Background Art Ultraviolet rays in sunlight causes skin photodamage which adversely affects skin beauty and skin health.

The skin photodamage is a phenomenon caused by a photobiological reaction occurring upon the exposure of the skin to light, and is classified into the following two categories: acute photodamage occurring immediately after exposure to light, and chronic photodamage occurring by long-term exposure to light.

Examples of the chronic photodamage include photoaging, such as pigmentation or phenomena where the skin becomes rough, as well as skin cancer, and examples of the acute photodamage include photoburn, pigmentation or the like.

The skin photodamage occurs in the epidermal layer and upper dermal layer into which most of ultraviolet rays penetrates. It is known that oxygen free radicals produced by ultraviolet irradiation has a close connection with ultraviolet photodamages, such as pigmentation, aging and skin cancer formation.

Of ultraviolet rays, ultraviolet-B (UVB, 290-320 nm) is a main factor of having the greatest photobiological effect of ultraviolet rays on the human body and

causing skin photodamage. Ultraviolet-C (UVC, 200-290 nm) is very strong in the force to break cells but shows weak penetration due to short wavelength, and ultraviolet-A (UVA, 320-400 nun) has an energy intensity of about 1/1000 of UVB, indicating that it has an insignificant effect on the human body.

In an attempt to prevent skin photodamage caused by ultraviolet rays, studies on ultraviolet blocking agents have been steadily performed. Photodamage- preventing agents developed till now are mostly used in the form of skin application agents which can reduce light absorption by chemically or physically absorbing, dispersing or reflecting light.

The existing ultraviolet blocking agents have a function to protect cells by blocking ultraviolet penetration, but have no inhibitory effect on a cell damage mechanism occurring after ultraviolet rays penetrated the epidermal layer and the upper dermal layer. Thus, it is impossible for such agents to efficiently inhibit the photodamage. Studies on compositions effective in inhibiting ultraviolet skin damage have been performed, but the results are still insignificant.

Meanwhile, green tea contain various substances, such as polyphenols, caffeine, free amino acids, and vitamin A, B1, B2, C and E, among of which, particularly polyphenol was reported to allow for prevention of the ultraviolet skin <BR> <BR> damage (Elmets CA et al, "Cutaneous photoprotection from ultraviolet injury by green tea polyphenols", JAm Acad Dermatol. 44: 425-32,2001 ; Katiyar SK et al, "Green tea polyphenols: DNA photodamage and photoimmunology", J Photochem <BR> <BR> Photobiol B. 65: 109-14.2001 ; Vayalil PK et al, "Treatment of green tea polyphenols in hydrophilic cream prevents UVB-induced oxidation of lipids and proteins, depletion of antioxidant enzymes and phosphorylation of MAPK proteins in SKH-1 hairless mouse skin", CarCinogeraesis, 24: 927-36.2003).

However, since a sufficient amount of the green tea polyphenol will be extracted only if the green tea draws in boiling water over 30 minutes, the photodamage-preventing effect of polyphenol is insufficient in conditions where dried green tea leaf powder is applied directly on the skin. Furthermore, either a powdered total extract from green tea leaves or powdered green tea extract has low polyphenol content, and thus, in actual applications, it hardly shows an effect at a theoretically expected level.

Among the components contained in the green tea, another component expected to show an effect on the prevention of photodamage is ascorbic acid known to have an antioxidant function. However, the ascorbic acid has low thermal stability, so that it is mostly broken down during processes of processing and hot water-extracting green tea leaves. Thus, a hot water extract from the green tea leaves contains only a very low amount of the ascorbic acid.

W addition, either compositions comprising vitamins with an antioxidant function, or antioxidant compositions comprising not only vitamins as a main component but also a very small amount of green tea extract, have been studied.

Such compositions are mainly used as aqueous emulsion or cream-type cosmetic compositions.

It is however known that the green tea polyphenol and the ascorbic acid when dissolved in water show a sharp reduction in their antioxidant effects with the elapse of time. Thus, the aqueous emulsion or cream compositions makes it difficult to expect the antioxidant effect by the polyphenol or the ascorbic acid, and ultimately show only an effect similar to that of a stabilized material composition.

