WO1999025369A1

WO1999025369A1 - Compositions for cosmetic and dermopharmaceutical use containing a plant extract obtained from kava piper methysticum roots

Info

Publication number: WO1999025369A1
Application number: PCT/FR1998/002393
Authority: WO
Inventors: Karl Lintner
Original assignee: Sederma S.A.
Priority date: 1997-11-17
Filing date: 1998-11-09
Publication date: 1999-05-27
Also published as: FR2771002B1; FR2771002A1; AU1161699A

Abstract

The invention concerns compositions for cosmetic and dermopharmaceutical use containing, in sufficient amount, a plant extract obtained from Kava Piper methysticum roots. The cosmetic or dermopharmaceutical compositions containing said plant extract are advantageously used in conditions of stress, whether physical, chemical or psychological, which affect the cutaneous metabolism and therefore the functions and appearance of the skin.

Description

Title Compositions for cosmetic or dermopharmaceutical use containing a plant extract obtained from the roots of Kava Piper methysticum.

Current living conditions subject organisms to attacks of all kinds, physical, chemical and psychological. As the skin constitutes the only interface between the individual and the outside world, it is clear that this organ is the first bodily element affected by external physical and chemical attacks, better known as pollution in general and atmospheric pollution in particular . Psychological stress, on the other hand, affects the skin in two different ways. On the one hand, mental stress has direct physiological repercussions. The skin undergoes alterations due to imbalances induced by sudden variations in the levels of circulating hormones, in response to the different sequences of daily stress. These abrupt variations modify at the intimate level of cells, skin and others, the biochemical regulations, delicate and fine, which ensure the sustainability of an organism. Although not localized in the skin, the best known consequence of this type of stress is stomach ulcer.

On the other hand, to cope with mental stress, individuals are increasingly resorting to palliative measures such as, for example, unbalanced diet which ranges from simple daily disorder to bulimia or anorexia, tobacco, l alcohol or even antidepressant products. The harmful consequences of excessive tobacco and alcohol consumption are well known in the skin: dryness and premature aging are two of the main characteristics.

These attacks are permanent and it is almost impossible to escape them continuously and effectively. It is therefore in the logic of the Cosmetics and Dermo-pharmaceutical industries to develop products that help the skin to better withstand, or even correct and / or repair, the harmful consequences of these attacks of all kinds. Kava Piper methysticum is a 1 to 2 meter shrub found from New Guinea to Fiji and Hawaii. Its usual use consists of crushed roots or stems to obtain a thirst-quenching drink, with a taste of liquorice or slightly peppery anise, which is highly prized by local people. This use of Kava has been known for a very long time since the Polynesians offered it to Captain COOK in 1769 as a token of welcome.

We have discovered that Kava Piper methysticum root extracts also have beneficial effects when applied topically. The invention which is the subject of this present patent resides in the discovery that a plant extract obtained from the roots of Kava Piper methysticum, is capable of protecting the skin from the effects of the various stresses mentioned above, by properties soothing, hydrating, regulating microcirculation and cellular respiration. The plant extract of Kava is obtained by extraction in a ratio of 15 grams of Kava Piper methysticum roots per 85 grams of a water / polyethylene glycol mixture (50/50, w / w) for 1 hour at 60 ° C. After drying, the dry extract is taken up in butylene glycol.

This example of obtaining the plant extract of Kava Piper methysticum, is not limiting It is indeed possible to produce the Kava extract by other methods such as, for example, simple decoction, leaching, l 'extraction under reflux, extraction by means of ultrasound or microwaves or finally against the current techniques, without this list being exhaustive. Furthermore, the extraction solvents mentioned above are not limiting and can be chosen from water, propylene glycol, butylene glycol, glycerin, polyethylene glycol, methyl or ethyl ethers of diglycols, polyols cyclic, ethoxylated or propoxylated diglycols, alcohols (methanol, ethanol, propanol, butanol), or any mixture of these solvents. Analysis by high pressure liquid chromatography (HPLC) of the Kava extract reveals the presence of various lactone-type compounds among which kawaïne dominates.

Although it is not limiting, the following example will illustrate a possible use of the plant extract obtained from Kava Piper methysticum in a cosmetic or dermopharmaceutical composition:

Body lotion

Polysorbate 60 2.5

Oleic acid 0.9

Lanolin oil 2.5

Carbopol 940 0.3

Beeswax 2.0

Triethanolamine 0.1

Glycerin 5.0

Kava Root Extract 4.0

Water & preservatives QSP 100g Among the various beneficial effects found during the development of the plant extract of Kava described above, two efficacy tests will be mentioned.

