EP4590290A1

EP4590290A1 - Method for inhibiting the growth of malassezia restricta

Info

Publication number: EP4590290A1
Application number: EP23764942.1A
Authority: EP
Inventors: Mingming PU; Zongxiu WANG
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Priority date: 2022-09-20
Filing date: 2023-09-05
Publication date: 2025-07-30
Also published as: WO2024061608A1; JP2025529543A; CN119894508A; MX2025002845A

Abstract

The present invention relates to use of glycine or a composition comprising glycine in inhibiting the growth of Malassezia restricta when applied on an external surface of a human body; wherein the composition comprises at least 0.04% of glycine by weight of the composition. It also relates to use of glycine or a composition comprising glycine in microbiome balancing on a surface, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes; wherein the composition comprises at least 0.04% of glycine by weight of the composition.

Description

METHOD FOR INHIBITING THE GROWTH OF MALASSEZIA RESTRICTA

Field of the Invention

The present invention relates to method for microbiome balancing on an external surface of a human body, preferably on human skin or scalp, more preferably on scalp. In particular, the invention relates to the use of glycine or a composition comprising a glycine for inhibiting the growth of harmful microbes which is Malassezia restricta. The invention also relates to the use of glycine or a composition comprising a glycine on microbiome balancing on an external surface of a human body.

Background of the Invention

Microbes e.g. bacteria, fungi, viruses, protozoa and mites are often found to be present on surfaces such as fabrics, hard surfaces and skin. Microbiome of a surface refers to this entire population of microbes that are present on a surface. Some of the microbes present on the surface considered to be beneficial whereas some of the other microbes that co-habits with the good microbes are detrimental in nature.

The scalp microbiome has recently become the focus of some attention for a potential causative role in dandruff progression. The major fungal/bacterial species present on the scalp, namely Malassezia restricta, Malassezia globosa, Cutibacterium acnes, Staphylococcus epidermidis and Staphylococcus capitis. The lipophilic yeast Malasssezia restricta is known associated with dandruff condition. Antifungals, such as zinc pyrithione, piroctone olamine, and selenium sulfide, have been demonstrated to be effective anti-dandruff agents by reducing the growth of Malassezia on scalp. Staphylococcus and Cutibacterium are the most abundant bacteria genera across both healthy and dandruff scalps. However, at species level, Staphylococcus capitis is reported to be positively associated with dandruff conditions, while Staphylococcus epidermidis and Cutibacterium acnes, are considered as commensal bacteria, which are is positively associated with non-dandruff scalp conditions in terms of relative or absolute abundance.

Antimicrobial compositions are commonly used by individuals to eliminate or reduce the number of harmful microbes. However, the application of broad-spectrum antimicrobial composition, such as zinc pyrithione, may also kills or inhibit the microbes which are beneficial.

There is a continuing need for treatments which are capable of providing microbiome balancing by selectively reducing the number of harmful microbes while having less effect on or selectively increasing the number of beneficial microbes.

Summary of the Invention

The present inventors have surprisingly found that glycine or a composition comprising glycine at certain level can inhibit the growth of Malassezia restricta when applied on an external surface of a human body, while having no inhibition effect on the commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes.

In a first aspect, the present invention is directed to use of glycine or a composition comprising glycine in inhibiting the growth of Malassezia restricta when applied on an external surface of a human body; wherein the composition comprises at least 0.04% of glycine by weight of the composition.

In a second aspect, the present invention is directed to use of of glycine or a composition comprising glycine in microbiome balancing on an external surface of a human body, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes', wherein the composition comprises at least 0.04% of glycine by weight of the composition.

In a third aspect, the present invention is directed to a method of applying glycine or a composition comprising glycine on an external surface of a human body for inhibiting the growth of Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition.

In a fourth aspect, the present invention is directed to a method of applying glycine or a composition comprising glycine on an external surface of a human body for microbiome balancing, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes’, wherein the composition comprises at least 0.04% of glycine by weight of the composition.

