Use of l-aspartate

Abstract

The invention provides the cosmetic use of L-aspartate in a cosmetic skin care composition as an active ingredient for increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual. The invention also provides L-aspartate, for use in increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual.

Description

[0001] P0000665 CPL 1 USE OF L-ASPARTATE Field of the Invention 5 The present invention relates to the use of L-aspartate for increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual. Background of the Invention 10 The stratum corneum (SC) contains layers of corneocytes embedded in a lipid matrix which is made up of a unique complex mixture of polar and nonpolar lipids that, unlike biological membranes, is almost devoid of phospholipids. Its main components are ceramides, cholesterol, and free fatty acids (predominantly long-chain and saturated) which are organized 15 into specific lamellar structures whose integrity depends not only on the quality of the fractions present but also on their respective proportions. The integrity of the SC is the primary determinant of the skin’s barrier function. Niacinamide, also known as nicotinamide, is a water-soluble B-complex vitamin which is the 20 amide isotype of vitamin B3 (VB3). It is a precursor to the cofactors nicotinamide adenine dinucleotide (NAD) and NADP. The reduced forms, NADH and NADPH, are potent intracellular antioxidants. NAD and NADP are the primary mediators in cell redox reactions and prevent the protein glycation mechanism that occurs when sugars crosslink with proteins. 25 Studies in the dermatological field have shown that niacinamide has the potential to play numerous beneficial roles in skin, especially ageing skin. Such roles include increasing the antioxidant capacity of skin, improving epidermal barrier function by upregulating the synthesis of ceramides and stimulating keratinocyte differentiation, decreasing epidermal hyperpigmentation by reducing melanosome transfer from melanocytes to keratinocytes, and 30 reducing fine lines and wrinkles by increasing synthesis of collagen and barrier layer proteins such as keratin, filaggrin, and involucrin. Acne vulgaris is also purported to improve following topical niacinamide application, owing to a combination of anti-inflammatory action and reduction of sebum production. 35 Evidently it is important to be able to stimulate the synthesis of niacinamide to allow it to carry out the important roles for which it is responsible. P0000665 CPL 2 The present invention addresses this problem. of the Invention 5 The invention provides the cosmetic use of L-aspartate in a cosmetic skin care composition as an active ingredient for increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual. 10 The invention also provides L-aspartate, for use in increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual. Detailed Description of the Invention 15 As used herein, “cosmetic skin care” means regulating and / or improving cosmetic qualities of the skin, as opposed to curing, treating, or preventing a disease or disorder. Accordingly, such cosmetic qualities are subject to regulation and / or improvement both in healthy subjects as well as those which present diseases or disorders of the skin such as psoriasis, lichen planus, folliculitis, or atopic dermatitis. 20 Examples of cosmetic skin care benefits in the context of this invention include providing a smoother, more even texture; improving the elasticity or resiliency of the skin; improving the firmness of the skin; improving the hydration status or moisturization of the skin; improving skin barrier properties; and reducing the appearance of redness or skin blotches. 