Patent Description:
Skin is the organ which completely covers the surface of the body with an extension of about <NUM>-<NUM><NUM> in the adult subject, and represents the border between our body and the outside world. Several important functions are attributed thereto: defence against chemical, physical and biological agents; perception of the outside world, thanks to the presence of a rich nervous network; synthesis of numerous substances (vitamin D, antimicrobials, moisturisers). Skin also contributes to thermoregulation and immune response and is a route of elimination, through sweating, not only of natural waste substances, but also of drugs and toxins. Finally, but of fundamental importance for survival, skin has the ability to retain water in our body, which has a much higher percentage than the external environment. Thanks to the particular morphological structure thereof, skin retains water inside, while communicating and adapting to external changes and thus allows us to live in an environment with extremely variable conditions.

Skin aging is a physiological process immediately observable by the person and is influenced by both intrinsic factors (genetic heritage, endocrine system) and extrinsic factors (exposure to the sun without protection, pollution, incorrect lifestyle).

Intrinsic skin aging consists of a progressive loss of cell matrix organization at the level of both the dermis and epidermis. The epidermis consists of <NUM>% keratinocytes, which are cells responsible for the continuous renewal thereof. As age progresses, several more or less profound changes occur: cell renewal slows down and, consequently, the epidermis becomes thinner. In addition, the lipid barrier between cells becomes insufficient and no longer functions properly. At a deeper level, in the dermis, fibroblasts decrease in number and begin to synthesize less collagen and elastin fibres, causing a change in skin tone and elasticity. The production of glycosaminoglycans (GAG) responsible for deep hydration is also reduced. Extrinsic skin aging is caused by many factors such as environmental pollution, alcohol consumption, drugs, and cigarette smoking which, above all of them, greatly reduces collagen synthesis. Among the environmental factors which cause skin aging, one of the most harmful is the incorrect exposure to solar radiation which determines an early aging process, especially by stimulating the production of free radicals, the main enemies of the skin.

In any case, both intrinsic and extrinsic aging cause structural changes in skin, and wrinkles are the most obvious sign of this.

Hyaluronic acid (HA) or better still the biologically acceptable salt thereof, sodium hyaluronate, is a polymer belonging to the heteropolysaccharides family called Glycosaminoglycans (GAG) and is formed by units of D-glucuronic acid and N-acetylglucosamine. HA is therefore an anionic unsulphated glycosaminoglycan, which is found in the epithelial, connective and nerve tissues of vertebrates. The synthesis thereof occurs on the inner side of the plasma membrane (rather than in the Golgi) and is not covalently bound to any protein. In addition, it can have different molecular weights, even very high compared to the other GAGS.

In fact, it is one of the main components of the extracellular matrix and, precisely for this reason, promotes both cell proliferation and migration.

Hyaluronic acid owes the effectiveness thereof to the extraordinary ability thereof to absorb and retain large amounts of water (up to about <NUM> times the weight thereof) and acts as a cellular cementing agent, ensuring an excellent degree of hydration of the skin tissues: the higher the content thereof in the epidermis, the plumper, smoother and intensely hydrated the skin.

However, our body produces less with advancing age already from the age of <NUM>, while after the age of <NUM> it reduces considerably with the result that the first signs of skin aging appear, such as loss of elasticity, firmness and even volume. As a person ages, the appearance of the face changes, it loses the natural fullness and elasticity thereof, the cheeks and cheekbones become empty. Applying this precious ingredient through cosmetic formulations that contain it as an active ingredient can help prevent and correct wrinkle imperfection.

However, the activity of exogenously administered hyaluronic acid can be counteracted by the endogenous activity of the enzyme hyaluronidase and other enzymes which reduce the ability to act thereof, in addition there is a need to modulate the hydration of hyaluronic acid and therefore the activity thereof over time.

Mintel GNPD RECORD ID3147359 "White serum" <NUM>. <NUM>, discloses a cosmetic composition comprising among the plethora of cosmetic ingredients the sodium sale of Hyaluronic acid the extract Helianthus tuberosus glycerine and propanediol.

Mintel GNPD RECORD ID65120223 Whitening Jelly <NUM>. <NUM> discloses a cosmetic composition comprising among the plethora of cosmetic ingredients the sodium salt of hyaluronic and the hydrolyzed form thereof, the extract Helianthus tuberosus, glycerine and propanediol.

Mintel GNPD RECORD ID <NUM> "Serum" <NUM>. <NUM> discloses a cosmetic composition comprising HYALURONIC ACIDM EXTRACT OF Helianthus tuberosus glycerin and propanediol.

Mintel GNPD RECORD ID4882669 "Moist lotion"<NUM>. <NUM> discloses a cosmetic composition containing <NUM> types of hyaluronic acid and also the hyaluronic acid salt, the extract of Helianthus Tuberosus.

<CIT> discloses a moisturizing cosmetic composition comprising two molecular fractions of HA having respectively a molecular weight ranging from <NUM> to <NUM> D and from <NUM>,<NUM> to <NUM>,<NUM> D.

<CIT> discloses a moisturizing cosmetic composition comprising two molecular fractions of HA having respectively a molecular weight ranging from <NUM> to <NUM>,<NUM> D and from <NUM>,<NUM> to <NUM>,<NUM>,<NUM> D.

<CIT> discloses a cosmetic composition comprising a mixture of <NUM> fraction of HA.

<CIT> discloses a cosmetic composition comprising from <NUM> to <NUM> % of Jerusalem artichoke leaf extract.

