FR2578422A1 - Therapeutic composition for external topical use, based on luteolin, and process for preparing it - Google Patents

Abstract

The present invention relates to therapeutic composition for external topical use, containing a biologically active amount of luteolin in aglucone form and/or luteolin glycosides and a biologically acceptable carrier. The present invention also relates to a process for preparing these compositions.

Description

 The present invention relates to external topical treatment compositions comprising a biologically active amount of luteolin and / or its glycosides and methods for their preparation.

 The brown spots or senescence spots that appear on the skin, especially on the skin of the hands, with age are due to hyperpigmentation of the skin by melanins, black pigments of the skin.

 Cosmetic formulas currently known to reduce senescence spots are based on the use of the depigmenting properties of hydroquinone. Hydroquinone has the disadvantage of not always being well tolerated. In addition, its depigmenting power is difficult to control; excessive use can lead to the appearance of white spots that are difficult to reverse. One way to regulate skin pigmentation is to facilitate the removal of cutaneous melanins, in particular by preventing their attachment to skin proteins.

 Flavonoids are a very common chemical family in the plant kingdom and have a large number of pharmacological activities. Some are particularly capable of forming flavone protein complexes, as shown by their inhibitory action on protein degrading enzymes.

 The Applicants have demonstrated that certain flavonoids, in particular 5,3,3-tetrahydroxyflavone, also called luteolin and some of its substituted derivatives, such as its glycoside derivatives, in particular its 7-glucoside, are capable of to change the rate of elimination of cutaneous melamine and thus to promote the disappearance of certain hypermelanic spots of the skin.

 In addition, these flavones can complex with proteins, they are able to modify the structure of keratin fibers of the hair, and thus improve the holding.

The present invention therefore provides compositions effective to remove hypermelanic spots, and without any harmfulness. These compositions are also useful for their properties improving the quality of the hair
The present invention relates to external topical treatment compositions comprising a biologically active amount of luteolin in aglucone form and / or luteolin glycosides and a biologically acceptable carrier.

 Luteolin or digitoflavone is a flavonoid that can be extracted from a large number of plants where it is usually in the form of its glycosides, and especially in the form of its 7-glucoside. In the compositions according to the invention, it is possible to use luteolin in aglucone form or in the form of its glycosides, in particular its 7-glucoside.

 As will be seen in the following examples, luteolin in aglucone form and its 7-glucoside have substantially comparable activities, the slightly higher activity of 7-glucoside being explained by its better bioavailability.

In a particular embodiment, use is made of luteolin in aglucone form or its glycosides extracted from plants or parts of plants chosen from
Achillea millefolium, Matricaria chamomilla, Cnicus benedictus, Cynara Scolymus, Mentha aquatica and Equisetum arvense.

 These species have been active in the mitigation of cutaneous melanic spots and have also shown a very interesting effect on the hair.

All these species possess various flavones in their chemical composition, the luteolin is common to them, in the form of various glycosides.

 One of these species, Achillea millefolium, has been very active in both dermatological and hair care applications.

One can use pure aglucone luteolin, its
Pure 7-glucoside, isolated from these extracts, or the extract itself containing luteolin aglucone or its glycosides, especially 7-glucoside.

 An extract of these plants titrated in total luteolin is then used.

 In the compositions according to the invention, the average total luteolin content is preferably between 0.1% and 5% by weight.

 In order to promote the penetration into the skin of luteolin or its glucoside in 7, it may be useful to associate with luteolin or its glucoside in 7 a keratolytic. This keratolytic aims to accelerate the elimination of superficial corneal layers.

As keratolytic, it is possible to use the usual keratolytics such as vitamin A or tretinolne, benzoyl peroxide, lactic acid.

 In a preferred embodiment, lactic acid is used which also has moisturizing properties.