In fact, the antioxidant effect of the compositions does not reach an expected level.

Meanwhile, a composition for preventing photodamage, which contains

green tea polyphenol as a main component so as to allow for the inhibition of skin cytotoxicity caused by ultraviolet rays, has not been known yet.

Accordingly, the present inventors have developed a composition comprising green tea polyphenol as a main component and ascorbic acid or its derivatives at the optimal ratio, as well as a method for inhibiting skin photodamage using the composition, thus perfecting the present invention.

Disclosure of the Invention The present invention provides a composition for preventing skin photodamage, which comprises green tea polyphenol, and ascorbic acid or its derivatives.

The inventive composition for preventing skin photodamage comprises 50- 95 parts by weight of the green tea extract and 5-50 parts by weight of the ascorbic acid or its derivatives.

The green tea polyphenol contained in the inventive composition for preventing skin photodamage may be selected from the group consisting of epigallocatechin gallate (EGCG), epicatechine gallate, epigallocatechine, and a mixture of two or more thereof.

The ascorbic acid or its derivatives contained in the inventive composition for preventing skin photodamage may be selected from the group consisting of ascorbic acid, ascorbyl palmitate, calcium ascorbates, magnesium ascorbates, zinc ascorbates, and a mixture of two or more thereof.

The inventive composition for preventing skin photodamage inhibits cytotoxicity caused by ultraviolet rays.

The inventive composition prevents the initiation of cytotoxic action caused

by particularly ultraviolet rays.

The inventive composition recovers cells damaged by particularly ultraviolet irradiation.

The inventive composition is used as cosmetic compositions, food compositions and pharmaceutical compositions.

Hereinafter, a preparation method of the inventive composition for preventing skin photodamage will be described.

The green tea polyphenol contained in the inventive composition for preventing skin photodamage may be prepared by any method by which polyphenol can be extracted from green tea, For example, the method described in Korean Patent Registration No. 10-377313 (entitled"a preparation method of green tea extract") may be used.

In the method described in said patent, 5-20 parts by weight of water is added to 1 part by weight of hot-air dried green tea powder, and heated for 15 minutes to 2 hours. Then, the green tea powder is removed and cooled, and a precipitate is removed. The remaining extract is heated again and cooled, a precipitate is removed, and the remaining extract is dried to obtain green tea polyphenol powder. In this case, the heating is preferably performed at a temperature of 60-110 °C, and the drying is preferably carried out by a spray drying process. The ascorbic acid or its derivatives contained in the inventive composition for preventing skin photodamage may be any product which is commercially available.

50-95 parts by weight of the green tea polyphenol prepared as described above, and 5-50 parts by weight of the ascorbic acid or its derivatives, are mixed with each other so as to prepare the inventive composition.

The inventive composition may additionally contain other active ingredients having the same or similar functions to the components as described above.

If the inventive composition is provided as a cosmetic composition, it may additionally contain moisturizers, skin protection agents, tackifiers, neutralizing agents, solubilizers, preservatives and/or solvents, if necessary.

The inventive cosmetic composition may be formulated into ingestible forms, such as tablets, capsules or pills, skin-applicable solid forms, such as patches, cream, gel, ointments or emulsion, or skin-applicable liquid forms, such as solution, suspension, lotion, serum or oil, or if necessary, other forms.

The most preferred form of the inventive cosmetic composition is a powder capsule, power or a microcapsule, which prevents a photodamage effect from being rapidly reduced by the direct reaction between the polyphenol contained in the inventive composition and water and allows the polyphenol to react with water only just before use, thus maximizing the photodamage inhibitory effect of the inventive composition.

When the inventive composition is provided as a food composition, it may additionally contain various assistant components, if necessary. Examples thereof include amino acids, carbohydrates, vitamins, minerals, such as copper, calcium, manganese, potassium and zinc, lactic acid bacteria, and yeast products.

The inventive food composition may additionally contain flavoring agents or natural carbohydrates as in conventional food compositions. The flavoring agents include natural sweeteners such as thaumain or stevia extracts, and synthetic sweeteners such as saccharine or aspartame. The natural carbohydrates include monosaccharides, such as glucose or fructose, disaccharides, such as sucrose, polysaccharides, such as dextrin or cyclodextrin, and sugar alcohols, such as xylitol,

sorbitol, or erythritol.