The first which is an ex-vivo test consists in exposing a reconstituted skin to different stresses. The reconstituted skin, or Living Skin Equivalent, obtained in the form of a ready-to-use kit, consists of a dermal layer on which are affixed keratinocytes which will form a multilayer epidermis, differentiated and similar to normal skin. This method is an alternative benchmark method in Cosmetics and Dermopharmacy since it allows products to be tested by an in vitro method but under conditions very close to vivo wine. By means of this system, we tested two different activities: the harmlessness of Kava extract on the cells used for the measurement of cellular respiration as well as the cellular regenerative power (anti-stress and repair) after a chemical attack carried out with a 30% triethanolamine solution. Body milk was tested in comparison with the same composition made without Kava root extract (placebo milk).

Mitochondrial respiration is conventionally evaluated by the MTT reagent ([3- (4,5-dimethylthiazol-2-yl) -2, '- diphenyltetrazolium bromide]) whose color changes from yellow to blue under the action of a dehydrogenase mitochondrial. Under these conditions, the safety of Kava root extract has been demonstrated since the level of cellular respiration was 5% higher than that observed with placebo milk. As between the two milks tested, the cell belts were identical in every respect, it is also possible to conclude that the cellular respiration improved in the presence of the Kava extract. The cell regeneration test consists in applying a solution of triethanolamine (30%), for 30 minutes, to the equivalent skin and then rinsing it several times with demineralized water. The test products are then applied for two hours, after which time the number of surviving cells is measured as above using MTT. Under these conditions, in the presence of milk containing Kava extract, the rate of cellular respiration, and therefore the number of surviving cells was 28% higher than that observed in the presence of placebo milk alone. Given the 5% higher mitochondrial respiration rate in the presence of the previously found Kava extract, it is possible to conclude that in the presence of the Kava extract, the number of living cells after chemical attack is higher about 20% than in his absence. The second test carried out, known as the "Stinging Test", is an in vivo test conventionally used to demonstrate soothing properties on the skin of cosmetic or dermopharmaceutical products and can be described as follows.

A 10% solution of lactic acid in physiological saline is applied to each of the two nasolabial folds. The tingling sensations are evaluated by the volunteer, immediately after application, at the level of the two grooves, by a well-defined rating system (no tingling = 0; slight = l; moderate = 2; significant = 3).

Body milk, the composition of which was given previously as an example of use, containing 4% of Kava root extract, is applied as it is, in one go, at the onset of tingling, on the side of the nose previously chosen from randomized by the investigator. At the same time, the other side receives the placebo (same composition except for the absence of Kava root extract). The intensity of the tingling is noted during the 5 minutes following the application, in the area having received the placebo or the Kava root extract, according to the same rating system as that determined for the evaluation of the initial reactivity. The entire test is carried out in an air-conditioned room, in which the ambient temperature and the humidity are kept constant. The average tingling intensity was determined at each time of the test, by calculating the arithmetic mean and the deviation from the mean (SEM) of the individual data obtained on all the volunteers.

The analysis of the results related to the values obtained at the level of the zone treated with the product studied, in comparison with the values acquired at the level of the control zone having received lactic acid alone before the application of the product studied ("time 0 "), for each of the treated and control zones.

This test was carried out on 20 volunteers, 18 women and 2 men, aged 21 to 47 who all had facial skin defined as "hypersensitive", by the "Stinging Test" method. Analysis of the results shows that compared to placebo, milk containing Kava root extract causes a significant decrease in the intensity of tingling, and this, from the first 5 seconds of application and during the 5 minutes that lasts the test. The body milk containing the Kava root extract described above therefore clearly demonstrates, at the cutaneous level, a powerful soothing effect against the tingling sensations felt by the volunteers following the chemical attack. It should be noted that in the same experimental conditions, body milk without Kava root extract (placebo milk) has the same scores as those usually observed in untreated areas, which clearly shows that it is only with Kava root extract previously described in this patent that the observed beneficial effect can be attributed. The effects described above (improvement in mitochondrial respiration, cellular regenerating power and soothing power) being given by way of example, it is possible to mention, without the following list being exhaustive, other beneficial effects of extract of Kava roots on the harmful skin consequences induced by all situations of stress, such as, for example, soothing, calming, relaxing, hydrating, regenerating, regulating microcirculation and cellular respiration; properties which are necessary to obtain anti-aging, anti-wrinkle, anti-inflammatory, slimming effects, on the scalp (anti-dandruff and or anti hair loss), on acne skin and therefore effects which prolong the suppleness and the protective function skin. The plant extract of Kava Piper methysticum is used either in liquid form or in dry form obtained by conventional techniques of precipitation, drying, evaporation, atomization or lyophilization

