Lacto-fermented extract of at least one red algae of the order Palmariales, preparation process and cosmetic use of this extract

Abstract

The present invention relates to a lacto-fermented extract of at least one red alga of the order Palmariales, this red alga having been lacto-fermented by lactic acid bacteria. The invention also relates to a process for producing such a lacto-fermented extract. The invention further relates to the cosmetic use of such a lacto-fermented extract and of a composition comprising it. Figure 3

Description

Title of the invention: Lacto-fermented extract of at least one red algae of the order Palmanales, process for preparing and cosmetic use of this extract. Technical field

[0001] The present invention belongs to the technical field of cosmetics, and in particular to fermented and seaweed-based natural active extracts for use in skin whitening / lightening. Previous art

[0002] It is known to those skilled in the art to extract active compounds, such as seaweed extracts, from algal biomass for cosmetic use. The use of algal biomass, which is a natural biomass, offers numerous advantages. In particular, it reduces the use of synthetic chemicals, which has a positive impact on the health of users and on the environment.

[0003] Furthermore, it is also known to those skilled in the art to produce, for cosmetic use, extracts of lacto-fermented algae, particularly with lactic acid bacteria. Indeed, those skilled in the art are aware of the benefits that lactic acid bacteria can provide to the skin, notably by acting on the regulation of the skin microbiota, thus improving the skin's barrier function, for example.

[0004] Thus, Korean patent KR101409764B1 teaches the production of a lacto-fermented extract of the red algae Gelidium amansii, used for anti-wrinkle cosmetic action. In this Korean patent, this lacto-fermented extract of Gelidium amansii is notably used to produce, among other things, cosmetic compositions such as a softening lotion, a nourishing lotion, or a nourishing cream. KR101409764B1 specifically teaches that the lacto-fermented extract of Gelidium amansii is used to improve collagen production in fibroblasts. This application can, for example, be implemented to combat skin aging caused by ultraviolet (UV) radiation, as this radiation can inhibit the production of the procollagen protein.

[0005] However, in the current state of the art, there is no known lacto-fermented algae extracts capable of acting specifically on pigmentary mechanisms related to skin whitening / lightening, in particular by acting on melanocytes.

[0006] Nowadays, the skin, and especially facial skin, is largely impacted by numerous everyday environmental stressors, such as pollution in Urban environments, or ultraviolet radiation. These stressors accelerate skin cellular aging, which notably results in the appearance of pigment spots on the skin. Summary of the invention

[0007] The aim of the invention is therefore to address this gap in the field of cosmetics, by providing lacto-fermented cosmetic extracts based on algae which make it possible to reduce these pigment spots, by acting on the whitening / lightening of the skin.

[0008] In particular, the present invention relates to a lacto-fermented extract of at least one red alga of the order Palmariales, this red alga having been lacto-fermented by lactic acid bacteria.

[0009] The inventors of the present invention have demonstrated in a completely surprising and innovative way that a lacto-fermented extract of a specific type of red algae, of the order Palmariales, acts on skin pigmentation, and acts in particular on different skin pigmentation mechanisms.

[0010] A first pigmentary mechanism impacted by the extract according to the invention is the mechanism related to melanocytes, linked to the production of melanin (a phenomenon called melanogenesis). Melanin is a pigment, generally black or brown, which develops in reaction to UV radiation (UVA and UVB), and which can cause skin pigmentation in the form of spots, called, for example, age spots or sun spots. The lacto-fermented extract according to the invention slows down, or even stops, melanogenesis, thus reducing these pigment spots on the skin, which are generally considered undesirable.

[0011] A second pigmentary mechanism on which the extract according to the invention acts This is the mechanism linked to the production of lipofuscin. Lipofuscin is a brown cellular pigment that develops in the skin during the aging of lysosomes, which are present in all cells. The accumulation of lipofuscin in skin cells results in the appearance of brown spots on the skin. This phenomenon is primarily caused by exposure to UV radiation, particularly UVA. The lacto-fermented extract according to the invention reduces the accumulation of lipofuscin, thus reducing these brown spots on the skin.

