FR3113236A1 - Purified fraction of fucoidans for the preparation of anti-aging cosmetic and/or dermatological compositions. - Google Patents

Abstract

Use of a purified fraction of fucoidans derived from an algae as an active ingredient, said fraction having a molecular weight of less than 30,000 daltons for the preparation of a topical composition, for preventing the reduction of telomere shortening in human fibroblasts and cause an effect of increasing the activity of telomerase in human keratinocytes, the other ingredients of the composition being the ingredients conventionally used in the cosmetology field, the purified fraction of fucoidans representing between 0.01 and 5.00% by mass of said topical composition.

Description

Purified fraction of fucoidans for the preparation of anti-aging cosmetic and/or dermatological compositions.

The technical sector of the present invention is that of fucoidans used in the treatment of signs of skin aging, in particular the appearance of wrinkles and slackening of the skin.

STATE OF THE ART

Fucoidans are sulfated polysaccharides belonging to the fucan family, present in marine organisms. They mainly consist of sulfated L-fucose. They also include ascophyllans (xylofucoglycuronan and xylofucomanuronan) and sargassans (glycuronofucogalactan) as set out in G. Michel et al, 2010 and Kloareg B. et al, 1981.

These polysaccharides were first discovered and described in 1913 by Kylin in the brown algae Ascophyllum nodosum , Fucus vesiculosus , Laminaria digitata and Laminaria saccharina (Kylin H., 1913).

Since then, fucoidans have been identified in seventy other species of brown algae, the Phaeophyceae, (Berteau O., 2003, Ale M.T., 2011), in the body wall of certain marine invertebrates such as the sea cucumber ( Holothurians) and in the jelly layer of sea urchin eggs (Echinoids) (Berteau O., 2003).

In brown algae, they are contained in the extracellular matrix of the brown algae walls (Michel G., et al, 2010). They are involved in ionic and osmotic regulation and in the mechanical support of the cell wall (Kloareg B. et al., 1988). As a result, the algae most exposed to drying seem to contain the highest proportion of fucoidans.

It is known in the prior art that fucoidans exhibit biological activities.

The biological activities of fucoidans seem mainly modulated by their molecular weight and their sulphate content. Research interest in fucoidans and especially their low molecular weight fraction (i.e. less than 40kDa) is primarily driven by the wide range of biological activities evidenced by their findings so far. .

For example, EP403377 describes anti-coagulant, anti-thrombotic and anti-angiogenic activities.

Document WO99/32099 also describes the use of compounds of this type for their activity in modulating the expression and/or activity of the twenty-five fibroblast metalloproteinases and inhibiting leukocyte elastase.

The document EP965323 presents the beneficial effect of these compounds on the growth of hair fibers as well as their manifestation of antimitotic properties.

The documents JP01031707 and US20060210516 describe a moisturizing effect on the skin of these compounds when they are used in cosmetic compositions.

The wide range of these biological activities prompted the inventors to study the properties of these low molecular weight fucoidans (less than 40 kDa) which surprisingly presented during in vitro tests, the property of significantly increasing the activity of telomerase in human keratinocytes and to significantly reduce telomere shortening in human fibroblasts.

It is the object of the present invention to propose a new composition having a specific activity on the skin.

A subject of the invention is therefore the use of a purified fraction of fucoidans derived from an algae as active principle, said fraction having a molecular weight of less than 30,000 daltons for the preparation of a topical composition, to prevent the reducing telomere shortening in human fibroblasts and causing an effect of increasing telomerase activity in human keratinocytes, the other ingredients of the composition being the ingredients conventionally used in the cosmetology field.

The purified fraction of fucoidans represents between 0.01 and 5% by weight of said topical composition.

The purified fraction of fucoidans advantageously represents 0.01% by weight of said topical composition.

The purified fraction of fucoidans advantageously still represents 0.05% by mass of said topical composition.

The purified fraction of fucoidans advantageously still represents 0.1% by weight of said topical composition.

The purified fraction of fucoidans advantageously still represents 0.5% by weight of said topical composition.

