Anti-grey hair care compositions

Abstract

The invention provides a hair care composition comprising: (i) taxifolin glucoside; (ii) N-acetyl tyrosine; (iii) at least one lipid PPAR [alpha] activator. The invention also provides uses and methods including the hair care composition of the invention.

Description

[0001]HAIR CARE COMPOSITIONS Field of the Invention The present invention relates to a hair care composition, particularly an anti-grey hair care composition. Background of the Invention As a person ages, the appearance of hair can become less desirable. Hair greying and canities is a common sign of aging. Hair also loses its elasticity, becomes thinner and more fragile. Further, hair follicle diameter and hair number can also decrease giving a sparse appearance to the scalp. To many consumers, maintaining colouring of hair and good thickness, volume and hair count is a way to alleviate the signs of aging. Many people chose to colour their hair to disguise age-related greying or whitening of the hair. However, colouring of hair does not help disguise other age-related changes in hair quality. Instead, conversely, chemical hair dyes are known to lead to increased damage of the hair over time. To this end, EP3873483A1 describes a hair care active agent comprising taxifolin glucoside and N- acetyl tyrosine which can provide some reduction in the occurrence of grey and white hair in an individual. In EP3873483A1 it was found that the hair care active agent on average reduced the mean number of white hairs by 17% after 4 months. However, despite this prior art, there is still a long felt need to provide consumers with compositions that provide effective reduction in age-related functional changes in hair pigmentation. It is also required to provide a composition which is also able to reduce or prevent other detrimental changes in hair associated with aging. Surprisingly, it has been found that when taxifolin glucoside and N-acetyl tyrosine are combined with a lipid peroxisome proliferator-activated receptor (PPAR) [alpha] activator according to the invention, an effective reduction in age-related functional changes of hair pigmentation can be achieved, while also providing a beneficial improvement in further hair characteristics associated with aging. Particularly, surprisingly it has been found that when taxifolin glucoside and N-acetyl tyrosine are combined with a lipid PPAR [alpha] activator according the invention, the antioxidant activity of a hair care composition can be improved and the oxidative stress of melanocytes in the scalp / hair follicle can be reduced. Improvements in antioxidant activity of melanocytes are linked to a reduction and / or delay in grey hair formation. Oxidative stress is known to damage melanocytes leading to the greying of hair. Enhancing antioxidant activity helps neutralize reactive oxygen species (ROS), reducing oxidative damage to melanocytes and grey hair formation. Also, by boosting antioxidant defences, melanocytes and their precursor cells in the hair follicles in the scalp can be better protected from oxidative stress. This protection helps maintain the melanocytes’ function, longevity and sustain melanin production for longer. Improved antioxidant activity is also known to be linked to restoration of pigmentation in grey hair due to reduced ROS levels, protection of melanocyte reservoirs, and reactivation of melanogenesis. Further, reducing oxidative stress in the scalp / hair follicle is also associated with improvements in other hair characteristics associated with aging such as a reduction in hair shedding and / or an enhancement of the growth of stronger hair. Summary of the Invention In a first aspect, the invention relates to a hair care composition comprising: (i) taxifolin glucoside; (ii) N-acetyl tyrosine; and (iii) at least one lipid peroxisome proliferator-activated receptor (PPAR) [alpha] activator selected from: C10-C18 saturated fatty acids which preferably are branched, or preferably derivatised with hydroxy groups if straight chain; C10-C20 monounsaturated fatty acids; and C10-C22 polyunsaturated fatty acids. In a further aspect the invention relates to the non-therapeutic use of the hair care composition of the invention for reducing the occurrence of grey or white hairs of an individual, for reducing age- related functional changes in hair pigmentation, for increasing melanin production in grey hair, for increasing cell proliferation, for increasing melanocyte proliferation, for increasing melanosome transfer, for increasing the level and / or activity of tyrosinase, for increasing gene and / or protein expression in pigmentation pathways associated with hair, for increasing the volume of hair, for increasing the thickness of hair, for increasing hair count, for increasing hair strength, for reducing hair fall and / or for hair fibre repair, for improving the health of the scalp, for reducing inflammation of the scalp, for reducing scalp itch, for reducing oxidative stress of the scalp / hair follicle, for reducing oxidized lipid species of the scalp / hair follicle, for improving sebum control, for improving the scalp barrier and / or for improving the microbiome balance of the scalp. In a further aspect the invention relates to a method of reducing the occurrence of grey or white hairs of an individual, reducing age-related functional changes in hair pigmentation, increasing melanin production in grey hair, increasing cell proliferation, increasing melanocyte proliferation, for increasing melanosome transfer, increasing the level and / or activity of tyrosinase and / or increasing gene and / or protein expression in pigmentation pathways associated with hair, increasing the volume of hair, increasing the thickness of hair, increasing hair count, increasing hair strength, reducing hair fall, providing hair fibre repair, improving the health of the scalp, reducing inflammation of the scalp, reducing scalp itch, reducing oxidative stress of the scalp / hair follicle, reducing oxidized lipid species of the scalp / hair follicle, improving sebum control, improving the scalp barrier and / or improving the microbiome balance of the scalp, said method comprising applying to scalp or hair, the hair care composition of the present invention. Preferably, the invention provides the non-therapeutic use of the hair care composition of the invention for reducing oxidative stress in melanocytes. Preferably, melanocytes in the hair follicle and / or scalp. Preferably, the invention provides the non-therapeutic use of the hair care composition of the invention for reducing oxidized lipid species on the scalp. Preferably, the invention provides a method for reducing oxidative stress in melanocytes. Preferably, melanocytes in the hair follicle and / or scalp, said method comprising applying to scalp or hair, the hair care composition of the present invention. Preferably, the invention provides a method for reducing oxidized lipid species on the scalp. said method comprising applying to scalp or hair, the hair care composition of the present invention. Surprisingly, the combination of ingredients of the hair care composition of the invention provide a reduction in the occurrence of grey or white hairs of an individual. In some embodiments, the ingredients of the hair care composition provide a synergistic reduction of grey or white hairs of an individual. In some embodiments the combination of ingredients of the hair care composition of the invention provide a reduction in age-related functional changes in hair pigmentation. In some embodiments, the ingredients of the hair care composition provide a synergistic reduction in age- related functional changes in hair pigmentation. For example, beneficially, the hair care composition of the invention can provide increased melanin production such as a synergistic increase in melanin production. The hair care composition of the invention beneficially provides an increase in cell proliferation such as an increase in melanocyte proliferation such as a synergistic increase in melanocyte proliferation. The hair care composition of the invention beneficially provides improved transfer of melanosomes from melanocytes to keratinocytes such as a synergistic improvement in the transfer of melanosomes from melanocytes to keratinocytes. The hair care composition of the invention beneficially provides increased levels and / or activity of tyrosinase such as a synergistic increase in the levels and / or activity of tyrosinase. Further, the hair care composition of