When the inventive composition is provided as a pharmaceutical composition, it may be formulated into a formulation comprising the active ingredients as described above and at least one pharmaceutically acceptable carrier.

Examples of the pharmaceutically acceptable carrier include saline solution, sterile water, Ringer's solution, buffered saline solution, dextrose solution, maltodextrin solution, glycerol, ethanol and a mixture of two or more thereof. If necessary, the inventive composition may also contain other conventional additives, such as antioxidants, buffers and bacteriostatic agents. Moreover, the inventive composition may additionally contain diluents, dispersants, surfactants, binders and lubricants in order to formulate it into injection formulations, such as aqueous solution, suspension and emulsion, pills, capsules, granules and tablets.

Furthermore, the inventive composition may preferably be formulated depending on particular diseases and its components, using the method described in Remington's Pharmaceutical Science (latest edition), Mack Publishing Company, Easton PA, which is a suitable method in the relevant field of art.

The inventive composition is preferably used in the form of agents for skin application, liquid, powder, tablets, syrup, granules, coated tablets, decoctions, extracts, suppositories, juice, suspensions, emulsions, or a sustained-release formation of active compounds.

The adult dosage or intake of the inventive composition may be suitably selected from a range of several hundreds mg to several g per time for a powder formulation and from a range of several ml to several hundreds ml per time for adults for a solution formulation. The dosage or intake can vary depending on various factors, including the kind and content of the active ingredients and other

components in the composition, the kind of a formulation, patient's weight, age, health condition, sex and diet, administration time, administration route, secretion rate, therapeutic period, drugs used in combination with the composition, etc.

Since the inventive pharmaceutical composition is an extract from natural food, it shows no side effect even when it is administered to the human body.

The inventive composition prepared as such efficiently inhibits cell phototoxicity caused by ultraviolet irradiation so as to remarkably increase cell viability, as compared to green tea polyphenol alone, ascorbic acid alone, total green tea extract alone, or the known 10% EGCG composition.

It is believed that the skin photodamage inhibitory effect of the inventive composition is shown because the green tea polyphenol and ascorbic acid or its derivatives contained in the inventive composition eliminate intracellular reactive free radicals which are increased by ultraviolet irradiation.

Furthermore, the inventive composition shows an excellent photodamage inhibitory effect whether it is used before or after the exposure of the skin to ultraviolet rays.

A photodamage inhibitory mechanism which occurs when the inventive composition is used before skin exposure to ultraviolet radiation can be considered as follows. It is known that a cell damage mechanism by ultraviolet irradiation is initiated just after ultraviolet irradiation. Accordingly, it is believed that the inventive composition will prevent the initiation of cytotoxic action by ultraviolet irradiation, thus inhibiting cytotoxicity caused by ultraviolet irradiation.

A photodamage inhibitory mechanism, which occurs when the inventive composition is used after exposure to ultraviolet radiation, can be considered as follows. A time point of about 30 minutes after exposure to ultraviolet radiation is a

state where cell damage by ultraviolet radiation was already progressed.

Accordingly, it is believed that the inventive composition recovers cells damaged by ultraviolet irradiation, thus inhibiting cytotoxicity caused by ultraviolet irradiation.

As a result, the inventive composition will be useful as a cosmetic, food or pharmaceutical composition for inhibiting skin photodamage caused by ultraviolet radiation.

In another aspect, the present invention provides a method for skin photodamage by ingesting the composition or applying the composition to the skin.

For example, when the inventive food composition for inhibiting skin photodamage is used in the form of powder capsules, powders or microcapsules, it will be preferable that the composition is formulated into a suitable form, such as capsules or tablets, and used in a daily dosage of several hundreds to several thousands mg before or after exposure to ultraviolet radiation.

For example, when the inventive cosmetic composition is used in the form of powder capsules, powders or microcapsules, a suitable amount of capsules or powders are dissolved in a small amount of water just before use. Since the polyphenol component of the inventive composition shows a reduction in activity with the elapse of time after mixed with water, the inventive composition after dissolved in water is rapidly applied on sites requiring its use, by means of a suitable tool, such as a cosmetic brush. In this case, the one-time dose of the composition is 1-10 g, and the use frequency of the composition is 2-3 times a week.