The purified fraction of fucoidans advantageously still represents 1.00% by mass of said topical composition

The purified fraction of fucoidans advantageously still represents 3% by weight of said topical composition.

The purified fraction of fucoidans advantageously represents 5.00% by weight of said topical composition.

According to one characteristic of the invention, the purified fucoidan fraction is obtained from, in particular, Ascophyllum nodosum , Fucus vesiculosus , Fucus spiralis , Undaria pinnatifida , Ecklonia kurome , Laminaria digitata or Laminaria japonica .

The purified fraction of fucoidans is preferably obtained from Ascophyllum nodosum .

The invention relates to the purified fraction of fucoidans obtained by extraction, purification and chemical or enzymatic depolymerization of dry algae, in particular Ascophyllum nodosum , Fucus vesiculosus , Fucus spiralis , Undaria pinnatifida , Ecklonia kurome , Laminaria digitata or Laminaria japonica .

Advantageously, the purified fraction of fucoidans is in a dry or liquid form.

The dry form is advantageously obtained by atomization or freeze-drying and the liquid form is obtained in solution in a diluting solvent, such as water, a glycol or a primary or secondary alcohol possibly incorporating a preservative.

The invention also relates to a cosmetic and/or dermatological composition for reducing telomere shortening in human fibroblasts and for increasing telomerase activity in human keratinocytes, characterized in that it comprises as active principle a purified fraction of fucoidans according to any one of Claims 12 to 15 according to a percentage by weight of between 0.001 and 12%, having a molecular weight of less than 30,000 DA, the other ingredients being those commonly used in this field.

A very first advantage of the invention lies in the surprising effect of the compositions containing the purified fraction of fucoidans on the skin.

Another advantage of the present invention lies in the absence of side effects on the skin.

Yet another advantage of the present invention resides in the ease of preparation of formulations containing this active principle.

Yet another advantage of the present invention resides in the stability of the formulations comprising the purified fraction of fucoidans.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the embodiments given below.

The invention will now be described in more detail using a few particular embodiments given by way of example without limiting its scope.

Fucoidans have been known since 1913, but no data have reported a possible effect of fucoidans on decreasing telomere shortening or increasing telomerase activity in human skin cells.

In addition, it has never been suggested that these fucoidans prevent and/or treat damage to the DNA of skin cells to correct or delay skin signs related to ageing. One of the first visible consequences of human aging is the modification of skin parameters characterized by the appearance of wrinkles and slackening of the skin.

At the cellular level, ageing, called senescence, is an irreversible state in which damaged cells no longer proliferate. Senescence is a biological process that affects all “normally” constituted cells of a human being. From a physiological point of view, this results in an overall aging of the human body, whether it is the cells of the skin, hair or organs. It has been scientifically demonstrated that senescence is caused in particular by the shortening of telomeres (replicative senescence) or by acute or chronic exposure to physiological stress signals such as oxidative stress. One of the means explored in order to limit the senescence of cells and consequently limit the manifestations of aging in humans, consists in limiting the shortening of telomeres by boosting the activity of telomerase.

This loss of telomeres is partially compensated by a reverse transcriptase, telomerase, which re-synthesizes telomere repeats on the ends of pre-existing telomeres, thus ensuring optimal length. The problem that arises is that the activity of this telomerase is extremely low in somatic cells, leading to telomeric shortening with each chromosomal replication.

One of the strategies currently used to limit the aging of the skin as well as its manifestations on it, consists in increasing the telomerase activity of the cells of the skin.

The objective of the present invention is to propose an active ingredient which can be used in the cosmetic and/or dermatological field which promotes the protection of the telomeres of human fibroblasts and which increases the activity of telomerase in human keratinocytes, to maintain the replicative potential cells and improve the appearance of the skin.

To this end, the invention relates to the use of specific molecules called fucoidans, obtained from Ascophyllum nodosum, a brown seaweed harvested in the Brittany region in the west of France and more particularly on the coasts of the island of 'Ushant. Fucoidans belong to a large family of marine sulfated polysaccharides called fucans mainly consisting of sulfated L-fucose, which also include ascophyllans (xylofucoglycuronan and xylofucomanuronan) and sargassans (glycuronofucogalactan).