In a fifth aspect, the present invention is directed to a method of applying glycine or a composition comprising glycine on an external surface of a human body for ensuring the growth of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes while protecting the surface against harmful microbes which is Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition.

In a sixth aspect, the present invention is directed to glycine or a composition comprising glycine for use in inhibiting the growth of Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition.

In a seventh aspect, the present inventio is directed to glycine or a composition comprising glycine for use in microbiome balancing on an external surface of a human body, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes’, wherein the composition comprises at least 0.04% of glycine by weight of the composition.

All other aspects of the present invention will more readily become apparent upon considering the detailed description and examples which follow.

Detailed Description

For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated. As used herein, the indefinite article “a” or “an” and its corresponding definite article “the” means at least one, or one or more, unless specified otherwise. The various features of the present invention referred to in individual sections above apply, as appropriate, to other sections mutatis mutandis. Consequently, features specified in one section may be combined with features specified in other sections as appropriate. Any section headings are added for convenience only and are not intended to limit the disclosure in any way.

“Hair care composition”, as used herein, is meant to include a composition for topical application to hair and/or scalp of mammals, especially humans. Such a composition may be generally classified as leave-on or rinse off, and includes any product applied to a human body for also improving appearance, cleansing, odor control or general aesthetics. The composition of the present invention can be in the form of a liquid, lotion, cream, foam, scrub, gel, or bar. Non-limiting examples of such compositions include leave-on hair lotions, creams, and rinse-off shampoos, conditioners, shower gels, or toilet bar.

Microbes

A microbe can be described as a tiny living organism, such as bacterium, fungus, virus protozoan, or mite. A microbiome on a surface refers collectively to all the microbes on the surface. In other words, a microbiome is a community of microbes.

The term “microbiome balancing” as used herein, means selectively eliminating/killing/reducing the microbes considered to be harmful existing on a surface whereas keeping the microbes considered to be beneficial substantially at the same level or even increasing the number of microbes which are considered to be beneficial.

The microbe considered to be harmful is Malassezia restricta (M. restricta), which a lipophilic yeast and one of the most abundant Malassezia species of the human skin microbiota. M. restricts is considered an opportunistic pathogen associated with skin disorders, such as seborrheic dermatitis and dandruff.

At least one of the microbes considered to be beneficial is Staphylococcus epidermidis (S. epidermidis). S. epidermidis is reported to be a beneficial bacterium that participates in the maintenance of skin health. It is a kind of normal microbe which is likely to be involved in competitive exclusion of pathogens. It is thus an indication of microbiome status of the surface. The increase and maintenance of S. epidermidis is an important route to maintain the composition of healthy microbiome.

At least one of the microbes considered to be beneficial is Cutibacterium acnes (C. ances). It is one or the main bacterial species that have been identified on the healthy scalp.

The present invention relates to the use of glycine or a composition comprising glycine in inhibiting the growth of Malassezia restricta when applied on an external surface of a human body. However, such use has no inhibition effect on the growth of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes. The surface is preferably human skin, for example, a surface like the hands, face, body or scalp. More preferably, the surface is scalp.

Microbiome balancing is obtained by selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from S. epidermidis and C. acnes.

The present invention relates to use of glycine or a composition comprising glycine in microbiome balancing on an external surface of a human body. The surface is preferably human skin, for example, a surface like the hands, face, body or scalp. More preferably, the surface is scalp.

It is also surprisingly to find that the use of glycine or the composition in accordance with the present invention has less impact on the growth of microbes of other Malassezia genus, such as Malassezia furfur. The use of glycine or the composition in accordance with the present invention has no inhibition effect on the growth of Malassezia furfur. Glycine

Glycine is an amino acid which is essential in the production of collagen, a protein that gives structure to bones, skin, muscles, and connective tissues. It is the simplest stable amino acid, with the chemical formula NH2-CH2-COOH.

Amino acids are usually considered as nutrient source for both microorganisms and human. It is surprisingly to be found that glycine or the composition comprising glycine at certain level can inhibit the growth of Malassezia restricta when applied on a surface. However such use has no inhibition effect on the growth of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes. Therefore, such use can provide microbiome balancing, selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from S. epidermidis and C. acnes.