[0012] A third pigmentary mechanism modified by the extract according to the invention is the mechanism related to protein carbonylation. During their lifetime in the human organism, proteins can undergo modifications that alter their structural and functional properties. An example of protein modification is their Carbonylation. This can be caused by environmental stresses, particularly oxidative stresses, such as those caused by air pollution or exposure to UV radiation (especially UVA). Carbonylation of skin proteins is one of the causes of cellular and tissue aging in the skin, and this phenomenon can manifest as increased skin pigmentation, for example, the appearance of age spots. The lacto-fermented extract according to the invention reduces this protein carbonylation, which can be harmful to the skin.

[0013] The inventors have discovered and demonstrated that the lacto-fermented red algae extract according to the invention can act on each of these pigmentary phenomena, making it possible to reduce skin discoloration, and in particular to reduce pigment spots, which are harmful to health and often considered unsightly. The invention thus provides the skin with a whitening / brightening effect. This reduction of pigment spots also has an impact on the skin's luminosity and radiance, which are also improved, as well as on the skin's texture.

[0014] Advantageously, the red algae of the order Palmariales is of the genus Palmaria.

[0015] More advantageously, the red algae of the genus Palmaria is the species Palmaria palmata.

[0016] The inventors have demonstrated that this specific red algae acts on the three pigmentary phenomena mentioned above, with very effective results on skin whitening / lightening for each of these mechanisms.

[0017] Advantageously, the red algae was lacto-fermented by lactic acid bacteria of the species Lactobacillus plantarum.

[0018] Lactic acid bacteria, and in particular those of the species Lactobacillus plantarum, advantageously strengthen the populations of microorganisms naturally present in the skin microbiota, thereby preventing, or at least reducing, the risk of disruption and imbalance of the skin microbiota. They also provide beneficial effects to the skin, particularly mature skin, as they possess various advantageous and sought-after properties, such as moisturizing, antioxidant, and anti-aging properties.

[0019] Preferably, the extract according to the invention is an aqueous extract.

[0020] According to an advantageous embodiment of the invention, the lactic acid bacteria are present in the lacto-fermented extract in the form of fragments.

[0021] Indeed, according to a technique for preparing the extracts of the invention, the lactic acid bacteria are not separated from the reaction medium, but are inactivated and fragmented. They therefore remain in the final algal extract in the form of fragments. These fragments include, in particular, pieces of the cell walls of the lactic acid bacteria. Such a lacto-fermented extract containing bacteria is therefore an aqueous extract, including water-soluble molecules, and also includes lipid compounds from fragments of bacterial membranes present in the extract.

[0022] The present invention also relates to a process for producing a lacto-fermented extract as defined above, comprising the following steps: - a step A) of lacto-fermentation of a red algae by lactic acid bacteria in an aqueous medium comprising sea salt, to form the lacto-fermented extract, the red algae being of the order Palmariales; - a step B) of filtration by clarification, to separate the residues of the red algae from the reaction medium; - a step C) of treatment of the reaction medium, to form the lacto-fermented extract.

[0023] To implement this method of preparing the extract according to the invention, the red algae used may have been cultivated or directly harvested. It may be dried and / or cut before being introduced into the reaction medium.

[0024] The duration of the lacto-fermentation stage is between 1 and 7 days.

[0025] According to one embodiment, step C) of processing constitutes a step additional filtration, to remove lactic acid bacteria from the lactofermented extract, this second filtration step being a sterilizing filtration.

[0026] According to this first embodiment, the process according to the invention results in the production of a lacto-fermented extract of a red algae that is free of lactic acid bacteria. The sterilizing filtration step, which is a finer filtration than clarification filtration (which is coarser using a membrane), eliminates the lactic acid bacteria that carried out the lacto-fermentation of the red algae used.

[0027] According to another embodiment, step C) of treatment constitutes an inactivation step of lactic acid bacteria within the lactofermented extract.

[0028] According to this second embodiment of the process of the invention, unlike the first embodiment detailed above, the final extract comprises fragments of lactic acid bacteria, which are, among other things, pieces of bacterial cell walls. This is due to the fact that this implementation of the process does not involve a second filtration step.