The inventors therefore proceeded to the extraction of a purified fraction of fucoidans containing fucoidans of low molecular weight from, in particular, Ascophyllum nodosum .

PREPARATION OF THE PURIFIED EXTRACT OF FUCOIDANES

The extraction protocol is as follows:

1. We mix a quantity of seaweed, dry or fresh, crushed with a quantity of water 1 to 30 times higher. The mixture is left to macerate for 20 to 36 hours at a temperature below 100°C.

2. This extraction mixture is then filtered in order to obtain a first raw juice from the extraction.

3. This first extraction juice is concentrated to reduce the volume of the solution from 1/5 to 1/10.

4. Depending on the desired molecular size, the clarified juice is then depolymerized by adding strong acid, hydrogen peroxide or an enzymatic mixture at a temperature between 40°C and 85°C for the necessary time. to arrive at a molecular weight of less than 30,000 Da.

5. The juice obtained is then concentrated under vacuum.

6. The concentrated juice is then dried by freeze-drying or atomization or zeodration or any other drying technique to obtain a pure powder without additives.

STUDY OF TELOMERASE ACTIVITY

Attempts were performed to test the effects of this purified fucoidan fraction on telomerase activity in a model composed of low-passage adult human keratinocytes in monolayer culture.

From a methodological point of view, the keratinocytes were used at a low passage level, namely passage No. 2 of cell isolation. Cells were cultured in a monolayer until they reached approximately 75% confluence before use. Finally, FK228 at 100 ng/ml was used as a reference product inducing telomerase activity.

Then, the cells were incubated with a reference product (control) and the compound to be tested at two concentrations (0.05 and 0.1 % w/v) for 24 hours.

The purified fraction of fucoidans was diluted in the incubation medium in order to reach the different concentrations described in the examples below and to obtain said fraction to be tested was solubilized in a 10% incubation medium then diluted to achieve different concentrations.

To assess the effects at the end of both incubation periods, harvested cells were washed once in phosphate-buffered saline before being lysed in telomerase-compatible lysis buffer.

At the end of the incubation period, telomerase was extracted from the cells to measure its activity using a specific kit that couples a PCR step where telomerase performs an elongation with an ELISA step allowing the semi-quantitative determination of the quantities telomerase elongation product.

The total proteins of the cells are then extracted from the cells and measured by the Bradford method (spectro-colorimetric method).

Analysis of the results shows that the purified fraction of fucoidans, tested at 0.1% by mass, showed a significant increase of 12.8% (p<0.01) in telomerase activity.

It should be noted that the biological activity may vary slightly from one model to another and from one protocol to another and even on the same cell model.

Tests were also performed to assess the effect of the low molecular weight fraction on telomere shortening in a model composed of normal human fibroblasts in monolayer culture.

Telomere length was measured by performing quantitative PCR (q-PCR) and comparing telomere length between cells at passages 2 and 5.

The fibroblasts were cultured for three consecutive passages in the absence (control) or in the presence of an increasing concentration of the compounds to be tested: 0.05 and 0.1% (w/v).

At the end of the incubation, the cells were trypsinized and the DNA was extracted from the cells using a dedicated DNA extraction kit. DNA was quantified by nanodrop.

Telomere length was measured by quantitative PCR (q-PCR). For each sample, the change in telomere length was measured by relative quantification using the SCR (single copy reference) gene as the reference gene.

For each sample, a q-PCR is performed using a telomere primer set which recognizes and amplifies telomere sequences and a second q-PCR is performed using the SCR primer set which recognizes and amplifies a region of 100bp on human chromosome 17 and serves as a reference for data normalization.

Analysis of the results shows that the purified fraction of fucoidans, tested at a concentration of 0.05% by mass, has a positive effect on the shortening of the telomeres of normal human fibroblasts by 23.0% significantly (p<0.05 ) and, at a concentration of 0.1% by mass, has a positive effect on the shortening of the telomeres of human fibroblasts by 32.2% significantly (p<0.05). The keratinocyte test is insignificant.