The composition of the present invention comprises at least 0.04% of glycine, preferably at least 0.1% of glycine, more preferably at least 0.15% of glycine by weight of the composition.

It is preferred that the composition comprises from 0.04 to 10% of glycine, preferably from 0.1% to 5% of glycine, more preferably from 0.15 to 2%, furthermore preferably from 0.2 to 2% by weight of the total composition and including all ranges subsumed therein.

In compositions intended to be diluted before application, the minium preferred concentration of the glycine can be higher. It is generally preferred that the concentration of the glycine in the composition in the use according to the present invention is equal or higher than the optimal concentrations in the working composition, because in many typical applications, the composition is either used pure or is diluted to form the working composition. For example, when washing hands with water and a composition of the present invention, the lather produced, typically is a 50 wt% dilution of the original composition. Similary, in hair wash , body wash situations, liquids soap or bars are typically diluted until about 8 wt% to 10wt% in water, corresponding to an approximately tenfould dilution of the product. Therefore, the concentration of the glycine in the composition is preferably such that, when the composition is diluted or dissolved with a suitable medium before or during use, the concentration in the diluted or dissolved mixture is still sufficient to provides microbiome balancing benefits on an external surface of a human body.

The composition is preferably a personal care composition. A personal care composition is a composition for the treatment, cleaning, caring or conditioning of the person. The foregoing includes, but not limited to, chemicals, compositions, products, or combinations thereof relating to or having use or application in the treatment, cleansing or conditioning of the person (including in particular the skin, hair, scalp and oral cavity), and the manufacture of all the foregoing. Examples of a personal care composition include but not limited to leave-on skin lotions and creams, shampoos, conditioners, shower gels, soap bars, antiperspirants, deodorants, shave creams, depilatories, lipsticks, foundations, mascara, sunless tanners or sunscreen lotions. Preferably, the composition is leave-on personal care composition.

Preferred personal care compositions for use in the invention include rinse-off or leave- on hair or scalp care compositions such as shampoos, conditioners, creams, lotions, gels, serums, mousses or oils. Leave-on hair or scalp care compositions are preferred, such as lotions, serums, oils, which are intended for topical application to the hair or scalp.

Compositions for use in the invention will generally include a cosmetically acceptable carrier. The term “cosmetically acceptable” means that the carrier is suitable for topical application to the skin, has good aesthetic properties, is compatible with any other ingredients, and will not cause any safety or toxicity concerns.

The carrier may comprise an aqueous phase, an oil phase, an alcohol, a silicone phase or a mixture thereof, and may be in the form of an emulsion. Emulsions can have a range of consistencies including thin lotions (which may also be suitable for spray or aerosol delivery), creamy lotions, light creams and heavy creams.

Compositions for use in the invention may also be formulated in a single-phase carrier such as a hydrophobic or hydrophilic liquid. Suitable hydrophobic liquid carriers include liquid polyorganosiloxanes, mineral oils, hydrogenated polyisobutene, polydecene, paraffins and isoparaffins of at least 10 carbon atoms, aliphatic or aromatic ester oils (such as isopropyl myristate, lauryl myristate, isopropyl palmitate, diisopropyl sebacate, diisopropyl adipate and C12 to C15 alkyl benzoates), polyglycol ethers (such as polyglycol butanol ethers) and mixtures thereof. Suitable hydrophilic liquid carriers include water, monohydric or polyhydric aliphatic alcohols having 2 to 8, preferably 2 or 3 carbon atoms (such as ethanol and isopropanol, oligoglycol ethers having 2 to 5 repeat units (such as dipropylene glycol) and mixtures thereof. A particularly preferred carrier is water.

Liquid form compositions for use in the invention may be thickened, for example using one or more water soluble or colloidally water soluble polymeric thickening agents.

It is preferred that the composition for use in the invention comprises a thickening agent.