the invention can beneficially provide increased gene and / or protein expression in pigmentation pathways (e.g. MITF, QYR, TYRP1, MSH, MC1R) such as a synergistic increase in gene and / or protein expression in pigmentation pathways. The beneficial effects of the hair care composition of the invention described above can surprisingly lead to a high level of observable reduction in age-related functional changes of hair pigmentation and / or the occurrence of grey or white hairs of an individual. In addition to reducing age related functional changes in hair pigmentation, the combination of ingredients of the hair care composition of the invention also provides beneficial improvements of other age-related hair characteristics. For example, the hair care composition of the invention can provide a beneficial increase in volume of the hair such as a synergistic increase in volume of the hair. The hair care composition of the invention can provide a beneficial increase in the thickness of the hair such as a synergistic increase in the thickness of the hair. The hair care composition of the invention can provide a beneficial increase in hair count such as a synergistic increase in hair count of the hair. The hair care composition of the invention can provide a beneficial increase in the strength of the hair / reduce hair fall such as a synergistic increase in the strength of the hair / reduction in hair fall. The hair care composition of the invention may also provide observable fibre repair such as a synergistic fibre repair. In addition to reducing age related functional changes in hair pigmentation, the combination of ingredients of the hair care composition of the invention also provides beneficial improvements in the health of the scalp. For example, the hair care composition of the invention can provide a beneficial reduction in inflammation of the scalp such as a synergistic reduction in inflammation of the scalp. The hair care composition of the invention may also provide a beneficial reduction in scalp itch. The hair care composition of the invention may also provide beneficial scavenging of reactive oxygen species (ROS) resulting in a reduction of oxidative stress of the scalp / hair follicle such as a synergistic reduction in oxidative stress of the scalp / hair follicle. The hair care compositions of the invention may also provide a beneficial reduction of oxidized lipid species of the scalp / hair follicle such as a synergistic reduction of oxidized lipid species of the scalp / hair follicle. The hair care compositions of the invention may also provide a beneficial improved sebum control such as a synergistic improved sebum control. The hair care compositions of the invention may also provide a beneficial improvement in the scalp’s health and barrier properties such as a synergistic improvement in the scalp’s health and barrier properties. The hair care composition may also provide a beneficial improvement in the microbiome balance of the scalp, such as a synergistic improvement in the microbiome balance of the scalp. Description of the Invention Aspects and embodiments of the present invention will now be discussed. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference. In the present invention the term "extract" refers to any isolated substance obtained by extraction from a raw material. The extract is obtained, for example, by dissolving a raw material in a solvent(s) e.g. water or alcohol followed by concentration and / or purification of the substances isolated from the raw material, for example, by evaporation of the solvents. (i) Taxifolin glucoside The composition of the invention comprises taxifolin glucoside. Preferably, at least part of the taxifolin glucoside is taxifolin alpha-D-glucoside. A suitable method of preparing taxifolin alpha-D-glucoside is described in WO 2007 / 144368. In a preferred embodiment, the hair care composition of the present invention further comprises taxifolin. A mixture of taxifolin and taxifolin glucoside may be prepared, for instance, by stopping the reaction according to WO 2007 / 144368 prior to full conversion, e.g. after about half of the taxifolin has been converted to obtain a roughly 1 : 1 mixture. Taxifolin glucoside and taxifolin may be present in a weight ratio of from 100:0 to about 40:60. Preferably the weight ratio of taxifolin glucoside to taxifolin is from 90:10 to 40:60, more preferably from 70:30 to 50:50, and most preferably about 60:40. The amount of taxifolin glucoside in the hair care composition of the present invention may be, for instance, from 0.0001% to 0.50% of the total weight of the composition, more preferably from 0.0005% to 0.025% of the total weight of the composition, more preferably 0.0007% to 0.009% of the total weight of the composition, such as 0.0009% to 0.007% of the total weight of the composition, for example 0.001% to 0.004% of the total weight of the composition, such as 0.001 to 0.002% of the total weight of the composition. In the hair care composition of the present invention, part of the taxifolin glucoside may be replaced by taxifolin. In particular, up to 60% of taxifolin glucoside may be replaced by taxifolin, preferably up to 50%, and even more preferably up to 40%. In some embodiments, the taxifolin glucoside and / or taxifolin of the invention may be derived from Larix Europaea Wood. For example, the taxifolin glucoside and / or taxifolin may be included in a Larix Europaea Wood Extract. The amount of Larix Europaea Wood Extract in the composition, for instance, is from 0.0001% to 0.1% of the total weight of the composition, more preferably from 0.001% to 0.01% of the total weight of the composition, and most preferably from 0.002% to 0.008% of the total weight of the composition. Preferably, the ratio of PPAR activator to larix europaea wood extract is from 1:0.0001 to 1:1, more preferably, the ratio of PPAR activator to larix europaea wood extract is from 1:0.0005 to 1:0.1, more preferably from 1:0.001 to 1:0.01. In some embodiments the ratio of PPAR activator to larix europaea wood extract is from 1:0.001 to 1:0.008. (ii) N-acetyl tyrosine The composition of the invention comprises N-acetyl tyrosine. The amount of N-acetyl tyrosine in the hair care composition of the present invention may be, for instance, from 0.01% to 30% of the total weight of the composition, more preferably from 0.05% to 20% of the total weight of the composition, more preferably from 0.1% to 5% of the total weight of the composition, and most preferably from 0.15% to 0.9% of the total weight of the composition, for example 0.15% to 0.4% of the total weight of the composition. In the hair care composition of the present invention, the weight ratio of taxifolin glucoside to N- acetyl tyrosine is preferably from 1:500 to 1:1, more preferably from 1:300 to 1:50, and most preferably from 1:200 to 1:100, for example about 1:150. Compositions comprising taxifolin glucoside and / or N-acetyl tyrosine may be as described in e.g. EP3873483A1 (incorporated herein by reference). Taxifolin glucoside and / or N-acetyl tyrosine may also be provided to the composition of the invention by the commercial material DarkenylTMavailable from Givaudan. (iii) An activator of a peroxisome proliferator-activated receptor The hair care composition of the invention comprises an activator of a peroxisome proliferator- activated receptor. The term "activator of a peroxisome proliferator activated receptor” means a compound, preferably a lipid, that activates the nuclear receptor PPAR. In the invention, the PPAR receptor activated is of sub-type [alpha]. The PPAR [alpha] activator is a lipid. Peroxisome proliferator activated receptors are a known family of nuclear hormone receptors having three subtypes, [alpha], [beta], [gamma], of varying tissue distribution. Peroxisome proliferator activated receptors subtype [alpha] (hereinafter referred to as PPAR [alpha]) are present in skin. Lipid activators of PPAR [alpha] such as linoleic acid are well known in the art. These have been shown to accelerate skin epidermal barrier development in vitro (Hanley et al,(1997) J.Clin.Inv 100,705-712). However, there is no disclosure or suggestion in the art of activators of PPAR [alpha] having use in cosmetic compositions in hair care compositions to reduce the age-related functional changes in hair described above. An established and widely accepted method by which PPAR activation can be demonstrated and thus by which lipid activators of PPARs can be identified is the reporter gene assay. Lipids that