The amount of keratolytic used in the compositions according to the invention may be usefully chosen between about 0.5 and 5% by weight. In the compositions according to the invention it may be useful to add a p1 regulatory agent in order to reach a pH compatible with the external topical use of these compositions. In particular, when these compositions contain lactic acid, a base is additionally added to compensate for the lowering of the pH. Any biologically acceptable base, for example triethanolamine, may be used.

 As a biologically acceptable carrier, it is possible to use all known biologically acceptable carriers that can be used in compositions in the form of cream, gel, lotion, milk, ointment, shampoo, hair lotions, emulsion shampoo, emulsion, spray solution, balm, applicator stick, or any other form of treatment composition for external topical use. The biologically acceptable carrier may further include water, perfumes and preservatives.

The present invention furthermore relates to a process for the preparation of the compositions according to the invention, characterized in that a) plants or parts of plants containing
luteolin in aglucone and / or glucoside form
luteolin by at least one decoction of said
plants or parts of plants in an alcohol,
father the alcoholic solution, b) concentrate the recovered alcoholic solution,
dilute this solution in water, c) treat the aqueous solution against the current with
ethyl ether, the ethereal extract is removed and
recovered the treated aqueous solution, d) the recovered aqueous solution is filtered, e) the aqueous solution recovered is mixed with a weight
equal to monopropylene glycol, f) the total luteolin content
by adding a monopropylene glycol / water mixture
50/50 by weight, g) and the mixture obtained is incorporated into a biolyster
acceptable.

In a particular embodiment of this process, dry plants are used as plants or parts of plants containing luteolin.
of Achillea millefolium. To carry out the decoction, as the lower aliphatic alcohol, methanol is preferably used. To filter the aqueous solution recovered in step d), a bed of diatoms is preferably used.

 Monopropylene glycol is particularly useful for its preservative properties.

 In a variant of this preparation process, to prepare compositions comprising, in combination, luteolin and a keratolytic such as lactic acid, the mixture obtained in step e) or in step f) is admixed with acid. lactic acid, in proportions of 0.5 to 5% by weight, for example, and a base such as triethanolamine to adjust the pE to a value compatible with external topical use, for example a slightly acidic pH.

 Other advantages and features of the present invention will become apparent in the examples below.

EXAMPLE 1
Preparation of an Achillea millefolium extract
One kilogram of dry aerial parts of Achillea millefolium is subjected to three successive decoctions in ten liters of methanol for one hour each time.

The extracts are combined and evaporated under reduced pressure to a syrupy consistency.

The residue is taken up in two liters of water, filtered and extracted against the current with ethyl ether. The ether extract is removed and the aqueous solution is removed from its ether by a partial concentration under reduced pressure, and the aqueous solution is filtered on diatom bed muées. The filtered aqueous solution is diluted with an equal weight of monopropylene glycol.

EXAMPLE 2
Preparation of an extract titrated with luteolin
To 5 ml of the solution obtained in Example 1, 1 ml of concentrated hydro-organic acid is added to a screw-plug tube and placed on a boiling water bath for one hour. The mixture is transferred to a separating funnel and then 100 ml of distilled water are added. This solution is then extracted with ethyl ether.

The ethereal extract is evaporated to dryness and taken up in 5 ml of methanol. One μl of this solution is deposited on a high performance chromatography plate and a luteolin control consisting of a 0.5% pure luteolin solution in methanol and diluted to 0.4-0.3-0. 2-0.1%.

The development is carried out by the following solvent
Ethyl acetate-formic acid-water 8-1-1
The revelation is carried out with aluminum chloride in 5% solution in ethanol. The spots are observed in ultraviolet light at 366 mm. The assay is carried out by densitometry at a wavelength of 340
The extract thus obtained has a titre of approximately 0.45% in total luteolin. It is adjusted to 0.30% by dilution with an equal weight mixture of water and monopropylene glycol.

EXAMPLE 3
Isolation of luteolin in aglucone form and its 7glucoside
The procedure is as in Example 1, until the diatom bed filtration.

The aqueous solution is treated with 100 g of activated carbon.

