CLIAMS:1. An anti-aging cosmetic composition comprising 0.001% to 2% by weight green tea extract and 0.001% to 1% by weight naringenin in a ratio selected from 2:1 to 4:1 and 1:2 to 1:3.
2. The composition as claimed in claim 1 wherein green tea extract and naringenin are present in ratios selected from 1:2, 1:3, 2:1, 3:1 and 4:1.
3. The composition as claimed in any preceding claim wherein green tea extract and naringenin are present in a ratio of 3:1.
4. The composition as claimed in any preceding claim wherein total concentration of green tea extract and naringenin is at least 0.01% by weight.
5. The composition as claimed in any preceding claim further comprising cosmetically acceptable excipients selected from preservatives, chelators, stabilizers, emulsifiers, surfactants, skin conditioning agents, emollients, viscosity modifiers, anti-foaming agents and skin protectants.
6. The composition as claimed in any preceding claim is in form of gel, serum, ointment, cream, sprays, powder, moisturizer, lotion, sunscreen products or in oily solution form.
,TagSPECI:FIELD OF THE INVENTION
The present invention relates to a cosmetic composition comprising green tea extract and naringenin in a defined ratio for reducing, delaying and preventing ageing of skin.

BACKGROUND AND THE PRIOR ART
Skin is subject to deterioration through dermatological disorders, environmental abuse (wind, air conditioning, and central heating) or through the normal aging process (chronoageing) which may be accelerated by exposure of skin to sun (photoageing).
The use of anti-aging cosmetic products are very popular to prevent premature skin aging. Appearance of visible lines on face, fine wrinkling, thinning of layers, loss of elasticity, dryness of skin, etc. are all signs of skin-aging. -. One of the most common bioactives used in anti-aging products include anti-oxidants as these help the skin cells fight against oxidative damage caused to the intracellular organelles. The most abundant natural antioxidants are polyphenols found in plants.
Polyphenols amongst many other classes of molecules also include the flavonoids. Naringenin is –one such flavonoid which has been used in various anti-aging skin care products to prevent wrinkles and photo damaged skin (US5665367, JP20050151788 20050525, JP19960282616 19961024. IND211355). Use of green tea extract as an active ingredient in anti-aging cosmetic products is known (KR20130070107, KR20120021407, KR20040005407, US8039012) because of its high content of polyphenols.
US5431912 teaches a cosmetic composition comprising an antioxidizing system for good preservation of cosmetic compositions. This antioxidizing system according to US5431912 protects the lipids of the skin from oxidation and comprises flavonoids, catechin, epicatechin, naringenin, etc. It is mentioned in US5431912 that such flavonoids are found, in particular, in green tea extracts sold under the name "Sunphenon" by the Company Nikko. Flavonoid extracts are present at a concentration between 0.1% and 5% by weight with respect to the total weight of the composition. US5686082 teaches a cosmetic composition where the flavonoids are combined with ginkgo extract to provide composition for controlling accelerated skin aging. Said flavonoids are selected from the group consisting of catechin, epicatechin, naringenin etc. The polyphenols or flavonoids defined in US5686082 are present in an amount of between 0.1 and 1% by weight with respect to the total weight of the composition.
Herbal extract containing polyphenols or flavonoids in cosmetic composition of above mentioned prior art documents have been used in very little amount. Presence of higher amount of herbal extracts in cosmetic formulations cause a colour change in the embodiment, affects aesthetics of the formulation and ultimately commercial viability of the product is affected. Further, products having herbal extracts leads to redox reactions when combined in any cosmetic formulation. Such reactions may lead to darkening of the products indicating a deterioration of the ingredient properties (cosmetic dermatology: products and procedure edited by Zoe Diana Draelos). The prior art has tried to reduce such risk and increased shelf-life of the product by reducing the amount of herbal extracts used in the cosmetic formulations.
It is evident that higher amount of herbal extracts cannot be used in cosmetic formulation in view of the above mentioned problems. Thus there is need to develop anti-aging herbal compositions wherein the actives like green tea and naringenin are used in limited amount, yet improved anti-aging effect is achieved without hampering product qualities and shelf-life.

OBJECTS OF THE INVENTION
An object of the present invention is to provide a composition which takes care of the problems of the prior art.
It is another object of the invention to provide an anti-aging composition comprising green tea extract and naringenin in acceptable amount.
It is a further object of the invention to provide an anti ageing composition comprising green tea extract and naringenin in a defined ratio so as to achieve holistic effects on anti aging.

SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided an anti-aging cosmetic composition comprising 0.001% to 2% by weight green tea extract and 0.001% to 1% by weight naringenin in a ratio selected from 2:1 to 4:1 and 1:2 to 1:3.

DETAILED DESCRIPTION OF INVENTION
The present invention relates to cosmetic composition comprising extract from green tea and a synthetic molecule naringenin. The present inventors have lowered amounts of green tea extract in the formulation and achieved a higher effect by adding a molecule of synthetic origin, naringenin, as loading too much of herbal extracts in cosmetic formulations cause a colour change in the formulation, gives rise to problems associated with redox reaction and affects the overall stability and aesthetics of the formulation.
Accordingly the present invention is related to a cosmetic composition comprising green tea extract and naringenin in a specific ratio for reducing, delaying and preventing the signs of skin ageing.
The inventors have surprisingly found that a composition comprising green tea extract and naringenin shows synergic anti-ageing effect when the said components are present in a ratio of 2:1 to 4:1 or 1:2 to 1:3.
The invention describes a holisitic approach to address ageing rather than conventional approaches wherein multiple pathways contributing to aging are studied, targets identified and molecules working towards particular targets are combined to obtain an anti-aging product.
In the present invention, green tea extract is selected from Naturex, NESSO, Herbasol and Tetly company. All green tea extracts are not enriched with naringenin. Naringenin is not present in detectable amount in green tea extract which has been used in the present invention. Inventors have used naringenin molecule of synthetic origin.
In the present invention, Caenorhabditis elegans is used as a model system for studying the aging process. Actives or molecules that improve the life-span of this micro- organism are used to create anti-aging cosmetic products.
In the present invention, an extract of green tea (GT) and naringenin were found to improve the longevity of C. elegans when used in a defined ratio, thus implying their role in anti-aging. Based on the same the inventors found a composition wherein green tea extract and naringenin are used in amount of 0.001% to 2% by weight and 0.001% to 1% by weight respectively. The preferred amount of green tea extract and naringenin are 0.01% to 1.0% by weight and 0.01% to 0.5% by weight respectively. The inventors have further found that green tea extract and naringenin may be present in ratio of 2:1 to 4:1 or 1:2 to 1:3 to provide the anti-aging effect. The most preferred ratio being 3:1.
Green tea extract and naringenin in the above mentioned ratio are also found to enhance the longevity of C. elegans when this microorganism is exposed to ultraviolet radiation (UVR) implying that the said components in the defined ratio are able to address photo aging. Accordingly the composition comprising Green tea extract and naringenin in the above mentioned ratio is effective in improving aging of skin caused by UVR.
The inventors have found that green tea extract when combined with the molecule naringenin and when used in specific ratio(s) synergistically improve longevity of C. elegans.
It has been found that green tea extract and naringenin when used in this ratio of 2:1 to 4:1 or 1:2 to 1:3 the amount required for each of the components is within the limit as permissible by the cosmetic industry. Thus the present invention provides for cost effective use of the herbal components and yet achieves good results in terms of anti aging properties while maintaining the integrity of the composition and exhibiting extended shelf life..
For use in the present invention green tea extract and naringenin are mixed in the ratio of 2:1 to 4:1 or 1:2 to 1:3. The extracts are mixed in small quantities of water and added in the cooling phase of the formulation (< 50°C) under constant stirring (300 rpm) towards the end of the batch.
According to a preferred embodiment, the cosmetic compositions of the present invention are provided in a form suitable to be applied topically on skin. Skin is referred to the skin of face, throat and neck and other exposed parts of the body. The composition can be provided in form of gel, serum, ointment, cream, sprays, powder, moisturizer, lotion, sunscreen products and in oily solution form.
The cosmetic compositions according to the present invention can additionally contain various conventional additives or ingredients, such as preservatives, chelators, stabilizers, emulsifiers, surfactants, skin conditioning agents, emollients, viscosity modifiers, anti-foaming agents and skin protectants.
The personal care compositions of the present invention may further comprise cosmetically acceptable excipients selected from structurants (0.001% to 5%), chelants (0.01% to 0.5%), emollients (0.01% to 30%), diluents (1% to 90%), humectants (0.01% to 10%), actives (0.0001% to 15%), neutralizers, pH modifiers, preservatives and fragrances. The list of structurants employed may include but not be limited to starch, modified starch, guar gum, carbomers, silicone based polymers, acrylates and cellulose based polymers. Emollients that may be employed include silicone oils and modifications thereof such as linear and cyclic polydimethylsiloxanes, volatile silicones, esters such as cetyloctanoate, myristyl lactate, cetyl lactate, isopropyl myristate, myristylmyristate, isopropyl palmitate, isopropyl adipate, isopropy stearate, butyl stearate, decyloleate, cholesterol isostearate, glycerol monostearate, glycerol distearate, glycerol tristearate, alkyl lactate, alkyl citrate and alkyl tartrate, higher alcohols such as lauryl, cetyl, stearyl, oleyl, behenyl, cholesterol and 2-hexydecanol alcohol, essential oils and extracts thereof and mixtures of any of the foregoing components. Diluents may be selected from water or alcohols such as ethanol. Humectants could be chosen from consisting of polyols such as glycerin, sorbitol, propylene glycol, butylene glycol, hexylene glycol, ethoxylated glucose, 1, 2-hexane diol, hexanetriol, dipropylene glycol, erythritol, trehalose, diglycerin, xylitol, maltitol, maltose, glucose, fructose, sodium chondroitin sultate, sodium hyaluronate, sodium adenosin phosphate, sodium lactate, pyrrolidone carbonate, glucosamine, cyclodextrin, and mixtures thereof. Chelants may be chosen fromethylenediaminetetraacetate or ethane 1-hydroxy-1, 1-diphosphonate. Preservatives may beselected from the group consisting of methyl paraben, propyl paraben, phenoxyethanol, methylisothiazolinone, sodiumhydroxymethylglycinate, diazolidinyl urea, benzyl alcohol, caprylyl glycol, ethyl hexyl glycerin, sodium benzoate, potassium benzoate, sorbic acid, potassium sorbate and mixtures thereof.
The levels of structurants in the formulation may range from 0.001% to 5%, chelants from 0.01% to 0.5%, emollients may be used in the range of 0.01% to 30%, diluents to the range of 1% to 90%, humectants may be present from 0.01% to 10%, actives may vary from 0.0001% to 15%, neutralizers, pH modifiers, preservatives and fragrances may be added as per the requirement.
The advantages of the invention would become apparent from the comprehensive description discussed below in the form of various examples which have been given by way of illustration and ought not to construe to limit the invention in any manner.