are activators of PPAR [alpha] are thus easily identifiable by those skilled in the art as those compounds which cause expression of luciferase or chloramphenicol acetyl transferase (hereinafter referred to as CAT) in a reporter gene assay the full protocol of which is provided by Kliewer et al. (1992) Nature, 358, 771-774. Thus if a lipid compound passes this in vitro reporter gene assay, that is it causes expression of luciferase or CAT in the reporter gene assay, it is a lipid PPAR [alpha] activator. In a preferred embodiment of the invention, the lipid PPAR [alpha] activator is a compound which promotes activation of the reporter gene at least 2-fold above background levels. The lipid PPAR [alpha] activators which satisfy the reporter gene assay test is selected from C10- C18 saturated fatty acids which preferably are branched, or preferably derivatised with hydroxy groups if straight chain, C10-C20 monounsaturated fatty acids and C10-C22 polyunsaturated fatty acids. The fatty acids may be straight or branched chain, saturated or unsaturated and may be substituted e.g. hydroxylated such as alpha hydroxy or beta hydroxy derivatives. The corresponding alcohols, triglycerides and phospholipids of any of those acids are also suitable for use in the present invention. Preferable derivatives include those derived from substitution of the carboxyl group of the acid, such as esters (e.g. triglyceride esters, monoglyceride esters, diglyceride esters, phosphoesters), amides (e.g. ceramide derivatives), salts (e.g. alkali metal and alkali earth metal salts, ammonium salts). In the case of triglyceride ester derivatives, all positional isomers on the glycerol backbone are included. Oils that are rich in fatty acid triglyceride are thus also suitable for use in the present invention. Such oils are commercially available and include coriander seed (rich in petroselinic acid), parsley seed oil (rich in petroselinic acid), evening primrose oil, (rich in gamma linolenic acid), borage seed oil (rich in gamma linolenic acid), Shea butter (rich in oleic and linoleic acid), fish oils and their concentrates (rich in DHA and EPA), cramb oil (rich in erucic acid) linseed oil (rich in alpha linolenic acid), almond oil (rich in oleic acid) and cotton seed oil (rich in linoleic acid). Preferable PPAR [alpha] activators according to the invention are 12-hydroxystearic acid, cis parinaric acid, trans-7-octadecenoic acid, cis 5,8,11,14,17 eicosapentanoic acid, cis-4,7,10,13,16,19 docosahexenoic acid, cojugated, linoleic acid (c9,t11), columbinic acid, linolenelaidic acid, ricinolaidic acid, stearidonic acid, 2-hydroxystearic acid, alpha-linolenic acid, arachidonic acid, cis- 11,14-eicosadienoic acid, conjugated linoleic (t10,c12), conjugated linoleic acid (t9,t11), conjugated linoleic acid (50:50 mix of c9, t11 and t10 c12), coriander acids, linolelaidic acid, monopetroselinic acid, petroselinic acid, ricinoleic acid, stearolic acid, thuja extract or trans vaccenic acid. Even other PPAR activators suitable for use include cis-11,14,17 eicosatrienoic acid, cis-5 eicosenoic acid, cis-8,11,14 eicosatrienoic acid, hexadecatrienoic acid, palmitoleic acid, petroselaidic acid, trans trans farnesol, cis 13, 16 docosadienoic acid, cis vaccenic acid, cis-11 eicosenoic acid, cis-13,16,19 docosatrienoic acid, cis-13-octadecenoic acid, cis-15-octadecanoic acid, cis-7,10,13,16 docosatetraenoic acid, elaidic acid, gamma-linolenic acid, geranic acid, geranyl geranoic acid, linoleic acid, oleic acid, petroselinyl alcohol, phytanic acid, pinolenic acid, trans-13- octadecenoic acid or tridecyl salicylic acid (TDS). Still other PPAR activators suitable for use include biochanin A (red clover phytoestrogen), chromolaena odorata extract, pomegranate saponifiable hydrolysable extract, buglossoides (stearidonic plant extract) or zanthalene (extract from Sichuan peppercorn), whereby it is within the scope of the invention to use a mixture of any of the herein noted PPAR activators. In an embodiment of the invention, the lipid PPAR [alpha] activator is petroselinic acid, conjugated linoleic acid, 12-hydroxystearic acid, ricinoleic acid or a mixture thereof. In the most preferable embodiment of the invention, the lipid PPAR [alpha] activator is 12- hydroxystearic acid. Typically, the lipid PPAR [alpha] activator will make up from 0.0001 to 8.0%, such as from 0.0002 to 8.0%, preferably from0.05 to 8.0% and preferably, from 1 to 6%, and most preferably, from 1.5 to 4.5% by weight of the composition. In an embodiment of the invention, the composition will have from 1.5 to 4%, and in still another embodiment, from 1.5 to 3.5% by weight of the PPAR activator. Typically, 12-hydroxystearic acid will make up from 0.0001 to 8.0%, such as from 0.0002 to 8.0%, preferably from 0.05 to 8.0% and preferably, from 1 to 6%, and most preferably, from 0.5 to 4.5% by weight of the composition. In an embodiment of the invention, the composition will have from 0.8 to 4%, and in still another embodiment, from 1 to 3% by weight 12-hydroxystearic acid. Preferably, the weight ratio of the lipid PPAR [alpha] activator to N-acetyl tyrosine is from 1:0.01 to 1:5, more preferably the weight ratio of the PPAR activator to N-acetyl tyrosine is from 1:0.02 to 1:3 more preferably from 1:0.05 to 1:1. In some embodiments the weight ratio of the PPAR activator to N-acetyl tyrosine is from 1:0.06 to 1:0.2. Preferably, the weight ratio of the lipid PPAR [alpha] activator to taxifolin glucoside is from 1:0.00001 to 1:1, more preferably, the weight ratio of the PPAR activator to taxifolin glucoside is from 1:0.0001 to 1:0.1, more preferably from 1:0.0002 to 1:0.01. In some embodiments the weight ratio of the PPAR activator to taxifolin glucoside is from 1:0.0005 to 1:0.002. Preferably, the weight ratio of 12-hydroxystearic acid to N-acetyl tyrosine is from 1:0.01 to 1:5, more preferably the weight ratio of 12-hydroxystearic acid to N-acetyl tyrosine is from 1:0.02 to 1:3 more preferably from 1:0.05 to 1:1. In some embodiments the weight ratio of 12-hydroxystearic acid to N- acetyl tyrosine is from 1:0.06 to 1:0.2. Preferably, the weight ratio of 12-hydroxystearic acid to taxifolin glucoside is from 1:0.00001 to 1:1, more preferably, the weight ratio of 12-hydroxystearic acid to taxifolin glucoside is from 1:0.0001 to 1:0.1, more preferably from 1:0.0002 to 1:0.01. In some embodiments the weight ratio of 12- hydroxystearic acid to taxifolin glucoside is from 1:0.0005 to 1:0.002. In an alternative preferred embodiment, the hair care composition comprises: (i) taxifolin glucoside; (ii) N-acetyl tyrosine; and (iii) 12-hydroxystearic acid. In a preferred embodiment, the hair care composition comprises: (i) 0.0005% to 0.25% taxifolin glucoside; (ii) 0.05% to 20% N-acetyl tyrosine; and (iii) 0.0001% to 3% of 12-hydroxystearic acid. In a preferred embodiment, the hair care composition comprises: (i) 0.0005% to 0.25% taxifolin glucoside; (ii) 0.05% to 20% N-acetyl tyrosine; and (iii) 0.01% to 3% of 12-hydroxystearic acid. Most preferably, the hair care composition comprises: (i) 0.0007% to 0.009% taxifolin glucoside; (ii) 0.1% to 5% N-acetyl tyrosine; and (iii) 0.1% to 2% of 12-hydroxystearic acid. Product Format and Other Ingredients The hair care composition of the present invention may further comprise other beneficial active agents, such as, for example, Zinc salts. Zinc can act as an inhibitor of enzymes associated with hair loss. Therefore, inhibition of the enzyme can contribute beneficially to reduction of hair fall or hair loss effects. Zinc salts suitable for use in the invention include zinc sulfate, zinc gluconate, zinc chloride, zinc pyrithione or combinations thereof. Preferably, the composition comprises zinc sulfate, zinc glutonate, zinc chloride or combinations thereof. More preferably, the compositions comprises zinc glutonate, zinc chloride or combinations thereof. Most preferably, the composition comprises zinc chloride. The amount of zinc salt in the hair care composition of the present invention maybe, for instance, from 0.00001% to 5% of the total weight of the composition, and preferably in an amount of from 0.0001% to 3% of the total weight of the composition, more preferably in an amount of from 0.001% to 1% of the total weight of the composition, more preferably in an amount of from 0.01% to 0.1% of the total weight of the composition, most preferably in a concentration of from 0.01% to 0.05% of the total weight of the composition, for example up to 0.03%. Compositions for use in the invention (as described