WO2025088021A1

WO2025088021A1 - Cosmetic composition comprising lacto-n-tetraose or lacto-n-neotetraose and hydroxyacetophenone

Info

Publication number: WO2025088021A1
Application number: PCT/EP2024/080043
Authority: WO
Inventors: Christine Mendrok-Edinger
Original assignee: DSM IP Assets BV
Current assignee: DSM IP Assets BV
Priority date: 2023-10-24
Filing date: 2024-10-24
Publication date: 2025-05-01
Anticipated expiration: 2026-04-24

Abstract

The present invention relates to cosmetic compositions comprising a combination of lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and hydroxyacetophenone. Said cosmetic compositions, respectively said combinations show a significant antimicrobial effect on microbes.

Description

DSM IP Assets B.V. 34667-WO-PCT COSMETIC COMPOSITION COMPRISING LACTO-N-TETRAOSE OR LACTO-N- NEOTETRAOSE AND HYDROXYACETOPHENONE Technical Field The present invention relates to the fields of lacto-N-tetraose (LNT) and lacto-N- neotetraose (LNnT) and cosmetic compositions. Background of the invention Microorganisms lead to the decay of food and goods of daily use such as cosmetic compositions, household products, plastics, paper or paints. Particularly, cosmetic products are prone to be attacked by microorganism. The reduction of growth of microorganisms is essential for the consumers safety and health when using a cosmetic product. By reducing the growth of microorganisms, the shelf life of a cosmetic product can be increased. Currently a variety of substances are known to reduce the growth of microorganism. As the use of certain antimicrobial agents are under public discussions a reduction of antimicrobial agents is a strong desire in the cosmetic industry. Furthermore, microorganisms are present spread all over the human body. Microorganisms are also known to play an important role for undesired cosmetic states and, therefore, any method of reducing the growth of undesired microorganisms is highly appreciated. Antimicrobials commonly used in the cosmetic industry are not mainly natural occurring compounds and, therefore, the market is very keen on reducing said artificial antimicrobials by using any naturally occurring antimicrobials, particularly antimicrobials which can be already found in the human body and/or to combine those with existing antimicrobials. Lacto-N-tetraose (LNT) and lacto-N-neotetraose (LNnT) are known human milk oligosaccharides (HMO) and can be found in human milk where they are generally known to benefit the gut microbiome, e.g., by stimulating the growth of beneficial bacteria such as Bifidobacteriaceae. Summary of the invention Therefore, the problem to be solved by the present invention is to offer a cosmetic composition comprising a naturally occurring antimicrobial which is able of reducing efficiently the growth of undesired microbes on the human body. The microbes on the body play an important role in its the aesthetics and appearance of skin and hair. Surprisingly, it has been found that the composition according to claim 1 offers a solution to this problem. Accordingly, in a first aspect the invention provides a cosmetic composition comprising a combination of a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone. In addition, the invention provides a use, preferably a non-therapeutic use, of a mixture of a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone for reducing growth of microbes. It has been particularly observed that the cosmetic composition has an antimicrobial effect on microbes, particularly on the microbes Corynebacterium xerosis, Malassezia furfur, Cutibacterium acnes, Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis, which are typical microbes leading to undesired cosmetic states. In most cases, the reduction of growth of microbes does not lead only to a strong reduction and slower growth but also to a continuous reduction, which finally leads to an elimination of the microbe. Further aspects of the invention are subject of further independent claims. Particularly preferred embodiments are subject of dependent claims. Detailed description of the invention In a first aspect the present invention relates to a cosmetic composition comprising a combination of a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone. In the present document, a “C_x-y-alkyl” group is an alkyl group comprising x to y carbon atoms, i.e., for example, a C_1-3-alkyl group is an alkyl group comprising 1 to 3 carbon atoms. The alkyl group can be linear or branched. For example -CH(CH₃)-CH₂-CH₃ is considered as a C₄-alkyl group. In case identical labels for symbols or groups are present in several formulae, in the present document, the definition of said group or symbol made in the context of one specific formula applies also to other formulae which comprises the same said label. The term "cosmetic composition " refers in the present document to a composition which is applied to the surface of a mammalian keratinous tissue. The cosmetic composition is, hence, a topical composition. The term “keratinous tissue" as used in