EXAMPLE 1:
To evaluate the effect of green tea extract and naringenin on longevity of C. elegans, the organisms were treated with 0.01% weight green tea extract alone and 0.01% weight naringenin alone along with one control set (without any treatment). C. elegans were also treated with various combination ratio of green tea extract and naringenin as provided in Table I. The total concentration of 0.01% is maintained whether green tea extract and naringenin are provided alone or in combination.

The results obtained are given in Table I below:
TABLE I:
No. of days survived by C elegans
Control Green tea Naringenin Combination ratio (GT: Naringenin) Longevity Synergistic activity
21 24 23 1:1 23 No
2:1 28 Yes
3:1 30 Yes
4:1 26 Yes
5:1 21 No
1:2 25 Yes
1:3 27 Yes
1:4 21 No
1:5 18 No

C. elegans normally survives for 21 days. As is evident from Table 1 the microorganisms upon treatment were found to survive upto 24 days when treated with 0.01% weight green tea extract and survived upto 23 days when treated with 0.01% weight naringenin.
Combination of green tea extract and naringenin at 1:1 ratio (maintaining the total active concentration to be 0.01% at all times) led to a survival of 23 days. This life-span extension also was achievable by using naringenin alone as a bioactive. This confirmed that there was no synergism observed when combined at 1:1 ratio.
Combination ratio of green tea extract and naringenin at 1:2 and 1:3 provide longevity of 25 and 27 days respectively to that microorganism. Synergistic anti-aging effect is found in those particular ratios. C. elegans shows longevity of 28 days when green tea extract and naringenin are combined in 2:1 ratio and a longevity of 30 days is found when green tea extract and naringenin are combined at 3:1 ratio. Thus this shows that when simple 1:1 ratio or ratios beyond 1:4 and 5:1 fails to achieve better results than each of the components i.e., green tea and naringenin alone, combination in other ratios shows better activity.