25 As used herein, “skin” is understood as the layers which comprise it, from the uppermost layer or stratum corneum to the lowermost layer or hypodermis, both inclusive. These layers are composed of different types of cells such as keratinocytes, fibroblasts, melanocytes, mastocytes, neurons, and adipocytes. The term “skin” also comprises the scalp. Preferably the 30 term “skin” as used herein denotes the epidermis and more preferably the stratum corneum of the epidermis. As used herein, the term “resident commensal” denotes a microbe which can normally be found on healthy human skin, whose interactions on the skin are either neutral or beneficial, and 35 which are permanent inhabitants on the surface of the skin, the stratum corneum and within the outer layer of the epidermis and the deeper crevices of the skin and hair follicles. Microbial P0000665 CPL 3 colonization is differentially shaped by the physiological and topological variation of the skin, and varies systematically among different skin habitats, such as between dry, moist, and sebaceous skin. Resident commensal microbes are characterized in that they can grow and multiply on the skin without invading or damaging the skin tissue. Another characteristic of 5 these microbes is that washing does not easily remove them in deeper skin regions. Examples of resident skin commensal microbes in the context of this invention, which are involved in the biosynthesis of niacinamide, include members of the species Lactobacillus crispatus. L.crispatus is one of the earliest colonizers of the skin after birth and is one of the 10 most prevalent lactobacilli on healthy adult skin. L-aspartate may be used as the sole active ingredient for increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual. Alternatively, a mixture of L-aspartate with L-valine may be used as said active ingredient. 15 Particularly good results have been observed when L-aspartate is used as the sole active ingredient. Compositions for use in the invention can be formulated in a variety of forms for topical 20 application and will generally contain from about 0.01 to about 10%, preferably from about 0.1 to about 5% of L-aspartate (by weight based on the total weight of the composition), in a cosmetically acceptable vehicle. The term “cosmetically acceptable” in the context of this invention means that the vehicle is 25 suitable for topical application to the skin, has good aesthetic properties and will not cause any ingredient compatibility, safety, or toxicity concerns. Suitable cosmetically acceptable vehicles may comprise an aqueous phase, an oil phase, an alcohol, a silicone phase, or a mixture thereof, and may be in the form of an emulsion. 30 Emulsions can have a range of consistencies including thin lotions (which may also be suitable for spray or aerosol delivery), creamy lotions, light creams, and heavy creams. Exemplary emulsions include water-in-oil emulsions, oil-in-water emulsions, silicone-in-water emulsions, water-in-silicone emulsions, polyol-in-silicone emulsions, silicone-in-polyol35 emulsions, polyol-in-oil emulsions, oil-in-polyol emulsions, wax-in-water emulsions, and water- P0000665 CPL 4 oil-water triple emulsions. Preferred emulsions include oil-in-water emulsions and water-in-oil emulsions. Compositions in the form of an emulsion, and suitable for use in the invention, typically have an 5 oil phase containing one or more cosmetically acceptable fatty materials which may be liquid or solid at room temperature (25°C). Suitable cosmetically acceptable fatty materials include naturally derived oils (such as sunflower oil, borage oil, soybean oil, castor oil, olive oil and almond oil); esters of monoalcohols or of 10 polyols with monocarboxylic or polycarboxylic acids, at least one of the alcohols and / or acids comprising at least one hydrocarbon-based chain containing at least 6 carbon atoms (such as octyl palmitate, isopropyl myristate, isopropyl palmitate, isopropyl isostearate, hexyl laurate, isohexyl laurate, isohexyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, dihexyldecyl adipate, lauryl lactate, myristyl lactate, cetyl lactate, oleyl stearate, oleyl 15 oleate, oleyl myristate, lauryl acetate, cetyl propionate, isononyl isononanoate, propylene glycol dicaprate, diisopropyl adipate, dibutyl adipate, and oleyl adipate); ethers (such as dicapryl ether); fatty alcohols (such as cetyl alcohol, stearyl alcohol and behenyl alcohol); isoparaffins (such as isooctane, isododecane and isohexadecane); silicone oils (such as dimethicones, cyclic silicones, and polysiloxanes); and hydrocarbon oils (such as mineral oil, petrolatum and 20 polyisobutene); fatty acids containing from 8 to 30 carbon atoms, (such as stearic acid, lauric acid, palmitic acid and oleic acid); vegetable fats (such as cocoa butter, coconut oil, palm oil and shea butter); petroleum-based, natural and synthetic