Suitable water soluble or colloidally water soluble polymeric thickening agents include hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polyquaternium-10, carrageenan, guar gum, hydroxypropyl guar gum, xanthan gum, polyvinylalcohol, acrylic acid/ethyl acrylate copolymers, carboxyvinyl polymers, crosslinked polyacrylate polymers and polyacrylamide polymers.

The composition for use in the invention may additionally comprise a conditioning agent to provide conditioning benefit. Preferably, the composition comprises discrete dispersed droplets of a water-insoluble conditioning agent, which has a mean droplet diameter (D3,2) of less than 15 microns, preferably less than 10 microns, more preferably less than 5 microns, most preferably less than 3 microns. The mean droplet diameter (D3,2) of a water-insoluble conditioning agent may be measured by means of a laser light scattering technique, for example using a 2600D Particle Sizer from Malvern Instruments.

The water-insoluble conditioning agent may include non-silicone conditioning agent comprising non-silicone oily or fatty materials such as hydrocarbon oils, fatty esters and mixtures thereof. Preferably, the water-insoluble conditioning agent is emulsified silicone oil. Suitable silicones include polydiorganosiloxanes, in particular polydimethylsiloxanes which have the CTFA designation dimethicone. Also suitable for use in compositions of this invention (particularly shampoos and conditioners) are polydimethyl siloxanes having hydroxyl end groups, which have the CTFA designation dimethiconol. Also suitable for use in compositions of this invention are silicone gums having a slight degree of cross-linking, as are described for example in WO 96/31188. Preferably, the silicone oil comprises dimethicone, dimethiconol or a mixture thereof.

Suitable emulsified silicones included in the compositions for use in this invention are available as pre-formed silicone emulsions from suppliers of silicones such as Dow Corning and GE silicones. The use of such pre-formed silicone emulsion is preferred for ease of processing and control of silicone particle size. Such pre-formed silicone emulsions will typically additionally comprise a suitable emulsifier, and may be prepared by a chemical emulsification process such as emulsion polymerisation, or by mechanical emulsification using a high shear mixer. Examples of suitable pre-formed silicone emulsions include DC1785, DC1788, DC7128, all available from Dow Corning. These are emulsions of dimethiconol/dimethicone.

Another class of silicones which may be used are functionalized silicones such as amino functional silicones, meaning a silicone containing at least one primary, secondary or tertiary amine group, or a quaternary ammonium group. Examples of suitable amino functional silicones include polysiloxanes having the CTFA designation “amodimethicone.”

The water-insoluble conditioning agent is generally present in the composition for use in this invention in an amount from 0.05 to 15%, preferably from 0.1 to 10%, more preferably from 0.5 to 8%, most preferably from 1 to 5%, based on total weight of the composition.

The pH of the composition for use according to the present invention is preferably equal to or higher than 4.0, more preferably in the range of 5.0 to 10.0.

Oils and lotions for use in the invention typically have an oil phase containing at one or more cosmetically acceptable fatty materials which may be liquid or solid at room temperature (25°C). Lotions are typically aqueous emulsions having an aqueous phase in addition to the oil phase.

