases the lipophilicity. Secondly, chemical modifications can help make the peptide more stable and thus protect it for example from degradation by peptidases.

[0143] So-called penetration enhancers, solubilizers and physical methods are able to increase the permeability of the skin and also further boost distribution in the skin.

[0144] An addition of solubilizers is therefore advantageous.

[0145] It is of course known to those skilled in the art that sophisticated cosmetic compositions are generally not conceivable without the customary auxiliaries and additives. These include for example consistency enhancers, fillers, dyes, emulsifiers, additional active substances such as vitamins or proteins, light stabilizers, stabilizers, insect repellents, alcohol, water, salts, EDTA, antimicrobial, proteolytic or keratolytic substances, etc., the addition of potential allergens being of course preferably avoided.

[0146] Mutatis mutandis, corresponding requirements apply to the formulation of medicinal preparations.

[0147] Allergy-triggering substances, such as urushiols, are intercepted by the peptides of the invention consisting of 2-10 amino acids, wherein at least one amino acid has one or more reactive side chains. This barrier effect of the peptides, particularly in preparations for topical application, results in a novel form of antiallergic therapy.

Example Preparations

[0148] The numerical values are contents by weight based on the total mass of the preparation.

TABLE-US-00009 1 2 3 4 INCI m [%] m [%] m [%] m [%] Caprylic/Capric Triglyceride 4.00 4.00 4.00 4.00 Cetyl Alcohol 3.00 3.00 3.00 3.00 Aqua + Trisodium EDTA 1.00 1.00 1.00 1.00 BHT 0.05 0.05 0.05 0.05 Phenoxyethanol 0.80 0.80 0.80 0.80 Hydrogenated Coco-Glycerides 2.00 2.00 2.00 2.00 Glycerol 7.50 7.50 7.50 7.50 Aqua + Sodium Hydroxide 0.01 0.01 0.01 0.01 Alcohol Denat. + Aqua 4.00 4.00 4.00 4.00 Xanthan Gum 0.30 0.30 0.30 0.30 Acrylates/C10-30 Alkyl Acrylate Crosspolymer 0.20 0.20 0.20 0.20 Glyceryl Stearate Citrate 2.00 2.00 2.00 2.00 Dicaprylyl Ether 4.00 4.00 4.00 4.00 Aqua to 100 to 100 to 100 to 100 Ac-RFAACAA 0.25 - - 0.2 GSH - 1 - - Ac-RFAALAA - - 0.4 0.1