above) may include additional actives for improving the physical and / or aesthetic characteristics of the scalp and / or the hair. Examples include amino acids, vitamins, minerals and / or antioxidants, emollients, humectants, sunscreens, anti-irritants, exfoliating agents, botanical extracts (such as pomegranate, white birch, green tea, chamomile and licorice extracts) and mixtures thereof, preservatives (such as sodium benzoate, potassium sorbate, phenoxyethanol, pentylene glycol and sodium metabisulfite), pH adjusters and fragrances (such as essential oils, flower oils, natural extracts from resins, gums, balsams, beans, mosses and other plants, as well as synthetic aromatic materials). In some embodiments, preferably the composition of the invention further comprises a thickening agent. Suitable thickening agents are selected from polyacrylic acids, cross-linked polymers of acrylic acid, copolymers of acrylic acid with a hydrophobic monomer, copolymers of carboxylic acid- containing monomers and acrylic esters, cross-linked copolymers of acrylic acid and acrylate esters, heteropolysaccharide gums and crystalline long chain acyl derivatives. The long chain acyl derivative is desirably selected from ethylene glycol stearate, alkanolamides of fatty acids having from 16 to 22 carbon atoms and mixtures thereof. Ethylene glycol distearate and polyethylene glycol 3 distearate are preferred long chain acyl derivatives, since these impart pearlescence to the composition. Polyacrylic acid is available commercially as Carbopol 420, Carbopol 488 or Carbopol 493. Polymers of acrylic acid cross-linked with a polyfunctional agent may also be used; they are available commercially as Carbopol 910, Carbopol 934, Carbopol 941 and Carbopol 980. An example of a suitable copolymer of a carboxylic acid containing monomer and acrylic acid esters is Carbopol 1342. All Carbopol (trademark) materials are available from Goodrich. Suitable cross- linked polymers of acrylic acid and acrylate esters are Pemulen TR1 or Pemulen TR2. A suitable heteropolysaccharide gum is xanthan gum, for example that available as Kelzan mu. The hair care composition of the invention may further comprise a penetration enhancer. “Penetration enhancers” can be understood according to the invention as compounds which can penetrate the skin e.g. the scalp to reversible decrease barrier resistance and increase the bioavailability of actives to e.g. the scalp and the hair bulb. In some embodiments, the penetration enhancer is selected from glycols such as polyethylene glycol; phospholipids for example in the form of one or more liposomes, non-ionic emulsifiers such as polysorbate, laurocapram, isohexadecane, dodecane, DMSO, ethanol, decanol, dimethyl isosorbide and / or combinations thereof. In some embodiments, the penetration enhancer is present in amount of between 0.01% to 20% of the total weight of the composition, more preferably at least 0.1%, even more preferably at least 1%, still even more preferably at least 2%, and most preferably at least 6% by weight of the composition. Preferably, the penetration enhancer is present in amount of no greater than 15%, even more preferably no greater than 10%, still even more preferably no greater than 8%, and most preferably no greater than 3% by weight of the composition. In some embodiments the penetration enhancer is selected from ethanol, dimethyl isosorbide or combinations thereof. Preferably, the penetration enhancer is a combination of dimethyl isosorbide and ethanol. In some preferred embodiments the penetration enhancer comprises dimethyl isosorbide. In one embodiment, dimethyl isosorbide is included in an amount of from 0.01 to 10% of the total weight of the composition, or in the alternative of from to 0.1 to 5% of the total weight of the composition, or from 1 to 3% of the total weight of the composition such as 2.5% of the total weight of the composition. In some embodiments the penetration enhancer comprises ethanol. Preferably, the ethanol is present in amount of between 0.01% to 20% of the total weight of the composition, more preferably at least 0.1%, even more preferably at least 1%, still even more preferably at least 2%, and most preferably at least 3% by weight of the composition. Preferably, the ethanol is present in amount of no greater than 15%, even more preferably no greater than 10%, still even more preferably no greater than 8%, and most preferably no greater than 7% by weight of the composition. Preferably, the weight ratio of penetration enhancer to N-acetyl tyrosine is from 1:0.001 to 1:10, more preferably the weight ratio of penetration enhancer to N-acetyl tyrosine is from 1:0.01 to 1:5 more preferably from 1:0.03 to 1:1. In some embodiments the weight ratio of penetration enhancer to N-acetyl tyrosine is from 1:0.1 to 1:0.5. Preferably, the weight ratio of penetration enhancer to taxifolin glucoside is from 1:0.00001 to 1:1, more preferably, the weight ratio of penetration enhancer to taxifolin glucoside is from 1:0.00005 to 1:0.1, more preferably from 1:0.0001 to 1:0.01. In some embodiments the weight ratio of penetration enhancer to taxifolin glucoside is from 1:0.001 to 1:0.005. Preferably, the weight ratio of dimethyl isosorbide to N-acetyl tyrosine is from 1:0.001 to 1:5, more preferably the weight ratio of dimethyl isosorbide to N-acetyl tyrosine is from 1:0.01 to 1:1 more preferably from 1:0.03 to 1:0.1. In some embodiments the weight ratio of dimethyl isosorbide to N- acetyl tyrosine is from 1:0.05 to 1:0.09. Preferably, the weight ratio of dimethyl isosorbide to taxifolin glucoside is from 1:0.00001 to 1:1, more preferably, the weight ratio of dimethyl isosorbide to taxifolin glucoside is from 1:0.00005 to 1:0.1, more preferably from 1:0.0001 to 1:0.01. In some embodiments the weight ratio of dimethyl isosorbide to taxifolin glucoside is from 1:0.002 to 1:0.006. Preferably, the weight ratio of ethanol to N-acetyl tyrosine is from 1:0.0001 to 1:5, more preferably the weight ratio of ethanol to N-acetyl tyrosine is from 1:0.001 to 1:1 more preferably from 1:0.01 to 1:0.5. In some embodiments the weight ratio of ethanol to N-acetyl tyrosine is from 1:0.02 to 1:0.05. Preferably, the weight ratio of ethanol to taxifolin glucoside is from 1:0.00001 to 1:1, more preferably, the weight ratio of ethanol to taxifolin glucoside is from 1:0.00005 to 1:0.1, more preferably from 1:0.0001 to 1:0.01. In some embodiments the weight ratio of ethanol to taxifolin glucoside is from 1:0.001 to 1:0.005. In some embodiments of the invention, the hair care composition further comprises additional antioxidants. For example, the composition of the present invention may further comprise epigallocatechin gallate and / or epigallocatechin gallatyl glucoside. Epigallocatechin gallate (EGCG, also known as epigallocatechin-3-gallate) is the ester of epigallocatechin and gallic acid, and is a type of catechin. Epigallocatechin gallate may aid hair growth. A suitable method of preparing epigallocatechin gallatyl alpha-D-glucoside is described in WO 2007 / 144368. Epigallocatechin gallatyl glucoside may be used in an amount of from 0.00001 to 0.60 wt%, more preferably from 0.00010 to 0.060 wt%, and most preferably from 0.00015 to 0.0045 wt%. Sources of epigallocatechin gallate and / or epigallocatechin gallatyl glucoside which can be included in the composition of the invention include Camellia Sinensis Leaf Extract. Preferably, the amount of Camellia Sinensis leaf Extract in the hair care composition of the present invention maybe, for instance, from 0.0001% to 1% of the total weight of the composition, and preferably in an amount of from 0.0005% to 0.1% of the total weight of the composition, more preferably in an amount of from 0.0009% to 0.01% of the total weight of the composition, more preferably in an amount of from 0.0009% to 0.005% of the total weight of the composition. In a preferred embodiment, the hair care composition of the invention comprises glycine. Glycine may be used in a concentration of from 0.001% to 0.50% of the total weight of the composition, more preferably from 0.001% to 0.30% of the total weight of the composition, and most preferably from 0.001% to 0.008% of the total weight of the composition. In some embodiment of the invention, the composition comprises in one or more cosmetically or pharmaceutically acceptable solvents such as, glycerol, propylene glycol, butylene glycol, ethoxylated or propoxylated diglycols, propanol, or isopropanol to help solubilise the active components of the composition. In some