The low molecular weight fucoidan extract can be presented in various dermatological formulations in order to offer a complete range of products to reduce the visible signs of skin aging, known as anti-aging care in the cosmetics field.

Thus, one can prepare anti-aging creams, anti-aging serums, anti-aging balms or restructuring creams.

The anti-wrinkle effect is remarkable because an increase in the viability of fibroblasts and keratinocytes is obtained through the increase in telomerase activity in keratinocytes and the decrease in telomere shortening in fibroblasts.

The following examples of compositions having the following formulation (mass percentages) were thus prepared.

Example 1: Well-being anti-aging cream

Ingredients Percentage INCI designation STAGE A Tego care PSC 3 (Evonik) 4.00 Polyglyceryl-3 stearate/citrate DC 5562 carbinol fluid (Dow Corning) 4.00 Bis-Hydroxyethoxypropyl Dimethicone DC 2503 (Dow Corning) 1.00 Stearyl dimethicone DC 1503 (Dow Corning) 1.00 Dimethicone/dimethiconol Dub PTS (Stéarinerie Dubois) 3.00 Pentaerythrityl tetrastearate Dub MCT (Stéarinerie Dubois) 3.00 Caprylic/capric triglyceride Ω ⁶ Ceramide cotton 0.75 Cotton seed oil/Palm oil aminopropanediol esters STAGE B Demineralized Water Qsp 100 Aqua Conservative Qsp Glycerin 3.00 Glycerine Ultrez 21 (Noveon) 0.50 Acrylates/C10-30 alkyl acrylate crosspolymer STAGE C Purified fraction of fucoidans (ALGUES & MER-Solabia group) 0.01 Ascophyllum nodosum extract STAGE D NaOH, 10% sol Qsp pH Sodium hydroxide Perfume Lychee Rose Brilliance 1014550 (Fragrance Expressions) 0.30 Fragrance

To prepare this cream, proceed as follows from different phases A, B, C and D.

Phase A is prepared at 70° C., then the Ceramide is added when this temperature is reached.

Phase B is prepared at 70°C.

The emulsion is made by pouring A into B with vigorous stirring.

The elements of phase C are added one by one with stirring.

The preparation obtained has the following physico-chemical characteristics:

pH=5.50-6.00 at 20°C,

viscosity: 45000±5000 cps at 20°C,

LVT 4, 12 rpm.

The pH is adjusted with the sodium hydroxide solution and the perfume is added when the mixture reaches a temperature of 35°C.

Example 2: Anti-Aging Serum

Ingredients percentages INCI designations STAGE A Demineralized Water Qsp 100 Aqua Conservative Qsp Glycerin 4.00 Glycerine Keltrol CG-SFT (CP Kelco) 0.40 Xanthan gum STAGE B Olivem 1000 (Hallstar) 3.50 Cetearyl olivate/ Sorbitan olivate DUB SIS 16 (Stéarinerie Dubois) 2.50 Isocetyl stearate Parafol 14-97 (Sasol) 2.50 Tetradecane STAGE C Purified fraction of fucoidans (ALGAE & SEA –Solabia group) 0.05 Ascophyllum nodosum extract Resist (Solabia group) 0.40 Propanediol/Aqua/Sophora japonica flower extract Perfume Divine (Robertet) 0.30 Scent Citric acid, 10% sol Qsp pH citric acid

Phase A is prepared at 70°C. Wet Keltrol in glycerin.

Phase B is prepared at 70°C.

The emulsion is produced by pouring B into A with vigorous stirring.

When the mixture reaches 40°C, the active substances are incorporated and the pH is adjusted as needed.

The serum obtained has the following physico-chemical characteristics: a pH of 5.0 to 6.0 at 20° C., a viscosity of 1500-2000 cP at 20° C., LVT 2, 12 rpm.

