Process for dyeing keratin fibres using a composition comprising indican, hydrolase and oxidase enzymes and water

Abstract

A subject-matter of the present invention is a method for the dyeing of keratin fibres employing a composition C comprising: (i) indican of formula (I) and / or a powder containing it; (ii) at least one exogenous enzyme of hydrolase type; (iii) at least one exogenous enzyme of oxidase type; and (iv) water.

Description

[0001] DESCRIPTION

[0002] TITLE: Process for dyeing keratin fibres using a composition comprising indican, hydrolase and oxidase enzymes and water

[0003] The present invention relates to a method for dyeing keratin fibres employing a composition comprising indican and / or a powder containing it, at least one exogenous enzyme of hydrolase type, at least one exogenous enzyme of oxidase type and water.

[0004] Technical field

[0005] Two major methods for dyeing keratin fibres, especially human keratin fibres, and especially head hair, are known.

[0006] The first, known as oxidation dyeing or permanent dyeing, consists in employing one or more oxidation dye precursors, more particularly one or more oxidation bases, optionally in combination with one or more couplers.

[0007] The second dyeing method, known as direct dyeing or semi-permanent dyeing, comprises the application of direct dyes, which are coloured and colouring molecules having an affinity for fibres. Given the nature of the molecules employed, they tend to remain at the surface of the fibre and penetrate relatively little into the fibre, when compared with the small molecules of oxidation dye precursors. The main advantage of this type of dyeing is that it does not require an oxidizing agent, which limits the degradation of the fibres.

[0008] A very well-known natural dye is indigo (see Ullmann's Encyclopaedia of Industrial Chemistry, Hair Preparation, point 5.2.3, 2006, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim; 10.1002 / 14356007.al2 571.pub2).

[0009] However, the colouring resulting from indican, corresponding to the precursor of indigo, and / or natural powder containing it, such as indigo powder resulting from crushed indigo plant leaves, generally results in grey-green colourings which change very rapidly over time.

[0010] The colourings resulting from these combinations are not very intense, dull, with a very unsightly major turning in colour. It is not uncommon to observe this change during the first week after dyeing, which makes this technology not very predictive.

[0011] In addition, this colouring requires large amounts of powder and of water. In addition, the colour visibility on keratin fibres generally requires a long application time of greater than 45 minutes, generally from 1 hour to 24 hours.

[0012] These points make the technology relatively unattractive because its use and its rinsing are very difficult. In addition, head hair coloured by this combination is particularly difficult to disentangle.

[0013] The process responsible for the colouring for indican and / or a natural powder containing it is a process involving in particular endogenous enzymes of hydrolase type, that is to say which are naturally present in this powder.

[0014] This is because, via a first enzymatic reaction of degluco sylation of indican, indoxyl is obtained which, by oxidation with oxygen or via a second enzymatic reaction, is transformed into indigo, making it possible to deliver a purple-blue colouration.

[0015] Nevertheless, this enzymatic process is lengthy, requires the use of hot water and of large amounts of ingredients, and the colouring obtained changes over time.

[0016] There thus exists a need to develop colouring methods starting from indican and / or from powder containing it, making it possible to improve the kinetics of the enzymatic process, and thus of colouring, and consequently to significantly increase the visibility of the colouring in short application times, that is to say rapid colouring with a good colour build-up, while obtaining natural shades which are intense, stable and without turning over time.

[0017] Moreover, the formulation of environmentally-friendly cosmetic products, that is to say products, the design and the development of which take environmental issues into account, is becoming a major concern in contributing to answering global challenges.

[0018] It is thus proving to be essential to provide more sustainable cosmetic methods, thus making it possible to meet these environmental challenges. The present invention is specifically targeted at meeting all or some of these needs.

[0019] Disclosure of the invention

[0020] A subject-matter of the present invention is a method for the dyeing of keratin fibres employing a composition C comprising:

[0021] (i) indican of following formula (I): and / or a powder containing it;

[0022] (ii) at least one exogenous enzyme of hydrolase type;

[0023] (iii) at least one exogenous enzyme of oxidase type; and

[0024] (iv) water.

[0025] The method according to the invention makes it possible to obtain an intense and chromatic colouring of keratin fibres with a good build up in the colour, in a short time, and without turning in colour over time, in particular at least after 7 days after application. In addition, the method according to the invention makes it possible to obtain an improved colour stability.