this document means the skin (body, face, contour of the eyes, scalp), head hair, eyelashes, eyebrows, bodily hairs, nails and/or lips. Preferably, in all embodiments the keratinous tissue is the skin and hair. The term "antimicrobial effect" is used in this document to describe that a substance reduces the growth of microorganisms when said microorganisms are brought in contact with said substance. An “antimicrobial agent” or “antimicrobial” is a substance which has an antimicrobial effect. LNT and LNnT The cosmetic composition comprises lacto-N-tetraose (LNT) or lacto-N- neotetraose (LNnT). Lacto-N-tetraose is a tetrasaccharide composed of four monosaccharide units in the order galactose, N-acetylglucosamine, another galactose, and glucose, joined by "1-3 β-linkages" in a linear chain and has the structure as shown below:

The systematic IUPAC name of LNT is β-D-Galactopyranosyl-(1→3)-2- (acetylamino)-2-deoxy-β-D-glucopyranosyl-(1→3)-β-D-galactopyranosyl-(1→4)-D-glucose and its CAS Number is [14116-68-8]. Often, the structure of LNT is indicated by Gal-(β1- 3)-GlcNAc-( β1-3)-Gal-( β1-4)-Glc Lacto-N-neotetraose (LNnT) is very similar to LNT, as it is also a tetrasaccharide composed of four monosaccharide units in a linear chain and has the structure as shown

The systematic IUPAC name of LNnT is β-D-Galactopyranosyl-(1→4)-2- (acetylamino)-2-deoxy-β-D-glucopyranosyl-(1→3)-β-D-galactopyranosyl-(1→4)-D-glucose and its CAS Number is [13007-32-4]. Often the structure of LNnT is indicated by Gal-(β1- 4)-GlcNAc-(β1-3)-Gal-(β1-4)-Glc. LNT and LNnT are both human milk oligosaccharides (HMO) and can be found in human milk. They can, hence, be isolated from breast milk or they can be produced chemically or biochemically according to methods well known in the art (see for example Bych et al Current Opinion in Biotechnology 2019, 56:130–137). For example, LNT can be commercially obtained from DSM-Firmenich Ltd. under the trade name GlyCare™ LNT 8001, and LNnT under the trade name GlyCare™ LNnT 9000. It is preferred that the amount of lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT) is 0.05 - 6 % by weight, preferably 0.1 - 5 % by weight, more preferably 0.2 - 4 % by weight, based on the total weight of the composition. Especially preferred is a cosmetic composition comprising a combination of a) lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone. As illustrated by the examples such a combination provides an exceptionally good antimicrobial effect. Hydroxyacetophenone Hydroxyacetophenones are a class of compounds which are well known in the field of cosmetic compositions. It is also known that hydroxyacetophenone has some antimicrobial activity. The hydroxyacetophenone is particularly either 2’-hydroxyacetophenone, 3’- hydroxyacetophenone, or 4’-hydroxyacetophenone. Particularly preferred is that the hydroxyacetophenone is 4’- hydroxyacetophenone. It is preferred that the amount of hydroxyacetophenone is 0.01 – 5 % by weight, preferably 0.05 – 4 % by weight, more preferably 0.1 – 3 % by weight, based on the total weight of the composition. Preferred compositions according to the invention are skin care preparations, decorative preparations, and functional preparations. Examples of skin care preparations are, in particular, body oils, body lotions, body gels, treatment creams, skin protection ointments, skin powders, moisturizing gels, moisturizing sprays, face and/or body moisturizers. Examples of decorative preparations are in particular lipsticks, eye shadows, mascaras, dry and moist make-up formulations, rouges and/or powders. Examples of functional preparations are cosmetic or pharmaceutical compositions containing active ingredients such as hormone preparations, vitamin preparations, vegetable extract preparations, anti-ageing preparations, and/or antimicrobial (antibacterial or antifungal) preparations without being limited thereto. The compositions of the invention (including the carrier) may comprise conventional adjuvants and additives, such as preservatives/antioxidants, fatty substances/oils, organic solvents, silicones, thickeners, softeners, emulsifiers, antifoaming agents, aesthetic components such as fragrances, surfactants, fillers, anionic, cationic, nonionic or amphoteric polymers or mixtures thereof, propellants, acidifying or basifying agents, dyes, colorings/colorants, abrasives, absorbents, chelating agents and/ or sequestering agents, essential oils, skin sensates, astringents, pigments or any other ingredients usually formulated into such compositions. In accordance with the present invention, the compositions according to the invention may comprise further ingredients such as ingredients for treatment of hyperpigmentation; preventing or reducing acne, wrinkles, lines, atrophy and/or inflammation; chelators and/or sequestrants; anti-cellulites and slimming (e.g. phytanic acid), firming, moisturizing and energizing, self-tanning, soothing agents, as well as agents to improve elasticity and skin barrier and carriers and/or excipients or diluents conventionally