FR3099991A1 - Cosmetic composition ingredient for sensitive scalp - Google Patents

Abstract

Cosmetic composition ingredient for soothing the scalp, characterized by the mixture of: 0.1% to 1.0% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacteria CNCM I-4352.10% to 50% by weight of an aqueous extract of the brown alga Laminaria digitata, 10% to 50% by weight of an aqueous extract of the green microalga Chlorella vulgaris, 10% to 50% by weight of an extract of Lavandula stoechas, 5 at 50% by weight of water.

Description

Ingredient of cosmetic composition for sensitive scalp

This technique relates to an ingredient of plant origin intended for use in cosmetic compositions to be applied to the scalp.

More specifically, the present technique relates to such an ingredient making it possible to soothe sensitive scalps, subject in particular to itching, tingling or tightness.

Prior art

The scalp is subject to many daily attacks that can weaken it. Pollution, stress, too frequent shampoos, certain nutritional deficiencies, or a lack of sebum production, can thus lead to increased sensitivity of the scalp and its irritation.

This irritation can result in a feeling of dryness, tightness, itching, painful hair roots.

Studies have shown that such irritations are often accompanied by an imbalance in the physiological flora (the microbiota) of the scalp.

The treatment of the discomfort associated with such irritations is offered by specific compositions of mild shampoos. However, such shampoos are products whose action disrupts the microbiota of the scalp. Indeed, during a shampoo, it undergoes not only the mechanical action of washing, but also that, chemical, of the degreasing surfactants and preservatives of the product. Even after careful rinsing, all the microbial components of this microbiota are more or less impacted by washing. In practice, it takes several days for the microbiota of the scalp to rebalance itself naturally. However, within such a period at least one new washing of the hair is generally carried out. In the majority of cases, treating scalp irritation with a single mild shampoo is therefore not enough to see it disappear completely.

There are also various hair lotions on the market whose use can soothe scalp irritations. Many of these use one or more plant-based ingredients. The present invention provides an alternative to these.

This technique concerns an ingredient of a cosmetic composition intended to be applied to the irritated scalp, allowing both to soothe it and to preserve its microbiota.

This ingredient is characterized is constituted by the mixture of:
0.1% to 1.0% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
10% to 50% by weight of an aqueous extract of the brown seaweed Laminaria digitata ,
10% to 50% by weight of an aqueous extract of the green microalgae Chlorella vulgaris ,
10% to 50% by weight of an extract of Lavandula stoechas ,
5 to 50% by weight of water.

The aqueous extract of the brown seaweed Laminaria digitata used in the context of the present invention contains polysaccharides, mainly alginates and laminarane, as well as polyols, mainly mannitol, and water.

This aqueous extract can easily be obtained from freeze-dried raw brown seaweed by subjecting it to a leaching process. One such process involves washing the freeze-dried seaweed with water, so as to separate the water-soluble substances from the non-water-soluble substances it contains. The water-soluble substances contained in the leaching product are then subjected to sterilizing microfiltration to obtain a liquid product, then to purification by reverse osmosis filtration of the liquid product resulting from the microfiltration leading to said extract.

The aqueous extract of the green microalgae Chlorella vulgaris used in the context of the present invention contains peptides, amino acids, water and glycerin. It can be obtained by any other aqueous extraction process in water or in water and glycerin. It can for example be obtained according to the method described in Figure 2 of patent application FR2728467A1, by grinding the algae in a basic medium, then acidifying the medium to bring the pH back to around 9, microfiltration, nanofiltration of the microfiltrate and diafiltration nanofiltrate.

The Lavandula stoechas extract used in the context of the present invention can itself be obtained by microwave-assisted hydrodistillation (technique known by the English term “VMHD” which means: Vacuum Microwave HydroDistillation ) . This method is described in European patent application EP0698076A1. It can also be obtained by any other aqueous extraction process in water or in water and glycerin.

The exopolysaccharide used in the context of the present invention is produced in a biofermentor from the marine bacterium registered at the Institut Pasteur under the reference CNCM I-4352. It has a specific composition of sugars (galactose, N-acetylated guluronic acid and N-acetylglucosamine). The molecular weight of this EPS is greater than 1 million Dalton (Dextran equivalent).

According to a preferred variant, the ingredient according to the invention is characterized in that it consists of the mixture of:
0.2% to 0.5% by dry weight of said exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
20% to 30% by weight of said aqueous extract of the brown seaweed Laminaria digitata ,
20% to 40% by weight of said aqueous extract of the green microalgae Chlorella vulgaris ,
20% to 30% by weight of said Lavandula stoechas extract,
10% to 30% by weight of water.

According to a preferred variant, the water used in the mixture constituting said ingredient is marine spring water.

Marine spring waters are waters that have different compositions from those of conventional seawater. It is generally groundwater that springs from the sea floor and is rich in trace elements. The marine spring water used in the context of the present invention may for example be that described in the patent application FR2777778A1.