[0026] Other subject-matters, characteristics, aspects and advantages of the invention will become even more clearly apparent on reading the description and the examples which follow.

[0027] The expression “at least one" means one or more.

[0028] Unless otherwise indicated, the limits of a range of values are included in that range, in particular in the expressions “of between” and “ranging from ... to ...”.

[0029] Within the meaning of the present invention, the expression “of greater than” and respectively the expression “of less than” are understood to mean an open range which is strictly greater, or respectively strictly less, and thus that the limits are not included.

[0030] According to the present application, the term “keratin fibres” is understood to mean particularly human keratin fibres, such as head hair, eyelashes, eyebrows and body hair, preferentially head hair, eyebrows and eyelashes, more preferentially still head hair.

[0031] Within the meaning of the present invention, the term “head hair" is understood to mean the hair of the head. This term does not correspond to body hair, eyebrows or eyelashes. Indican of formula (I) and / or powder containing it

[0032] As indicated above, the composition C employed in the context of the method according to the invention comprises indican of following formula (I): and / or a powder containing it.

[0033] Indican, a colourless material, is a precursor of indigo.

[0034] Indican is found naturally in certain plants, especially in indigoferous plants, in particular in the leaves of the indigo plant.

[0035] Preferably, mention may be made, as indigoferous plants in which indican is found, of numerous species resulting from the genera:

[0036] - Indigofera, such as Indigofera tinctoria, Indigo suffruticosa, Indigofera articulata, Indigofera arrecta, Indigofera gerardiana, Indigofera argentea, Indigofera indica, Indigofera longiracemosa',

[0037] - Isatis, such as Isatis tinctoria;

[0038] - Polygonum or Persicaria such as Polygonum tinctorium (Persicaria tinctoria) ;

[0039] - Wrightia, such as Wrightia tinctoria',

[0040] - Calanthe, such as Calanthe veratrifolia; and

[0041] - Baphicacanthus, such as Baphicacanthus cusia.

[0042] Leaves of the indigo plant are preferably dried and ground into powder before being introduced into the composition C applied in the method according to the invention.

[0043] Thus, according to a first preferred embodiment of the invention, indican is introduced into the composition C in powder form.

[0044] Advantageously, according to this first preferred embodiment of the invention, the powder containing indican of formula (I) comprises indigo powder, preferably powder of indigo resulting from indigoferous plant(s), in particular from leaves of indigoferous plant(s), more preferentially of the genus Indigofera, and more particularly Indigofera tinctoria, and better still the powder containing indican of formula (I) is indigo powder, preferably powder of indigo resulting from indigoferous plant(s), in particular from leaves of indigoferous plant(s), more preferentially of the genus Indigofera, and more particularly Indigofera tinctoria.

[0045] According to the invention, the powder containing indican of formula (I) is different from an extract of indican of formula (I).

[0046] According to a second embodiment of the invention, indican is introduced into composition C in the form of an extract of indican of formula (I), preferably an aqueous extract.

[0047] The first embodiment is the preferred embodiment in the context of the invention.

[0048] "Extract of indican of formula (I)" is understood to mean a product of maceration of indigoferous plants in at least one aqueous and / or organic solvent.

[0049] The extract of indican of formula (I) can be obtained by mixing 1g to 100g of powder containing indican of formula (I) with 100g of an aqueous and / or organic solvent for 1 to 15 minutes at a temperature ranging from 15°C to 90°C. Then, the biomass is separated from the liquid medium, preferably by filtration, in order to obtain a filtrate comprising the indican of formula (I).

[0050] The formation of indigo from indican is the result of an enzymatic process.

[0051] A first enzymatic deglucosylation reaction (RE1) of indican of formula (I) results in indoxyl of following formula (II):

[0052] This enzymatic reaction additionally produces a glucose residue.

[0053] Then, indoxyl of formula (II) can be subjected to a second oxidative enzymatic reaction (RE2) to form indigo of following formula (III):

[0054] Advantageously, the total content of indican of formula (I) ranges from 0.1% to 20% by weight, preferably from 0.5% to 15% by weight, more preferentially from 0.7% to 10% by weight, more preferentially still from 0.8% to 9% by weight and better still from 0.9% to 8% by weight, with respect to the total weight of the powder containing it.