Suitable cosmetically acceptable fatty materials include naturally derived oils (such as sunflower oil, borage oil, soybean oil, castor oil, olive oil and almond oil); esters of monoalcohols or of polyols with monocarboxylic or polycarboxylic acids, at least one of the alcohols and/or acids comprising at least one hydrocarbon-based chain containing at least 6 carbon atoms (such as octyl palmitate, isopropyl myristate, isopropyl palmitate, isopropyl isostearate, hexyl laurate, isohexyl laurate, isohexyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, dihexyldecyl adipate, lauryl lactate, myristyl lactate, cetyl lactate, oleyl stearate, oleyl oleate, oleyl myristate, lauryl acetate, cetyl propionate, isononyl isononanoate, propylene glycol dicaprate, diisopropyl adipate, dibutyl adipate, and oleyl adipate); ethers (such as dicapryl ether); fatty alcohols (such as cetyl alcohol, stearyl alcohol and behenyl alcohol); isoparaffins (such as isooctane, isododecane and isohexadecane); silicone oils (such as cyclomethicone, dimethicone and dimethiconol); hydrocarbon oils (such as mineral oil, petrolatum and polyisobutene); fatty acids containing from 8 to 30 carbon atoms, (such as stearic acid, lauric acid, palmitic acid and oleic acid); vegetable fats (such as cocoa butter, coconut oil, palm oil and shea butter); petroleum-based, natural and synthetic waxes (such as lanolin wax, beeswax, carnauba wax, candelilla wax, paraffin wax, lignite wax, microcrystalline waxes, ceresin, ozokerite, and polyethylene waxes); hydrogenated oils which are solid at 25° C (such as hydrogenated castor oil, hydrogenated jojoba oil, hydrogenated palm oil, hydrogenated tallow and hydrogenated coconut oil) ;and fatty esters that are solid at 25°C (such as C20-40 alkyl stearate).

The aqueous phase of lotions for use in the invention may also include one or more organic liquids that are miscible with water at room temperature (25°C). Exemplary water-miscible organic liquids include monohydric and polyhydric alcohols and derivatives thereof such as C2-C6 alkanols (such as ethanol and isopropanol); C2-C10 glycols and polyols (such as glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, caprylyl glycol, dipropylene glycol, and diethylene glycol); C3- C16 glycol ethers (such as mono-, di-, or tripropylene glycol (C1-C4) alkyl ethers and mono-, di-, or triethylene glycol (C1-C4) alkyl ethers) and polyethylene glycol having 2 to 12 oxyethylene units. Lotions for use in the invention may also include surface active ingredients, such as emulsifiers and solubilizers, to enable two or more immiscible components to be combined homogeneously and to help stabilize the composition. Emulsifiers that may be used to form O/W or W/O emulsions include sorbitan oleate, sorbitan sesquioleate, sorbitan isostearate, sorbitan trioleate, PEG-20 sorbitan isostearate, polyglyceryl-3- diisostearate, polyglycerol esters of oleic/isostearic acid, polyglyceryl-6 hexaricinolate, polyglyceryl-4-oleate, polyglyceryl-4 oleate/PEG-8 propylene glycol cocoate, polyglyceryl-2 dipolyhydroxystearate, PEG-30 dipolyhydroxystearate, oleamide DEA, TEA myristate, TEA stearate, magnesium stearate, sodium stearate, potassium laurate, potassium ricinoleate, sodium cocoate, sodium tallowate, potassium castorate, sodium oleate, cetyl phosphate, diethanolamine cetyl phosphate, potassium cetyl phosphate, sodium glyceryl oleate phosphate, dimethicone copolyol, cetyl dimethicone copolyol, octyldimethicone ethoxyglucoside copolyol, dimethicone copolyol crosspolymer and laurylmethicone copolyol.

Combinations of any of the above described materials or product forms may also be used.

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.

Compositions for use in the invention (as described above) may include additional functional ingredients for improving the physical and/or aesthetic characteristics of the composition per se. Examples include inorganic pigments (such as titanium oxide, zirconium oxide, cerium oxide, zinc oxide, iron oxide, chromium oxide, manganese violet, ultramarine blue, chromium hydrate and ferric blue); organic pigments (such as carbon black and the organic lakes of barium, strontium, calcium or aluminium); pearlescent agents (such as mica coated with titanium oxide and/or iron oxide); dyes, preservatives (such as disodium EDTA, benzyl alcohol, methylparaben, phenoxyethanol, propylparaben, ethylparaben, butylparaben and isobutylparaben); pH adjusters and fragrances (such as essential oils, flower oils, natural extracts from resins, gums, balsams, beans, mosses and other plants, as well as synthetic aromatic materials).

Mixtures of any of the above described materials may also be used.