[0029] Preferably, the lactic acid bacteria in the final extract are inactivated by a heat treatment step. This heat treatment also fragments the bacteria, so that they are present in fragment form in the final extract. This heat treatment is carried out in an autoclaving chamber at a temperature of 120°C for a duration of between 10 and 30 minutes, and preferably 20 minutes.

[0030] Thus, the two types of extracts according to the invention, i.e. respectively with and without fragments of lactic acid bacteria, comprise cosmetic actives which have been extracted directly from the algae, as well as compounds which are derived from the transformation of algal biomass by lactic acid bacteria.

[0031] The present invention also relates to the use of a lacto-fermented extract as defined above in a cosmetic composition.

[0032] Advantageously, the use of a lacto-fermented extract according to the invention, or a composition comprising it, is for topical cosmetic application.

[0033] The extract according to the invention does not exhibit cytotoxic effects on skin cells. It can therefore be applied safely to the skin, without risk, and in particular without side effects.

[0034] More advantageously, the use according to the invention is for an application of whitening, and / or skin lightening, and / or improvement of skin brightness, and / or improvement of skin radiance.

[0035] More advantageously, the use according to the invention is for an application of improving the firmness and texture of the skin.

[0036] Indeed, the lacto-fermented red algae extracts according to the invention are capable of reducing protein carbonylation, which has the effect of reducing pigment spots on the skin, but which also has the effect of acting on the skin's texture and firmness, for example via an action on keratinocytes. Brief description of the figures

[0037] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for the understanding of which reference should be made to the accompanying figures (as well as to the examples referring to these figures), in which:

[0038] [Fig.1] - the [Fig.1] is a graph illustrating the evolution of the cell viability of fibroblasts as a function of the concentration of extracts of the red algae Palmaria palmata, respectively fermented and unfermented;

[0039] [Fig.2] - [Fig.2] is a graph illustrating the evolution of cell viability of keratinocytes as a function of the concentration of extracts of the red algae Palmaria palmata, respectively fermented and unfermented;

[0040] [Fig.3] - [Fig.3] is a set of photos comparing the accumulation of lipofuscin in skin expiants, treated or not with the extracts according to the invention;

[0041] [Fig.4] - [Fig.4] is a set of photos comparing the carbonylation rate of proteins in skin expiants, treated or not with the extracts according to the invention. Detailed description of the invention

[0042] Other advantages and features of the present invention will result from the following description, given by way of non-limiting example and made with reference to the examples. EXAMPLES

[0043] EXAMPLE 1: Analysis of the cytotoxicity of a lacto-fermented extract of the red algae Palmaria palmata according to the invention, not comprising fragments of lactic acid bacteria, respectively on fibroblasts and on keratinocytes of the skin.

[0044] The graph in [Fig.1] illustrates the cell viability (in percent) of fibroblasts as a function of the concentration (in percent) of a lacto-fermented extract of Palmaria palmata according to the invention (curve with triangles).

[0045] By comparison, this graph also illustrates the cell viability of fibroblasts as a function of the concentration of an extract of Palmaria palmata outside the invention, i.e. an extract of Palmaria palmata which is not fermented (curve with the points).

[0046] This study was carried out on normal human dermal fibroblasts (NHDF), which were treated respectively with the extract according to the invention (lacto-fermented) and with the extract outside the invention (non-fermented) for 48 hours.

[0047] This graph demonstrates that a lacto-fermented extract according to the invention does not have a toxic effect on fibroblasts, and that it even stimulates the cell viability of these skin cells, compared with the behavior of the non-fermented extract.

[0048] Similarly, the graph in [Fig.2] illustrates the cell viability (in percent) of keratinocytes as a function of the concentration (in percent) of a lacto-fermented extract of Palmaria palmata according to the invention (curve with triangles).

[0049] By comparison, this graph also illustrates the cellular viability of keratinocytes as a function of the concentration of an extract of Palmaria palmata outside the invention, i.e. an extract of Palmaria palmata which is not fermented (curve with the points).