used in compositions. If nothing else is stated, the excipients, additives, diluents, etc. mentioned in the following are suitable for compositions according to the present invention. The necessary amounts of the cosmetic and dermatological adjuvants and additives can, based on the desired product, easily be determined by the skilled person. The additional ingredients can either be added to the oily phase, the aqueous phase or separately as deemed appropriate. The mode of addition can easily be adapted by a person skilled in the art. Examples of cosmetic excipients, diluents, adjuvants, additives as well as active ingredients commonly used in the skin care industry which are suitable for use in the cosmetic compositions of the present invention are for example described in the International cosmetic Ingredient Dictionary & Handbook by Personal Care Product Council, without being limited thereto. The cosmetically active ingredients useful herein can in some instances provide more than one benefit or operate via more than one mode of action. Of course, one skilled in this art will take care to select the above mentioned optional additional ingredients, adjuvants, diluents and additives and/or their amounts such that the advantageous properties intrinsically associated with the combination in accordance with the invention are not, or not substantially, detrimentally affected by the envisaged addition or additions. Preferred compositions in all embodiments of the present invention are emulsions containing an oily phase and an aqueous phase such as in particular an O/W, W/O, Si/W, W/Si, O/W/O, W/O/W multiple or a pickering emulsions. The amount of the oily phase (i.e. the phase containing all oils and fats) present in such emulsions is preferably at least 10 wt.-%, such as in the range from 10 to 60 wt.-%, preferably in the range from 15 to 50 wt.- %, most preferably in the range from 15 to 45 wt.-%, based on the total weight of the composition. According to one even more preferred embodiment, the compositions according to the present invention as outlined herein are O/W emulsions comprising an oily phase dispersed in an aqueous phase in the presence of an O/W emulsifier. The preparation of such O/W emulsions is well known to a person skilled in the art. In one advantageous embodiment, the O/W emulsifier is a phosphate ester emulsifier. Among the preferred phosphate ester emulsifier are C8-10 alkyl ethyl phosphate, C9-15 alkyl phosphate, C20-22 alkyl phosphate, ceteareth-2 phosphate, ceteareth-5 phosphate, ceteth-8 phosphate, ceteth-10 phosphate, cetyl phosphate, C6-10 pareth-4 phosphate, C12-15 pareth-2 phosphate, C12-15 pareth-3 phosphate, DEA- ceteareth-2 phosphate, DEA-cetyl phosphate, DEA-oleth-3 phosphate, potassium cetyl phosphate, deceth-4 phosphate, deceth-6 phosphate and trilaureth-4 phosphate. Particular preferred phosphate ester emulsifiers in all embodiments of the present invention are C8- C25 alkyl phosphates, such as in particular C20-22 alkyl phosphates and cetyl phosphates, and in particular the respective potassium salts thereof. A particular preferred phosphate ester emulsifier according to the invention is potassium cetyl phosphate e.g. commercially available as Amphisol® K at DSM Nutritional Products Ltd Kaiseraugst. Further suitable O/W emulsifiers according to the present invention encompass PEG 30 Dipolyhydroxystearate, PEG-4 Dilaurate, PEG-8 Dioleate, PEG-40 Sorbitan Peroleate, PEG-7 Glyceryl Cocoate, PEG-20 Almond Glycerides, PEG-25 Hydrogenated Castor Oil, Glyceryl Stearate (and) PEG-100 Stearate , PEG-7 Olivate, PEG-8 Oleate, PEG-8 Laurate, PEG-60 Almond Glycerides, PEG-20 Methyl Glucose Sesquistearate, PEG-40 Stearate, PEG-100 Stearate, PEG-80 Sorbitan Laurate, Steareth-2, Steareth-12, Oleth-2, Ceteth-2, Laureth-4, Oleth-10, Oleth-10/Polyoxyl 10 Oleyl Ether, Ceteth-10, Isosteareth-20, Ceteareth-20, Oleth-20, Steareth-20, Steareth-21, Ceteth-20, Isoceteth-20, Laureth-23, Steareth-100, glycerylstearatcitrate, glycerylstearate (self-emulsifying), stearic acid, salts of stearic acid, polyglyceryl-3-methylglycosedistearate. Further suitable emulsifiers are sorbitan oleate, sorbitan sesquioleate, sorbitan isostearate, sorbitan trioleate, Lauryl Glucoside, Decyl Glucoside, Sodium Stearoyl Glutamate, Sucrose Polystearate and Hydrated Polyisobuten. Furthermore, one or more synthetic polymers may be used as an emulsifier. For example, PVP eicosene copolymer, acrylates/C10-30 alkyl acrylate crosspolymer, acrylates/steareth-20 methacrylate copolymer, PEG-22/dodecyl glycol copolymer, PEG- 45/dodecyl glycol copolymer, and mixtures thereof. Another particular suitable class of O/W emulsifiers are non-ionic self-emulsifying system derived from olive oil e.g. known as (INCI Name) cetearyl olivate and sorbitan olivate (Chemical Composition: sorbitan ester and cetearyl ester of olive oil fatty acids) sold under the tradename OLIVEM 1000. Further suitable are commercially available polymeric emulsifiers such as hydrophobically modified polyacrylic acid such as Acrylates/C10-30 Alkyl