AU2011290175A1 - Composition for improving skin quality - Google Patents

Abstract

Provided are a cosmetic product, a pharmaceutical composition, and a food product having a strong skin quality-improving effect, in which the starting material is a natural material. The cosmetic product composition, pharmaceutical composition, and food product for improving skin quality comprise black current fruit as an active ingredient, particularly a polysaccharide that is contained in black current fruit juice and is obtained by enzymatic limited partial decomposition.

Description

DESCRIPTION COMPOSITION FOR SKIN QUALITY IMPROVEMENT Technical Field The present invention relates to a composition having effects of skin quality improvement comprising, as an active ingredient, a substance derived from black currant fruit. More particularly, the present invention relates to a cosmetic composition, a pharmaceutical composition, and a food product for skin quality improvement comprising, as an active ingredient, a polysaccharide that can be obtained via limited and partial decomposition of a polysaccharide fraction contained in black currant juice with a specific enzyme. Background Art There are two major theories regarding the causes of skin aging. One of these theories is the "theory of programs," according to which an organism inevitably experiences aging and eventually dies. The other is the "theory of molecular damage," according to which an organism experiences aging due to damage caused by various factors. According to the concept behind the "theory of molecular damage," active oxygen is considered to be the worst damaging factor. Active oxygen is more often generated on skin exposed to ultraviolet rays. Examples of active oxygen include superoxide anion, hydrogen peroxide, hydroxyl radical, and singlet oxygen. Such active oxygen activates various cytokines and cell surface receptors and accelerates expression of a target gene. A representative example of a target gene is an epidermal growth factor receptor (EGF-R). Activated EGF-R activates the transcription factor AP-1 via the Jun N-terminal kinase. As a result, collagen synthesis is inhibited, matrix metalloprotease (MMP) expression is enhanced, and decomposition of extracellular matrix components, such as collagen and elastin, is accelerated. As the influences of active oxygen, accordingly, symptoms characteristics of photoaging, such as development of wrinkles and sagging, unclear sulcus cutis and crista cutis, and uneven skin color such as senile pigment freckles, are consequently observed in skin 1 regions that have been exposed to ultraviolet rays for a long period of time. To date, a variety of studies have been conducted with the goal of suppressing photoaging of the skin caused by ultraviolet rays. While application of all-trans retinoic acids to the skin is extensively known to be effective for amelioration of photoaging symptoms, a method involving the use of a cyclic amide derivative having active oxygen scavenging activity (JP Patent Publication (Kokai) No. H-08-081442 (A)), a method involving the use of honeysuckle saponin (JP Patent Publication (Kokai) No. H-09-175988 (A)), a method involving the use of a calycinal extract of Diospyros kaki L. having active oxygen scavenging activity (JP Patent Publication (Kokai) No. 2006-83070 (A)), and other methods are known. In these methods, however, active ingredients are used in the form of topical medications, and there are few cases involving oral administration (J. Invest. Dermatol., Jun 2004, 122 (6), 1480-7; J. Nutr. Sci. Vitaminol. (Tokyo), Apr. 2008, 54 (2), 117-23; and Journal of Nutritional Biochemistry 20, 2009, 389-398). Black currant is known as a fruit comprising anthocyanin, such as cyanidin 3-rutinoside or delphinidin rutinoside, as a polyphenol having excellent effects of blood flow improvement (JP Patent Publication (Kokai) No. 2004-262878 (A)). Also, a polysaccharide contained in black currant is reported to have immunostimulatory activity (JP Patent Publication (Kokai) No. 2006-137712 (A); JP Patent Publication (Kokai) No. 2004-107660 (A); and Biosci. Biotechnol. Biochem., 69 (11), 2042-2050, 2005). However, no reports have heretofore been made regarding the activity of black currant for skin quality improvement. Summary of the Invention Object to Be Attained by the Invention It is an object of the present invention to provide a cosmetic product, a pharmaceutical composition, a food product, and other products having satisfactory effects of skin quality improvement prepared from naturally occurring materials that can be easily obtained. Means for Attaining the Object 2 The present inventors have conducted concentrated studies in order to attain the above object. As a result, they discovered that naturally occurring black currant fruit, which can be easily obtained and eaten; in particular, a polysaccharide contained in black currant fruit, and, more preferably, a polysaccharide that has been subjected to limited and partial decomposition have satisfactory effects of skin quality improvement. This has led to the completion of the present invention. Specifically, the present invention include the features [1] to [12] below. [1] A composition for skin quality improvement comprising, as an active ingredient, a substance derived from black currant fruit. [2] The composition according to [1], wherein the substance derived from black currant fruit includes a polysaccharide contained in black currant fruit. [3] The composition according to [2], wherein the polysaccharide contained in black currant fruit is subjected to limited and partial decomposition. [4] The composition according to [3], wherein the average molecular weight of the polysaccharide is from 10,000 to 200,000. [5] The composition according to any of [1] to [4], which has a skin-moisturizing effect. [6] A pharmaceutical composition for skin quality improvement comprising the composition according to any of [1] to [5]. [7] A cosmetic composition for skin quality improvement comprising the composition according to any of [1] to [5]. [8] A food or beverage product for skin quality improvement comprising the composition according to any of [1] to [5]. [9] A method for preparing a composition for skin quality improvement comprising adding a substance derived from black currant fruit. [10] The method according to [9], wherein the substance derived from black currant fruit includes a polysaccharide contained in black currant fruit. [11] The method according to [10], which comprises performing limited and partial decomposition of a polysaccharide contained in black currant fruit. [12] The method according to [11], wherein the average molecular weight of the 3 polysaccharide is from 10,000 to 200,000. This description includes part or all of the content as disclosed in the description and/or drawings of Japanese Patent Application No. 2010-181324, which is a priority document of the present application. Effects of the Invention The present invention can provide a cosmetic product, a pharmaceutical composition, a food product, and other products having satisfactory effects of skin quality improvement, which are prepared from black currant fruit that can be easily obtained. Brief Description of the Drawings Fig. 1 is a characteristic diagram showing the effects of ingestion of black currant juice for suppressing a decrease in cuticle moisture content caused by ultraviolet application. Fig. 2 is a characteristic diagram showing the effects of ingestion of black currant juice for suppressing an increase in transepidermal water loss caused by ultraviolet application. Fig. 3 is a characteristic diagram showing the effects of ingestion of black currant juice for ameliorating skin roughness determined via human testing. Embodiments of the Invention The composition for skin quality improvement of the present invention comprises, as an active ingredient, a substance derived from black currant fruit. A wide variety of generally available black currants can be used in the present invention without particular limitation, and varieties such as BenArd, BenRua, and Boskoop Giant can be used. "Black currant fruit" may be underripe or ripe, and use of ripe fruit is preferable. "Black currant fruit" may be in any state without particular limitation, and it may be raw, dry, or dry powder. In the present invention, "a substance derived from black currant fruit" is a roughly purified or purified form of a polysaccharide contained in black currant fruit. The term "roughly purified form of a polysaccharide" refers to, for example, black currant fruit, a 4 crushed form thereof, or a puree thereof (e.g., a substance containing a solid component derived from seeds, seed coat, or fruit or a substance remaining after removal of such solid component via centrifugation or other means (i.e., fruit juice)) or a lyophilization product thereof. A "purified form of a polysaccharide" can be prepared in accordance with a known technique (JP Patent Publication (Kokai) No. 2004-107660 (A), Immunostimulatory Effects of a Polysaccharide-Rich Substance with Antitumor Activity Isolated from Black Currant (Ribes nigrum L.), Biosci. Biotechnol. Biochem., 69 (11), 2042-2050, 2005). Specifically, fruit juice is filtered through a cation-exchange resin and an anion-exchange resin to remove various ionic substances. The resultant is then allowed to pass through a C-18 reversed phase column to remove a polyphenol compound. The fraction that has passed through the column is subjected to dialysis against pure water and lyophilized. Thus, a purified form of a polysaccharide can be obtained. In the present invention, "a substance derived from black currant fruit" is preferably obtained by subjecting a polysaccharide contained in black currant fruit to limited and partial decomposition. The phrase "a polysaccharide is subjected to limited and partial decomposition" or the term "limited and partial decomposition of a polysaccharide" used herein refers to a condition in which a polysaccharide contained in black currant fruit is decomposed to fractions with molecular weights of 10,000 to 200,000. In this context, the average molecular weight of a contained polysaccharide is preferably about 10,000 to 150,000, more preferably about 10,000 to 96,000, further preferably about 10,000 to 56,000, and still further preferably about 10,000 to 34,000. (The average molecular weight of a polysaccharide is determined based on a known technique, such as gel filtration analysis via HPLC.) Accordingly, the phrase "a polysaccharide is subjected to limited and partial decomposition" or the term "limited and partial decomposition of a polysaccharide" used herein does not refer to a condition in which all polysaccharide components in black currant fruit are completely decomposed to monosaccharides. Limited and partial decomposition of a polysaccharide contained in black currant fruit can be carried out by treating the substance derived from black currant fruit with an acid or enzyme, with enzyme treatment being preferable. 