[0055] Advantageously, the total content of powder containing indican of formula (I) ranges from 0.1% to 50% by weight, preferably from 0.5% to 45% by weight, more preferentially from 1% to 40% by weight, more preferentially still from 3% to 35% by weight and better still from 5% to 30% by weight, with respect to the total weight of the composition C.

[0056] Advantageously, the total content of indican of formula (I) ranges from 0.0001% to 10% by weight, preferably from 0.0015% to 6.75% by weight, more preferentially from 0.007% to 4% by weight, more preferentially still from 0.024% to 3.15% by weight and better still from 0.045% to 2.4% by weight, with respect to the total weight of the composition C.

[0057] Exogenous enzyme of hydrolase type

[0058] As indicated above, the composition C employed in the context of the method according to the invention comprises (ii) at least one exogenous enzyme of hydrolase type.

[0059] Within the meaning of the present invention, "exogenous enzyme" is understood to mean an enzyme introduced externally into the medium, i.e. added in addition to the enzymes which may be naturally present in the indican-containing powder employed in the method according to the invention. The exogenous enzyme can be identical to or different from those which may be naturally present in the indican-containing powder employed in the method according to the invention.

[0060] Within the meaning of the present invention, “enzyme of hydrolase type” is understood to mean an enzyme which catalyses the cleavage of chemical bonds by the addition of a water molecule and which is classified under the EC 3 nomenclature of the IUBMB (International Union of Biochemistry and Molecular Biology, iubmb.org).

[0061] Exogenous enzymes of hydrolase type are involved in the enzymatic reaction RE1 as described above.

[0062] They are used in particular in the process for the deglucosylation of indican (RE1) present in the leaves of the indigo plant, to give indoxyl.

[0063] Advantageously, the exogenous enzyme(s) of hydrolase type (ii) are chosen from glycosylases (EC 3.2), preferably from glycosidases (EC 3.2.1), more preferentially from P-glucosidases (E C 3.2.1.21), cellulases (EC 3.2.1.4), and their mixtures.

[0064] The glycosidases of the invention are glycoside hydrolase enzymes which catalyse the hydrolysis of glycoside bonds, releasing at least one glycoside compound.

[0065] The glycosidases within the meaning of the present invention can be in solid form, in particular powder form, in solution or immobilized on a solid support.

[0066] "Solid support" carrying one or more enzyme(s) is understood to mean a "matrix" on which one or more enzymes has / have been immobilized; said enzymes have retained their catalytic functions. Said enzymes are immobilized on a support by chemical or physical immobilization methods and remain in a defined space within which they can be used several times in succession or continuously.

[0067] Mention may be made, as methods for the immobilization of said enzymes, of the conventional methods known to a person skilled in the art (see, for example, "Enzyme Immobilization: An Overview on Techniques and Support Materials, 3 Biotech"; 3(1): 1-9 (2013 Feb), Doctoral thesis, Ecole Nat. Sup. Chimie Montpellier, H. Jarrar, "Bioelectrodes enzymatiques pour des applications en biocapteurs et en biopiles" ["Enzymatic Bioelectrodes for Applications in Biosensors and in Biocells"] (16 / 12 / 2011), in particular chap. 1.7), such as adsorption, crosslinking, covalent grafting, encapsulation or recognition by affinity / bioaffinity, such as recognition of antigen / antibody type.

[0068] The matrices used are those known to a person skilled in the art. Mention may in particular be made of i) organic polymers, such as agarose, cellulose, dextrans, polymers, such as polyvinyl chloride, acrylates, nylons, polystyrene, ii) inorganic materials: silica in the form of microporous glass beads and of silica gel and iii) hybrids of the two matrices i) and ii) above, such as agarose-acrylamide and polymer- coated silica.

[0069] Preferably, the matrix is other than polysaccharides or polysaccharide derivatives.

[0070] Within the meaning of the present invention, "polysaccharide derivatives" is understood to mean a compound obtained by chemical modification of a polysaccharide, and comprising at least two monosaccharides linked together by O- glycoside bonds within the structure of said compound.

[0071] The glycosidase enzyme(s) can be of plant, animal, fungal (yeasts, moulds, fungi) or bacterial origin.

