Processed strawberry leaf product and composition containing the same, and method for producing strawberry leaf extract

Abstract

The present invention provides a processed product of young strawberry leaves and a composition containing said processed product of young strawberry leaves. [Solution] A processed strawberry leaf product comprising dried strawberry leaves and / or extracts. A composition containing this processed strawberry leaf product has antioxidant, tyrosinase inhibitory, elastase inhibitory, IL-1α production inhibitory, and IL-8 production inhibitory effects, and can be suitably used as a composition for topical application to the skin or as an oral composition.

Description

TECHNICAL FIELD

[0001] The present invention relates to a processed strawberry young leaf product, and a composition containing the processed strawberry young leaf product. BACKGROUND ART

[0002] Strawberries (genus Fragaria) are perennial plants belonging to the Rosaceae family, and their fruits are known to contain vitamin C, citric acid, malic acid, polyphenols (ellagic acid and anthocyanins), xylitol, pectin, and the like. These components have been reported to have various physiological activities such as antioxidant action, anti-inflammatory action, and whitening action. As a composition containing a component derived from strawberry fruit, for example, Patent Document 1 discloses an oral or external dermal composition containing polyphenols derived from strawberries (strawberry fruits).

[0003] On the other hand, strawberries are known to contain useful components not only in their fruits but also in their leaves. For example, Patent Document 2 reports that an extract extracted from a dried product of mature strawberry leaves after fruit harvest or isolated agrimoniin is suitable for external dermal applications. Furthermore, Patent Document 3 reports that a strawberry leaf extract obtained using mature strawberry leaves has an IL-8 production inhibitory action and a collagenase production inhibitory action. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0004] PATENT DOCUMENT 1 Japanese Unexamined Patent Application Publication No. 2011-26207 PATENT DOCUMENT 2 Japanese Unexamined Patent Application Publication No. 2010-215516 PATENT DOCUMENT 3 Japanese Unexamined Patent Application Publication No. 2023-147780 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] As mentioned above, Patent Documents 2 and 3 both report on the various effects of mature strawberry leaves, but research on unripe strawberry leaves (young strawberry leaves) has not progressed sufficiently. In particular, there is no knowledge regarding the components contained in young strawberry leaves and their functionality.

[0006] Under these circumstances, the object of the present invention is to provide a processed product of young strawberry leaves and a composition containing said processed product of young strawberry leaves. [Means for solving the problem]

[0007] The inventors of this invention conducted extensive research to solve the above problems and discovered that young strawberry leaves before maturation contain more beneficial components and have different physiological activities compared to mature strawberry leaves, leading to the present invention.

[0008] In other words, the present invention relates to the following invention. <1> A processed strawberry leaf product consisting of dried strawberry leaves and / or extracts. <2> Contains casuarictin and strictinin. <1> The processed strawberry leaf product described above. <3> The aforementioned strawberry leaves are strawberry leaves that, on a dry basis, contain 6.0 mg / g or more of causarictin and 1.5 mg / g or more of strictinin. <1> or <2> The processed strawberry leaf product described above. <4> The aforementioned strawberry leaf extract is a solvent extract obtained by using one or more extraction solvents selected from the group consisting of water, lower alcohols, polyhydric alcohols, and aromatic alcohols. <1> from <3> A processed strawberry leaf product as described in any of the following. <5> The aforementioned strawberry leaf extract is a solvent extract obtained using a mixed solvent of water and ethanol. <4> The processed strawberry leaf product described above. <6> The aforementioned strawberry leaf extract is a strawberry leaf extract containing 16.0 mg / g or more of causarictin and / or 5.0 mg / g or more of strictinin. <4> or <5> The processed strawberry leaf product described above.

[0009] <1a> <1> from <6> A composition containing a processed strawberry leaf product as described in any of the following. <2a> The composition according to <1a> for at least one use selected from antioxidant, tyrosinase inhibitor, elastase inhibitor, IL-1α production suppression, and IL-8 production suppression. <3a> The composition described in <1a> or <2a> for external use on the skin. <4a> The composition according to <1a> or <2a>, which is for oral use.

[0010] <1b> An antioxidant composition containing processed strawberry leaves. <2b> A tyrosinase inhibitory composition containing a processed product of young strawberry leaves. <3b> A composition for inhibiting elastase containing processed strawberry leaves. <4b> A composition for inhibiting IL-1α production containing a processed product of young strawberry leaves. <5b> A composition for inhibiting IL-8 production containing a processed product of young strawberry leaves.

[0011] <1c> A method for producing strawberry leaf extract, characterized by contacting dried strawberry leaves with an extraction solvent to extract components contained in the strawberry leaves. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a processed product of young strawberry leaves and a composition containing the processed product of young strawberry leaves. [Brief explanation of the drawing]

[0013] [Figure 1] These are photographs of a whole strawberry plant (before drying), with (a) being a general view and (b) being a close-up of the area near the base. [Figure 2] This is a photograph classifying whole strawberry leaves into strawberry leaves (small), strawberry leaves (medium), strawberry leaves (large), and strawberry leaves (extra-large). [Figure 3] These are the measurement results of the amount of ellagitannins in the strawberry leaf (small, medium, large, extra-large) extracts. [Figure 4] These are the results of LC-MS hierarchical cluster analysis on the strawberry leaf (small, medium, large, extra-large) extracts. [Mode for Carrying Out the Invention]

[0014] Hereinafter, the present invention will be described in detail with reference to illustrative examples and the like, but the present invention is not limited to the following illustrative examples and the like, and can be arbitrarily modified and implemented without departing from the gist of the present invention. In this specification, the symbol "~" is used as an expression including the numerical values or physical quantities before and after it. Further, in this specification, the expression "A and / or B" includes "A alone", "B alone", and "both A and B".