5 Limited and partial decomposition of a polysaccharide contained in black currant fruit with an enzyme can be carried out by adding p-galactosidase to the substance derived from black currant fruit. The amount of P-galactosidase added can be adequately determined in accordance with, for example, the type of a substance derived from black currant fruit, the pH level, reaction temperature, reaction time, and the origin and the degree of purification of p-galactosidase. If the amount of P-galactosidase added is too small, it may take too long to complete the reaction, and a decomposition product with a target molecular weight occasionally may not be obtained because of the inactivation of an enzyme during the course of the reaction. If the amount is excessive, however, the reaction may proceed too rapidly, which makes it difficult to terminate the reaction at an adequate time. In addition, it may increase the production cost. In this respect, the amount (range) of p-galactosidase added can be adequately determined in a range from, for example, 0.01% to 10% (w/v), and preferably 0.05% to 5% (w/v). It should be noted that the amount (range) of p-galactosidase added is provided for illustrative purposes, and the amount can be adequately determined in view of the above conditions. In the present invention, a wide variety of P-galactosidases can be used without particular limitation, provided that a polysaccharide contained in black currant fruit can be decomposed into fractions with preferable sizes as described above. Use of P-galactosidase derived from Aspergillus oryzae is preferable. P-galactosidases with other origins can also be used. Examples of P-galactosidases with other origins that can be used include those derived from Kluyveromyces lactis, Saccharomycesfragilis, and Escherichia coli. In the enzyme treatment, the reaction is terminated when the peak of a polysaccharide (MW > 1,000) appears at a level of interest for obtaining a target polysaccharide that has been subjected to limited and partial decomposition, while ignoring the peak of a low-molecular-weight saccharide (a monosaccharide to an oligosaccharide) having a molecular weight of about 1,000 or less. In such a case, part of the reaction solution is sampled with the elapse of time after the initiation of the reaction, the sampled reaction solution is analyzed by gel filtration via high-performance liquid chromatography (HPLC), and the timing of the reaction termination can be monitored. High-performance liquid chromatography (HPLC) is carried out using a differential refractometer, and, basically, 6 saccharides (i.e., monosaccharides, disaccharides, oligosaccharides, and polysaccharides) are selectively detected. Enzyme reaction can be carried out at a temperature close to the optimal temperature for the enzyme (e.g., about 35*C to 55*C). Since the pH of black currant juice is as low as about 2.9, it is preferable that a substance derived from black currant fruit, including black currant juice, be subjected to an enzyme reaction at a temperature lower than the temperature at which an isolated or partially purified polysaccharide is subjected to decomposition with an enzyme. Enzyme reaction can be terminated by inactivating an enzyme for several minutes, such as by boiling for 5 to 10 minutes, due to high thermostability of a polysaccharide generated. This procedure can also achieve sterilization. According to an embodiment of the present invention, enzyme-treated substances derived from black currant fruit can include rhamnose, mannose, arabinose, galactose, xylose, and glucose as neutral sugar at a ratio of about 18:3:19:30:1:29 by mole (WO 2007/125823). After the enzyme has been inactivated, a polysaccharide having a molecular weight within the aforementioned average molecular weight range may be purified, according to need. Purification techniques are not particularly limited, and, for example, a small amount of an insoluble precipitate resulting from boiling can be removed via centrifugation. After the insoluble precipitate has been removed, the remnant may further be subjected to ultrafiltration with a molecular-weight-cut-off of 1,000, so as to remove low-molecular-weight saccharides (monosaccharides to oligosaccharides) with molecular weights of 1,000 or less, for example. By purification, the content of a polysaccharide within the average molecular weight range of interest in the substance derived from black currant fruit can be adjusted to, for example, 50% to 95% by