[0072] The glycosidases can also be obtained by biotechnology. P-Glucosidases carry out a hydrolysis of the -O-glucoside bond in P- glucosides of a monosaccharide or oligosaccharide comprising a glucose part.

[0073] These enzymes are known under the names of gentiobiase, cellobiase, emulsin, elaterase, aryl-P-glucosidase, P-D-glucosidase, P-glucoside glucohydrolase, arbutinase, amygdalinase, p-nitrophenyl P-glucosidase, primeverosidase, amygdalase, linamarase, salicilinase and P-l,6-glucosidase (EC 3.2.1.21). The latter are also known under the names amygdalin P-glucosidase, prunasin P-glucosidase, vicianin P-glucosidase, glucosylceramidase, and enzymes of cellulase type produced essentially by fungi, bacteria, and protozoa which catalyse the hydrolysis of cellulose.

[0074] Mention may be made, as examples of glycosidases, of:

[0075] - the cellulase(s) sold under the name “ Cellulase from Trichoderma reesei ", for example by Sigma- Aldrich,

[0076] - the P-glucosidases sold by DuPont under the names Multifect® CX 15L and Optimase CX 15L; glucosidases of natural origin, such as almond P-glucosidases, for example in particular sweet almond P-glucosidase; the almond P-glucosidase sold by Sigma- Aldrich under the name 49290 “P-Glucosidase from almonds” lyophilized powder,

[0077] - and their mixtures.

[0078] Advantageously, the total content of exogenous enzyme(s) of hydrolase type (ii) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001 % to 0.5 % by weight and better still from 0.0025 % to 0.1 % by weight, with respect to the total weight of the composition C.

[0079] Advantageously, the total content of glycosylase(s) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001% to 0.5% by weight and better still from 0.0025% to 0.1% by weight, with respect to the total weight of the composition C.

[0080] Preferably, the total content of glycosidase(s) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001% to 0.5% by weight and better still from 0.0025% to 0.1% by weight, with respect to the total weight of the composition C. Exogenous enzyme of oxidase type

[0081] As indicated above, the composition C employed in the context of the method according to the invention comprises (iii) at least one exogenous enzyme of oxidase type.

[0082] Within the meaning of the present invention, “enzyme of oxidase type” is understood to mean an oxidoreductase enzyme which catalyses oxidation-reduction reactions involving the transfer of electrons, preferably 4 electrons, from a given substrate to molecular oxygen (O2), thus resulting in the formation of oxidized products and of reactive oxygen derivatives, and which is classified under the EC 1 nomenclature of the IUBMB (International Union of Biochemistry and Molecular Biology, iubmb.org).

[0083] Exogenous enzymes of oxidase type are involved in the enzymatic reaction RE2 as described above.

[0084] They are used in particular in the process of oxidation of indoxyl to give indigo (RE2), responsible for the purple-blue colour.

[0085] Advantageously, the exogenous enzyme(s) of oxidase type (iii) are chosen from polyphenol oxidases (EC 1.10.3), preferably from laccases (EC 1.10.3.2), tyrosinases (EC 1.10.3.1) and their mixtures, more preferentially from laccases.

[0086] These laccases can in particular be chosen from laccases of plant origin, of animal origin, of fungal origin (yeasts, moulds, fungi) or of bacterial origin, it being possible for the source organisms to be mono- or multicellular.

[0087] The laccases can also be obtained by biotechnology.

[0088] Mention may be made, among the laccases of plant origin which can be used according to the invention, of the laccases produced by plants carrying out chlorophyll synthesis, such as those indicated in Patent Application FR-A-2 694 018.

[0089] Mention may be made, among the laccases of fungal origin, optionally obtained by biotechnology, which can be used according to the invention, of the laccase(s) resulting from Polyporus versicolour, from Rhizoctonia praticola and from Rhus vemicifera, such as described, for example, in Patent Applications FR-A-2 112 549 and EP-A-504 005; the laccases described in Patent Applications WO 95 / 07988, WO 95 / 33836, WO 95 / 33837, WO 96 / 00290, WO 97 / 19998 and WO 97 / 19999.