Acrylate Crosspolymers which are commercially available under the tradename Pemulen® TR-1 and TR-2 by Lubrizol. Another class of particularly suitable emulsifiers are polyglycerol esters or diesters of fatty acids also called polyglyceryl ester/ diester (i.e. a polymer in which fatty acid(s) is/ are bound by esterification with polyglycerine), such as e.g. commercially available at Evonik as Isolan GPS [INCI Name Polyglyceryl-4 Diisostearate/Polyhydroxystearate/Sebacate (i.e. diester of a mixture of isostearic, polyhydroxystearic and sebacic acids with Polyglycerin-4)] or Dehymuls PGPH available at BASF (INCI Polyglyceryl-2 Dipolyhydroxystearate). Also suitable are polyalkylenglycolether such as Brij 72 (Polyoxyethylen(2)stearylether) or Brij 721 (Polyoxyethylene (21) Stearyl Ether e.g. available at Croda. Particularly advantageous O/W emulsifiers according to the present invention are one or more of Polyglyceryl-3 Methylglucose Distearate, Lauryl Glucoside (and) Polyglyceryl-2 Dipolyhydroxystearate, Glyceryl Sterate Citrate, Sodium Cetearyl Sulfate, Cetearyl Glucoside; Polyglyceryl-6 Stearate (and) Polyglyceryl-6 Behenate, Cetearyl Olivate (and) Sorbitan Olivate, Arachidyl Alcohol (and) Behenyl Alcohol (and) Arachidyl Glucosides, Cetearyl Alcohol (and) Coco-Glucoside, Coco-Glucoside (and) Coconut Alcohol, PEG-100 Stearate (and) Glyceryl Stearate, Sodium Stearoyl Glutamate, Steareth- 20, Steareth-21, Steareth-25, Steareth-2, Ceteareth-25 and Ceteareth-6 (all listed by their INCI names). In one embodiment it is particularly preferred in accordance with the invention if the composition comprises a C8-C25 alkyl phosphate, preferably a C20-22 alkyl phosphate and/ or a cetyl phosphate, most preferably a cetyl phosphate such as in particular potassium cetyl phosphate as emulsifier or at least as a co-emulsifier. In another embodiment it is particularly preferred in accordance with the invention if the composition comprises Polyglyceryl-6 Stearate and/ or Polyglyceryl-6 Behenate as emulsifier, preferably in the presence of a cetyl phosphate, more preferably potassium cetyl phosphate as a co-emulsifier. The at least one O/W respectively Si/W emulsifier is preferably used in an amount of 0.5 to 10 wt. % such as in particular in the range of 0.5 to 5 wt.-% such as most in particular in the range of 0.5 to 4 wt.-% or in the range of 0.5 to 3 wt.-%, based on the total weight of the composition. If the phosphate ester emulsifier with all the definitions and preferences as given herein is used as a co-emulsifier, the amount is preferably selected in the range of 0.1 to 1 wt. % such as in particular in the range of 0.25 to 0.75 wt.-% such as most in particular in the range of 0.3 to 0.7 wt.-% or in the range of 0.4 to 0.6 wt.-%, based on the total weight of the composition. Suitable W/O- or W/Si-emulsifiers according to the present invention are polyglyceryl-2-dipolyhydroxystearat, PEG-30 dipolyhydroxystearat, cetyl dimethicone copolyol, polyglyceryl-3 diisostearate polyglycerol esters of oleic/isostearic acid, polyglyceryl-6 hexaricinolate, polyglyceryl-4-oleate, oleate/PEG-8 propylene glycol cocoate, magnesium stearate, sodium stearate, potassium laurate, potassium ricinoleate, sodium cocoate, sodium tallowate, potassium castorate, sodium oleate, and mixtures thereof. Further suitable W/Si-emulsifiers are Lauryl Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone and/or PEG-9 Polydimethylsiloxyethyl Dimethicone and/or Cetyl PEG/PPG- 10/1 Dimethicone and/or PEG-12 Dimethicone Crosspolymer and/or PEG/PPG-18/18 Dimethicone. The at least one W/O emulsifier is preferably used in an amount of about 0.001 to 10 wt.-%, more preferably in an amount of 0.2 to 7 wt.-% with respect to the total weigh of the composition. The compositions according to the present invention furthermore advantageously contain at least one co-surfactant such as e.g. selected from the group of mono- and diglycerides and/ or fatty alcohols. The co-surfactant is generally used in an amount selected in the range of 0.1 to 10 wt.-%, such as in particular in the range of 0.5 to 7 wt.-%, such as most in particular in the range of 1 to 5 wt.-%, based on the total weight of the composition. Particular suitable co-surfactants are selected from the list of alkyl alcohols such as cetyl alcohol (Lorol C16, Lanette 16), cetearyl alcohol (Lanette O), stearyl alcohol (Lanette 18), behenyl alcohol (Lanette 22), polyhydroxystearic acid, glyceryl stearate, glyceryl myristate (Estol 3650), hydrogenated coco-glycerides (Lipocire Na10) as well as mixtures thereof. In all embodiments of the present invention, it is particular advantageous if the composition also comprises cetearyl alcohol and/or glycerylstearate. Advantageous embodiments of the composition of the present invention also include those wherein the composition comprises one or more oils selected from butylene glycol dicaprylate/dicaprate, phenethyl benzoate, C12-C15 alkyl benzoate, dibutyl adipate, diisopropyl sebacate, dicaprylyl carbonate, di-C12-13 alkyl tartrates, diethylhexyl syringylidene