mass or higher, 60% to 95%.by mass or higher, or 80% to 95% by mass or higher. The enzyme-treated substance derived from black currant fruit may contain a protein or polyphenol compound, in addition to the polysaccharide. According to need, the enzyme-treated substance derived from black currant fruit or the purified polysaccharide having the average molecular weight as described above may be concentrated or lyophilized. The term "skin quality improvement" used herein refers to prevention or repair of skin damage caused by external factors induced by ultraviolet rays or irritating materials, such as detergents or chemicals, or internal factors such as hormone imbalances. Since skin 7 damage involve phenomena such as lowered barrier functions of the horny layer, reduced moisture content of the horny layer, enhanced epidermal turnover, or cuticle roughening caused by scale formation (scaling), skin damage and effects of skin quality improvement can be diagnosed and/or evaluated based on such phenomena. The lowered barrier functions of the horny layer and the reduced moisture content of the horny layer can be identified by measuring cuticle moisture content or transepidermal water loss (TEWL). The composition for skin quality improvement of the present invention comprises, as an active ingredient, the substance derived from black currant fruit. Use or administration of the composition for skin quality improvement of the present invention for a skin region or a subject with skin damage or susceptible to damage enables prevention and/or amelioration of skin damage through skin moisturizing effects of a substance derived from black currant fruit (specifically, desquamation, flaky skin, dryness, cracking, chapping, cornification, sclerotization, face wrinkles, lowered skin flexibility, skin roughness, itching, dry skin, sensitive skin, irritated skin, and atopic skin), although forms of damage are not limited thereto. The composition for skin quality improvement of the present invention can be provided in a variety of forms, provided that the effects described above can be maintained. According to an embodiment of the present invention, for example, the composition for skin quality improvement can be provided in the form of a cosmetic composition. The term "cosmetic composition" used herein refers to cosmetic products and quasi drugs specified by the Pharmaceutical Affairs Act, and examples thereof include cosmetic products, bath agents, and aromatic products for dermal applications. Examples of such cosmetic compositions include: wash agents, such as soap, synthetic cosmetic soap, liquid body wash (body soap), and. face wash; cosmetic products, such as cleansing cream, wash lotion, face lotion, emulsion, beauty essence, lotion, facial masks such as liquid or paste facial masks, powder products such as face powder, liquid face paint, and face paste powder, talcum powder, foundation, lipstick, and blusher; cosmetic products for areas around eyes such as eye liners and eye shadow; cosmetic agents, such as sunscreen cosmetics, suntan cosmetics, and depilatory cosmetics; and shaving cosmetics, such as shave lotion and after-shave lotion, although cosmetic compositions are not limited thereto. 8 The cosmetic composition of the present invention comprises an effective amount of the substance derived from black currant fruit, and the use thereof enables prevention and/or amelioration of skin damage. The cosmetic composition can comprise a substance derived from black currant fruit in an amount equivalent to 0.0 1% by weight to 10% by weight thereof, and such amount can be adequately selected and determined in accordance with the form of the cosmetic composition. In addition to the substance derived from black currant fruit, ingredients that are commonly used for cosmetic products can be adequately selected and added to the cosmetic composition in a manner such that the object, mechanisms, and effects of the present invention would not be adversely affected. Examples of such ingredients include, but are not limited to, a surfactant, an oil, a moisturizing agent, a softening agent, a texture-improving agent, an oil agent, an emulsifier, an antioxidant, a preservative, an antifungal agent, an emollient, a pH control agent, a chelating agent, a stabilizer, an ultraviolet ray absorber, an alcohol, a silicon compound, a thickener, a viscosity modifier, a solubilizer, a pearlescent, an aromatic substance, a refreshing agent, a sterilizer, an antibacterial agent, a natural extract, a coloring agent, an anti-discoloration agent, purified water, another solvent, and a propellant. According to another embodiment of the present invention, a composition for skin quality improvement can be provided as a pharmaceutical composition. The pharmaceutical composition of the present invention is capable of prevention, alleviation, and treatment of skin damage, and it is effective for prevention, alleviation, and/or treatment of dermal diseases or symptoms associated with skin damage. Examples of such dermal diseases or symptoms include, but are not limited to, senile xerosis, infantile dry skin, ichthyosis vulgaris, atopic dermatitis, allergic