Another example of wording is as follows:

Example 3 : Anti-aging balm

Ingredients Percentages INCI designations STAGE A Demineralized Water Qsp 100 Aqua Conservative Qsp Ultrez 21 (Lubrizol) 0.30 Acrylates/ C10-30 alkyl acrylate crosspolymer 1,3-Propanediol (Connect chemicals) 3.50 Propanediol Covacryl AC (Sensient) 0.10 Sodium Polyacrylate STAGE B Montanov 68 (Seppic) 2.50 Cetearyl alcohol/ Cetearyl glucoside Montanov 202 (Seppic) 1.50 Arachidyl alcohol/ Behenyl alcohol/ Arachidyl glucoside Dub Zenoat (Stéarinerie Dubois) 2.50 Propanediol dicaprylate Crodamol W (Croda) 1.50 Stearyl Heptanoate/ Stearyl Caprylate Dub PTO (Stéarinerie Dubois) 2.50 Pentaerythrityl tetraethylhexanoate Dub PTL (Stéarinerie Dubois) 3.50 Pentaerythrityl tetralaurate Cromolient DP3-A (Croda) 2.50 DI-PPG-3 Myristyl ether adipate KSP-105 (Shin-Etsu) 1.50 Vinyl dimethicone/ Methicone silsesquioxane crosspolymer STAGE C Xiameter PMX-1503 fluid (Dow Chemical) 2.50 Dimethicone/dimethiconol STAGE D Purified fraction of fucoidans (ALGAE & SEA – Solabia group) 0.1 Ascophyllum nodosum extract NaOH, 10% solution Qsp pH Sodium hydroxide

The preparatory mode is as follows:

Phase A is prepared at 70°C.

Phase B is prepared at 70°C.

The emulsion is then produced by pouring phase B into phase A with vigorous stirring.

After the emulsion, phase C is added.

When the mixture reaches 40° C., the purified fraction of fucoidans is incorporated, then the pH is adjusted if necessary.

The physico-chemical characteristics of the mixture are as follows: pH: 5.8-6.2 at 20° C., viscosity: 40000-50000 cP at 20° C., LVT 4, 12 rpm.

Another example of possible wording is as follows.

Example 4: Skin restructuring cream

Ingredients Percentages INCI designations STAGE A Natragem EW-FL (Croda) 5.50 Glyceryl stearate/ Polyglyceryl-6 palmitate/ succinate/ Cetearyl alcohol Hydracire S (Gattefossé) 2.50 Acacia decurrens/ Jojoba/ Sunflower seed wax/ Polyglyceryl-3 esters Compritol 888 (Gattefosse) 2.50 Glyceryl dibehenate/ Tribehenin/ Glyceryl behenate Tegosoft CR (Evonik) 2.50 Cetyl ricinoleate Isofol 20 3.50 Octyldodecanol Cetiol CC (BASF) 2.00 Dicaprylyl carbonate DC EL 7040 (Dow Corning) 2.50 Capryl methicone/ PEG-12 Dimethicone/ PPG-20 Crosspolymer Omega 6 ceramide New (Solabia group) 0.60 Safflower oil/ Palm oil aminopropanediol esters/ Ceramide NP STAGE B Demineralized Water Qsp 100 Aqua Conservative Qsp Glycerin 5.00 Glycerine Keltrol CG-SFT (CP Kelco) 0.20 Xanthan gum STAGE C DC 1503 (Dow Corning) 2.50 Dimethicone/ Dimethiconol STAGE D Novemer EC-2 polymer (Lubrizol) 1.60 Sodium acrylates/ Beheneth-25 methacrylate crosspolymer/ Hydrogenated polydecene/ Lauryl glucoside Purified fraction of fucoidans (ALGUES & Mer – Solabia group) 0.5 Ascophyllum nodosum extract STAGE E Perfume Essence 40120-01 (Nactis) 0.15 Perfume (Fragrance)

The method of preparation is as follows:

Phase A is prepared at 75°C.

Phase B is prepared at 70°C.

The emulsion is produced by pouring phase A into phase B with vigorous stirring.

The elements of phase C are then added one by one with stirring.