malonates, hydrogenated castor oil dimerates, triheptanoin, C12-13 alkyl lactates, C16-17 alkyl benzoates, propylheptyl caprylates, caprylic/capric triglycerides, diethylhexyl 2,6-naphthalates, octyldodecanol, ethylhexyl cocoates, and phenethyl alcohol. Preferably, the composition according to the present invention comprises as oil(s) dibutyl adipate, phenylethyl benzoate, butylene glycol, phenethyl benzoate, phenethyl alcohol, C12-C15 alkylbenzoate, diisopropyl sebacate, as well as mixtures thereof. In a still further advantageous aspect of the invention, the compositions of the present invention further comprise a preservative and/ or a preservative booster. When present, the preservative respectively the preservative booster is preferably used in an amount of 0.01 to 5 wt. %, more preferably in an amount of 0.05 to 4 wt.-%, most preferably in an amount of 0.1 to 3.0 wt.-%, based on the total weight of the composition. In another advantageous aspect, the compositions according to the present invention are free of any parabenes, benzethoniumchlorid, piroctone olamine, lauroylarginat, methylisothiazolinon, chlormethylisothiazolinon, bronopol, benzalkoniumchloride, formaldehyd releasing compounds, salicylic acid, triclosan, DMDM hydantoin, chlorphenesin and IPBC (Iodopropinylbutyl carbamate). The compositions according to the invention may further contain one or more emollients which soothe and soften the skin. As an example, the emollient may be silicone (dimethicone, cyclomethicone), vegetable oils (grape seed, sesame seed, jojoba, etc.), butters (cocoa butter, shea butter), and petrolatum derivatives (petroleum jelly, mineral oil). In another aspect, the composition of the invention may comprise one or more fragrances selected from limonene, citral, linalool, alpha-isomethylionone, geraniol, citronellol, 2-isobutyl-4-hydroxy-4-methyltetrahydropyran, 2-tert-pentylcyclohexyl acetate, 3-methyl-5-phenyl-1-pentanol, 7-acetyl-1,1,3,4,4,6-hexamethyltetralin, adipic diester, cinnamal, amyl salicylate, alpha-amylcinnamaldehyde, alpha-methylionone, butylphenylmethylpropional, cinnamal, amylcinnamyl alcohol, anise alcohol, benzoin, benzyl alcohol, benzyl benzoate, benzyl Cinnamate, benzyl salicylate, bergamot oil, bitter orange oil, butylphenylmethylpropional, cardamom oil, cedrol, cinnamal, cinnamyl alcohol, citronellyl methylcrotonate, citrus oil, coumarin, diethyl succinate, ethyllinalool, eugenol, Evernia furfuracea extract, Evernia prunastri extract, farnesol, guaiacwood oil, hexylcin- namal, hexyl salicylate, hydroxycitronellal, lavender oil, lemon oil, linalyl acetate, mandarin oil, menthyl PCA, methyl hexadecan, nutmeg oil, rosemary oil, sweet orange oil, terpineol, tonkabean oil, triethyl citrate, vanillin. The composition of the invention may advantageously comprise moisturizers. Moisturizers are compounds or mixtures of compounds which give cosmetic compositions the quality, after application to or distribution on the skin surface, of reducing the loss of moisture of the stratum corneum (also called transepidermal water loss (TEWL)) and/or of positively influencing the hydration of the stratum corneum. Non-limiting examples of advantageous moisturizers for use in the present invention include glycerol, lactic acid and/or lactates, especially sodium lactate, butylene glycol, propylene glycol, 1,3-propanediol, biosaccharide gum-1, Glycine soya, ethylhexyloxyglycerol, pyrrolidonecarboxylic acid, and urea. Of further advantage, in particular, is the use of polymeric moisturizers from the group of the polysaccharides which are water-soluble and/or swellable in water and/or gellable with the aid of water. Especially advantageous, for example, are hyaluronic acid, chitosan and/or a fucose-rich polysaccharide which is registered in Chemical Abstracts under the registry number 178463-23-5 and is available, for example, under the Fucogel®1000 name from the company SOLABIA S.A. Moisturizers may also be used advantageously as active antiwrinkle ingredients for protection from changes to the skin of the kind occurring in skin aging, for example. Particularly advantageous moisturizers to be used in the compositions according to the present invention are glycerin, sodium hyaluronate, saccharide isomerate and/ or 1,3-propanediol, more preferably in a total amount selected in the range of 0.1 to 5 wt.-%, more preferably in the range from to 0.1 to 3 wt.-%, even more preferably in the range of 0.5 to 3 wt.