dermatitis, sensitive skin, seasonal xerosis, and housewives eczema. The pharmaceutical composition can be prepared in the form of an oral or parenteral agent, with an oral agent being preferable. Examples of oral agents include granules, powder, tablets (including sugar-coated tablets), pills, capsules, syrups, emulsions, and suspensions. Examples of parenteral agents include injection preparations (e.g., hypodermic, intravenous, intramuscular, and intraperitoneal injection preparations), drops, external preparations (e.g., nasal preparations, percutaneous preparations, and ointments), and 9 suppositories (e.g., rectal suppositories and vaginal suppositories). Such preparations can be obtained by general techniques in the art with the use of pharmaceutically acceptable carriers. Examples of pharmaceutically acceptable carriers include excipients, binders, diluents, additives, aromatic substances, buffers, thickeners, coloring agents, stabilizers, emulsifiers, dispersants, suspending agents, and preservatives. Specific examples of carriers that can be used include magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, gum tragacanth, methylcellulose, sodium carboxymethylcellulose, low-melting wax, and cacao butter. The amount of the substance derived from black currant fruit, which is an active ingredient of the pharmaceutical composition, to be administered or ingested should be an amount that can exert therapeutic effects on symptoms or applications of interest. Such amount is adequately determined by a person skilled in the art based on animal testing or clinical testing, and conditions such as the age, gender, and body weight of the subject, diseases and symptoms thereof, the dosage form, and the route of administration should be taken into consideration. When the pharmaceutical composition of the present invention is an oral agent, for example, the amount to be administered or ingested is 0.01 to 100 mg/kg of body weight/day, and preferably 0.01 to 40 mg/kg of body weight/day. According to another embodiment of the present invention, further, a composition for skin quality improvement can be provided in the form of a food product. The beverage or food product of the present invention comprises an effective amount of the substance derived from black currant fruit. The beverage or food product can comprise the substance derived from black currant fruit without processing or in the form of a composition comprising the same. More specifically, the beverage or food product of the present invention can be a product made from a substance derived from black currant fruit or a product prepared by adding various proteins, saccharides, fats, trace elements, vitamins, and the like to the substance derived from black currant fruit. The substance derived from black currant fruit may be added to a general beverage or food product. The beverage or food product of the present invention may be in the form of a liquid, semi-liquid, solid, or paste. In the present invention, examples of "beverage or food products" include beauty food products, health food products, functional food products, food products for specified 10 health use, nutritional supplements, food products with reduction of disease risk claims, and food products for sick people. Reduction of disease risk claims indicate that the food product is intended for treatment, improvement, suppression, and/or prevention of skin damage, for example. Specific examples of the beverage or food product of the present invention include: carbohydrate-containing beverage or food products, such as boiled rice, rice cake, noodles, bread, and pasta; western confectioneries, such as cookies and cakes; Japanese confectionaries, such as buns stuffed with adzuki-bean paste and sweet bean jelly; various confectionaries, such as candies, chewing gum, cold desserts such as jelly, yogurt, and pudding, and frozen desserts; various beverage products, such as juice, refreshing beverages, milk beverages, tea beverages, functional beverages, nutritional supplemental beverages, and non-alcoholic beer products; alcoholic beverages, such as beer and sparkling low-malt beverages resembling beer; liquid food products, such as soup, miso soup, and Japanese clear broth; processed products using eggs; processed seafood or meat products; and seasonings. The beverage or food product of the present invention can comprise other ingredients, such as nutritional supplements, in addition to the substance derived from black currant fruit. Examples of such ingredients include: vitamins; minerals; various plants and extracts, purified products, or fractions thereof; microorganisms, growth factors thereof, and substances produced thereby; dietary fibers and enzyme-degraded dietary fibers; animals, extracts, purified products, and degradation products thereof, and substances produced thereby; various oligosaccharides; lipids; and various proteins and degraded proteins. The content of the substance derived from black currant fruit as an active ingredient of the beverage or food product of the present invention is generally 0.01% to 50% by weight, and preferably about 1% to 30% by weight. An adult may ingest such substance in an amount of about 0.5 g to 500 g per day. The composition for skin quality improvement of the present invention comprises, as an active ingredient, a naturally occurring ingredient, as described above. Accordingly, there is a low risk of side effects in any of the aforementioned forms, and such composition can be used, administered, and/or ingested continuously over a long period of time in a cost-effective manner. 