[0090] Within the meaning of the present invention, the enzymes of oxidase type can be in solid form, in particular in powder form, in solution or immobilized on a solid support. Mention may be made, among the exogenous enzymes of oxidase type, for example, of those sold under the trade name “Laccase from Trametes versicolor “Laccase from Agaricus bisporus" or also “Laccase from Aspergillus sp”, “Laccase from Rhus vernicifera” or “Tyrosinase from mushroom”, for example by Sigma- Aldrich.

[0091] By virtue of the exogenous enzymes of hydrolase type and of the exogenous enzymes of oxidase type, respectively involved in the enzymatic deglucosylation and oxidation reactions, the kinetics of said enzymatic reactions are significantly increased, advantageously resulting in the formation of indigo, reducing the leave-on time and thus very significantly increasing the intensity and the visibility of the colouring while limiting the turning in colour over time.

[0092] Advantageously, the total content of exogenous enzyme(s) of oxidase type (iii) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001 % to 0.5 % by weight and better still from 0.0025 % to 0.1 % by weight, with respect to the total weight of the composition C.

[0093] Advantageously, the total content of polyphenol oxidase(s) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001% to 0.5% by weight and better still from 0.0025% to 0.1% by weight, with respect to the total weight of the composition C.

[0094] Advantageously, the total content of laccase(s) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001% to 0.5% by weight and better still from 0.0025% to 0.1% by weight, with respect to the total weight of the composition C.

[0095] Advantageously, the total content of exogenous enzymes of hydrolase type (ii) and of oxidase type (iii) ranges from 0.0002% to 20% by weight, preferably from 0.0005% to 10% by weight, more preferentially from 0.001% to 2% by weight, more preferentially still from 0.002% to 1% by weight and better still from 0.005% to 0.2% by weight, with respect to the total weight of the composition C.

[0096] Advantageously, if only a single supported exogenous enzyme is employed (either oxidase or hydrolase), the ratio by weight of the total content of exogenous enzymes of hydrolase type (ii) to the total content of exogenous enzymes of oxidase type (iii) ranges from 0.1 to 100, preferably from 0.5 to 50, more preferentially from 0.7 to 20, more preferentially still from 0.8 to 12; better still, said ratio by weight is equal to 10.

[0097] Advantageously, if none of the exogenous enzymes (hydrolase and oxidase) is employed in supported form or if both types of enzymes are employed in supported form, the ratio by weight of the total content of exogenous enzymes of hydrolase type (ii) to the total content of exogenous enzymes of oxidase type (iii) ranges from 0.1 to 10, preferably from 0.5 to 5, more preferentially from 0.7 to 2, more preferentially still from 0.8 to 1.2; better still, said ratio by weight is equal to 1.

[0098] Within the meaning of the present invention, "supported enzyme" is understood to mean an enzyme immobilized on a solid support.

[0099] Water

[0100] The composition C employed in the context of the method according to the invention comprises water.

[0101] Advantageously, the total content of water (iv) ranges from 30% to 95% by weight, preferably from 35% to 90% by weight, more preferentially from 40% to 85% by weight with respect to the total weight of the composition C.

[0102] Henna powder

[0103] The composition C employed in the context of the method according to the invention can additionally comprise henna powder.

[0104] "Henna powder" is understood to mean a pure natural product originating from henna plants, reduced to fine particles by grinding or other mechanical means.

[0105] According to the invention, henna powder is different from a henna extract.

[0106] "Henna extract" is understood to mean a product of maceration in at least one aqueous and / or organic solvent.

[0107] The henna powder is obtained from Lawsoma inermis leaves, preferably reduced to fine particles by mechanical grinding.

[0108] Advantageously, when the composition C comprises henna powder, the total content of henna powder ranges from 0.1% to 50% by weight, preferably from 0.5% to 45% by weight, more preferentially from 1% to 40% by weight, more preferentially still from 3% to 35% by weight and better still from 5% to 30% by weight, with respect to the total weight of the composition C. Additional agent

[0109] The composition C employed in the context of the method according to the invention can comprise at least one additional agent chosen from isatin, cysteine and their mixture.

[0110] According to a preferred embodiment of the invention, the composition C comprises at least two additional agents, which are isatin and cysteine.

[0111] Advantageously, the composition C does not comprise cysteine as additional agent.

[0112] According to a preferred embodiment, the composition C comprises at least isatin and does not comprise cysteine as additional agent.

[0113] Advantageously, the composition C does not comprise isatin as additional agent.

