WO2002039973A2 - Product preparing and protecting the skin against uv radiation, countering cellular ageing and exerting an immunostimulant action - Google Patents

Abstract

The invention concerns a product for oral administration for simultaneously protecting the skin against UV radiation, protecting it against cellular ageing processes and for exerting an immunostimulant action, and based on a combination of beta -carotene, at least a flavonoid and vitamins. The invention is characterised in that the beta -carotene is associated with catechins.

Description

 Product preparing and protecting the skin against UV rays, acting against cellular aging and exerting an immunostimulatory action

The present invention relates to a product which can be administered orally and which is aimed jointly at the preparation and protection of the skin against UV radiation, protection against the mechanisms of cell aging, and at the same time exerting an immunostimulatory action. This product is essentially based on a combination of β-carotene, at least one flavonoid and various vitamins. Products with this association are already known, in particular intended to prepare the skin for a momentarily more intense exposure to solar radiation, before and during a stay in a region benefiting from generous sunshine.

There are, for example, capsules to be taken a few days before and during exposure to said radiation, and which contain a combination of β-carotene, vitamins C and E and flavonoids.

In general, the multiple products available in pharmacies or drugstores certainly aim to protect the skin, but also to accelerate tanning, tanned skin causing a certain craze and meeting current aesthetic criteria. To this end, they are all based on carotenoids, of which β-carotene is only one example.

Carotenoids have a direct protective role, since they act as a filter or screen. They also have a function of coloring the skin (yellow-orange) imitating the natural tan. The vitamins which are added, in general mainly vitamins C and E, have an antioxidant power and consequently oppose the skin aging process.

Finally, tanning preparation products generally have essential fatty acids, which act on the hydration of the epidermis. More specifically, carotenoids are used in the body mainly for their antioxidant function at the plasma level (especially in relation to circulating lipids), but also at the cell level since they are incorporated into the membranes. Β-carotene, in particular, is subject to a conversion mechanism because it is the precursor of vitamin A. It is therefore highly likely to undergo transformation or use reactions before it reaches the skin. which of course considerably diminishes its interest as a constituent of preparations for tanning and or for protecting the skin, in which it is mainly useful in the skin, where it is used as a pigment and antioxidant.

In fact, the aforementioned products would be much more effective if we succeeded in controlling the place of use of β-carotene, and in particular in curbing its consumption at the plasma level to allow it to arrive in greater quantity at skin level.

The main objective of the invention is to solve this problem, by optimizing for a specific objective the use of β-carotene in the body, in order to protect and prepare the skin against UV radiation, against the mechanisms of cell aging, and finally to promote an immunostimulatory action.

To meet these objectives, the product of the invention is mainly characterized in that β-carotene is associated with catechins.

We have indeed realized that catechins delay the use of β-carotene at the plasma level. Indeed, supplementation with catechins slows down on the one hand the decrease in β-carotene levels, and on the other hand decreases its level of use in plasma. This observation results from experiments carried out using green tea, which we realized that regular intake allowed to reach blood levels of catechins likely to contribute to exercise the activity described above. The β-carotene can then arrive in greater quantity at the level of the skin, since it is less used at the plasma level, its antioxidant function being fulfilled by certain types of catechins.

In other words, if β-carotene supplementation is to be effective at the cutaneous level, it must be accompanied by catechin supplementation.

Preferably, the β-carotene used for the supplements is of the all-trans isomeric type.

The all-trans form of β-carotene is indeed absorbed faster than the other known isomeric form, the 9-cis form. It is more theoretically less degraded in the gastrointestinal tract than the latter, and its serum concentration is thus higher.

Finally, the all-trans isomeric form is more strongly absorbed regardless of the type of administration, single or repeated dose. It therefore presents optimal bioavailability due to its particular molecular and physicochemical state. Supplementation with all-trans β-carotene therefore guarantees maximum efficiency, in particular to satisfy the above-mentioned objectives.

Preferably, the β-carotene used is more of the synthetic type. The latter, for example, is indeed much better absorbed than plant β-carotene, which is probably "trapped" within chloroplasts, and then probably undergoes a phenomenon of complexation with the proteins of these cells. The lack of absorption of β-carotene from plants could also be the consequence of its physical state in vegetables. In carrots for example, it is in the form of microcrystals which probably do not have the gastrointestinal transit time necessary to allow their solubilization. This microcrystals form is therefore weakly bio-available compared to synthetic β-carotene.