11 Hereafter, the present invention is described in detail with reference to the examples, although the present invention is not limited thereto. Examples Example 1: Preparation of black currant juice via treatment with polysaccharide-decomposing enzyme Black currant fruit (BenRua) was crushed, and solid components such as pericarps were separated to obtain black currant juice. Thereafter, an enzyme (Sumylact L; manufactured by Shin Nihon Chemical Co., Ltd.) was added in an amount equivalent to 0.3% (w/v), the resultant was treated at 42*C for 6 hours, and black currant juice in which polysaccharides had been partially decomposed was obtained (hereafter, referred to as "partially decomposed black currant juice"). Separately, black currant juice was treated with an enzyme under the conditions described above for 18 hours. Thus, black currant juice in which polysaccharides had been completely decomposed to monosaccharides was obtained (hereafter, referred to as "completely decomposed black currant juice"). Hereafter, black currant juice that was not subjected to enzyme treatment is referred to as "untreated black currant juice." Example 2: Molecular weight analysis of polysaccharides in untreated, partially decomposed, and completely decomposed black currant juices Molecular weight analysis of polysaccharides contained in untreated, partially decomposed, or completely decomposed black currant juice was carried out in the following manner. Molecular weight analysis was carried out by means of gel filtration via high-performance liquid chromatography (HPLC) (column: OHpak SB-804 HQ; manufactured by Showa Denko K. K.). The results of molecular weight analysis of polysaccharides contained in untreated black currant juice, partially decomposed black currant juice, and completely decomposed black currant juice are shown in Table 1 below. 12 Table 1 Results of molecular weight analysis of black currant juice Molecular weight of polysaccharide Untreated black currant juice 199,000 Partially decomposed black currant juice 27,000 Completely decomposed black currant juice Not detected Example 3: Analysis of defense against ultraviolet application using hairless mice Mouse feeds containing untreated black currant juice, partially decomposed black currant juice, and completely decomposed black currant juice, respectively, were prepared. Fruit juice was lyophilized and used in the form of powder when preparing the mouse feeds. Compositions of feeds are shown below. <Feed containing fruit juice> AIN93G 1,000 g Fruit juice powder 50 g <Control feed> AIN93G 1,000 g Dextrin powder 50g A sample feed containing untreated black currant juice, partially decomposed black currant juice, or completely decomposed black currant juice or a control feed was administered to mice of four groups each consisting of 10 hairless mice (Hos:HR-1, 5-week-old, female, Japan SLC-Inc.) for 2 weeks. The feed mixture was orally administered in an amount of 4 g/day on average. Thereafter, mice were irradiated once with ultraviolet rays at 90 mJ/cm 2 in the dorsal region. The levels of cuticle moisture content and transepidermal water loss were measured 3 days after ultraviolet application, and skin damage caused by ultraviolet application was evaluated. Ultraviolet rays were applied using San-Ei Supercure-204S (San-Ei Electric Co., Ltd.), and cuticle moisture content and transepidermal water loss were measured using Corneometer CM825 and Tewameter TN300 (Integral Corporation). Apparatuses were used in accordance with the manufacturers' instructions. A multiple comparison test was carried out using Dunnett's method. Fig. 1 shows the results of measurement of cuticle moisture content. 13 Cuticle moisture content of mice in groups irradiated with ultraviolet rays was significantly lowered compared with cuticle moisture content of mice that had not been irradiated with ultraviolet rays. In the groups that had ingested fruit juice, however, a downward trend was observed in reduction in cuticle moisture content. As a result of a comparison among the groups that had ingested fruit juice, reduction in cuticle moisture content was found to be suppressed to a significant extent in the groups that had ingested untreated black currant juice and partially decomposed black currant juice, compared with the group that had ingested completely decomposed black currant juice. In particular, reduction in cuticle moisture content was found to be suppressed to the most significant extent in the group that had ingested partially decomposed black currant juice. Fig. 2 shows the results of measurement of transepidermal water loss. An upward trend was observed in the levels of transepidermal water loss of mice of the groups irradiated with ultraviolet rays, compared with the level