The charcoal is washed successively with cold water, boiling water, cold methanol and boiling methanol until the wash solution is colorless each time. Then, the charcoal is extracted with boiling 7% carbolic water. Flavonoids are then desadsorbed from the coal which is reactivated and recycled. The aqueous extract of flavonoids is stripped of its phenol by extraction with ethyl ether against the current.

The aqueous solution is then evaporated to dryness.

The residue is 20 to 25 g depending on the periods of collection of the raw material with a peak at the time of flowering of the plant.

This residue is then subjected to silica gel column chromatography using ethyl acetate-methanol 60-40 as eluent. Eight fractions with specific chemical reactions of flavonoids (cyanidin) are recovered. Among these eight fractions, the free luteolin and its glucoside are detected in plate chromatography in 7 by comparison with authentic controls. These two fractions are set aside.

The other six fractions collected are then separately subjected to acid hydrolysis followed by extraction with ethyl ether. The ether extract is evaporated to dryness and the resulting flavones identified by plate chromatography against authentic controls of luteolin and apigenin.

A 13 C-NMR spectrum of luteolin is made for confirmation.

EXAMPLE 4
Clinical trials of luteolin, con 7-glucoside and an extract of Achillea willefoliut titrated in total luteolin in glow regulating activity of cutaneous pigmentation.

A selection of people, ten men, and ten women was selected in the age group of forty to sixty years, with hypermelanic spots on the hands.

The subjects each receive two vials of one hundred milliliters labeled "right" and "left" respectively for applications on the right hand and the left hand.

The bottle for the left hand receives a placebo solution and that for the right hand a solution of flavonoids to be tested, adjusted to 0.3% of total luteolin.

An application is prescribed three times a day for one minus.

After one month of treatment, we note the possible improvements by comparison between the two hands.

RESULTS

<tb><SEP> slight <SEP> net <SEP> Disappearance
<tb> Aggravations <SEP> without <SEP> effect <SEP> improvement <SEP> improvement <SEP> complete
<tb><SEP> 1 <SEP> 3 <SEP> 2 <SEP><SEP> 7 <SEP> 7 <SEP>
<tb><SEP> 1 <SEP> 2 <SEP> 3 <SEP> 8 <SEP> 6
<Tb>
LINE 1: Luteolin
LINE 2: Luteolin 7-glucoside
LINE 3: Achillea millefolium extract
It is found that luteolin glucoside may be a little more active than luteolin itself which is probably due to better bioavailability of the product. It is also noted that the activity of the extract is substantially correlated with its luteolin content and that the presence of other flavonoids does not disturb or potentiate the bleaching effect of luteolin.

EXAMPLE 5
Clinical trials of luteolin, its 7-glucoside and Achillea millefolium extract combined with 2% lactic acid
The above flavones have also been tested with lactic acid which, in addition to its keratolytic power, also has a certain moisturizing power. the employment concentration is 2 t. The lowering of the pH must generally be compensated by the addition of a base such as triethanolamine.

RESULTS

<tb><SEP> Slight <SEP> clean <SEP> Disappear <SEP>
<tb> Aggravations <SEP> without <SEP> effect <SEP> improvement <SEP> mlioratlon <SEP> complete <SEP>
<tb><SEP> l <SEP> 2 <SEP> 2 <SEP> 6 <SEP> 9
<tb><SEP> o <SEP> I <SEP> 2 <SEP> 6 <SEP> It <SEP>
<tb><SEP> l <SEP> O <SEP> 4 <SEP> 9 <SEP> 6
<Tb>
LINE 1: Luteolin
LINE 2: Luteolin 7-Glucoside
LINE 3: Achillea millefolium extract
There is a clear improvement in the results with the acid. lactic.

EXAMPLE 6
Attempts to fix luteolin and its glucoside at 7 on keratin fibers.

The support used is virgin sheep wool not colored.