Preservatives may also be incorporated into the composition for use in this invention to protect against the growth of potentially harmful microorganisms. Suitable traditional preservatives include alkyl esters of parahydroxybenzoic acid, hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Illustrative yet non-limiting examples of the types of preservatives that may be used in this invention include, for examples, phenoxyethanol, sodium salicylate, methyl paraben, butyl paraben, propyl paraben, diazolidinyl urea, sodium dehydroacetate, benzyl alcohol, sodium benzoate, iodopropynyl butylcarbamate, caprylyl glycol, disodium EDTA or mixtures thereof. In an especially preferred embodiment, the preservative is sodium benzoate, phenoxyethanol, sodium salicylate or a mixture thereof. Preservatives are preferably employed in amounts ranging from 0.01 to 2% by weight of the composition.

It is further preferred that the composition for use in the invention comprises a cosmetic ingredient. Preferably the cosmetic ingredient is selected from the group consisting of a silicone, an antibacterial agent other than antidandruff agents, a foam booster, a perfume, encapsulates (for example encapsulated fragrance) a dye, a colouring agent, a pigment, a preservative, a thickener, a protein, a phosphate ester, a buffering agent, a pH adjusting agent, a pearlescer (for example; mica, titanium dioxide, titanium dioxide coated mica, ethylene glycol distearate (INCI glycol distearate)) and/or opacifier, a viscosity modifier, an emollient, a sunscreen, an emulsifier, a sensate active (for example menthol and menthol derivatives), vitamins, mineral oils, essential oils, lipids, natural actives, glycerin, natural hair nutrients such as botanical extracts, fruit extracts, sugar derivatives and amino acids, microcrystalline cellulose and mixtures thereof.

Preferably, the composition for use in the present invention includes from 0.01 to 20 wt% of the at least one cosmetic ingredient, more preferably from 0.05 to 10 wt%, still more preferably from 0.075 to 7.5 wt% and most preferably, from 0.1 to 5 wt% of the at least one cosmetic ingredient, by weight of the total composition. Method

The present invention provides for use of glycine or a composition comprising glycine in inhibiting the growth of Malassezia restricta when applied on an external surface of a human body; wherein the composition comprises at least 0.04% of glycine by weight of the composition. Such inhibition can be used for the treatment of dandruff. The use is preferably non-therapeutic in nature, more preferably cosmetic in nature.

The present invention provides for use of glycine or a composition comprising glycine in microbiome balancing on an external surface of a human body, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes', wherein the composition comprises at least 0.04% of glycine by weight of the composition. Such microbiome balancing can be used for the treatment of dandruff. The use is preferably non-therapeutic in nature, more preferably cosmetic in nature.

The present invention provides for a method of applying glycine or a composition comprising glycine on an external surface of a human body for inhibiting the growth of Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition. Such inhibition can be used for the treatment of dandruff. The method is preferably non-therapeutic in nature, more preferably cosmetic in nature.

The present invention provides for a method of applying glycine or a composition comprising glycine on an external surface of a human body for microbiome balancing, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes', wherein the composition comprises at least 0.04% of glycine by weight of the composition.

Such microbiome balancing can be used for the treatment of dandruff. The method is preferably non-therapeutic in nature, more preferably cosmetic in nature.

The present invention provides for a method of applying glycine or a composition comprising glycine on an external surface of a human body for ensuring the growth of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes while protecting the surface against harmful microbes which is Malassezia restricta, wherein the composition comprises at least 0.04% of glycine by weight of the composition. The method is preferably non-therapeutic in nature, more preferably cosmetic in nature.

The present invention provides for glycine or a composition comprising glycine for use in inhibiting the growth of Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition. Such inhibition can be used for the treatment of dandruff.

The present invention provides for glycine or a composition comprising glycine for use in microbiome balancing on an external surface of a human body, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes wherein the composition comprises at least 0.04% of glycine by weight of the composition. Such microbiome balancing can be used for the treatment of dandruff.