<CIT> discloses the use of Helianthus tuberosus for improving skin moisturization and elasticity.

<CIT> discloses the use oof aerial shoot and/or tube of Helianthus tuberosus for skin calming and regeneration thereof.

The applicant has now found that it is possible to obtain cosmetic compositions in which the activity of hyaluronic acid is enhanced by the fact that hyaluronic acid or a biologically acceptable salt thereof is associated with an osmoprotectant comprising an extract of Helianthus tuberosus.

Hyaluronic acid in contact with body fluids which essentially consist of water tends to hydrate and increase volume. The presence of this osmoprotectant helps stabilize the polymer in a more compact globular form, which is however capable of binding a normal amount of water. The globular structure of hyaluronic acid, more compact in the presence of the osmoprotectant, makes it less exposed to degradative phenomena which normally occur with a direct exposure of hyaluronic acid to an aqueous environment.

The object of the present invention are therefore cosmetic compositions as claimed in claim <NUM> comprising as active ingredient:.

in combination with suitable excipients.

The extract of Helianthus Tuberosus obtained is a cosmetic-grade raw material which, in addition to being rich in polysaccharides, at low and medium molecular weight, also contains polyphenols.

The present invention thus relates to the use of said cosmetic compositions for the treatment and prevention of extrinsic and intrinsic skin aging.

For the purposes of the present invention, the definitions "comprising" and "containing" do not exclude the presence of additional components other than those mentioned after such definition.

The definition "consisting of" excludes the presence of additional components listed after such a definition.

In the cosmetic compositions object of the invention, the biologically acceptable salt is an alkali metal salt, and more preferably is sodium salt.

According to a preferred solution the cosmetic compositions object of the present invention comprise one or all three types of hyaluronic acid in concentrations between <NUM>% and <NUM>% by weight on the total weight of said cosmetic compositions.

Thereby, an action on the entire skin barrier is guaranteed.

Helianthus tuberosus, commonly known as Jerusalem artichoke, belongs to the genus Helianthus of the botanical family Asteraceae.

It is a tuber plant which, unlike the potato tuber, does not contain starch but inulin at a rate of <NUM>-<NUM>% in weight on the total weight of the plant. Because of the inulin content, Jerusalem artichoke tubers are often used in the food industry and distillery.

For the purposes of the present invention an extract of Helianthus tuberosus, also known as Topinambur, is meant, which is obtained only from the roots or tubers of said plant by a digestive process of the roots (tubers) processed so as to obtain a raw material of vegetable origin which is "cosmetic grade" and free of preservatives.

Preferably the extraction comprises the following steps: the fresh root is added with water respectively in a weight ratio between <NUM>/<NUM> and <NUM>/<NUM>, preferably <NUM>/<NUM>. These components are then mixed for <NUM> minutes at a temperature between <NUM> and <NUM>, allowed to digest for <NUM> hours at a temperature between <NUM> and <NUM>, possibly adding the water which has evaporated, thus obtaining the aqueous extract.

This type of extract is characterized by a colouration which could affect the organoleptic characteristics of the finished cosmetic product. Therefore, dilution is necessary before inserting the extract as it is in the cosmetic formula.

The diluent substance must be chosen so that it is compatible with use in cosmetic formulations, as required by Regulation <NUM>/<NUM>, in addition to supporting the desired organoleptic characteristics and pH conditions in a cosmetic product.

Therefore, a post-extraction dilution step is included using different extract/diluent ratios, such a diluent also being chosen to respect the desired characteristics described above.

Preferably the extract obtained is generally diluted with a polyol or a mixture of polyols, so that the diluent also performs the technical function of sequestrant of the aqueous phase, so as to prevent any microbial contamination.

Preferably the extract obtained is diluted with glycerine, propanediol or mixtures thereof.

Even more preferably the Heliantus tuberosus extract achieves optimal stability conditions with the mixture of glycerine and propanediol diluents, and, according to a particularly preferred solution with a glycerine/propanediol/extract weight ratio of <NUM>/<NUM>/<NUM>. The Helianthus Tuberosus extract thus obtained was analysed and, in addition to being rich in low and medium molecular weight polysaccharides, it also contains polyphenols such as chlorogenic acid, which allows an anti-aging effect to be obtained by working on the production of oxygen radicals (ROS) known to promote photo-aging induced by the exposure to UV rays. The cosmetic compositions can then be used for the treatment and prevention of extrinsic and intrinsic skin aging. The cosmetic compositions object of the present invention preferably comprise hyaluronic acid or component a) and osmoprotectant or component b) in a ratio comprised between <NUM>:<NUM> and <NUM>:<NUM>, more preferably <NUM>:<NUM>.

The cosmetic compositions according to the present invention comprise component a) in concentrations between <NUM> and <NUM>% by weight on the total weight of said cosmetic compositions, component b) in concentrations between <NUM> and <NUM>% by weight on the total weight of said compositions.

Some cosmetic compositions object of the present invention are given for illustrative but non-limiting purposes.

Claim 1:
Cosmetic compositions comprising as active principle:
a) hyaluronic acid or a biologically acceptable salt thereof,
b) an osmoprotector comprising an extract of Helianthus tuberosus in combination with suitable excipients, wherein
- component a) is in concentrations comprised between <NUM> and <NUM>% by weight on the total weight of said cosmetic compositions,
- component b) is in concentrations comprised between <NUM> and <NUM>% by weight on the total weight of said compositions;
- Helianthus tuberosus extract is obtained from roots or tubers of said plant by a digestive process.