The plant extract obtained from Kava Piper methysticum described above can be used in any galenic form used in Cosmetics or Dermopharmacy: O / W and W / O emulsions, milks, lotions, ointments, hair lotions, shampoos, soaps, sticks and pencils, sprays, body oils, without this list being exhaustive. It is possible to incorporate the plant extract obtained from Kava Piper methysticum previously described, in cosmetic vectors such as liposomes, chylomicrons, macro-, micro- and nanoparticles as well as macro-, micro- and nanocapsules , absorb them on powdery organic polymers, talcs, bentonites and other mineral supports.

The plant extract obtained from Kava Piper methysticum described above can be combined in cosmetic compositions with any other ingredient usually used in cosmetics: extraction and / or synthetic lipids, gelling and viscosifying polymers, surfactants and emulsifiers, active ingredients water- or fat-soluble, extracts from other plants, tissue extracts, marine extracts.

The concentrations of the plant extract obtained from Kava Piper methysticum previously described can vary between 0.01% and 50% (w / w), preferably between 0.5% and 7% by weight, in the finished product.

Claims

1. Cosmetic or dermopharmaceutical compositions, characterized in that they contain a plant extract of the roots of Kava Piper methysticum.

2. Cosmetic or dermopharmaceutical compositions according to claim 1, characterized in that the extraction solvents used are chosen from water, propylene glycol, butylene glycol, glycerin, polyethylene glycol, methyl or ethyl ethers of diglycols, cyclic polyols, ethoxylated or propoxylated diglycols, alcohols (methanol, ethanol, propanol, butanol), or any mixture of these solvents.

3. Cosmetic or dermopharmaceutical compositions according to claims 1 to 2, characterized in that the extract of Kava Piper methysticum is obtained by a water / propylene glycol mixture (50/50, w / w), then, only after drying, l 'dry extract is taken up in butylene glycol.

4. Cosmetic or dermopharmaceutical compositions according to any one of claims 1 to 3, characterized in that the extraction carried out from the roots of Kava Piper methysticum is replaced by maceration techniques or by other methods such as, for example, simple decoction, leaching, extraction under reflux, extraction using ultrasound or microwaves or finally countercurrent techniques.

5 Cosmetic or dermopharmaceutical compositions according to any one of claims 1 to 4 characterized in that the extract of Kava Piper methysticum is used either in liquid form or in dry form obtained by conventional techniques of precipitation, drying, evaporation, atomization or lyophilization.

6. Cosmetic or dermopharmaceutical compositions according to any one of claims 1 to 5, characterized in that the concentration of the extract of Kava Piper methysticum is between 0.01% and 50% (w / w), preferably between 0.5% and 7% by weight, in the finished product.

7. Cosmetic or dermopharmaceutical compositions according to any one of claims 1 to 6, characterized in that the extract of Kava Piper methysticum is used in any galenic form used in cosmetics or dermopharmacy: O / W and W / O emulsions, milks, lotions, ointments, hair lotions, shampoos, soaps, sticks and pencils, sprays, body oils.

8. Cosmetic or dermopharmaceutical compositions according to any one of claims 1 to 7, characterized in that the extract of Kava Piper methysticum is incorporated into cosmetic vectors such as liposomes, chylomicrons, macro-, micro- and nanoparticles as well as macro-, micro- and nanocapsules, or absorbed on powdery organic polymers, talcs, bentonites and other mineral supports.

9. Cosmetic or dermopharmaceutical compositions according to any one of claims 1 to 8, characterized in that the extract of Kava Piper methysticum is combined in the cosmetic compositions with any other ingredient usually used in cosmetics: extraction lipids and / or synthesis, gelling and viscosifying polymers, surfactants and emulsifiers, water- or liposoluble active principles, extracts from other plants, tissue extracts, marine extracts.

10. Use of cosmetic or dermopharmaceutical compositions containing a plant extract of Kava Piper methysticum for the preparation of drugs against the cutaneous effects of stress, to soothe, calm, relax, hydrate, regenerate the skin, to regulate microcirculation and cellular respiration, prevent aging of the skin and scalp, to obtain anti-inflammatory, slimming and anti-cellulite and anti-acne effects.