[0050] This study was carried out on normal human epidermal keratinocytes (NHEK), which were treated respectively with the extract according to the invention (lacto-fermented) and with the extract outside the invention (non-fermented) for 48 hours.

[0051] This graph demonstrates that a lacto-fermented extract according to the invention does not have a toxic effect on skin keratinocytes.

[0052] EXAMPLE 2: analysis of the effect of lacto-fermented extracts of the red algae Palmaria palmata according to the invention, respectively with and without fragments of lactic acid bacteria, on skin pigmentation.

[0053] Example 2a: In vitro analysis of the effect of the lacto-fermented extract of the red alga Palmaria palmata according to the invention, without fragments of lactic acid bacteria, on the pigment mechanism related to melanogenesis Test 1

[0054] Test conditions:

[0055] Control: 0.5mM L-tyrosine solution. L-tyrosine is known to stimulate the expression of many genes involved in melanogenesis.

[0056] Control: 0.02% alpha-arbutin solution. Alpha-arbutin is known to be used to combat pigment spots. It is also a control used to reduce melanin production.

[0057] Sample (invention): fermented extract of the red algae Palmaria palmata at 0.1%, not including fragments of lactic acid bacteria.

[0058] These three solutions were respectively applied to a biological model of normal human epidermal melanocytes (NHEM), for a period of 12 days.

[0059] A quantitative PCR (qPCR) analysis was performed on these NHEMs to determine the expression of certain genes involved in the mechanism of melanogenesis.

[0060] The results are presented in Table 1 below.

[0061] [Tables 1] Genes Reduction in the expression of these genes (in %): application of the control, compared to the standard control Reduction in the expression of these genes (in %): application of the sample (invention), compared to the standard control CRTC1 - 51 -63 MITF -29 -36 PMEL -46 -58 TYR - 33 -52 TYRP1 - 30 -52 SLC45A2 - 37 -50 CD63 -43 -44 MILANA -42 -45 RAB38 -28 -40 FZD1 -42 -54 WLS - 36 -45 MAPK3 -40 -55 RASA4 - 34 -60 EDNRB -41 -47 PRKCA -43 -54

[0062] The CRTC1, MITF, PMEL, TYR and TYRP1 genes encode enzymes and structural proteins involved in melanogenesis.

[0063] The SLC45A2 gene codes for channels and support proteins involved in melanogenesis.

[0064] The CD63 and MILANA genes code for melanosome proteins.

[0065] The RAB38 gene codes for proteins involved in the transport of melanosomes.

[0066] The FZD1 and WLS genes are involved in the WNT pathway.

[0067] The MAPK3 and RASA4 genes are involved in the SCF / KIT pathway.

[0068] The EDNRB and PRKCA genes are involved in the endothelin (ET1) pathway.

[0069] Thus, the extract according to the invention reduces the expression of genes involved in melanin production. In particular, the reduction in the expression of these genes by the extract according to the invention is greater than for the comparative alpha-arbutin control solution.

[0070] The extract according to the invention therefore has a strong impact on melanocytes, effectively reducing melanin synthesis, which allows for an improved whitening / lightening effect on the skin compared to the active ingredients usually used for this cosmetic application. Test 2

[0071] Test conditions:

[0072] Control: 0.5mM L-tyrosine solution.

[0073] Control 1: 5 pg / mL lipoic acid solution mixed with 0.5 mM L-tyrosine solution. Lipoic acid is known to be used to combat pigment spots. It is also a control used to reduce melanin production.

[0074] Control 2: 0.02% alpha-arbutin solution, mixed with 0.5mM L-tyrosine solution.

[0075] Sample (invention): fermented extract of the red algae Palmaria palmata at 0.1%, not including fragments of lactic acid bacteria, mixed with L-tyrosine solution at 0.5mM.

[0076] These four solutions were respectively applied to a biological model of normal human epidermal melanocytes (NHEM), for a period of 10 days.