[0114] According to a preferred embodiment of the invention, the composition C comprises at least cysteine and does not comprise isatin as additional agent.

[0115] According to another embodiment of the invention, the composition C does not comprise an additional agent chosen from isatin, cysteine and their mixture.

[0116] Advantageously, when it is (they are) present, the total content of additional agent(s) ranges from 0.001% to 5% by weight, with respect to the total weight of the composition C.

[0117] Additives

[0118] The composition C employed in the context of the method according to the invention can additionally comprise additives commonly used in cosmetics, such as, for example, antifoaming agents, thickening agents, moisturizing agents, clays, inorganic fillers, UV-screening agents, fragrances, anionic, cationic, non-ionic or amphoteric surfactants, vitamins, preservatives, silicones, waxes, mordants and their mixtures. These additives can be present in said composition C in an amount ranging from 0% to 20% by weight, with respect to the total weight of the composition C.

[0119] A person skilled in the art will take care to choose these optional additives and their amounts so that they do not adversely affect the properties of said composition C.

[0120] Preferably, the composition C employed in the context of the method according to the invention comprises a total content of mordants chosen from organic or inorganic iron, aluminium, titanium, calcium, manganese, copper, zinc or strontium salts, and the mixtures of these salts, of less than 1% by weight, preferably of less than 0.1% by weight, more preferentially of less than 0.01% by weight, more preferentially still of less than 0.001% by weight, with respect to the weight of the composition C.

[0121] More preferentially, the composition C employed in the context of the method according to the invention is devoid of mordants chosen from organic or inorganic iron, aluminium, titanium, calcium, manganese, copper, zinc or strontium salts, and the mixtures of these salts.

[0122] Method

[0123] The composition C can be employed on wet or dry head hair, in rinse-out or leave-on mode.

[0124] Advantageously, the application of the composition C is carried out between 20°C and 50°C, preferably between 20°C and 45°C.

[0125] The composition C can optionally be applied to keratin fibres after the application of a shampoo and of a rinsing with water.

[0126] Preferably, the application of the composition C is carried out after the application of a shampoo and then of a rinsing with water.

[0127] After the application of the composition C, and after optionally a combing, said composition C can be left on the keratin fibres.

[0128] Advantageously, the composition C is left on the keratin fibres for a period of time of less than or equal to 45 minutes, preferably of less than or equal to 30 minutes, more preferentially ranging from 1 minute to 30 minutes, more preferably still from 5 minutes to 30 minutes.

[0129] When the composition C is left on the keratin fibres, said keratin fibres can be covered in an occlusive manner, for example using a plastic film or a cap.

[0130] After the application of the composition C, the keratin fibres can be rinsed with water and / or subjected to one or more shampooing operations.

[0131] Preferably, the keratin fibres are rinsed with water and then optionally subjected to one or more shampooing operations after the application of the composition C.

[0132] The keratin fibres can subsequently be rinsed with water after the application of a shampoo.

[0133] After the application of the composition C to the keratin fibres, said keratin fibres can be dried. The keratin fibres can be dried in the open air or using a drying device, such as a hood dryer, a hand-held hair dryer or a Climazon. When the drying stage is carried out with a hood dryer or a hand-held hair dryer, the temperature of the drying is greater than 40°C.

[0134] Preferably, if the keratin fibres are dried after the application of the composition C, they are dried, in addition to a supply of heat, with a flow of air.

[0135] Advantageously, the method according to the invention does not comprise a stage of denaturation, such as denaturation by heating, and / or of separation of the endogenous enzymes of the indican-containing powder.

[0136] In fact, the powder containing indican as described above can contain endogenous enzymes, i.e. enzymes naturally present in said indican-containing powder.

[0137] The denaturation stage can, for example, be carried out by heating, in particular at a temperature ranging from 60°C to 200°C.

[0138] The separation stage can, for example, be carried out by extraction using a solvent.

[0139] The indican of formula (I) can be introduced, or not, into the composition C in the form of an extract of indican of formula (I).

[0140] Preferably, the indican of formula (I) is not introduced into the composition C in the form of an extract of indican of formula (I).

[0141] The present invention will now be described more specifically by means of examples, which do not in any way limit the scope of the invention. However, the examples make it possible to support specific characteristics, alternative forms and preferred embodiments of the invention.