The aim being to reach optimal serum and tissue concentrations, β-carotene supplementation must therefore be carried out in a synthetic form, rather than by an increase in the intake of food naturally containing β-carotene. According to the invention, β-carotene is present in an amount by weight of between 2 mg and 50 mg.

More specifically, the said product may contain 14 mg thereof, tests having shown that this value makes it possible to achieve an optimization of the ratio administered quantity / therapeutic effect. According to one possibility, the catechins which are associated according to the invention with β-carotene are present in an amount by weight of between 25 m g and 600 mg.

More particularly, the product of the invention contains 250 mg thereof, this value being considered as an average value leading to good experimental results.

Preferably, the catechins used essentially comprise catechins of the epigallocatechin gallate type and of the epicatechin gallate type.

Studies have in fact classified catechins according to their ability to delay the decrease in plasma concentration of β-carotene under oxidation conditions.

In decreasing order of activity, and specifically for β-carotene, catechins are classified as follows: epigallocatechin gallate, epicatechin gallate, epigallocatechin, then with much less interesting effects, epicatechin and catechin. It is therefore functionally preferable to use the first two

The product of the invention also comprises, as mentioned before, a combination of vitamins E and vitamins C.

We know that vitamin E is the main antioxidant in body tissues. It protects cell membranes in one of the first stages of radical attack by its ability to trap free radicals. It is therefore considered to be the first line of defense against lipoperoxidation. Free radicals, when not captured by an antioxidant, attack polyunsaturated fatty acids in cell membranes in a chain reaction. However, these free radicals are apparently involved in the development of a number of diseases and degenerative states, such as for example coronary heart disease, cancer, Alzheimer's disease, arthritis, early aging, cataracts, etc. ..

A drop in vitamin E concentration therefore causes a higher rate of lipid peroxidation which largely contributes to the aging process and to the development of pathologies associated with this aging. In particular, vitamin E has a protective effect on skin aging by reducing the level of expression of collagenase, induced by environmental damage and aging. In addition, vitamin E has an immunostimulatory action, because it fights the decrease in action of the body's immune defenses.

In the invention, vitamin E is associated with vitamin C because this association produces a synergistic effect on the induced protection. This effect is for example notable on the skin inflammation caused by solar radiation.

It should be noted that the association β-carotene / vitamin E is also interesting, because it causes a synergy which leads to a more effective protection against erythemas in particular due to exposure to UV.

According to one possibility, vitamin E is present in the product of the invention in a weight amount between 2 mg and 20 mg, vitamin C being present in a weight amount between 20 mg and 200 mg.

Preferably, said product more precisely comprises 10 mg of vitamin E and 120 mg of vitamin C. By generalizing, this product may contain an association of ascorbic acid /

D-alpha-tocopherol, one of the stereoisomers of vitamin E. This conjunction is as previously necessary because of the synergistic effect on the induced protection, equivalent to that which is mentioned above. This effect again reinforces the protective action of β-carotene. The product of the invention also contains vitamin B5. This vitamin is the precursor of co-enzyme A, its main constituent, and intervenes as such in the metabolism of lipids, carbohydrates and proteins. It is therefore involved in the synthesis of steroid hormones derived from cholesterol and in the synthesis of hemoglobin. This vitamin also promotes growth and resistance of the skin and mucous membranes, and it is beneficial against the effects of UV rays because it calms the signs of skin irritation and redness, thanks to its healing properties. According to one possibility, this vitamin B5 is present in an amount by weight of between 2 and 12 mg. Preferably, the product of the invention in fact comprises 6 mg thereof.

The product of the invention may also contain, in addition to catechins, other flavonoids, one of the major properties of which is that they are capable of trapping the radicals formed in various circumstances.

However, although their physiological role is not fully studied, it is assumed that said radicals are responsible for alterations of nucleic acids and for the mutation, initiation and promotion of cancerization processes, as well as for cellular degradations due, in particular , of their reaction with membrane phospholipids.

In addition, flavonoids are enzyme inhibitors, anti-inflammatories, and even anti-allergics.

Like vitamin B5, flavonoids are therefore an important active ingredient in the product of the invention, notably strengthening vascular resistance, and making it possible to reduce the edema and redness caused by UV radiation.