embodiment, the hair care composition comprises a first active component and a second active component. The first active component and the second active component may be blended optionally with further ingredients and components to form the hair care composition of the invention. In some embodiments, the first active component comprises: (i) taxifolin glucoside; and (ii) N-acetyl tyrosine. The amount of taxifolin glucoside in the first active component may be, for instance, from 0.01% to 0.50% of the total weight of the first active component, more preferably from 0.05% to 0.25% of the total weight of the first active component, and most preferably from 0.07% to 0.15% of the total weight of the first active component, for example about 0.10% of the total weight of the first active component. The ratio of taxifolin glucoside to taxifolin in the first active component may be as described above for the total hair care composition. In some embodiments, the taxifolin glucoside and / or taxifolin of the first active component may be derived from Larix Europaea Wood. For example, the taxifolin glucoside and / or taxifolin may be included in a Larix Europaea Wood Extract. The amount of Larix Europaea Wood Extract in the first active component may be, for instance, from 0.01% to 0.1% of the total weight of the first active component, more preferably from 0.05% to 0.8% of the total weight of the first active component, and most preferably from 0.1% to 0.7% of the total weight of the first active component, for example about 0.55% of the total weight of the first active component. The amount of N-acetyl tyrosine in the hair care active agent of the present invention may be, for instance, from 1.0% to 30% of the total weight of the first active component, more preferably from 10% to 20% of the total weight of the first active component, and most preferably from 15% to 20% of the total weight of the first active component, for example about 17.5%. The first active component may comprise glycine. For instance, glycine may be used in an amount of from 0.01% to 1% of the total weight of the first active component, more preferably from 0.10% to 0.80% of the total weight of the first active component, and most preferably from 0.20% to 0.60% of the total weight of the first active component, for example about 0.55% of the total weight of the first active component. The first active component may comprise Camellia Sinensis Leaf Extract. For instance, Camellia Sinensis Leaf Extract may be included in an amount of from 0.01% to 1.5% of the total weight of the first active component, more preferably from 0.05% to 1% of the total weight of the first active component, and most preferably from 0.08% to 0.5% of the total weight of the first active component, for example about 0.1% of the total weight of the first active component. The first active component may comprise epigallocatechin gallatyl glucoside. For instance, epigallocatechin gallatyl glucoside may be included in an amount of from 0.001% to 0.60% of the total weight of the first active component, more preferably from 0.010% to 0.060% of the total weight of the first active component, and most preferably from 0.015% to 0.045% of the total weight of the first active component, for example about 0.03% of the total weight of the first active component. The first active component may comprise preservatives such as sodium metabisulfite. For instance, preservative may be included in an amount of from 0.01% to 1.00% of the total weight of the first active component, more preferably from 0.10% to 0.750% of the total weight of the first active component, and most preferably from 0.45% to 0.55% of the total weight of the first active component, for example about 0.50% of the total weight of the first active component. In some embodiments, the first active component may comprise zinc salts, preferably zinc chloride. For instance, zinc salts may be included in an amount of from 0.01% to 1% of the total weight of the first active component, more preferably from 0.05% to 0.5 % of the total weight of the first active component, and most preferably from 0.08% to 0.2% of the total weight of the first active component, for example about 0.1% of the total weight of the first active component. The first active component may comprise a one or more cosmetically or pharmaceutically acceptable solvents such as, glycerol, propylene glycol, butylene glycol, ethoxylated or propoxylated diglycols, ethanol, propanol, or isopropanol to help solubilise the active components of the ingredients of the first active component. For instance, glycerol may be included in an amount of from 1% to 95% of the total weight of the first active component, more preferably from 10% to 80% of the total weight of the first active component, and most preferably from 20% to 60% of the total weight of the first active component, for example about 50% of the total weight of the first active component. The first active component may be present in the hair care composition in an amount of 0.001% to 20% of the total weight of the composition, for instance, in an amount of from 0.005% to 10% of the total weight of the composition, more preferably from 0.01% to 5% of the total weight of the composition, more preferably from 0.1% to 3% of the total weight of the composition, and most preferably from 0.5% to 2% of the total weight of the composition, for example about 1% of the total weight of the composition. The first active component may be provided e.g. as the commercial material DarkenylTMavailable from Givaudan. In some embodiments, the second active component comprises: (iii) at least one lipid PPAR [alpha] activator selected from: C10-C18 saturated fatty acids which preferably are branched, or preferably derivatised with hydroxy groups if straight chain; C10-C20 monounsaturated fatty acids; and C10-C22 polyunsaturated fatty acids. The PPAR activator is as defined above. The hair care compositions of the invention are primarily intended for application to the hair and / or scalp of a human subject in order to improve hair properties. Preferably, the hair care composition is selected from a rinse-off hair composition, a hair mask, a leave-on hair care composition, and a pre-treatment hair care composition, and most preferably selected from a rinse-off hair composition, a hair mask and a leave-on composition. The treatment composition is preferably a leave-on hair care composition. The hair care compositions of the invention may also be a "rinse-off " compositions to be applied to the hair and then, in part, rinsed away. Rinse off composition for use in the invention are typically left on wet hair for 1 to 2 minutes before being rinsed off. Typically, from about 1g to about 50g of the composition is applied to the hair or scalp. Hair masks for use in the present invention are treatments that are typically left on the hair for 3 to 10 minutes, preferably from 3 to 5 minutes, more preferably 4 to 5 minutes, before being rinsed off. Leave-on compositions for use in the invention are typically applied to the hair and left on the hair for more than 10 minutes, and preferably are applied to the hair after washing and not rinsed out until the next wash. The hair care compositions of the invention will generally comprise from about 20% to about 95% of water, preferably at least 30%, more preferably at least 40%, still more preferably at least 50%, even more preferably at least 60% or even at least 70%, but typically not more than 94%, preferably not more than 93%, more preferably not more than 92%, still more preferably not more than 91%, even more preferably not more than 90% or even not more than 80% by weight based on total weight. Other organic solvents may also be present, such as lower alkyl alcohols and polyhydric alcohols. Examples of lower alkyl alcohols include C1 to C6 monohydric alcohols such as ethanol and isopropanol. Examples of polyhydric alcohols include propylene glycol, hexylene glycol, glycerin, and propanediol. Mixtures of any of the above-described organic solvents may also be used. Preferably, the composition comprises polyhydric alcohol. Polyhydric alcohols may be selected from group of glycerin, propylyene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1,3-butylene glycol, isoprene glycol, ethoxylated glycerol, propoxylated glycerol or a mixture thereof. Most preferred polyhydric alcohol is glycerol known also as glycerin. The amount of polyhydric alcohol may range anywhere from 0.1 to 20%, preferably 0.5 to 15% and more preferably 2 and 10% by