-%, based on the total weight of the composition. The cosmetic compositions of the invention may further comprise advantageously, although not mandatorily, fillers which have the effect, for example, of further improving the sensorial and cosmetic properties of the formulations and evoking or intensifying a velvety or silky skin sensation, for example. Advantageous fillers in the sense of the present invention are starch and starch derivatives (such as tapioca starch, distarch phosphate, aluminum or sodium starch octenylsuccinate, and the like, for example), and/or Aerosils® (CAS No.7631-86-9) and/or talc and/or polyethylene, nylon, and silica dimethyl silylate. The water phase of the compositions of the invention may advantageously comprise customary cosmetic auxiliaries, such as, for example, alcohols, particularly those of low C number, preferably ethanol and/or isopropanol, or polyols of low C number, and also ethers thereof, preferably propylene glycol, glycerol, electrolytes, and also, in particular, one or more thickeners, which may be advantageously selected from the group of silicon dioxide, aluminum silicates, polysaccharides and/or derivatives thereof, e.g., hyaluronic acid, xanthan gum, hydroxypropylmethylcellulose, particularly advantageously from the group of polyacrylates, preferably a polyacrylate from the group referred to as Carbopols, examples being carbopols of types 980, 981, 1382, 2984, and 5984, in each case individually or in combination. Further thickeners advantageous in accordance with the invention are those having the INCI designation Acrylates/C10-30 Alkyl Acrylate Crosspolymer (e.g., Pemulen TR 1, Pemulen TR 2, Carbopol 1328 from Lubrizol) and also Aristoflex AVC (INCI: Ammonium Acryloyldimethyltaurate/VP Copolymer) as well as Simugel NS (INCI: Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer & Squalane & Polysorbate 60). It is further preferred in accordance with the invention if the composition comprises a thickener. Suitable thickeners to be used according to the present invention encompass xanthan gum, crosslinked acrylate/C10-C30 alkyl acrylate polymer, hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer, and/or vinylpyrrolidone/hexadecane copolymer, preferably xanthan gum and/ or hydroxyethyl acrylate/sodium acryloyldimethyl Taurate, most preferably xanthan gum. The amount of xanthan gum, if present is preferably selected in the range of 0.1 to 1 wt.-%, more preferably in the range of 0.15 to 0.75 wt.-%, most preferably in the range of 0.2 to 0.4 wt.-%, based on the total weight of the composition. The oil phase of the compositions of the invention may advantageously also comprise customary cosmetic auxiliaries, such as, for example, thickeners for the oil phase such as Dextrin Palmitate (Rheopearl KL2, Chiba Flour Milling), Dextrin Palmitate and C15- 19 Alkane (TILAMAR Fits, DSM), Polyurethane-79 and Caprylic/Capric Triglyceride (Oilkemia 5S, Lubrizol), Ethylene / Propylene / Styrene Copolymer and Butylene/Ethylene/Styrene Copolymer and Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate and Squalane (Veggi Gel, Aiglon), Dibutyl Lauroyl Glutamide and Dibutyl Ethylhexanoyl Glutamide and Octyldodecanol (AJK-OD246, Ajinomoto). The amount of the thickener (e.g. the active thickening polymer), if present is preferably selected in the range of 0.1 to 15 wt.-%, more preferably in the range of 0.5 to 10 wt.-%, most preferably in the range of 1.0 to 8.0 wt.-%, based on the total weight of the composition. Advantageously in accordance with the invention, the composition of the invention comprises film formers. Film formers in the sense of the present invention are substances of various constitutions, and are characterized by the following properties: When a film former is dissolved in water or other suitable solvents, and when the solution is then applied to the skin, the film former, following evaporation of the solvent, forms a film which serves essentially to fix the UV-filters on the skin and thus to increase the water resistance of the product. It is especially advantageous to select the film formers from the group of the polymers based on polyvinylpyrrolidone (PVP) Particular preference is given to copolymers of vinylpyrrolidone, as for example the PVP hexadecane copolymer and the PVP eicosene copolymer, which are available under the trade names Antaron V216 and Antaron V220 from Ashland. Likewise advantageous are further polymeric film formers, such as, for example, sodium polystyrene sulfonate, which is available under the trade name Flexan 130 from National Starch and Chemical Corp., and/or polyisobutene, available from Rewo under the trade name Rewopal PIB1000. Examples of further suitable polymers are polyacrylamides (Sepigel 305), polyvinyl alcohols, PVP, PVP/VA copolymers, polyglycols, acrylate/octylacrylamide copolymer (Dermacryl 79). Likewise advantageous is the use of hydrogenated castor oil dimer dilinoleate (CAS 646054-62-8, INCI Hydrogenated Castor Oil Dimer Dilinoleate), which can be acquired from Kokyu Alcohol Kogyo under the name Risocast DA-H, or else PPG-3 benzyl ether myristate (CAS 403517-45-3), which can be acquired under trade name Crodamol STS from Croda Chemicals. In accordance with the invention, the composition of the invention may or may not comprise lactose, suitably D-lactose. In one embodiment the composition comprises equal to or less than 1 wt.-% lactose, more preferably equal to or less than 0.1 wt.-% lactose, still more preferably equal to or less than 0.01 wt.-% lactose, yet more preferably equal to or less than 0.001 wt.-%, most preferably no or essentially no lactose. In another embodiment the composition comprises equal to or more than 0.001 wt.