The product of the invention, thus defined by its essential constituents, can obviously be envisaged in different gallenic forms, preferably administrable by oral route. According to a preferential possibility, it is in the form of a drink consisting of:

- cranberry juice rich in flavonoids;

- fructose;

- inulin; - plant extract rich in catechins;

- vitamins C, E and B5;

- β-carotene; and

- aromas.

Other packaging for oral administration is also possible, as shown by the following two examples.

It is thus possible to package said product in the form of capsules consisting of a gelatin tunic or a vegetal envelope, and containing the following components:

- plant extract rich in catechins; - vitamins C, E and B5; and

- β-carotene.

Alternatively, this product can be presented in the form of capsules with a gelatin coat, and consisting of: - yellow wax;

- oil ;

- plant extract rich in catechins;

- vitamins C, E and B5;

- β-carotene; and - lecithin.

Finally, the invention can be made available in the form of a preparation for beverages, for example herbal teas, be made for this purpose of a support such as sucrose, maltodextrin or inulin, and comprise:

- plant extract rich in catechins; - vitamins C, E and B5; and

- β-carotene.

In all of these packages, according to the invention, the plant extract rich in catechins consists, for example, of green tea extract.

Of course, the above examples are not limitative of the invention, which on the contrary encompasses variants in particular of packaging, and substitutions of components which are within the reach of those skilled in the art.

Claims

1. Oral product intended jointly for the preparation and protection of the skin against UV radiation, protection against the mechanisms of cell aging and exerting an immunostimulatory action, and based on a combination of β-carotene, at least one flavonoid and vitamins, characterized in that the β-carotene is associated with catechins. 2. Product according to the preceding claim, characterized in that the β-carotene used is of the all-trans isomeric type. 3. Product according to the preceding claim, characterized in that the β-carotene used is of synthetic type. 4. Product according to any one of the preceding claims, characterized in that the β-carotene is present in an amount by weight of between 2 mg and 50 mg. 5. Product according to the preceding claim, characterized in that it comprises 14 mg of β-carotene. 6. Product according to any one of the preceding claims, characterized in that the catechins are present in an amount by weight of between 25 mg and 600 mg. 7. Product according to the preceding claim, characterized in that it comprises 250 mg of catechins. 8. Product according to any one of the preceding claims, characterized in that the catechins used comprise catechins of the epigallocatechin gallate type and of the epicatechin gallate type. 9. Product according to any one of the preceding claims, characterized in that it comprises a combination of vitamins E and vitamins C. 10. Product according to the preceding claim, characterized in that vitamin E is present in an amount by weight between 2 mg and 20 mg, and vitamin C is present in a weight amount between 20 mg and 200 mg. 11. Product according to the preceding claim, characterized in that it comprises 10 mg of vitamin E and 120 mg of vitamin C. 12. Product according to any one of claims 1 to 8, characterized in that it contains an ascorbic acid / D-alpha-tocopherol association. 13. Product according to any one of the preceding claims, characterized in that it contains vitamin B5. 14. Product according to any one of the preceding claims, characterized in that the vitamin B5 is present in an amount by weight of between 2 and 12 mg. 15. Product according to the preceding claim, characterized in that it comprises 6 mg of vitamin B5. 16. Product according to any one of the preceding claims, characterized in that it is in the form of a drink consisting of: - cranberry juice rich in flavonoids; - fructose; - inulin; - plant extract in catechins; - vitamins C, E and B5; - β-carotene; and - aromas. 17. Product according to any one of claims 1 to 15, characterized in that it is in the form of capsules consisting of a gelatin coat or a vegetable envelope, and containing the following components: - plant extract rich in catechins; - vitamins C, E and B5; and - β-carotene. 18. Product according to any one of claims 1 to 15, characterized in that it is in the form of capsules provided with a gelatin coat, and consisting of: - yellow wax; - oil ; - plant extract rich in catechins; - vitamins C, E and B5; - β-carotene; and - lecithin. 19. Product according to any one of claims 1 to 15, characterized in that it is in the form of a preparation for drinks, for example herbal teas, consisting of a support such as sucrose, maltodextrin or inulin, and comprising: - plant extract rich in catechins; - vitamins C, E and B5; and - β-carotene. 20. Product according to any one of claims 16 to 19, characterized in that the plant extract rich in catechins consists of green tea extract.