When the mixture reaches 45° C., the elements of phase D are added, one by one, with stirring.

When the mixture reaches 35°C, the perfume is incorporated.

The physico-chemical characteristics of the mixture are as follows:

The pH is between 5.5 and 6.0 at 20°C.

The viscosity is between 20,000 and 25,000 cP at 20° C., LVT 4, 12 rpm.

Extracts of Fucus vesiculosus , Fucus spiralis , Undaria pinnatifida , Ecklonia kurome , Laminaria digitata or Laminaria japonica were also prepared which were used in the same way with the same ingredients and according to the same proportions as in the previous examples. The physico-chemical characteristics, the pH and the viscosity are globally identical for each of the extracts of Fucus vesiculosus , Fucus spiralis , Undaria pinnatifida , Ecklonia kurome , Laminaria digitata or Laminaria japonica .

It goes without saying that various preparations incorporating the fraction of low molecular weight fucoidans can be envisaged in the field of cosmetics.

The examples of embodiments described in this application are given for information only and should not be understood as presenting a limiting nature of the invention.

Example 5: moisturizing anti-aging cream

INGREDIENT % INCI NAME STAGE A Demineralized Water Qsp 100 Aqua Conservatives Qsp / 1,3 Propanediol (Connect Chemical) 3.00 Propanediol Actigum VSX 20 (Cargill) 0.40 Sclerotium gum / Xanthan gum STAGE B Olivem 1000 (Hallstar) 4.00 Cetearyl olivate / Sorbitan olivate Oliwax LC (Hallstar) 2.00 Cetyl palmitate / Sorbitan palmitate / Sorbitan olivate Cetiol C5 (BASF) 7.00 Coco-caprylate Lipex Shea (Aarhus Karlshamns) 2.00 Butyrospermum parkii (Sheabutter) Passion Fruit Oil (Solabia group) 1.00 Passiflora edulis (Maracuja) seed oil STAGE C Demineralized Water 10.00 Aqua Purified fraction of fucoidans (ALGUES & MER-Solabia group)
1.00 Fucus Vesiculosus Extract

OPERATING MODE

Prepare the fatty phase at 70°C, add the Lipex Shea and the Passion Fruit oil when the temperature is reached.

Prepare the aqueous phase at 70°C: heat the water then add the Actigum previously moistened in the Propanediol, with stirring.

Make the emulsion by pouring the fatty phase into the aqueous phase with vigorous stirring.

At 45°C, add phase C.

Example 6: B-quiet anti-wrinkle cream

INGREDIENTS % INCI NAME STAGE A Emulium Mellifera (Gattefosse) 4.00 Polyglyceryl-6 distearate / Jojoba esters / Polyglyceryl-3 beeswax / Cetyl alcohol Axol C62 (Evonik) 0.30 Glyceryl stearate citrate Sonnenatural (Sonneborn) 3.00 Olus oil Nacol 16 98 (Sasol) 2.00 Cetyl alcohol Dub MCT (Stéarinerie Dubois) 5.00 Caprylic/capric triglyceride Isofol 20 (Sasol) 5.00 Octyldodecanol STAGE B Demineralized Water Qsp 100 Aqua Conservative Qsp Fucogel Powder (Solabia) 0.30 Maltodextrin / Biosaccharide gum-1 Glycerin 4.00 Glycerine Actigum VSX 20 (Cargill) 0.30 Sclerotium gum / Xanthan gum STAGE C Purified fraction of fucoidans (ALGUES & MER-Solabia group)
3.00 Ecklonia Kurome Extract

PHYSICO-CHEMICAL CHARACTERISTICS

pH = 6.0 – 6.5 at 20°C

Viscosity: 25,000 to 30,000 cps at 20°C, LVT 4, 12 rpm

OPERATING MODE

Prepare phase A at 75°C.

Prepare phase B at 70°C (the Actigum will first be wetted in glycerin).

Make the emulsion by pouring A into B with vigorous stirring.

At 45°C, add phase C.