[0077] An analysis was performed on these NHEMs to determine melanin production in these expiants. This analysis is based on spectrophotometric measurement by reading the absorbance at a wavelength of 405 nm, and total protein measurement by a colorimetric protein assay method (Lowry (Pierce) method), to relate the amount of melanin to the protein content.

[0078] The results are presented in Table 2 below.

[0079] [Tables2] Reduction in melanin production (in %), compared to control: Control 1 -45, Control 2 -57, Invention sample -51

[0080] The lacto-fermented extract of Palmaria palmata according to the invention reduces melanin production by 51%. Furthermore, the extract according to the invention reduces melanin production more significantly compared to the first control solution, which is based on lipoic acid, and almost equivalently compared to the second control solution, which is based on alpha-arbutin.

[0081] The results of this second test relating to the pigmentary mechanism in connection with melanogenesis are consistent with the results of the first test, and demonstrate that the extract according to the invention makes it possible to effectively reduce melanin synthesis, which allows a whitening / lightening effect on the skin at least equal to, or even improved upon, compared to the active ingredients usually used for this cosmetic application.

[0082] Example 2b: Ex vitro analysis of the effect of lacto-fermented extracts of the red alga Palmaria palmata according to the invention, respectively with and without fragments of lactic acid bacteria, on the pigmentary mechanism related to lipofuscin production

[0083] Test conditions:

[0084] Two lacto-fermented extracts of the red algae Palmaria palmata at 2% in water were prepared: respectively, an extract not including fragments of lactic acid bacteria, and an extract including fragments of lactic acid bacteria.

[0085] These two extracts according to the invention were respectively applied to fragments of human skin (expiants) belonging to a donor individual aged 44 years, of phototype III.

[0086] 24 hours after the application of the extracts according to the invention, these expiants were exposed to UVA radiation (6J / cm2).

[0087] Two hours after this UVA exposure, the expiants were fixed in a solution d'OCT, then frozen at a temperature of -80°C.

[0088] A skin expiant that has not been subjected to the application of an extract according to the invention has also been treated with UVA in the same way as skin expiants with extracts according to the invention.

[0089] A control sample was also prepared, which corresponds to a skin expiant that has not been subjected to the application of an extract according to the invention, and which has not been treated with UVA.

[0090] Sections were then made using a microtome on these different expiants, and lipofuscin was detected by staining with Sudan Black, a dye known to detect lipids and to allow visualization of lipofuscin in particular.

[0091] The results are presented in Table 3 below.

[0092] [Tables3] Mean versus control (in %) Standard deviation Lipofuse production reduction efficacy (in %) p-value (versus UVA stress) Control 100 1 100 ***; <0.001 Skin expiratory sample without extract and exposed to UVA 115 1 0 / Skin expiratory sample with extract (without bacteria) and exposed to UVA 102 2 89 ***; <0.001 Skin expiratory sample with extract (with bacteria) and exposed to UVA 105 1 68 ***; 0.001

[0093] Thus, the lacto-fermented extracts of Palmaria palmata according to the invention, with and without fragments of lactic acid bacteria, significantly reduce lipofuscin production when the skin is exposed to UVA radiation. A decrease in lipofuscin production of 89% is observed for the extract without bacterial fragments, and a still significant decrease of 68% for the extract with bacterial fragments.

[0094] These results are confirmed with [Fig.3], which illustrates the presence of lipofuscin at the level of these different skin expiants tested.

[0095] The first image, top left, illustrates the control skin expiant which has not been treated with UVA, and therefore does not contain lipofuscin, or contains only a very minimal amount.

[0096] The second image, top right, illustrates the skin expiry which does not include any extract according to the invention, and which has been treated with UVA: there are areas in dark black visible, which correspond to areas of the skin expiry where lipofuscin has accumulated, due to UVA radiation.

[0097] The third and fourth images, on the bottom line, respectively on the left and right, illustrate UVA-treated skin expiants comprising an extract according to the invention, respectively with and without fragments of lactic acid bacteria. These images are visually similar to the first image: they do not include areas of dark black, but only areas of gray, or even light gray, which illustrates that these skin expiants do not include areas in which lipofuscin has accumulated significantly.