EXAMPLE2:
To evaluate the effect of green tea and naringenin on longevity of UV exposed C. elegans, it is treated with 0.01% weight green tea extract alone and 0.01% weight naringenin alone along with one control set which is without any treatment. C. elegans is also treated with various combination ratio of green tea extract and naringenin as provided in Table II. The total concentration of 0.01% is maintained whether green tea extract and naringenin are provided alone or in combination.
The results obtained are given in Table II below:
TABLE II
No. of days survived by C. elegans (with UV exposure)
Control Green tea Naringenin Combination ratio (GT: Naringenin) Longevity Synergistic activity
17 21 19 1:1 19 No
2:1 25 Yes
3:1 26 Yes
4:1 24 Yes
5:1 19 No
1:2 22 Yes
1:3 24 Yes
1:4 20 No
1:5 16 No

UV exposed C. elegans normally survives upto 17 days. As evident from Table II the microorganisms survive upto 21 days when treated with 0.01% weight green tea extract alone and survived upto 19 days when treated with 0.01% weight naringenin alone.
Combination ratio of green tea extract and naringenin at 1:1 ratio provide 19 days longevity to UVR exposed C. elegans. This ratio also does not show any synergic effect as found in C. elegans not treated by UVR.
It is surprising that when green tea and naringenin when combined at ratios 1:2, 1:3, 2:1, 3:1 and 4:1 exhibit synergistic efficacy in improving the life-span of the organism despite being subjected to UV radiation. This shows that the synergistic combinations can be used to address photoaging as well. Extension in the life-span of the organism of upto 9 days (3:1 ratio of green tea: naringenin) is observed which is remarkable.
Two examples (Example 3 and Example 4) of cosmetic formulations according to the invention are given below by way of illustration. All the compositions are given in percentages by weight unless otherwise indicated.

EXAMPLE 3:
An anti-aging facial hydrogel:
The facial hydrogel in accordance with the present invention comprises the following components given in Table III:
TABLE III
Phase Name of ingredient % wt Functionality
A Water 85.33
A Disodium EDTA 0.05 Chelant
A Carbomer 0.05 Structurant
A Xanthum gum 0.10 Structurant
A Glycerine 3.00 Humectant
A Butylene glycol 2.00 Humectant
B Caprylic/Capric triglyceride 5.00 Emollient
B Isopropyl myristate 2.00 Emollient
B Dimethicone 1.00 Feel enhancer
C Triethanol amine 0.08 Neutralizer
D Green tea extract 0.75 Anti-aging active
D Naringenin 0.25 Anti-aging active
E Phenoxyethanol 0.40 Preservative

Method of preparation:
Step 1 All ingredients in Phase A are weighed and dispersed and stirred for 15 min at 300 rpm.
Step 2 Ingredients of Phase B are weighed and mixed and added to above mix and stirred for 10 min at 300 rpm.
Step 3 The above mixture was neutralized using C and stirred for 10 min at 400 rpm.
Step 4 Phase D ingredients were weighed and added and stirred for 5 min at 300 rpm.
Step 5 The batch was completed by adding Phase E and stirred for 5 min at 300 rpm.

EXAMPLE 4:
An anti-aging cream:
An anti-aging cream in accordance with the present invention is provided in the below Table IV:
TABLE IV
S.No Phase INCI Weight %
1 A Water 81.62
2 Disodium EDTA 0.05
3 Glycerine 2.86
4 Propylene Glycol 2.00
5 Carbomer 0.25
6 B STEARETH-21 1.20
7 Steareth-2 0.60
8 Isopropyl myristate 1.00
9 Isohexadecane 1.00
10 Glyceryl Stearate 0.50
11 Mineral Oil 4.00
12 Cetyl alcohol 1.00
13 Glycol Distearate 1.00
14 Methyl Paraben 0.16
15 Propyl Paraben 0.04
16 C Triethanolamine 0.35
17 D Cyclopentasiloxane (and) Phenyl Trimethicone (and) Dimethiconol (and) C12-15 Alkyl Benzoate (and) Dimethicone Crosspolymer 1.42
18 E Green Tea Extract 0.10
19 Naringenin 0.30
20 F Phenoxetol 0.20
21 G Fragrance 0.35

Process:
Step 1: Phase A ingredients were weighed in a beaker and heated to 80°C for 15 minutes.
Step 2: Phase B ingredients were weighed in a beaker and heated to 80°C for 15 minutes.
Step 3: Phase B was added to phase A and the mixture was homogenized at 5000 RPM for 15-20 minutes.
Step 4: Phase C ingredients were mixed with 1% water and added to step 3 mixture. The resultant mixture was stirred for 5 min at 500 RPM.
Step 5: Phase D ingredients were added to the step 4 mixture. The resultant mixture was stirred for 5 min at 500 RPM
Step 6: Phase E ingredients were added to the above mixture and mixed for 5 min at 300 RPM.
Step 6: Phase F ingredient was added to the above and mixed for 5 min at 300 RPM.
Step 7: Phase G ingredient was added to step 6 mixture and mixed for 5 min at 300 rpm to complete the batch.