weight of the composition. Uses and Methods In a further aspect, the present invention relates to the non-therapeutic use of the hair care composition of the present invention. In some embodiments, the present invention relates to the non-therapeutic use of the hair care composition of the present invention for reducing the occurrence of grey or white hairs in of an individual, for reducing age-related functional changes in hair pigmentation, for increasing melanin production in grey hair, for increasing cell proliferation, for increasing melanocyte proliferation, for increasing the level and / or activity of tyrosinase, for increasing gene and / or protein expression in pigmentation pathways associated with hair. In some embodiment, the present invention relates to the non-therapeutic use of the hair care composition of the present invention for reducing age related functional change in hair pigmentation and for increasing the volume of hair, for increasing the thickness of hair, for increasing hair count, for increasing hair strength, for reducing hair fall and / or for fibre repair. In some embodiment, the present invention relates to the non-therapeutic use of the hair care composition of the present invention for reducing age related functional change in hair pigmentation and for improving the health of the scalp, for reducing inflammation of the scalp, for reducing scalp itch, for reducing oxidates stress of the scalp / hair follicle, for reducing oxidized lipid species of the scalp / hair follicle, for improving sebum control, for improving the scalp barrier and / or for improving the microbiome balance of the scalp. In some embodiments, the current invention relates to the non-therapeutic use of the hair care composition of the invention for reducing oxidative stress in melanocytes. Preferably, melanocytes in the hair follicle and / or scalp. In some embodiments, the present invention relates to a hair care composition of the present invention for use in reducing the occurrence of grey or white hairs in of an individual, for reducing age-related functional changes in hair pigmentation, for increasing melanin production in grey hair, for increasing cell proliferation, for increasing melanocyte proliferation, for increasing the level and / or activity of tyrosinase, for increasing gene and / or protein expression in pigmentation pathways associated with hair. In some embodiment, the present invention relates to a hair care composition of the present invention for use in reducing age related functional change in hair pigmentation and for increasing the volume of hair, for increasing the thickness of hair, for increasing hair count, for increasing hair strength, for reducing hair fall and / or for fibre repair. In some embodiment, the present invention relates to ta hair care composition of the present invention for use in reducing age related functional change in hair pigmentation and for improving the health of the scalp, for reducing inflammation of the scalp, for reducing scalp itch, for reducing oxidates stress of the scalp / hair follicle, for reducing oxidized lipid species of the scalp / hair follicle, for improving sebum control, for improving the scalp barrier and / or for improving the microbiome balance of the scalp. In some embodiments, the current invention relates to a hair composition for use in reducing oxidative stress in melanocytes. Preferably, melanocytes in the hair follicle and / or scalp. In a further aspect, the present invention relates to methods of treatment comprising the hair care composition of the present invention. In some embodiments, the present invention relates to a method of reducing the occurrence of grey or white hairs in of an individual, of reducing age-related functional changes in hair pigmentation, increasing melanin production in grey hair, increasing cell proliferation, increasing melanocyte proliferation, increasing the level and / or activity of tyrosinase and / or increasing gene and / or protein expression in pigmentation pathways associated with hair; said method comprising applying the hair care composition of the present invention to the hair or scalp. In some embodiment, the present invention relates to a method of reducing age-related functional changes in hair pigmentation and to a method of increasing the volume of hair, increasing the thickness of hair, increasing hair count, increasing hair strength, reducing hair fall and / or providing fibre repair; said method comprising applying the hair care composition of the present invention to the hair or scalp. In some embodiment, the present invention relates to a method of reducing age-related functional changes in hair pigmentation and to a method of improving the health of the scalp, reducing inflammation of the scalp, reducing oxidative stress of the scalp / hair follicle, reducing oxidized lipid species of the scalp / hair follicle, improving sebum control, improving the scalp barrier and / or for improving the microbiome balance of the scalp; said method comprising applying the hair care composition of the present invention to the hair or scalp. In some embodiments, the invention relates to a method of reducing oxidative stress in melanocytes said method comprising applying to hair or scalp the hair care composition of the invention. Preferably, melanocytes in the hair follicle and / or scalp. The invention also surprisingly shows that inclusion of 12-hydroxystearic acid (12-HSA) in a hair care composition without a further active provides improved antioxidant activity compared to a control. Thus, in a further aspect of the invention, provided is the non-therapeutic use of 12-hydroxystearic acid for reducing the occurrence of grey or white hairs in of an individual, for reducing age-related functional changes in hair pigmentation, for increasing melanin production in grey hair. In some embodiment, the present invention relates to the non-therapeutic use of 12-hydroxystearic acid for reducing age related functional change in hair pigmentation and for increasing the volume of hair, for increasing the thickness of hair, for increasing hair count, for increasing hair strength, for reducing hair fall and / or for fibre repair. In some embodiment, the present invention relates to the non-therapeutic use of 12-hydroxystearic acid of the present invention for reducing age related functional change in hair pigmentation and for improving the health of the scalp, for reducing inflammation of the scalp, for reducing scalp itch, for reducing oxidates stress of the scalp / hair follicle, for reducing oxidized lipid species of the scalp / hair follicle. In some embodiments, the current invention relates to the non-therapeutic use of 12-hydroxystearic acid for reducing oxidative stress in melanocytes. Preferably, melanocytes in the hair follicle and / or scalp. In some embodiments, the present invention relates to 12-hydroxystearic acid for use in reducing the occurrence of grey or white hairs in of an individual, for reducing age-related functional changes in hair pigmentation, for increasing melanin production in grey hair, for increasing cell proliferation, for increasing melanocyte proliferation, for increasing the level and / or activity of tyrosinase, for increasing gene and / or protein expression in pigmentation pathways associated with hair. In some embodiment, the present invention relates to 12-hydroxystearic acid for use in reducing age related functional change in hair pigmentation and for increasing the volume of hair, for increasing the thickness of hair, for increasing hair count, for increasing hair strength, for reducing hair fall and / or for fibre repair. In some embodiment, the present invention relates to 12-hydroxystearic acid for use in reducing age related functional change in hair pigmentation, for improving the health of the scalp, for reducing inflammation of the scalp, for reducing scalp itch, for reducing oxidates stress of the scalp / hair follicle, for reducing oxidized lipid species of the scalp / hair follicle. In some embodiments, the current invention relates to 12-hydroxystearic acid for use in reducing oxidative stress in melanocytes. Preferably, melanocytes in the hair follicle and / or scalp. In a further aspect, the present invention relates to methods of treatment comprising 12- hydroxystearic acid. In some embodiments, the present invention relates to a method of reducing the occurrence of grey or white hairs in of an individual, of reducing age-related functional changes in hair pigmentation, increasing