Best Mode for Carrying Out the Invention Hereinafter, the present invention will be described in further detail by examples. It is to be understood, however, that these examples are given for a

better understanding of the present invention and not intended to limit the scope of the present invention.

Example: Preparation of inventive composition The inventive composition was prepared, and at the same time, compositions to be used as Comparative Examples were also prepared. Comparative Example 1 was a sample consisting of only green tea polyphenol, Comparative Example 2 was a sample consisting of only ascorbic acid, Comparative Example 3 consisting of only total green tea extract, and Comparative Example 4 was the commercially available polyphenol (epigallocatechin gallate; EGCG). Comparative Example 4 was prepared as a sample consisting of a 10% aqueous solution of Cat. No. E4243 (Sigma Chemical Co. , USA).

The inventive composition was prepared by mixing 900 g of green tea polyphenol powder with 100 g of ascorbic acid.

The green tea polyphenol powder contained in the inventive composition and Comparative Example 1 was prepared by extraction, isolation and purification according to the method described in Korean Patent Registration No. 10-377313 (entitled"a preparation method of green tea extract).

In order to confirm that the purified extract contains a large amount of green tea polyphenol, the component analysis of the extract was performed as follows.

Each of polyphenol and caffeine was measured by HPLC (high performance liquid chromatography, and total polyphenol was measured by a spectrophotometric redox assay using a Prussian blue method. The results showed that the green tea polyphenol powder obtained in this Example contained more than 83% of polyphenol. This polyphenol content is a level sufficient to exhibit the physical and chemical properties of pure polyphenol. The ascorbic acid contained in the

inventive composition and Comparative Example 2 was a commercially available product (A5960, Sigma Co. , USA).

Comparative Example 3 was prepared by adding 5-10 parts by weight of water to 1 part by weight of hot-air dried green tea leaf powder, heating the solution for 1 hour, removing the green tea powder and drying the remaining extract.

The 10% EGCG solution of Comparative Example 4 was prepared by dissolving 0.1 mg of EGCG in distilled water to 1 ml aqueous solution.

Test Example 1 : Examination of photodamae preventive effect of inventive composition-change in cell viability upon ultraviolet irradiation after addition of inventive composition In order to examine the photodamage preventive effect of the inventive composition, a change in cell viability when the inventive composition had been added before ultraviolet irradiation was observed.

Human skin cells to be used in the test were prepared in the following manner.

The human glans skin was excised, washed with cooled PBS (phosphate buffered saline; Gibco, USA) and then treated with trypsin (Gibco, USA) to isolate keratinocytes. 2 X105 of the isolated keratinocytes were placed in each well of a 96- well plate, to which serum-free keratinocyte medium (Gibco, USA) was added and cultured in a C02 incubator at 37 °C.

After one day of the cell cultivation, each of the inventive composition prepared in Example and the control group samples was added to the cell culture medium to concentrations of 0, 0.025, 0.05, 0.1, 0.2, 0.5, 1,2 and 4mg/ml.

At 30 minutes after the addition of each sample group, each of the sample groups was irradiated with ultraviolet radiation. The ultraviolet irradiation was

performed at 50 J/cm2 using a UVB lamp with a wavelength of 300 nm. Also, a group which had not been irradiated with ultraviolet radiation was separately prepared for subsequent use for the comparison of cell viability to the ultraviolet- irradiated groups.

The cells were added with the medium containing each of the samples, and after 30 minutes, irradiated with ultraviolet radiation. Next, the ultraviolet- irradiated cells were cultured in a C02 incubator at 37 °C for 24 hours and then measured for cell viability by a MTT (3- (4, 5-dimethylthiazol-2-yl) -2, 5-diphenyl- tetrazolium bromide) method. The measured cell viability was expressed as a ratio to the normal control group which had not been irradiated with ultraviolet radiation, and the results are shown in Table 1 below.