waxes (such as lanolin wax, beeswax, carnauba wax, candelilla wax, paraffin wax, lignite wax, microcrystalline waxes, ceresin, ozokerite, and polyethylene waxes); hydrogenated oils which are solid at 25° C (such as 25 hydrogenated castor oil, hydrogenated jojoba oil, hydrogenated palm oil, hydrogenated tallow and hydrogenated coconut oil);and fatty esters that are solid at 25°C (such as C20-40alkyl stearate). Compositions in the form of an emulsion, and suitable for use in the invention, typically have an 30 aqueous phase, which may also include one or more organic liquids that are miscible with water at room temperature (25°C). Exemplary water-miscible organic liquids include monohydric and polyhydric alcohols and derivatives thereof such as C2-C6alkanols (such as ethanol and isopropanol); C2-C10glycols and polyols (such as glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, caprylyl glycol, dipropylene glycol, and diethylene glycol); C3- 35 C16glycol ethers (such as mono-, di-, or tripropylene glycol (C1-C4) alkyl ethers and mono-, di-, P0000665 CPL 5 or triethylene glycol (C1-C4) alkyl ethers) and polyethylene glycol having 2 to 12 oxyethylene units. Compositions in the form of an emulsion, and suitable for use in the invention, generally include 5 surface active ingredients, such as emulsifiers and solubilizers, to enable two or more immiscible components to be combined homogeneously and to help stabilize the composition. Emulsifiers that may be used to form O / W or W / O emulsions include sorbitan oleate, sorbitan sesquioleate, sorbitan isostearate, sorbitan trioleate, PEG-20 sorbitan isostearate, polyglyceryl- 3-diisostearate, polyglycerol esters of oleic / isostearic acid, polyglyceryl-6 hexaricinolate, 10 polyglyceryl-4-oleate, polyglyceryl-4 oleate / PEG-8 propylene glycol cocoate, polyglyceryl-2 dipolyhydroxystearate, PEG-30 dipolyhydroxystearate, oleamide DEA, TEA myristate, TEA stearate, magnesium stearate, sodium stearate, potassium laurate, potassium ricinoleate, sodium cocoate, sodium tallowate, potassium castorate, sodium oleate, cetyl phosphate, diethanolamine cetyl phosphate, potassium cetyl phosphate, sodium glyceryl oleate phosphate, 15 dimethicone copolyol, cetyl dimethicone copolyol, octyldimethicone ethoxyglucoside copolyol, dimethicone copolyol crosspolymer and laurylmethicone copolyol. Compositions for use in the invention may also be formulated in a single-phase carrier such as a hydrophobic or hydrophilic liquid. Suitable hydrophobic liquid carriers include liquid 20 polyorganosiloxanes, mineral oils, hydrogenated polyisobutene, polydecene, paraffins and isoparaffins of at least 10 carbon atoms, aliphatic or aromatic ester oils (such as isopropyl myristate, lauryl myristate, isopropyl palmitate, diisopropyl sebacate, diisopropyl adipate and C12to C15alkyl benzoates), polyglycol ethers (such as polyglycol butanol ethers) and mixtures thereof. Suitable hydrophilic liquid carriers include water, monohydric or polyhydric aliphatic 25 alcohols having 2 to 8, preferably 2 or 3 carbon atoms (such as ethanol and isopropanol, oligoglycol ethers having 2 to 5 repeat units (such as dipropylene glycol) and mixtures thereof. Liquid form compositions for use in the invention may be thickened, for example using one or more water soluble or colloidally water-soluble polymeric thickening agents. Suitable water 30 soluble or colloidally water-soluble polymeric thickening agents include hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polyquaternium-10, carrageenan, guar gum, hydroxypropyl guar gum, xanthan gum, polyvinylalcohol, acrylic acid / ethyl acrylate copolymers, carboxyvinyl polymers, cross-linked polyacrylate polymers and polyacrylamide polymers. 