of transepidermal water loss of mice that had not been irradiated with ultraviolet rays. Regarding the groups that had ingested fruit juice, it was observed that an increase in transepidermal water loss would be suppressed to a significant extent. As a result of a comparison among the groups that had ingested fruit juice, a trend of suppression of increase in transepidermal water loss was observed in the groups that had ingested untreated black currant juice and partially decomposed black currant juice, compared with the group that had ingested completely decomposed black currant juice. In particular, increase in transepidermal water loss was found to be suppressed to the most significant extent in the group that had ingested partially decomposed black currant juice. The results of analysis demonstrate that reduction in cuticle moisture content caused by ultraviolet application can be suppressed by ingestion of black currant juice, and, in particular, partially decomposed black currant juice, and skin damage caused by ultraviolet rays can be suppressed. Example 4: Production of test beverage In the same manner as in Example 1, partially decomposed black currant juice was produced, and 50 ml each of the beverages with the formulations shown in the table below were prepared (low-dose groups and high-dose groups). 14 Test sample Test sample Placebo Low-dose group High-dose group (control group) Partially decomposed black currant juice (ml) 6 12.5 0 Purple sweet potato (beni-imo) pigment (g) 0.13 0.13 0.13 Citric acid (g) 0 0 0.075 Sodium citrate (g) 0 0 0.115 High-fructose corn syrup (g) 3 3 3 Black currant flavor (g) 0 0 0.00005 Water (g) 40.87 34.37 43.68 Total (ml) 50 50 50 Example 5: Human testing Healthy female subjects aged 35 to 56 (36 individuals) were divided into 3 groups each consisting of 12 individuals. Each individual was requested to ingest 50 ml of a beverage prepared in Example 4 (a beverage containing a low-dose or high-dose partially decomposed black currant juice) or a control beverage (a beverage not containing partially decomposed black currant juice) every day for 8 weeks. Questionnaires regarding skin roughness were completed at the initiation of testing, 4 weeks after the initiation of testing, and 8 weeks after the initiation of testing (the score increases when the subject is concerned about skin roughness). Testing was carried out in winter when skin roughness is likely to occur. Fig. 3 shows the results. The score before ingestion was designated as 1, and changes in scores were compared. As a result, the scores were found to have significantly increased in control groups, reflecting a "concern about skin roughness." In contrast, no change was observed in the scores of groups that had ingested samples (low-dose groups and high-dose groups). Comparison of changes in the scores after 8 weeks of ingestion demonstrated that changes in the scores of the groups that had ingested samples (low-dose groups and high-dose groups) were significantly smaller than those of control groups. This indicates that skin roughness can be ameliorated via ingestion of partially decomposed black currant juice. Comparison of the scores with those before ingestion was carried out using a student t test (paired t test), and comparison between groups was carried out using Dunnett's method. A 0.05 level of 15 significance was employed in a two-sided test. Example 6 Thirty cookies were prepared in accordance with the formulation shown below by a conventional technique. Partially decomposed black currant juice produced in Example 4 (5-fold concentrate) 6 g Lemon juice Juice from 1 lemon (30 to 40g) Salt-free butter 100 g Sugar 80 g Egg yolk Yolk from one egg Ground almonds 50 g Soft flour 130 g Granulated sugar A small amount Example 7 Four loaves of bread were prepared in accordance with the formulation shown below by a conventional technique. Partially decomposed black currant juice produced in Example 4 (5-fold concentrate) 12 g Hard flour 1 kg Sugar 50 g Salt 20 g Skim milk powder 20 g Shortening 60 g Yeast (raw) 30 g Yeast food 1 g Water 650 g Example 8 Thirty pieces of chewing gum were prepared in accordance with the formulation shown below by a conventional technique. Partially decomposed black currant juice produced in Example 4 (5-fold concentrate) 1 g Gum base 25 g Sugar 63 g Starch syrup 10 g Aromatic substance 1 g 16 Example 9 Twenty pieces of candy were prepared in accordance with the formulation shown below by a conventional technique. Partially decomposed black currant juice produced in Example 4 (5-fold concentrate) 0.8 g Sugar 80 g Starch syrup 20 g Industrial Applicability The composition of the present invention comprising, as an active ingredient, a substance derived from black currant fruit exerts effects of preventing or repairing skin damage by skin-moisturizing effects. Thus, the present invention can be used for a novel cosmetic product, a pharmaceutical composition, a beauty food product, a health food product, and other applications aimed at prevention or repair of skin damage. All publications, patents, and patent applications cited herein are incorporated herein by reference in their entirety. 17