[0142] Examples

[0143] The compositions A, B and D, as described in Table 1 below, were prepared: the amounts are expressed as g of starting material as obtained, unless otherwise mentioned.

[0144] [Table 1] (1) sold by Sigma Aldrich under the reference 13750

[0145] (2) 50 mg / ml aqueous solution of "P-Glucosidase from almonds"

[0146] (3) 50 mg / ml aqueous solution of "Cellulase from Trichoderma reesei”

[0147] (4) 50 mg / ml aqueous solution of "Laccase from Trametes versicolor”

[0148] The compositions A, B and D were prepared by mixing the indican of formula (I) with water at 19°C. The mixture was then stirred vigorously for 30 seconds until a homogeneous mixture was obtained.

[0149] The enzymes of glucosidase type and of oxidase type were subsequently added to the mixture for the preparation of compositions A and B.

[0150] The enzyme of glucosidase type was subsequently added to the mixture for the preparation of composition D.

[0151] The combined mixture was homogenized with a wooden spoon, or a spatula of “Maryse” type in order to produce a poultice.

[0152] The poultice obtained was applied to locks of natural Caucasian head hair containing 90% of white hairs (NW) of 0.5 g, on both faces of the locks.

[0153] The locks were then left for 30 minutes at 33°C under a transparent plastic film.

[0154] On conclusion of the leave-on time, the locks were rinsed with water until the dyeing composition had been completely removed, and then they were subjected to a shampooing operation, the protocol of which is described below.

[0155] The methods involving the use of composition A or B are methods according to the invention. The method involving the use of composition D is a comparative method.

[0156] The locks were then rinsed with water and dried with a hand-held hair dryer.

[0157] Protocol of the shampooing operation:

[0158] The locks of dyed head hair were combed and moistened under water at 35°C before being passed between the fingers 5 times for 5 seconds. The locks of head hair were subsequently squeezed dry between two fingers.

[0159] A standard shampoo (Gamier Ultra Doux) was applied uniformly to the dyed locks, in a proportion of 0.4 g of standard shampoo per gram of locks, the locks of head hair being massaged gently along their lengths (6 passes) for 15 seconds, from the root to the end. The locks of head hair were subsequently placed on a watch glass and left for 1 minute.

[0160] Subsequently, the locks of head hair were rinsed with water while passing the locks between the fingers (15 passes). The locks of head hair were subsequently squeezed dry between two fingers.

[0161] Results

[0162] The build-up in the colouring of the locks was evaluated in the CIE L*a*b* system using a Konica Minolta CM2600d spectrophotometer (illuminant D65).

[0163] In this L*a*b* system, L* represents the intensity of the colour, a* indicates the green / red colour axis and b* indicates the blue / yellow colour axis.

[0164] The build-up in the colouring is evaluated by the colour difference AE between the undyed locks and the dyed locks. The higher the value of AE, the greater the buildup in the colouring.

[0165] The AE value is calculated according to the following equation:

[0166] In this equation, L*, a* and b* represent the values measured after dyeing the head hair and Lo*, ao* and bo* represent the values measured before dyeing the head hair.

[0167] The measurements were carried out immediately after dyeing (T = 0 day), then optionally after 5 days (T = 5 days) and then after 7 days (T = 7 days).

[0168] The results are collated in Table 2 below.

[0169] [Table 2] It is clearly apparent from the above table that the locks of head hair dyed by means of the methods according to the invention exhibit a good build-up in the colour immediately after dyeing (at T = 0 day).

[0170] Moreover, the methods according to the invention make it possible to obtain colourings which are stable after 7 days, i.e. colourings which do not change after 7 days.

[0171] Furthermore, it is clear from the table above that the locks of head hair dyed by means of the methods according to the invention (involving the use of composition A or B) produce stable colours after 7 days, namely colours that do not change after 7 days, whereas this is not the case for the locks of head hair dyed by means of the comparative method (involving the use of composition D).

[0172] Consequently, the method according to the invention, thanks to the presence of the enzyme of oxidase type, provides improved colour stability.

Claims

CLAIMS1. Method for the dyeing of keratin fibres employing a composition C comprising:(i) indican of following formula (I):and / or a powder containing it;(ii) at least one exogenous enzyme of hydrolase type;(iii) at least one exogenous enzyme of oxidase type; and(iv) water.