melanin production in grey hair, increasing cell proliferation, increasing melanocyte proliferation, increasing the level and / or activity of tyrosinase and / or increasing gene and / or protein expression in pigmentation pathways associated with hair; said method comprising applying 12- hydroxystearic acid to the hair or scalp. In some embodiment, the present invention relates to a method of reducing age-related functional changes in hair pigmentation and to a method of increasing the volume of hair, increasing the thickness of hair, increasing hair count, increasing hair strength, reducing hair fall and / or providing fibre repair; said method comprising applying 12-hydroxystearic acid to the hair or scalp. In some embodiment, the present invention relates to a method of reducing age-related functional changes in hair pigmentation and to a method of improving the health of the scalp, reducing inflammation of the scalp, reducing oxidative stress of the scalp / hair follicle, reducing oxidized lipid species of the scalp / hair follicle; said method comprising applying 12-hydroxystearic acid to the hair or scalp. In some embodiments, the invention relates to a method of reducing oxidative stress in melanocytes said method comprising applying to hair or scalp 12-hydroxystearic acid. Preferably, melanocytes in the hair follicle and / or scalp. The features disclosed in the foregoing description, or in the following claims, as appropriate, may separately, or in any combination of such features, be utilised for realising the invention. While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention. For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations. Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise” and “include”, and variations such as “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example + / - 10%. The invention will now be further described by reference to the following Examples. All percentages are by weight based on total weight, unless otherwise specified. Examples A vessel was filled with deionized water. Separately, carbomer was dispersed and then added to the vessel ensuring proper hydration is achieved. The vessel was heated to 70-75°C, 12-HSA, and Montanov 68TMwere added to the vessel, then preservatives including pentylene glycol were added until solubilized. The vessel was cooled to room temperature. Once at 35°C or below DarkenylTMwas added with continued mixing. The remaining ingredients where added and mixed. The pH of the solution was then adjusted to 4.5-5.0 using sodium hydroxide and / or citric acid solution as needed. Example 1: Hair Care Lotion Table 1 Ingredient % (w / w) 12-hydroxystearic acid 2% Montanov 68TM(Cetearyl Alcohol and Cetearyl Glucoside) 2% DarkenylTM(Acetyl Tyrosine, Larix Europaea Wood Extract, Glycine, Zinc Chloride, Camellia Sinensis Leaf Extract, Sodium Metabisulfite, Glycerin, 1% Water / Eau / Aqua) Dimethyl isosorbide 2.5% Ethanol 5% Carbomer 0.25% Pentylene Glycol 3% Water / Solvent / Fragrance / Preservatives q.s. Example 2 - Catalase Activity Assay Adult primary human epidermal melanocytes were cultured in melanocyte medium supplemented with melanocyte growth factor mix and antibiotic mix in T75 flasks maintained at 37ºC in a humidified chamber with 5% CO2. Cells were further sub-cultured in microtiter plates at a density of ~5x104 cells / well and incubated at 37ºC in a humidified chamber with 5% CO2as above for 24 hours. After 24 hours, cells were then treated with test materials or combinations of test materials at desired concentrations along with 5µM menadione and further incubated as above for 6hrs. Post incubation cells were assessed for catalase activity using the Catalase Colorimetric Activity Kit. The experiment was run in duplicate (n=2) on 3 different donor cells (n=3). The data was represented as % Catalase activity compared to menadione. Test Material Concentrations in Cell medium: DarkenylTMcontaining taxifolin glucoside / acetyl tyrosine (available from Givaudan) - 0.005% 12-hydroxystearic acid (12-HSA) - 0.00024% Statistical analysis For every test, data was shown as a percent difference from a menadione treated control using an average of two replicates across three distinct experiments. T-test statistical significance was performed for comparisons against menadione control vs respective treatment. For identification of synergistic combinations, a T-test statistical significance was performed by comparing combination data against individual data using JMP. For a combination to be termed synergistic, the combination should exhibit statistical significance over all individuals. Table 2 Average %Catalase Treatment SE T.test Synergy activity (N=3) Control 122 1.86 0.0003 N / A Menadione 5µM100 N / AMenadione +DarkenylTM(taxifolin 109 3.51 0.0625 N / A glucoside / N-acetyl tyrosine) Menadione +12-HSA 108 6.30 0.2961 N / A Menadione +12-HSA+ DarkenylTM(taxifolin 146 12.55 0.02097 Synergistic glucoside / N-acetyl tyrosine) Menadione induces oxidative stress in melanocytes by generating reactive oxygen species (ROS). The antioxidant effect of the test materials on melanocyte cells stressed with menadione was assessed by comparing the catalase activity of treated and untreated stressed cells. An enhancement in catalase activity indicates an increased ability for cells to reduce oxidative stress. Surprisingly, the catalase activity of cells treated with taxifolin glucoside and N-acetyl tyrosine in combination with 12-HSA showed a statistically significant synergistic increase in catalase activity compared to untreated stressed cells and stressed cells treated with one or two actives only. The catalase activity was also improved compared to the activity in unstressed control cells. The experiments indicate that compositions comprising the combination of the actives taxifolin glucoside, N-acetyl tyrosine and 12-HSA are effective at reducing oxidative stress in melanocytes of the hair follicle associated with unwanted greying of hair and age associated hair changes. Example 3 - Dichlorofluorescin Diacetate (DCFDA) Assay Adult primary human epidermal melanocytes were cultured in melanocyte medium supplemented with melanocyte growth factor mix and antibiotic mix in T75 flasks maintained at 37ºC in a humidified chamber with 5% CO2. Cells were further sub-cultured in microtiter plates at a density of ~5x104cells / well and incubated at 37ºC in a humidified chamber with 5% CO2as above for 24 hours. After 24 hours, cells were then treated with test materials or combinations of test materials at desired concentrations along with 5µM menadione and further incubated as above for 6hrs. Post incubation, cells were assessed for ROS levels by incubating the cells for 45 mins in DCFDA dye. The cells were then washed, and the fluorescence was measured at Excitation: 485nm and emission 535nm. The experiment was run in duplicate (n=2) on 3 different donor cells (n=3). The data was represented as % ROS levels compared to menadione. Test Material Concentrations in Cell medium: DarkenylTMcontaining taxifolin glucoside / acetyl tyrosine (available from Givaudan) - 0.005% 12-hydroxystearic acid (12-HSA) - 0.00024% Statistical analysis For every test, data was shown as a percent difference from a menadione treated control using an average of two replicates across three distinct experiments. T-test statistical significance was performed for comparisons against menadione control vs respective treatment. Table 3 Average %ROS Treatment SE T.test levels (N=3) Control 79 2.11 0.0006 Menadione 5µM 100Menadione +DarkenylTM(taxifolin 75 1.94 0.0002 glucoside / N-acetyl tyrosine) Menadione +12-HSA 70 3.61 0.0011 Menadione induces oxidative stress in melanocytes by generating reactive oxygen species (ROS). The antioxidant effect of the test materials on melanocyte cells stressed with menadione was assess using a dichlorofluorescin diacetate assay to identify the level of reactive oxygen species in the treated and untreated stressed cells. A reduction in ROS level indicates an increased ability for the actives to reduce oxidative stress in cells. Surprisingly, the ROS level of cells treated with 12-HSA showed a statistically significant reduction in ROS levels compared to untreated stressed cells. The ROS level was also reduced compared to the ROS level in unstressed control cells. The experiments indicate that compositions comprising 12-HSA are effective at reducing oxidative stress in melanocytes of the hair follicle associated with unwanted greying of hair and age associated hair change.