The present invention provides for glycine or a composition comprising glycine for use as a medicament. It provides for glycine or a composition comprising glycine for use as a medication for inhibiting the growth of Malassezia restricta when applied on an external surface of a human body; wherein the composition comprises at least 0.04% of glycine by weight of the composition. It provides for glycine or a composition comprising glycine for use as a medication for microbiome balancing on an external surface of a human body, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes, wherein the composition comprises at least 0.04% of glycine by weight of the composition.

The composition is suitably applied to the hair or scalp and massaged into the surface of the scalp. Generally, an amount corresponding to about 1 to 15 ml of the composition per application is applied uniformly over the area of treatment daily or at least once a week over a time interval of at least 7 (seven) days, preferably at least 28 days, more preferably at least 30 (thirty) days. The invention will be further illustrated by the following, non-limiting Examples.

M. restricta (CBS 7877) was revitalized on modified Leeming and Notman agar (mLNA) plates from -80 °C freezer by incubation at 32 °C for 5 days. The microbe was further cultured in 20ml of liquid growth medium modified Leeming and Notman broth (mLNB) at 32 °C for 48 hrs with shaking. Then, 1ml of the first broth culture was transferred into 9 ml of fresh mLNB and incubated at 32 °C for 48 hrs with shaking and ready to use.

Malassezia. furfur (CBS 1878) was revitalized on Pityrosporum Broth (PB) agar by incubation at 32 °C for 2 days. The microbe was further cultured in 20) ml of liquid growth medium PB broth at 32 °C for 48 hrs with shaking. Then, 1ml of the first broth culture is transferred into 9ml of fresh PB and incubated at 32 °C for 48 hrs with shaking and ready to use.

S. epidermidis (ATCC_12228) was revitalized on Tryptic soy agar (TSA) by incubation at 37 °C overnight. The microbe was further cultured in 20 ml of liquid growth medium Tryptic soy broth (TSB) at 37 °C overnight and ready to use.

C. acnes (ATCC_6919) were revitalized on TSA plates by incubation at 37 °C for 5 days anaerobically. The microbe was further cultured in 20 ml of liquid growth medium TSB at 37 °C for 4 days anaerobically and ready to use.

Prepare the growth medium agar plate without glycine (control) and with different levels (weight percentage) of glycine: 0.04, 0.05, 0.1 , 0.15, and 0.2%. For the fungi M. restricta and M. furfur, mLNA was used. For the bacteria S. epidermidis and C. acnes, TSA was used.

The optical density (OD) of each microbial culture was adjusted. For M. restricta, OD = 2, 1, 0.5 and 0.25; For M. furfur, OD = 0.8, 0.4, 0.2 and 0.1 ; For S. epidermidis and C. acnes, OD = 0.6, with serial 10-fold dilutions to achieve 0.6, 0.6X10M , 0.6X10^A-2, 0.6X10^A-3, 0.6X10^A-4, 0.6X10^A-5, and 0.6X10^A-6. Transfer 4pL of each microbial inoculum onto the corresponding plates and incubate to monitor microbial growth. Duplicate experimental sets were performed. Finally, the plates with the growing colonies were visually observed at daily base up to 7 days for Malassezia and C. acnes and up to 2 days for S. epidermidis. The microbial growth at different conditions were compared by colony densities. “No inhibition” means there’s no change of microbial colony densities visually observed, “inhibition” means the growth of the microbes is inhibited with at least 75% reduced microbial colony densities, and “no growth” means almost no visible growth of microbial colony is observed.

Results

The growth of microbes was recorded and showed in Table- 1 below:

TABLE - 1

It is evident from the table above that samples 1 to 5 comprising glycine at a level consistent with the present invention were able to selectively inhibit the growth of harmful microbes (/W. restricta) while having no inhibition effect on the growth of beneficial microbes (S.epidermidis and C. acnes). Furthermore, the result in table above indicates that the using of composition comprising glycine at a level consistent with the present invention has less impact on the number of other Malassezia genus, such as Malassezia furfur (M. furfur).