-%, more preferably equal to or more than 0.01 wt.-%, suitably equal to or more than 0.1 wt.-%. Without wishing to be bound by any kind of theory, it is believed that even in small amounts lactose can provide multiple benefits to a cosmetic composition, including hydration, skin conditioning, gentle exfoliation, texture enhancement, stabilization and/or soothing effects. Lactose, suitably D-lactose, may therefore be present in an amount in the range from equal to or more than 0.001 wt.- %, more preferably from equal to or more than 0.01 wt.-%, suitably from equal to or more than 0.1 wt.-%, to equal to or less than 3.0 wt.-%, more preferably to equal to or less than 1.0 wt.-%, most preferably to equal to or less than 0.3 wt.-%. The compositions according to the invention in general have a pH in the range of 3 to 10, preferably a pH in the range of 4 to 8 and most preferably a pH in the range of 4 to 7.5. The pH can easily be adjusted as desired with suitable acids such as e.g. citric acid or bases such as NaOH or suitable amines such as tromethamine according to standard methods in the art. The cosmetic composition can be used for the cosmetic treatment of keratinous substances such as in particular the skin, wherein a composition as defined herein is applied to the said keratinous tissues such as in particular to the skin. The amount of the cosmetic composition to be applied to the skin is not critical and can easily be adjusted by a person skilled in the art. Preferably the amount is selected in the range of 0.1 to 3 mg/cm² skin, such as preferably in the range of 0.1 to 2 mg/cm² skin and most preferably in the range of 0.5 to 2 mg/cm² skin. In another embodiment, said cosmetic composition is free of a UVA filter selected from the group of butyl methoxydibenzoyl methane and diethylamino hydroxybenzoyl hexyl benzoate, particularly free of a UVA filter selected from the group of butyl methoxydibenzoyl methane and diethylamino hydroxybenzoyl hexyl benzoate, and free of any vitamin B. In another embodiment, said cosmetic composition is free of any sunscreen active agent, particularly free of any sunscreen active agent. The term ‘sunscreen active agent’ as used herein refers to compounds absorbing light in the UV-B and/ or the UVA-range (also referred to UVA-, UVB- and broadband (UVA&B) filters). Preferably, such compounds have an E1/1 value (i.e. UV absorbance at a concentration of 1% at 1cm thickness of absorbing layer at λ_max) of at least 150, more preferably of at least 180, most preferably of at least 190. Both butyl methoxydibenzoyl methane and diethylamino hydroxybenzoyl hexyl benzoate are known sunscreen active agents. It has been found that the cosmetic composition, as described above in great detail, particularly the mixture of a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone, has a significant antimicrobial effect. The antimicrobial effect has been found particularly for the following microbes: - Corynebacterium xerosis - Malassezia furfur - Cutibacterium acnes - Staphylococcus capitis - Candida albicans - Aspergillus brasiliensis; especially for the following microbes: - Staphylococcus capitis - Candida albicans - Aspergillus brasiliensis; It has been found that said antimicrobial effects leads to a strong reduction of microbes after application of the cosmetic composition on the keratinous tissue of a human body, particularly on the skin and hair, and, hence, showing an antimicrobial effect. The growth of microbes is strongly reduced. In other cases, the reduction of growth prolongates the time of recovery of microbes after the initial attack to the microbes on topical application of the composition. Not only the elimination of microbes, but also this extension of recovery time is important, as this allows other, particularly, beneficial, microbes to grow faster and, hence, influence positively the composition of microbes on the body, i.e. microbiome, in such a way that the undesired cosmetic states can be avoided. It has been also observed that the combination of lacto-N-tetraose (LNT) or lacto- N-neotetraose (LNnT); and hydroxyacetophenone has a synergistic antimicrobial effect. Therefore, in a further aspect, the invention relates to a cosmetic composition comprising a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone; as an antimicrobial agent, preferably against a microbe selected from the group consisting of Corynebacterium xerosis, Malassezia furfur, Cutibacterium acnes, Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis, preferably from the group consisting of Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis. Such a cosmetic composition may advantageously benefit from the combination of lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and hydroxyacetophenone having a synergistic antimicrobial effect. Preferences for such cosmetic composition are as described herein above and below. In an even further aspect, the invention relates to the use of a mixture of a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT), more