2. Method according to Claim 1, characterized in that the powder containing indican of formula (I) comprises indigo powder, preferably powder of indigo resulting from indigoferous plant(s), in particular from leaves of indigoferous plant(s), more preferentially of the genus Indigofera, and more particularly Indigofera tinctoria, and better still the powder containing indican of formula (I) is indigo powder, preferably powder of indigo resulting from indigoferous plant(s), in particular from leaves of indigoferous plant(s), more preferentially of the genus Indigofera, and more particularly Indigofera tinctoria.

3. Method according to Claim 1 or 2, characterized in that the total content of indican ranges from 0.1% to 20% by weight, preferably from 0.5% to 15% by weight, more preferentially from 0.7% to 10% by weight, more preferentially still from 0.8% to 9% by weight and better still from 0.9% to 8% by weight, with respect to the total weight of the powder containing it.

4. Method according to any one of the preceding claims, characterized in that the total content of powder containing indican of formula (I) ranges from 0.1% to 50% by weight, preferably from 0.5% to 45% by weight, more preferentially from 1%to 40% by weight, more preferentially still from 3% to 35% by weight and better still from 5% to 30% by weight, with respect to the total weight of the composition C.

5. Method according to any one of the preceding claims, characterized in that the total content of indican of formula (I) ranges from 0.0001% to 10% by weight, preferably from 0.0015% to 6.75% by weight, more preferentially from 0.007% to 4% by weight, more preferentially still from 0.024% to 3.15% by weight and better still from 0.045% to 2.4% by weight, with respect to the total weight of the composition C.

6. Method according to any one of the preceding claims, characterized in that the exogenous enzyme(s) of hydrolase type (ii) are chosen from glycosylases, preferably from glycosidases, more preferentially from P-glucosidases, cellulases and their mixtures.

7. Method according to any one of the preceding claims, characterized in that the total content of exogenous enzyme(s) of hydrolase type (ii) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001% to 0.5% by weight and better still from 0.0025% to 0.1% by weight, with respect to the total weight of the composition C.

8. Method according to any one of the preceding claims, characterized in that the exogenous enzyme(s) of oxidase type (iii) are chosen from polyphenol oxidases, preferably from laccases, tyrosinases and their mixtures, more preferentially from laccases.

9. Method according to any one of the preceding claims, characterized in that the total content of exogenous enzyme(s) of oxidase type (iii) ranges from 0.0001% to 10% by weight, preferably from 0.00025% to 5% by weight, more preferentially from 0.0005% to 1% by weight, more preferentially still from 0.001% to 0.5% by weight and better still from 0.0025% to 0.1% by weight, with respect to the total weight of the composition C.

10. Method according to any one of the preceding claims, characterized in that the total content of exogenous enzymes of hydrolase type (ii) and of oxidase type (iii) ranges from 0.0002% to 20% by weight, preferably from 0.0005% to 10% by weight, more preferentially from 0.001% to 2% by weight, more preferentially still from 0.002% to 1% by weight and better still from 0.005% to 0.2% by weight, with respect to the total weight of the composition C.

11. Method according to any one of the preceding claims, characterized in that the total content of water (iv) ranges from 30% to 95% by weight, preferably from 35% to 90% by weight and more preferentially from 40% to 85% by weight, with respect to the total weight of the composition C.

12. Method according to any one of the preceding claims, characterized in that the composition C comprises at least one additional agent chosen from isatin, cysteine and their mixture.

13. Method according to any one of Claims 1 to 11, characterized in that the composition C does not comprise isatin as additional agent.

14. Method according to any one of Claims 1 to 11 and 13, characterized in that the composition C does not comprise cysteine as additional agent.

15. Method according to any one of the preceding claims, characterized in that the indican of formula (I) is not introduced into the composition C in the form of an extract of indican of formula (I).

16. Method according to any one claims 1 and 5 to 14, characterized in that indican is introduced into composition C in the form of an extract of indican of formula (I), preferably an aqueous extract.

17. Method according to any one of the preceding claims, characterized in that the composition C is left on the keratin fibres for a period of time of less than or equal to 45 minutes, preferably of less than or equal to 30 minutes, more preferentially ranging from 1 minute to 30 minutes, more preferentially still from 5 minutes to 30 minutes.

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