[0098] Thus, the results of these tests demonstrate that the extracts according to the invention, with and without fragments of lactic acid bacteria, effectively reduce lipofuscin production. This demonstrates that these two types of extracts according to the invention act on skin pigmentation and provide a whitening and / or lightening effect on the skin.

[0099] Example 2c: Ex vitro analysis of the effect of lacto-fermented extracts of the red algae Palmaria palmata according to the invention, respectively with and without fragments of lactic acid bacteria, on the pigmentary mechanism in connection with protein carbonylation.

[0100] Test conditions:

[0101] Two lacto-fermented extracts of the red algae Palmaria palmata at 2% in water were prepared: an extract not including fragments of lactic acid bacteria, and an extract including fragments of lactic acid bacteria.

[0102] These two extracts according to the invention were respectively applied to fragments of human skin (expiants), which were exposed to UVA radiation (6J / cm2).

[0103] A skin expiant that has not been subjected to the application of an extract according to the invention has also been treated with UVA, in the same way as skin expiants with extracts according to the invention.

[0104] A control sample was also prepared, which corresponds to an expiant that has not been subjected to the application of an extract according to the invention, and which has not been treated with UVA.

[0105] Carbonylated proteins in all of these expiants were then detected and analyzed by specific labeling and fluorescence imaging (Oxi-Proteome), at the level of the different layers of the skin.

[0106] The results are presented in Tables 4 to 7 below.

[0107] [Tables4] Mean versus control (in %) Standard deviation Ipofuscin production reduction efficiency (in %) p-value (versus UVA stress) Whole skin Control 100 10 100 ***; <0.001 Skin expiratory without extract and exposed to UVA 201 8 0 / Skin expiratory with extract (without bacteria) and exposed to UVA 120 15 80 ***; <0.001 Skin expiratory with extract (with bacteria) and exposed to UVA 112 2 88 ***; <0.001

[0108] [Tables5] Mean versus control (in %) Standard deviation Ipofuscin production reduction efficiency (in %) p-value (versus UVA stress) Stratum Coma Control 100 13 100 ***; <0.001 Skin expiratory without extract and exposed to UVA 302 34 0 / Skin expiratory with extract (without bacteria) and exposed to UVA 160 21 71 ***; <0.001 Skin expiratory with extract (with bacteria) and exposed to UVA 134 19 83 ***; <0.001

[0109] [Tableauxô] Mean versus control (in %) Standard deviation I-hypofuscin production reduction efficiency (in %) p-value (versus UVA stress) Epidermis Control 100 5 100 ***; <0.001 Skin expiratory without extract and exposed to UVA 167 5 0 / Skin expiratory with extract (without bacteria) and exposed to UVA 114 8 79 ***; <0.001 Skin expiratory with extract (with bacteria) and exposed to UVA 120 13 70 ***; <0.001

[0110] [Tables?] Mean versus control (in %) Standard deviation I-hypofuscin production reduction efficacy (in %) p-value (versus UVA stress) Dermis Control 100 2 100 ***; <0.001 Skin expiratory without extract and exposed to UVA 271 40 0 ​​ / Skin expiratory with extract (without bacteria) and exposed to UVA 135 14 79 ***; <0.001 Skin expiratory with extract (with bacteria) and exposed to UVA 119 20 89 ***; <0.001

[0111] The lacto-fermented extracts of Palmaria palmata according to the invention, with and without fragments of lactic acid bacteria, make it possible to reduce protein carbonylation significantly, when the skin is exposed to UVA. This reduction in protein carbonylation is observed throughout the skin, as well as at the individual level, i.e. at the level of each layer of the skin (the Stratum Comeum, the epidermis and the dermis).

[0112] In particular, the lacto-fermented extract according to the invention, which includes fragments of lactic acid bacteria, has a greater impact on reducing protein carbonylation than the lacto-fermented extract according to the invention that does not include bacteria, and this result is observed in virtually all layers of the skin, with the exception of the epidermis. However, in the latter case (epidermis), the reduction of protein carbonylation by the lacto-fermented extract containing protein fragments remains very effective.