Advantageously, said marine spring water has a pH of approximately 7, and a higher content than that of seawater in zinc, iron, lithium and manganese.

The aqueous extract of Chlorella vulgaris containing water and glycerin, and the aqueous extracts of Laminaria Digitata and Lavandula Stoechas containing water, the ingredient according to the invention thus preferably comprises:
0.1% to 1.0% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
0.5% to 5% by dry weight of Laminaria digitata extract,
0.1% to 1% by dry weight of Chlorella vulgaris extract,
0.01% to 1% by dry weight of Lavandula stoechas extract,
5% to 30% glycerine,
5% to 50% marine spring water,
40% to 90% water.

Preferably, the ingredient according to the invention comprises:
0.1% to 1.0% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
1% to 3% by dry weight of Laminaria digitata extract,
0.2% to 0.4% by dry weight of Chlorella vulgaris extract,
0.02% to 05% by dry weight of Lavandula stoechas extract,
10% to 20% glycerine,
10% to 30% marine spring water,
50% to 70% water.

The invention also relates to any product for hair use, such as lotion, cream, shampoo) containing 0.1% to 10 % by weight of the ingredient according to the invention

The invention also relates to any use of such a product to soothe sensitive scalps and rebalance their microbiota.

tricks

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment, given by way of a simple illustrative and non-limiting example, and the appended drawings, among which:

is a graph illustrating the evolution of the functional signs observed on the scalp of subjects having tested a lotion for sensitive scalp incorporating an ingredient according to the present invention;

is a graph illustrating the evolution of itching;

is a graph illustrating the evolution of tingling;

is a graph illustrating the evolution of tightness;

is a graph illustrating the evolution of the physical signs observed on the scalp of subjects having tested a lotion for sensitive scalp incorporating an ingredient according to the present invention;

is a graph illustrating the development of erythema;

is a graph illustrating the evolution of drought;

is a graph illustrating the evolution of desquamation;

is a graph illustrating the evolution of the erythema index.

Description of one embodiment of the invention.

An ingredient according to the present invention was produced by mixing the following compounds:
0.25% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
24.50% by weight of an aqueous extract of the brown seaweed Laminaria digitata ,
30.00%% by weight of an aqueous extract of the green microalgae Chlorella vulgaris ,
24.25% by weight of an aqueous extract of Lavandula stoechas ,
20.00% by weight of marine spring water,
1.00% by weight preservative.

The aqueous extract of Laminaria digitata comprising 95% water, the extract of Chlorella vulgaris comprising almost 50% water and almost 50% glycerin, and the extract of Lavandula stoechas comprising 99% water , the ingredient according to the invention thus contains:
0.25% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
1.25% by dry weight of an aqueous extract of the brown seaweed Laminaria digitata ,
0.40% by dry weight of an aqueous extract of the green microalgae Chlorella vulgaris ,
0.10% by dry weight of an extract of Lavandula stoechas ,
62.00% by weight of water,
20.00% by weight of marine spring water,
15.00% by weight of glycerine,
1.00% by weight preservative.

A hair lotion according to the invention was then produced by integrating 0.6% by weight of this ingredient therein, 0.01% sodium citrate, 0.1% disodium EDTA, 0.27% chlorphenesin ; 0.80% phenoxyethanol and 98.22% water.

Tests were then carried out with this lotion by applying it to the scalp of a standardized panel of 32 people with sensitive scalps, complaining of itching, tingling, and/or presenting scales and/or redness. on the scalp.

Every day, for 4 weeks, these people applied 5ml of the said lotion to their entire scalp, immediately afterwards massaging their scalp for 1 to 2 minutes.

The day before the start of the trial (D0), after 2 weeks of application (D14), and after 4 weeks of application (D28), a clinical assessment of the condition of each person's scalp was was performed by the same dermatologist.

In this context, the functional signs reported by the subjects (itching, tingling and tightness) were collected by them and noted on a scale of 0 to 9 - according to which the value 0 corresponding to no sign and the value 9 corresponds to a lot of signs -, and the physical signs (erythema, dryness, desquamation (dandruff)) were evaluated by him on the same scale from 0 to 9.

The results of this clinical evaluation of the functional signs and the physical signs are given below, with reference to figures 1 to 9.

Referring to Figure 1, the application of the lotion according to the invention on the scalp decreases by 51% after 14 days and by 66.7% after 28 days the sum of the functional signs (itching, tingling and tightness) observed on this one.

Specifically, itching is reduced by 46.4% after 14 days and 58.9% after 28 days (Figure 2), tingling is reduced by 52.5% after 14 days and 77.6% after 28 days (Figure 3), tightness is reduced by 62.7% after 14 days and by 68.6% after 28 days (Figure 4).

These results demonstrate that the lotion incorporating the ingredient according to the invention has a significant soothing effect on the scalp.

Regarding the physical signs, with reference to Figure 5, the application of the lotion according to the invention on the scalp decreases by 31.8%% after 14 days and by 43.2% after 28 days the sum of the physical signs (erythema, dryness and desquamation) assessed on it.