About 10 grams of wool, weighed exactly, are immersed in a 3% hydrogen glycolic solution of luteolin for 5 minutes. Then the wool is washed extensively with distilled water until the washing water contains no residue on evaporation, and dried in the oven at 1200 C constant weight. We note the weight gain. The operation is carried out with a glycolic solution of glycoside in 7 of luteolin titrated with 3% of luteolin after hydrolysis, and with a hydroglycolic solution of Achillea millefolium extract titrated with 3% of total luteolin.

In these three cases, weight gains of 56 mg, 62 mg and 66 mg were noted respectively.

The difference in coloration of the wool is not sensitive.

 It is possible to extract luteolin and its glucoside from the wool by boiling methanol, so it is possible to demonstrate that it is the luteolin that is attached to the fiber. In the case of the extract there is also a slight fixation of apigenin and its derivatives but in a low proportion (less than 5% compared to luteolin in general).

EXAMPLE 7
Tests in hair cosmetics - Luteolin, its glucoside in 7 and an Achillea millefolium extract.

At the same time, tests are conducted on twenty subjects, ten men and ten women of various hair colors,
Three of the ten women have discolored hair and artificially rests with undefined products.

The subjects applied lotions consisting of the above solutions diluted tenth in distilled water with 0.5% of a mixture of nipaesters in phenoxytol as a preservative. They let the lotion work for 15 minutes then they wash their hair all with the same shampoo. The operation is performed every two days for 10 days. We note the impressions of the subjects according to the following questionnaire 1. Annoying effects, intolerance having led or not
stopping the use of the product.

2. Variation of hair color: clean, not very distinct,
without.

3. Hair washability: modified, unmodified.

4. Electrostatic properties of the hair: markedly improved, improved, without improvement, decayed.

5. Hair holding: significantly improved; improved, without improvement, deteriorated.

6. Hair volume: significantly improved, improved, without improvement, deteriorated.

RESULTS 1.- None 2 - Without all 3 - No change 4 - Deteriorated: 1
No improvement: 5
Upgraded: 12
Significantly improved: 2 5 - Deteriorated: O
No improvement: 2
Enhanced: 12
Significantly improved: 6 6 - Damaged:
Without improvement: '1
Enhanced: 6
Significantly improved: 13
EXAMPLE 8
Acute tolerance tests of luteolin, its 7-gluco.

and an extract of Achillea millefolium associated with lactic acid in the guinea pig externally.

The flavones are placed in solution in a mixture of e; and monopropylene glycol has a concentration corresponding in all cases to 1% of total luteolin.

This concentration was chosen to be much higher than the current use concentration for safety purposes. Lactic acid is employed at a concentration of 4 and pH of the solutions is adjusted to 5.3 by triethanolamine.

The tolerance tests were carried out by the method of DRAIZE recommended by the Food and Drug Administration (DRAIZE J.H., WOODWARD G., CALVERY H.O. J. Pharmacol.

Exper. Ther.1944.82, p.377.

As a result of this test, no signs of cutaneous or general intolerance, no toxicity and no weight loss, no change in animal behavior were noted.

EXAMPLE 9
Regulatory cosmetic composition of cutaneous hyperpigmentation based on Achillea millefolium extract combined with lactic acid, in the form of a lotion
Glycerol '10
Lactic acid 2
Excerpt from A. millefolium 10
Triethanolamine 3
Water, perfume, preservatives qsp1OO
pH 5
EXAMPLE 10
Regulatory cosmetic composition of cutaneous hyperpigmentation based on luteolin associated with lactic acid, in gel form
Monopropylene glycol 40
Polyacrylic acid
crosslinked 3
Lactic acid 1
Triethanolamine 5
Luteolin 0.3
Water, perfume, preservatives
osp 100
pH 5
EXAMPLE 11
Regulatory cosmetic composition of cutaneous hyperpigmentation based on 7-glucoside of luteolin associated with lactic acid, in the form of cream
Glycerol Stearate 15
Polyoxyethylene 3 cetostearate
Di-n-butyladipate 10
paraffin oil 3
Glycerol 5
Lactic acid 2
Triethanolamine 3
Luteolin 7-glucoside 0.8
Water, perfume, preservatives qsp100
pH 5
EXAMPLE 12 Cosmetic regulator of cutaneous hyperpigmentation based on an extract of Ac-hillea millefolium associated with lactic acid, in the form of milk.