Example 2

The antimicrobial efficacy of different amino acids was tested against Malassezia restricta (M. restricta). M. restricta growth was monitored with or without adding 0.5% of different amino acids by culturing M. restricta in mLNB liquid medium for 3 days. To make sure different amino acids do not impact the pH of the growth medium, the pH of the solutions was all adjusted to the same level of pH 5.5. The same protocol was used to observe the growth of the microbes.

Results

The growth of microbes was recorded and showed in Table-2 below:

TABLE - 2

It is evident from the table above that sample 6 comprising glycine at a level consistent with the present invention were able to inhibit the growth of harmful microbes {M. restricta), while the samples comprising other amino acids cannot.

Example 3

This example demonstrated the leave-on lotions comprising glycine at certain level can inhibit the growth of Malassezia restricta {M. restricta). The compositions according to the formulations detailed in Table-3 are prepared. All ingredients are expressed by weight percent of the total formulation, and as level of active ingredient. Table - 3

Experimental methods: Use the Agar Dilution MIC assay as Example 1 Prepare mLNA with lotion samples. Mix 10g lotion and 90g 1.1 X mLNA medium.

The optical density (OD) of M. restricta was adjusted to OD = 2, 1 , 0.5 and 0.25. 4 P L of M. restricta. suspension was added onto the agar, cultured at 32 °C for 7 days. M. restricta growth was visually observed at daily base up to 7 days. The microbial growth were compared by colony densities. “No inhibition” means there’s no change of microbial colony densities visually observed, “inhibition” means the growth of the microbes is inhibited with at least 75% reduced microbial colony densities, and “no growth” means almost no visible growth of microbial colony is observed.

Results

The growth of microbes was recorded and showed in Table-4 below:

Table - 4

It is evident from the table above that compositions comprising glycine at a level consistent with the present invention (Samples 7 to 9) were able to inhibit the growth of harmful microbes (M. restricta).

Claims

1. Use of glycine, or a composition comprising glycine in inhibiting the growth of Malassezia restricta when applied on an external surface of a human body; wherein the composition comprises at least 0.04% of glycine by weight of the composition.

2. Use as claimed in claim 1 wherein the composition comprising glycine in an amount of from 0.04 to 10%, preferably from 0.15 to 5%, more preferably from 0.2 to 2% by weight of the composition.

3. Use as claimed in claims 1 or 2 wherein the surface is human skin, preferably scalp.

4. Use as claimed in any of claims 1 to 3 wherein said use is for inhibiting dandruff to promote scalp health.

5. Use as claimed in any of claims 1 to 4 wherein said use has no inhibition effect on the growth of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes.

6. Use as claimed in any of claims 1 to 5 wherein the composition is a hair or scalp composition, preferably leave-on hair or scalp composition.

7. Use of glycine or a composition comprising glycine in microbiome balancing on an externalsurface of a human body, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes', wherein the composition comprises at least 0.04% of glycine by weight of the composition.

8. Use as claimed in claim 7 wherein the surface is human skin, preferably scalp.

9. Use as claimed in claims 7 or 8 wherein said use is for inhibiting dandruff to promote scalp health. A method of applying glycine or a composition comprising glycine on an external surface of a human body for inhibiting the growth of Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition. A method of applying glycine or a composition comprising glycine on an external surface of a human body for microbiome balancing, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes’, wherein the composition comprises at least 0.04% of glycine by weight of the composition. A method of applying glycine or a composition comprising glycine on an external surface of a human body for ensuring the growth of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes while protecting the surface against harmful microbes which is Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition. A method as claimed in any of claims 10 to 12 wherein the surface is human skin, preferably scalp. Glycine or a composition comprising glycine for use in microbiome balancing on an external surface of a human body, wherein balancing means selectively reducing the number of harmful microbes which is Malassezia restricta, while having no reduction effect on the number of commensal microbes selected from Staphylococcus epidermidis and Cutibacterium acnes’, wherein the composition comprises at least 0.04% of glycine by weight of the composition. Glycine or a composition comprising glycine for use in inhibiting the growth of Malassezia restricta’, wherein the composition comprises at least 0.04% of glycine by weight of the composition.