35 Solid form compositions for use in the invention, such as gels and sticks, generally include one or more structurants, in an amount ranging from about 1% to about 35% (by weight based on P0000665 CPL 6 the total weight of the composition), depending upon the desired product consistency. Examples of structurants include fatty acid gelling agents selected from saturated fatty acids or hydroxy acids containing from about 8 to 30 carbon atoms and their salts, esters or amides (such as sodium and potassium stearate, 12-hydroxystearic acid, esters of 12-hydroxystearic 5 acid and amides of 12-hydroxystearic acid); saturated, unsubstituted monohydric fatty alcohols containing from about 8 to 30 carbon atoms (such as cetyl alcohol, myristyl alcohol and stearyl alcohol); acyl amino acid derivatives such as N-lauroyl-L-glutamic acid di-n-butylamide; amide derivatives of di or tribasic carboxylic acids such as alkyl N,N′ dialkylsuccinimide; inorganic particulate thickening agents selected from siliceous and alumino-siliceous materials (such as 10 fumed silicas, bentonites, hectorites, colloidal magnesium aluminum silicates and organoclays such as stearalkonium bentonite, disteardimonium hectorite, quaternium 90-bentonite), quaternium-18 bentonite and quaternium-18 hectorite); and petroleum-based, natural and synthetic waxes (such as lanolin wax, beeswax, carnauba wax, candelilla wax, castor wax, montan wax, paraffin wax, lignite wax, microcrystalline waxes, ceresin, ozokerite, 15 polymethylene and polyethylene waxes). Combinations of any of the above-described materials or product forms may also be used. Compositions for use in the invention may include additional skin care actives for improving the 20 physical and / or aesthetic characteristics of the skin. Examples of additional skin care actives include vitamins, minerals and / or antioxidants, skin anti-hyperpigmentation agents, sunscreens, anti-irritants, exfoliating agents, and mixtures thereof. 25 Suitable vitamins, minerals and / or antioxidants include natural botanical antioxidants derived from plant materials such as fruits, vegetables, herbs and spices (such as goji berry, white tea, rosemary, green tea, grape seed and lemongrass extracts); vitamin A and its precursors or derivatives (such as beta-carotene, retinyl palmitate); vitamin B5 and its precursors or 30 derivatives (such as panthenol and its precursors or derivatives); vitamin C and its precursors or derivatives (such as tetrahexyldecyl ascorbate, ascorbyl palmitate); vitamin E and its precursors or derivatives (such as d-alpha-tocopherol, tocopheryl acetate); vitamin K and its precursors or derivatives; selenium and its derivatives (such as L-selenomethionine); and alpha lipoic acid. 35 Suitable skin anti-hyperpigmentation agents include natural botanical agents derived from plant materials (such as Arctostaphylos patula and Arctostaphylos viscida extracts, Emblica officinalis P0000665 CPL 7 extract, Mitracarpus scaber extract, Uva ursi (bearberry) extract, Morus bombycis (mulberry) extract, Morus alba (white mulberry) extract, Broussonetia papyrifera (paper mulberry) extract, licorice extract, acerola cherry extract, Chlorella vulgaris extract, Aloe ferrox extract and Rumex occidentalis extract); synthetic or natural sugar amines (such as glucosamine, N-acetyl 5 glucosamine, glucosamine sulfate, mannosamine, N-acetyl mannosamine, galactosamine, N- acetyl galactosamine and their hydrochloride salts); retinoids (such as retinol, retinal, retinoic acid and C2-20esters of retinol such as retinyl palmitate, retinyl acetate, retinyl propionate, retinyl linoleate and retinyl oleate); kojic acid and C2-20esters thereof (such as kojic acid monobutyrate, kojic acid monocaprate, kojic acid monopalmitate, kojic acid monostearate and 10 kojic acid monobenzoate); hydroquinone, hydroquinone monomethyl ether, hydroquinone monoethyl ether, hydroquinone monobenzyl ether, α and β-arbutin, deoxyarbutin (4- [(tetrahydro-2H-pyran-2-yl)oxy]phenol), mequinol (4-hydroxyanisole), glutathione, cysteine, N- acetyl-L-cysteine, azelaic acid, magnesium ascorbyl phosphate, sodium ascorbyl phosphate, peroxides (such as hydrogen peroxide, zinc peroxide, sodium peroxide and benzoyl peroxide); 15 3-aminotyrosine, glycyrrhizinic acid and 4-substituted resorcinol derivatives (such as 4-methyl resorcinol, 4-ethyl resorcinol, 4-propyl resorcinol, 4-isopropyl resorcinol, 4-butyl resorcinol, 4- pentyl resorcinol, 4-hexyl resorcinol, 4-heptyl resorcinol, 4-octyl resorcinol, 4-nonyl resorcinol, 4- decyl resorcinol, 4-undecyl resorcinol, 4-dodecyl resorcinol, 4-cyclopentyl resorcinol, 4- cyclohexyl resorcinol, 4-cycloheptyl resorcinol, and 4-cyclooctyl resorcinol). 