Claims

CLAIMS 1. A hair care composition comprising: (i) taxifolin glucoside; (ii) N-acetyl tyrosine; and (iii) at least one lipid peroxisome proliferator-activated receptor (PPAR) [alpha] activator selected from: C10-C18 saturated fatty acids which preferably are branched, or preferably derivatised with hydroxy groups if straight chain; C10-C20 monounsaturated fatty acids; and C10-C22 polyunsaturated fatty acids.

2. A hair care composition according to any of the preceding claims wherein the lipid PPAR [alpha] activator is selected from 12-hydroxystearic acid, cis parinaric acid, trans-7- octadecenoic acid, cis 5,8,11,14,17 eicosapentanoic acid, cis-4,7,10,13,16,19 docosahexenoic acid, conjugated linoleic acid (c9,t11), columbinic acid, linolenelaidic acid, ricinolaidic acid, stearidonic acid, 2-hydroxystearic acid, alpha-linolenic acid, arachidonic acid, cis-11,14-eicosadienoic acid, conjugated linoleic (t10,c12), conjugated linoleic acid (t9,t11), conjugated linoleic acid (50:50 mix of c9, t11 and t10 c12), coriander acids, linolelaidic acid, monopetroselinic acid, petroselinic acid, ricinoleic acid, stearolic acid, thuja extract or trans vaccenic acid, cis-11,14,17 eicosatrienoic acid, cis-5 eicosenoic acid, cis- 8,11,14 eicosatrienoic acid, hexadecatrienoic acid, palmitoleic acid, petroselaidic acid, trans trans farnesol, cis 13, 16 docosadienoic acid, cis vaccenic acid, cis-11 eicosenoic acid, cis- 13,16,19 docosatrienoic acid, cis-13-octadecenoic acid, cis-15-octadecanoic acid, cis- 7,10,13,16 docosatetraenoic acid, elaidic acid, gamma-linolenic acid, geranic acid, geranyl geranoic acid, linoleic acid, oleic acid, petroselinyl alcohol, phytanic acid, pinolenic acid, trans-13-octadecenoic acid, tridecyl salicylic acid (TDS), biochanin A (red clover phytoestrogen), chromolaena odorata extract, pomegranate saponifiable hydrolysable extract, buglossoides (stearidonic plant extract) or zanthalene (extract from Sichuan peppercorn).

3. A hair care composition according to any of the preceding claims wherein the lipid PPAR [alpha] activator is selected from petroselinic acid, conjugated linoleic acid, 12- hydroxystearic acid, ricinoleic acid or a mixture thereof.

4. A hair care composition according to any of the preceding claims wherein the lipid PPAR [alpha] activator is 12-hydroxystearic acid.

5. A hair care composition according to any of the preceding claims wherein the lipid PPAR [alpha] activator is present in an amount of 0.05 to 8.0% and preferably, from 1 to 6%, and most preferably, from 1.5 to 4.5% by weight of the composition, preferably the composition will have from 1.5 to 4%, more preferably from 1.5 to 3.5% by weight of PPAR activator.

6. A hair care composition according to any of the preceding claims wherein the amount of taxifolin glucoside in the hair care composition is from 0.0001% to 0.50% of the total weight of the composition, more preferably from 0.0005% to 0.25% of the total weight of the composition, more preferably 0.0007% to 0.009% of the total weight of the composition, preferably 0.0009% to 0.007% of the total weight of the composition, most preferably 0.001 to 0.004 wt% of the total weight of the composition.

7. A hair care composition according to any of the preceding claims wherein the amount of N- acetyl tyrosine in the hair care composition is from 0.001% to 30% of the total weight of the composition, preferably from 0.05% to 20% of the total weight of the composition, more preferably from 0.1% to 5% of the total weight of the composition, and more preferably from 0.15% to 0.9% of the total weight of the composition, most preferably 0.15% to 0.4% of the total weight of the composition.

8. A hair care composition according to any of the preceding claims wherein the weight ratio of taxifolin glucoside to N-acetyl tyrosine is preferably from 1 :500 to 1:1, more preferably from 1:300 to 1:50, and most preferably from 1:200 to 1:100, for example about 1:

150.

9. A hair care composition according to any of the preceding claims wherein the weight ratio of the lipid PPAR [alpha] activator to N-acetyl tyrosine is from 1:0.01 to 1:5, more preferably the weight ratio of PPAR activator to N-acetyl tyrosine is from 1:0.02 to 1:3, more preferably from 1:0.05 to 1:1, more preferably, the weight ratio of PPAR activator to N-acetyl tyrosine is from 1:0.06 to 1:0.

2.

10. A hair care composition according to any of the preceding claims wherein , the weight ratio of the lipid PPAR [alpha] activator to taxifolin glucoside is from 1:0.00001 to 1:1, more preferably, the weight ratio of PPAR activator to taxifolin glucoside is from 1:0.0001 to 1:0.1,more preferably from 1:0.0002 to 1:0.01, more preferably, the weight ratio of PPAR activator to taxifolin glucoside is from 1:0.0005 to 1:0.

002.

11. Non-therapeutic use of the hair care composition of any of the preceding claims for reducing the occurrence of grey or white hairs of an individual, for reducing age-related functional changes in hair pigmentation, for reducing oxidative stress of the scalp / hair follicle, for reducing oxidized lipid species of the scalp / hair follicle.

12. Non-therapeutic use of the hair care composition of any one of claims 1-10 for reducing oxidative stress in melanocytes.

13. A method of reducing the occurrence of grey or white hairs of an individual, reducing age- related functional changes in hair pigmentation, reducing oxidative stress of the scalp / hair follicle, reducing oxidized lipid species of the scalp / hair follicle, , said method comprising applying to hair or scalp the hair care composition of any of claims 1-10.

14. A method of reducing oxidative stress in melanocytes said method comprising applying to hair or scalp the hair care composition of any of claims 1-10.

15. Non-therapeutic use of 12-hydroxystearic acid for reducing oxidative stress in melanocytes.