[0113] The results of reducing protein carbonylation by each of the extracts of the invention (with and without bacteria) are always advantageously very close to the results of the control expiant.

[0114] These results are confirmed with [Fig.4], which illustrates the presence of carbonylated proteins at the level of these different skin expiants tested.

[0115] The first image, top left, illustrates the control skin expiant which has not been treated with UVA, and therefore includes a very small amount of carbonylated proteins (bleached area of ​​the image).

[0116] The second image, top right, illustrates the skin expiant which does not include any extract according to the invention, and which has been treated with UVA: it is visible that almost the entire surface of the expiant, which is white in color, comprises carbonylated proteins, which is due to UVA radiation.

[0117] The third and fourth images, on the bottom line, respectively on the left and right, illustrate UVA-treated skin expiants comprising an extract according to the invention, respectively with and without fragments of lactic acid bacteria. These two images are visually almost identical and visually resemble the first control image: a very small proportion of the surface of these expiants is white, which corresponds to the fact that a very small proportion of the surface of these expiants comprises carbonylated proteins.

[0118] Thus, the results of these tests demonstrate that the extracts according to the invention, with and without fragments of lactic acid bacteria, very effectively reduce protein carbonylation at all levels of the skin. This demonstrates that these two types of extracts according to the invention act on skin pigmentation and provide a whitening and / or lightening effect on the skin. In particular, these tests demonstrated the ability of the lacto-fermented extracts according to the invention to protect skin cells.

[0119] Therefore, the extracts according to the invention, respectively with and without fragments of lactic acid bacteria, make it possible to influence skin pigmentation by acting on several pigmentary mechanisms, namely melanogenesis, lipofuscin production, and protein carbonylation. Both types of extracts according to the invention reduce the expression of numerous genes involved in melanin synthesis. They also reduce lipofuscin production. Furthermore, they reduce the protein carbonylation process. All of these effects result in influencing skin pigmentation, and in particular, whitening and lightening it. These effects also improve skin luminosity and radiance.The texture of the skin can also be improved by the extracts according to the invention, in particular via the reduction of protein carbonylation.

Claims

Demands [Clause 1] Lacto-fermented extract of at least one red alga of the order Palmariales, said red alga having been lacto-fermented by lactic acid bacteria.

2. Extract according to claim 1, wherein said red algae of the order Palmariales is of the genus Palmaria.

3. Extract according to claim 2, wherein said red algae of the genus Palmaria is the species Palmaria palmata.

4. Extract according to any one of claims 1 to 3, wherein said red algae has been lacto-fermented by lactic acid bacteria of the species Lactobacillus plantarum.

5. Extract according to any one of claims 1 to 4, said extract being an aqueous extract.

6. Extract according to any one of claims 1 to 5, wherein said lactic acid bacteria are present in said lacto-fermented extract in the form of fragments.

7. A process for producing a lacto-fermented extract as defined according to any one of claims 1 to 6, comprising the following steps: - a step A) of lacto-fermentation of a red alga by lactic acid bacteria in an aqueous medium comprising sea salt, to form said lacto-fermented extract, said red alga being of the order Palmariales; - a step B) of filtration by clarification, to separate the residues of said red alga from the reaction medium; - a step C) of treatment of said reaction medium, to form said lacto-fermented extract.

8. A process for producing a lacto-fermented extract according to claim 7, wherein said processing step C) constitutes an additional filtration step, for removing said lactic acid bacteria from said lacto-fermented extract, said additional filtration step being a sterilizing filtration.

9. A process for producing a lacto-fermented extract according to claim 7, wherein said processing step C) constitutes an inactivation step of said lactic acid bacteria within said lacto-fermented extract.

10. Use of a lacto-fermented extract as defined in any one of claims 1 to 6 in a cosmetic composition.

11. Use of a lacto-fermented extract as defined according to any one of claims 1 to 6, or of a composition according to claim 10, for topical cosmetic application.

12. Use according to claim 10 or 11 for an application of whitening, and / or skin lightening, and / or skin brightness enhancement, and / or skin radiance enhancement.

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