20 Suitable sunscreens protect the skin from ultraviolet (UV) solar radiation falling within both the UVB region (between 290nm to 320 nm wavelengths) and the UVA region (between 320nm and 400nm wavelengths). Examples of sunscreens include methoxycinnamate derivatives (such as octyl methoxycinnamate and isoamyl methoxycinnamate); camphor derivatives (such as 4- 25 methyl benzylidene camphor, camphor benzalkonium methosulfate, and terephthalylidene dicamphor sulfonic acid); salicylate derivatives (such as octyl salicylate and homosalate); sulfonic acid derivatives (such as phenylbenzimidazole sulfonic acid); benzone derivatives (such as dioxybenzone, sulisobenzone, and oxybenzone); benzoic acid derivatives (such as aminobenzoic acid and octyldimethyl para-amino benzoic acid); octocrylene, diethylhexyl 30 butamido triazone, octyl triazone, butyl methoxydibenzoyl methane, drometrizole trisiloxane, menthyl anthranilate and inorganic UV-absorbing particles (such as zinc oxide and titanium dioxide). Suitable anti-irritants include allantoin, aloe vera, α-bisabolol, caffeine, chamomile extract, Cola 35 nitada extract, cucumber extract, dipotassium glycyrrhizinate, glycyrrhizic acid, green tea extract, lecithin or hydrogenated lecithin, licorice extract, Avena sativa (oat) meal extract, tea P0000665 CPL 8 tree oil, salicylic acid, acetylsalicylic acid, strontium acetate, strontium chloride, strontium nitrate, fatty acids with anti-irritant properties (such as linoleic acid and linolenic acid) and aromatic aldehydes with anti-irritant properties (such as 4-methoxy benzaldehyde, 4-ethoxy benzaldehyde, 4-butoxy benzaldehyde and 4-pentoxy benzaldehyde). 5 Suitable exfoliating agents include benzoyl peroxide, benzoic acid, 3-hydroxy benzoic acid, salicylic acid, acetic acid, trichloroacetic acid, 1-pyrrolidone-5-carboxylic acid, α-hydroxy acids (such as glycolic acid, lactic acid, malic acid, tartaric acid, and citric acid); β-hydroxy acids (such as β-hydroxybutyric acid); α-keto acids (such as pyruvic acid, 2-oxopropanoic acid, 2- 10 oxobutanoic acid and 2-oxopentanoic acid); and oxa acids (such as 3,6,9-trioxaundecanedioic acid). Mixtures of any of the above-described materials may also be used. 15 Compositions for use in the invention may also include additional functional ingredients for improving the physical and / or aesthetic characteristics of the composition. Examples of suitable additional functional ingredients include water soluble or colloidally water soluble polymeric thickening agents (such as hydroxyethyl cellulose, methyl cellulose, 20 hydroxypropyl methyl cellulose, polyquaternium-10, carrageenan, guar gum, hydroxypropyl guar gum, xanthan gum, polyvinylalcohol, acrylic acid / ethyl acrylate copolymers, carboxyvinyl polymers, cross-linked polyacrylate polymers and polyacrylamide polymers); structurant clays (such as magnesium aluminum silicate, attapulgite, bentonite, montmorillonite and hectorite); inorganic pigments (such as titanium oxide, zirconium oxide, cerium oxide zinc oxide, iron 25 oxide, chromium oxide and ferric blue); organic pigments (such as carbon black and barium, strontium, calcium, and aluminum lakes); pearlescent agents (such as mica coated with titanium oxide and / or iron oxide); dyes, preservatives (such as disodium EDTA, benzyl alcohol, methylparaben, phenoxyethanol, propylparaben, ethylparaben, butylparaben and isobutylparaben); pH adjusters and fragrances. 30 Mixtures of any of the above-described materials may also be used. P0000665 CPL 9 Packaging Compositions for use in the invention may be packaged in a suitable container to suit its viscosity and intended use by the consumer. For example, a lotion or a cream can be packaged 5 in a bottle or a roll-ball applicator, or a propellant-driven aerosol device or a container fitted with a pump suitable for finger operation. When the composition is a cream, it can simply be stored in a non-deformable bottle or squeeze container, such as a tube or a lidded jar. Use 10 Suitably, in carrying out the use of this invention, the composition as defined above is applied to the desired region of treatment of the skin. Generally, an amount corresponding to about 1 to 2 ml of the composition is applied uniformly over the desired region of treatment of the skin, once or twice daily for a period of at least 7 (seven) days, preferably at least 30 (thirty) days. 15 The invention will be further illustrated by the following, non-limiting Example.