More specifically, erythema is reduced by 23.7% after 14 days and by 34.2% after 28 days (Figure 6), dryness is reduced by 34.2% after 14 days and by 42% after 28 days (Figure 7). Desquamation is reduced by 38.4% after 14 days and by 48% after 28 days (Figure 8).

These results demonstrate that the lotion containing the ingredient according to the present invention allows a notable improvement in the condition of the scalp.

At the same time, photographic acquisitions were carried out on the scalp of the subjects tested on D0, D14 and D28, using equipment marketed under the C-Cube® brand by the company PIXIENCE, making it possible to locate any erythema and assess its evolution over time using an “erythema index”.

Analysis of these photographic acquisitions revealed that the erythema index of the scalp was reduced by 15.5% after 14 days and by 20.8% after 28 days.

These results confirm those obtained during the clinical study, namely that the lotion containing the ingredient according to the present invention reduces erythema, dryness and desquamation of sensitive scalps. It helps to improve the condition of the scalp.

Finally, an analysis of the microbiota, more specifically bacteriota and mycobiota, was carried out on the scalp of the people tested.

On D0 and D28, an aseptic sample of microbiota from the scalp of each person was taken by swab. DNA extraction and RT-PCR amplification were performed on all samples at the same time.

The characterization of the diversity of the bacteriote and the mycobiota was thus carried out by high-throughput sequencing. The characterization of the bacteriota was carried out by 16S RNA sequencing using primers V1-V3, and the characterization of the mycobiota by the sequencing of ITS1.

The analysis of the results at the bacterial level shows great stability over time between D0 and D28. The Shannon index, which is an index linked to biodiversity, is thus globally the same before and after treatment.

With reference to Table 1 below, the analysis of the bacterial phyla shows that these are remarkably stable between D0 and D28.

The more precise analysis of the bacterial families showed that these are consistent with those described in the literature on so-called "normal" scalps with weak dandruff.

Finally, the analysis of bacterial genera and species showed stability in the presence of Propionibacterium acnes and Staphylococcus epidermidis after treatment on D28.

The bacterial landscapes of the scalps are therefore comparable, before and after the treatment.

These results demonstrate that the lotion containing the ingredient according to the present invention respects the bacteriota of the scalp.

With regard to the analysis of the mycobiota, a decrease in the Shannon index of 14% was observed between D0 and D28, reflecting a favorable reduction in its biodiversity.

The genus Malassezia and its species Malassezia restricta and Malassezia globosa , considered in the literature as the most representative, have been more precisely studied.

After 28 days of treatment with the lotion comprising the ingredient according to the invention, stability of the M. restricta species and a 75% increase in the M. globosa species were observed. The ratio between these two species after 28 days approaches the normal ratio reported in the literature and reflects the transition from a dandruff state to a non-dandruff state.

These results demonstrate that the lotion containing the ingredient according to the present invention has a beneficial effect on the mycobiota of the scalp.

Claims (7)

Ingredient of a cosmetic composition for the scalp, characterized in that it consists of a mixture of:
0.1% to 1.0% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
10% to 50% by weight of an aqueous extract of the brown seaweed Laminaria digitata ,
10% to 50% by weight of an aqueous extract of the green microalgae Chlorella vulgaris ,
10% to 50% by weight of an extract of Lavandula stoechas ,
5 to 50% by weight of water. Ingredient according to Claim 1, characterized in that it consists of a mixture of:
0.2% to 0.5% by dry weight of said exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
20% to 30% by weight of said aqueous extract of the brown seaweed Laminaria digitata ,
20% to 40% by weight of said aqueous extract of the green microalgae Chlorella vulgaris ,
20% to 30% by weight of said Lavandula stoechas extract,
10% to 30% by weight of water. Ingredient according to claim 1 or 2, characterized in that said water is marine spring water. Ingredient according to one of Claims 1 to 3, characterized in that it comprises:
0.1% to 1.0% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
0.5% to 5% by dry weight of Laminaria digitata extract,
0.1% to 1% by dry weight of Chlorella vulgaris extract,
0.01% to 1% by dry weight of Lavandula stoechas extract,
5% to 30% glycerine,
5% to 50% marine spring water,
40% to 90% water. Ingredient according to Claim 4, characterized in that it comprises:
0.1% to 1.0% by dry weight of an exopolysaccharide obtained by fermentation of the marine bacterium CNCM I-4352,
1% to 3% by dry weight of Laminaria digitata extract,
0.2% to 0.4% by dry weight of Chlorella vulgaris extract,
0.02% to 0.5% by dry weight of Lavandula stoechas extract,
10% to 20% glycerine,
10% to 30% marine spring water,
50% to 70% water. Product for hair use containing 0.1 % to 10% by weight of the ingredient according to any one of claims 1 to 5. Use of the product according to claim 6 to soothe sensitive scalps and rebalance their microbiota.