Example 7: Anti-Irritation Anti-Aging Balm

INGREDIENTS % INCI NAME STAGE A Olivem 1000 (Hallstar) 5.00 Cetearyl olivate / Sorbitan olivate Olivem 800 (Hallstar) 2.00 Ceteareth-6 olivate Isofol 20 (Sasol) 2.00 Octyldodecanol Cetiol CC (BASF) 4.00 Dicaprylyl carbonate Microcare silicone M8100 (Thor) 3.00 Caprylyl methicone DC 2503 (Dow Corning) 3.00 Stearyl dimethicone Dub DONPG (Stéarinerie Dubois) 3.00 Neopentyl glycol diethylhexanoate Tegosoft CR (Evonik) 5.00 Cetyl ricinoleate Dub Shorea T (Stéarinerie Dubois) 5.00 Shorea robusta seed butter STAGE B Demineralized Water Qs 100 Aqua Conservative qsp Ultrez 21 (Noveon) 0.15 Acrylates/C10-30 alkyl acrylate crosspolymer STAGE C Sunshine soft green (SunChemical) 2.00 CI 77891 (Titanium dioxide) / Synthetic fluorophlogopite Purified fraction of fucoidans (ALGUES & MER-Solabia group) 5.00 Laminaria japonica Extract STAGE D NaOH, 10% sol Qsp pH Sodium hydroxide

OPERATING MODE

Prepare phase A at 70°C.

Prepare phase B at 70°C.

Make the emulsion by pouring A into B with vigorous stirring.

Cool while maintaining agitation.

At 45°C, add the elements of phase C one by one, then adjust the pH with sodium hydroxide.

PHYSICO-CHEMICAL CHARACTERISTICS

pH = 5.8 +/- 0.5 at 20°C

Viscosity: 45,000cps +/- 5,000 at 20°C, LVT 4, 12 rpm

Claims (14)

Purified fraction of fucoidans obtained by extraction, purification and chemical or enzymatic depolymerization of dry algae, in particular fromAscophyllum nodosum, ofFucus vesiculosus, ofFucus spiralis, ofUndaria pinnatifida,ofEcklonia kurome, ofLaminaria digitataor ofLaminaria japonica, said fraction having a molecular weight of less than 30,000 daltons, as an active ingredient in a topical dermatological composition, for preventing telomere shortening in human fibroblasts and causing an increase in telomerase activity in human keratinocytes. Purified fraction of fucoidans according to Claim 1, characterized in that it represents between 0.01 and 5.00% by mass of said topical composition. Purified fraction of fucoidans according to Claim 2, characterized in that it represents 0.01% by mass of the said topical composition. Purified fraction of fucoidans according to Claim 2, characterized in that it represents 0.05% by mass of the said topical composition. Purified fraction of fucoidans according to Claim 2, characterized in that it represents 0.10% by mass of the said topical composition. Purified fraction of fucoidans according to Claim 2, characterized in that it represents 0.50% by mass of the said topical composition. Purified fraction of fucoidans according to Claim 2, characterized in that it represents 1.00% by mass of the said topical composition. Purified fraction of fucoidans according to Claim 2, characterized in that it represents 3.00% by mass of the said topical composition. Purified fraction of fucoidans according to Claim 2, characterized in that it represents 5.00% by mass of the said topical composition. Purified fucoidan fraction according to one of the preceding claims, characterized in that it is preferably obtained fromAscophyllum nodosum. Purified fraction of fucoidans according to one of the preceding claims, characterized in that it is in a dry or liquid form. Purified fraction of fucoidans according to Claim 11, characterized in that the dry form is obtained by atomization or freeze-drying. Purified fraction of fucoidans according to Claim 11, characterized in that the liquid form is obtained in solution in a diluting solvent, such as water, a glycol or a primary or secondary alcohol optionally incorporating a preservative. Dermatological composition for reducing telomere shortening in human fibroblasts and for increasing telomerase activity in human keratinocytes, characterized in that it comprises as active principle a purified fraction of fucoidans according to any of the preceding claims according to a percentage by mass comprised between 0.01 and 5.00%, having a molecular weight of less than 30000DA.