[0002] P0000665 CPL 10 EXAMPLE Biosynthesis of niacinamide by resident commensal microbes 5 L-aspartate and L-valine were evaluated for their ability to promote the production of niacinamide by the following bacteria: Staphylococcus epidermidis1, S. hominis2& Lactobacillus crispatus3. These are examples of resident commensal microbes which may be found on healthy human skin. 10 Staphylococcus epidermidis NCTC12228 Staphylococcus hominis NCTC 11320 Lactobacillus crispatus DSM20584 15 Test bacterial inoculums were prepared in recommended growth media for up to 48 hours at 37°C under aerobic(1 & 2)& anaerobic conditions(3). Inoculums were centrifuged and resuspended in 0.1M MOPS buffer. This procedure was repeated and then the inoculums were adjusted to an optical density (OD) at 600nm of 7. 20 Each reaction consists of 4ml 0.27M MOPS buffer, 2ml 16% glucose and 2ml test substrate of either 200mM L-aspartate, 200mM L-valine, or a mix of 100mM L-valine & 100mM L-aspartate prepared in sterile distilled water, and a 0.8ml aliquot of bacterial inoculum. Growth controls were included where sterile distilled water replaced the test substrates. 25 The tubes were incubated at 37°C for 24 hours under aerobic(1 & 2)& anaerobic conditions(3). Tubes were centrifuged and the supernatants removed and filtered using a 0.22µM filter and syringe. Three technical replicates were prepared for each tube. Samples were analyzed via high-perform ance liquid chrom atography(HPLC).30 The following Table 1 shows the production of niacinamide by the tested bacterial species after incubation with valine, aspartate, and a mix of the two substrates. 35 P0000665 CPL 11 Table 1 Substrate S. epidermidis S. hominis L. crispatus Average Average Average Std Dev Std Dev Std Dev (ng / ml) (ng / ml) (ng / ml) No substrate2.332 0.048 1.523 0.144 2.155 0.103L-valine1.383 0.138 0.931 0.088 1.721 0.081L-aspartate1.023 0.125 0.986 0,177 6.174 0.276L-aspartate / L-valine0.818 0.242 0.845 0.027 3.826 0.0925 It can be seen from the results that L. crispatus shows elevated niacinamide production with the addition of aspartate (p=<0.0001) and valine / aspartate mix (p=<0.0001) compared to the control. Niacinamide production was significantly higher with the addition of aspartate compared to the valine / aspartate mix (p=<0.0001) 10 By contrast, neither S. epidermidis or S. hominis show elevated niacinamide production when supplemented with L-valine or L-aspartate or L-aspartate / L-valine mix. The following Table 2 illustrates a skin care composition for use in the present invention. 15

[0003] P0000665 CPL 12 Table 2 Skin Cream Ingredient wt.% (a.i.) Stearic acid 17 Potassium stearate 3 Polyoxyethylene lauryl ether 2 4-tert-butyl-4′-methoxydibenzoylmethane 1.2 Octyl methoxycinnamate 2.4 Acrylates / Steareth-20 methacrylate copolymer 1 sc-FOS(1)1 L-aspartate 0.2 Water, fragrance, preservative, pH adjuster, chelating agent to 100 5 (1)Actilight® 950P (ex Beghin-Meiji Industries, France)

Claims

P0000665 CPL 13 Claims 1. The cosmetic use of L-aspartate in a cosmetic skin care composition as an active ingredient for increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual, in which the L-aspartate is the sole active ingredient for increasing the biosynthesis of niacinamide by resident commensal microbes on the skin of an individual which are members of the species Lactobacillus crispatus. .