Glycerol stearate 8
Polyoxyethylene 3 cetostearate
Stearyl Isononanoate 10
Glycerol 5
Lactic acid 1
Triethanolamine 2
Excerpt from A. millefolium 10
Water, preservatives, perfume qsp100
EXAMPLE 13
Hair product based on luteolin in the form of a lotion -capillary:
95% Ethanol
Luteolin 0.3
Water, perfume qs 100
EXAMPLE 14
Hair product based on an extract of Achillea millefolium in the form of shampoo.

Triethanolamine lauryl ether sulfate 17
Coconut fatty acid diethanolamide 3
Sodium chloride 1
Excerpt from A. millefolium 10
Water, perfume, preservatives qs 100
EXAMPLE 15
Hair product with luteolin 7-glucoside in the form of s-hampobing, -emulsion.

Sodium lauryl ether sulfate 11
Diethanolamide of copra fatty acids 3,5
Polyethylene glycol cocoate and
glycerol 10
Luteolin 7-glucoside 0.5
Water, perfume, preservative qs 100

Claims (14)

 An external topical treatment composition comprising a biologically active amount of luteolin in aglucone form and / or luteolin glycosides and a biologically acceptable carrier.  2. Composition according to claim 1, characterized in that the luteolin is in aglucone-form.  3. Composition according to claim 1, characterized in that the luteolin is in the form of its 7-glucoside.  4. Composition according to one of claims 1 to 3, characterized in that it further comprises a biologically active amount of a keratolytic.  5. Composition according to one of claims 1 to 4, characterized in that the keratolytic is lactic acid.  6. Composition according to one of claims 1 to 5, characterized in that the total luteolin content is between 0.1% and 5% by weight.  7. Composition according to one of claims 4 to 6, characterized in that the amount of keratolytic is between 0.5 and 5% by weight.  8. Composition according to one of claims 4 to 7, characterized in that it further comprises a pH regulating agent, such as triethanolamine.  9. Composition according to one of Claims 1 to 8, characterized in that the luteolin aglucone and / or the gly sides of luteolin are extracted from a plant chosen from: Achillea millefolium, Matricaria chamomilla, Cnicus benedizus, Cynara Scolymus, Mentha aquatica and Equisetum arvense  10. Composition according to one of claims 1 to 9, characterized in that it is in the form of cream, gel, lotion, milk, ointment, shampoo, hair lotion, shampoo emulsion, emulsion, spray solution, balm, baron applicator.  11. Process for the preparation of a composition according to one of claims 1 to 10, characterized in that a) is extracted plants or parts of plants compor  both luteolin aglucone and / or  glycoside of luteolin by at least one decoction  said plants or parts of plants in an alcohol,  the alcoholic solution is recovered, b) the recovered alcohol solution is concentrated, diluted  this solution in water, c) the aqueous solution is treated against the current with  ethyl ether, the ethereal extract is removed and  recovering the aqueous solution treated, d) filtering the recovered aqueous solution, e) mixing the aqueous solution recovered with a weight  equal weight of monopropylene glycol, f) the total luteolin content  by adding a monopropylene glycol / water mixture  50/50 by weight, g) and the mixture obtained is incorporated into a biolyster  acceptable.  12. The method of claim 11, characterized in that in step a), the lower aliphatic alcohol is methanol.  13. The method of claim 11 or 12, charac terized in that in step d) is filtered diatom bed.  14. Process according to one of Claims 11 to 13, characterized in that lactic acid is added to the mixture obtained in step e) or in step f), and the pH is adjusted by addition of a base such as triethanolamine.