preferably lacto-N- neotetraose (LNnT); and b) hydroxyacetophenone; for reducing growth of microbes, preferably of microbes selected from the group consisting of Corynebacterium xerosis, Malassezia furfur, Cutibacterium acnes, Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis, preferably from the group consisting of Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis. It is preferred that the use is a non-therapeutic use, particularly a cosmetic use. Examples The following examples are provided to further illustrate the compositions and effects of the present invention. These examples are illustrative only and are not intended to limit the scope of the invention in any way. Preparation of cosmetic compositions Different aqueous compositions have been prepared by mixing under stirring the ingredients indicated in tables 1-5 in distilled water in amounts as to obtain the concentrations (numbers in weight-%) as indicated in tables 1 to 5. Evaluation of antimicrobial effects The antimicrobial efficacy is assessed on a selection of microbial strains through a miniaturized method performed in liquid media in 96 deepwell plates format. The inhibition of the strain growth is analyzed over a time period of 4 hours. Thus, the respective active(s) were dissolved in physiological serum with 0.85 wt.-% NaCl in the concentrations as outlined in the tables below under sterile conditions. Then, the solutions of the active(s) were deposed in 96-deep well plates (1.6 ml/well) and the wells were contaminated with the inoculum as follows: 7.75*10⁴ cfu/ml Candida albicans, 9*10⁴ cfu/ml Aspergillus brasiliensis, and 3.1*10⁵ cfu/ml Staphylococcus capitis. After the contamination, each well was thoroughly mixed to ensure a homogeneous distribution. Then each plate was incubated at 37°C +/- 2.5°C for 4 hours. At each defined time (i.e.0.5 h, 2 h 4 h), a pick-up of the contaminated samples was performed (20µl) after gentle agitation. To perform the counting, aliquots of the contaminated samples were serially diluted (decimal dilutions) in culture medium in 96-well plates with triphenyltetrazolium and incubated at 37°C +/- 2.5°C during 48 hours. After 48h at optimal growth conditions, the last dilution showing a pink color (triphenyltretrazolium) or turbidity indicated the contamination rate and allowed the determination of the corresponding microbe concentration according to the MNP method (most probable number method).

The results of tables 1-5 show that the mixture of LNnT or LNT and hydroxyacetophenone has an antimicrobial effect on microbes. It can be observed that said antimicrobial effect leads to a significant diminution of the number of the microbes after 0.5 hours incubation, which continues over time of incubation (2 hours resp.4 hours) in most cases (i.e. leads to a killing of the microbes) and in other cases the increase of the number of microbes on incubation (i.e. extension of recovery time) is significantly slower as compared to the respective references which do not comprise the inventive combination. It can be also observed that mixture of LNnT or LNT and hydroxyacetophenone have a synergistic antimicrobial effect.

Claims

Claims 1. A cosmetic composition comprising a combination of a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone. 2. The cosmetic composition according to claim 1, comprising a combination of a) lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone. 3. The cosmetic composition according to claim 1 or 2, characterized in that the hydroxyacetophenone is 4’-hydroxyacetophenone. 4. A cosmetic composition comprising a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone as an anti-microbial agent against Corynebacterium xerosis, Malassezia furfur, Cutibacterium acnes, Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis, preferably against Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis. 5. The cosmetic composition according to any of the preceding claims characterized in that the amount of lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT) is 0.05 - 6 % by weight, preferably 0.1 - 5 % by weight, more preferably 0.2 - 4 % by weight, based on the total weight of the composition. 6. The cosmetic composition according to any of the preceding claims characterized in that the amount of hydroxyacetophenone is 0.01 – 5 % by weight, preferably 0.05 – 4 % by weight, more preferably 0.1 – 3 % by weight, based on the total weight of the composition. 7. Non-therapeutic use of a mixture of a) lacto-N-tetraose (LNT) or lacto-N-neotetraose (LNnT); and b) hydroxyacetophenone for reducing growth of microbes. 8. The non-therapeutic use according to claim 7 characterized in that the microbe is selected from the group consisting of Corynebacterium xerosis, Malassezia furfur, Cutibacterium acnes, Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis, preferably against Staphylococcus capitis, Candida albicans and Aspergillus brasiliensis. 9. Use non-therapeutic according to claim 7 or 8, characterized in that the use is a cosmetic use.