Table 1: Effect of ultraviolet irradiation on cell viability at 30 minutes after addition of each sample to skin keratinocytes Composition Cell viability ratio (%) concentration Comparative Comparative Comparative Comparative Example (mg/ml) Example 1 Example 2 Example 3 Example 4 Group treated Group treated Group treated Group treated Group treated with green tea with ascorbic with total with 10% with polyphenol acid sample green tea EGCG sample inventive sample extract sample composition 0 22 25 25 24 24 0.05 29 32 25 25 35 0.1 46 28 34 24 87 0.2 57 21 45 25 98 0.5 73 10 52 25 101 1 65 11 51 31 98 2 28 7 32 43 74

(numerical values = average values) As shown in Table 1, the group treated with the inventive composition

showed an increase in cell viability with an increase in the concentration of the composition. Particularly, when the inventive composition was used at a concentration of 0.5 mg/ml, the cell viability was 77% higher than that of the case untreated with the inventive composition (0 mg/ml).

Although the group treated with only the green tea polyphenol also showed an increase in cell viability with an increase in the concentration of the sample, its effect was insignificant as compared to the inventive composition. When the sample was used at a concentration of 0.5 mg/ml, the cell viability was 51% increased as compared to the case untreated with the sample (0 mg/ml). When the sample concentration was increased to more than 0.5 mg/ml, the cell viability was rather reduced.

Although the group treated with only the ascorbic acid powder also showed an increase in cell activity with an increase in the concentration of the sample, its effect was insignificant as compared to the inventive composition. When the sample was used at a concentration of 0.5 mg/ml, the cell viability was only 7% increased as compared to the case untreated with the sample (0 mg/ml). When the sample concentration was increased to more than 0.5 mg/ml, the cell viability was rather reduced.

Although the group treated with only the total green tea extract also showed an increase in cell activity with an increase in the concentration of the sample, its effect was insignificant as compared to the inventive composition. When the sample was used at a concentration of 0.5 mg/ml, the cell viability was 27% increased as compared to the case untreated with the sample (0 mg/ml). When the sample concentration was increased to more than 0.5 mg/ml, the cell viability was rather reduced.

The group treated with the 10% EGCG solution showed 7% and 19% increases in cell viability when the sample was used at concentrations of 1 mg/ml and 2 mg/ml, respectively. However, such cell viability values were very insignificant as compared to 74% and 50% obtained in the group treated with the inventive composition.

In the comparison of an increase in cell viability between all the groups, the cell viability of the group treated with the inventive composition was 26% higher than that of the group treated with the green tea polyphenol, 70% higher than that of the group treated with the ascorbic acid, 50% higher than that of the group treated with the total green tea extract, and 76% higher than that of the group treated with the 10% EGCG solution.

This suggests that the application of the inventive composition before exposure to ultraviolet radiation allows the efficient inhibition of skin cytotoxicity caused by ultraviolet radiation as compared to the existing skin photodamage inhibitory substances.

Furthermore, the addition of the inventive composition before ultraviolet irradiation caused a reduction in cytotoxicity. In view of this fact, it is believed that the photodamage-inhibiting effect of the inventive composition is shown because the inventive composition prevents the initiation of a cytotoxic mechanism caused by ultraviolet irradiation, thus inhibiting cytotoxicity caused by ultraviolet irradiation.

Test Example 2: Examination of photodamage therapeutic effect of inventive composition-change in cell viability upon addition of inventive composition after ultraviolet irradiation In order to examine the photodamage therapeutic effect of the inventive composition, a change in cell viability when the inventive composition had been

added after ultraviolet irradiation was observed.

The human skin cells to be used in the test was prepared in the same manner as in Example 1.

After one day of the cell cultivation, the cells were irradiated with ultraviolet radiation. The ultraviolet irradiation was performed at 50 J/cm2 using a UVB lamp with a wavelength of 300 nm. Also, a group which had not been irradiated with ultraviolet radiation was separately prepared for subsequent use for the comparison of cell viability to the ultraviolet-irradiated groups.

At 30 minutes after the ultraviolet irradiation, a medium containing each of the inventive composition and the control group samples was added the ultraviolet- irradiated cells at concentrations of 0, 0.025, 0.05, 0.1, 0.2, 0.5, 1,2 and 4mg/ml.

Next, the ultraviolet-irradiated cells of each group were cultured in a C02 incubator at 37 °C for 24 hours and then measured for cell viability by a MTT (3- (4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide) method. The measured cell viability was expressed as a ratio to the normal control group which had not been irradiated with ultraviolet radiation, and the results are shown in Table 2 below.

Table 2: Effect of ultraviolet irradiation on cell viability when each sample had been added at 30 minutes after ultraviolet irradiation Concentration Cell viability ratio (%) of composition Comparative Comparative Comparative Comparative Example (mg/ml) Example 1 Example 2 Example 3 Example 4 Group treated Group treated Group treated Group treated Group treated with green tea with ascorbic with total with 10% with polyphenol acid sample green tea EGCG sample inventive sample extract sample composition 0 23 23 22 23 24 0.05 29 31 26 24 37 0.1 38 23 33 23 57 0.2 55 10 35 25 78 0.5 51 8 41 25 72 1 32 11 38 29 49

(numerical values = average values) As shown in Table 2, the group treated with the inventive composition showed an increase in cell viability with an increase in the concentration of the composition. Particularly, when the inventive composition was used at a concentration of 0.2 mg/ml, the cell viability was 54% higher than that of the case untreated with the inventive composition (0 mg/ml).

Although the group treated with only the green tea polyphenol also showed an increase in cell viability with an increase in the concentration of the sample, its effect was insignificant as compared to the inventive composition. When the sample was used at a concentration of 0.2 mg/ml, the cell viability was 32% increased as compared to the case untreated with the sample (0 mg/ml). When the sample concentration was increased to more than 0.2 mg/ml, the cell viability was rather reduced.

Although the group treated with only the ascorbic acid powder also showed an increase in cell activity with an increase in the concentration of the sample, its effect was insignificant as compared to the inventive composition. When the sample was used at a concentration of 0.2 mg/ml, the cell viability was only 8% increased as compared to the case untreated with the sample (0 mg/ml). When the sample concentration was increased to more than 0.2 mg/ml, the cell viability was rather reduced.

Although the group treated with only the total green tea extract also showed

an increase in cell activity with an increase in the concentration of the sample, its effect was insignificant as compared to the inventive composition. When the sample was used at a concentration of 0.2 mg/ml, the cell viability was 19% increased as compared to the case untreated with the sample (0 mg/ml). When the sample concentration was increased to more than 0.2 mg/ml, the cell viability was rather reduced.

The group treated with the 10% EGCG solution showed only 5% increase in cell viability only when it was used at concentrations of 1 mg/ml and 2 mg/ml, respectively. Thus, the effect of the 10% EGCG solution was very insignificant as compared to that of the inventive composition.

In the comparison of an increase in cell viability between all the groups, the cell viability of the group treated with the inventive composition was 23% higher than that of the group treated with the green tea polyphenol, 47% higher than that of the group treated with the ascorbic acid, 31% higher than that of the group treated with the total green tea extract, and 53% higher than that of the group treated with the 10% EGCG solution.

This suggests that the application of the inventive composition after exposure to ultraviolet radiation allows the efficient inhibition of skin cytotoxicity caused by ultraviolet radiation as compared to the existing skin photodamage inhibitory substances.

Furthermore, the irradiation of ultraviolet radiation to cells immediately initiates cell damage, and a time point of 30 minutes after the ultraviolet irradiation is in a state where the cell damage by ultraviolet radiation was already progressed. In view of these facts, it is believed that the photodamage inhibitory effect of the inventive composition is shown because the inventive composition recovers cells

damaged by ultraviolet irradiation, thus inhibiting cytotoxicity caused by ultraviolet irradiation.

Industrial Applicability As described above, the inventive composition is very excellent in the effects of inhibiting the initiation of cell photodamage caused by ultraviolet irradiation and recovering cells damaged by ultraviolet irradiation, as compared to the prior compositions for inhibiting skin photodamage.

The photodamage-inhibiting effect of the inventive composition is shown in all cases, whether it is used before or after ultraviolet irradiation.

Accordingly, the inventive composition will be useful as a cosmetic, food or pharmaceutical composition for inhibiting skin photodamage caused by ultraviolet radiation.