[0015] [1. Processed Strawberry Young Leaf Product] The present invention relates to a processed strawberry young leaf product composed of a dried product and / or an extract of strawberry young leaves (hereinafter sometimes referred to as "the processed strawberry young leaf product of the present invention").

[0016] In addition, the processed strawberry young leaf product of the present invention contains ellagitannins (particularly casuarictin and strictinin) derived from the strawberry young leaves that are the raw material. As shown in the Examples described later, the content of casuarictin and strictinin tends to decrease as the strawberry leaves mature. That is, casuarictin and strictinin are abundantly contained in pre-mature young strawberry leaves among strawberry leaves. The details of casuarictin and strictinin will be described later.

[0017] The strawberry leaf processed product of the present invention possesses various physiological activities, including antioxidant activity, tyrosinase inhibitory activity, elastase inhibitory activity, IL-1α production inhibitory activity, and IL-8 production inhibitory activity. Furthermore, these physiological activities of the strawberry leaf processed product of the present invention are far superior to those of mature strawberry leaves. For this reason, the strawberry leaf processed product of the present invention can be suitably used in compositions for topical application to the skin (e.g., cosmetics) and oral compositions (supplements, functional foods, etc.).

[0018] The strawberry leaf processed product of the present invention will be described in more detail below.

[0019] The "young strawberry leaves" used as a raw material for the strawberry leaf processed product of the present invention are the young leaves of the strawberry plant belonging to the genus Fragaria of the family Rosaceae.

[0020] In this specification, "strawberry leaf portion" refers to the entire leaf blade and petiole of a strawberry plant. Runners (stolons or vines) extending from the parent plant are not included in the definition of strawberry leaf portion as defined herein. Furthermore, in this specification, "young strawberry leaves" refers to the undeveloped leaves of strawberries before maturity, including new leaves and young leaves, and specifically refers to "strawberry leaves with a combined length of the leaf blade and petiole of 30 cm or less." Furthermore, when classifying strawberry leaves based on their maturity, young strawberry leaves can be clearly distinguished from mature leaves by morphological characteristics such as the combined length of the leaf blade and petiole, as well as the leaf's color and hardness.

[0021] As shown in the examples described later, the components contained in strawberry leaves change significantly depending on their maturity. Therefore, the content of specific components can be used as an indicator of strawberry leaf maturity. Casuarictin and strictinin can be used as indicators of the maturity of strawberry leaves. As shown in the examples, young strawberry leaves contain higher levels of causallictin and strictinin compared to mature strawberry leaves (with a combined length of leaf blade and petiole exceeding 30 cm). In particular, young strawberry leaves are preferable if the combined length of the leaf blade and petiole is 15 cm or less, as this results in a higher content of casu alictin and strictinin.

[0022] The content of causallicin and strictin in strawberry leaves can be defined as dry matter. By defining the content as dry matter, the content of causallicin and strictin, which serve as indicators of strawberry leaf maturity, can be determined without depending on the moisture content of the strawberry leaves. Herein, in this specification, "content on a dry basis (of strawberry leaves)" means that the dry product (in the example, 45°C for 18 hours) of undried young strawberry leaves dried at 40°C or higher for 15 hours or more is used as the standard for the content of components in strawberry leaves. In other words, "content of causallicin on a dry basis" and "content of strictin on a dry basis" mean the content of causallicin and strictin in the dried strawberry leaves dried by the above method.

[0023] The amount of causallicin in the young strawberry leaves used as raw material is 6.0 mg / g or more on a dry basis, preferably 8.0 mg / g or more, 9.0 mg / g or more, 10.0 mg / g or more, or 12.0 mg / g or more, and the amount of strictin in the young strawberry leaves used as raw material is 1.5 mg / g or more on a dry basis, preferably 2.0 mg / g or more, 2.5 mg / g or more, 3.0 mg / g or more, 4.0 mg / g or more, or 5.0 mg / g or more. The content of causallicin and strictinin in young strawberry leaves (based on dry matter) was measured by LC-MS, as described in the examples below.

[0024] The variety, brand, and origin of the strawberries used as raw materials for the strawberry leaf product are not particularly limited; any strawberry can be used. Specifically, examples include, but are not limited to, Ichigosan, Shiro Ichigo, Saga Honoka, Toyonoka, Tochiotome, Amaou, Akihime, Asuka Ruby, Aiberry, Tochihime, Red Pearl, Sachinoka, Benihoppe, and Momoi Ichigo. These can be used individually or in combination of two or more varieties.

[0025] The strawberry leaves used as a raw material may be natural or artificially cultivated, as long as they do not impair the effects of the present invention.

[0026] While young strawberry leaves can be used as is without any prior processing, they are usually sliced, crushed, pressed, or grated to create a fine granule.

[0027] As mentioned above, the strawberry leaf processed product is the dried and / or extracted form of strawberry leaves. In this invention, "dried material" refers to dried raw plant material. Specifically, it refers to strawberry leaves dried by known drying methods such as sun drying, heat drying, or freeze drying. The drying conditions are not particularly limited as long as they do not impair the effects of this invention. From the standpoint of usability, the dried material is usually crushed into a powder and used as a dried powder. There are no particular limitations on the crushing method; conventionally known crushers can be used. The particle size of the powder is determined appropriately depending on its intended use.

[0028] Furthermore, in this invention, "extract" is a general concept encompassing a form in which the content of active ingredients is increased by pressing or solvent extraction of the target raw material plant, or by drying and finely chopping it as necessary. Specifically, this includes extract obtained using young strawberry leaves as the raw material, a diluted or concentrated extract, or crude or refined products thereof. Dried products obtained by drying the extract are also considered to be extracts.

[0029] Strawberry leaf processed products may use dried strawberry leaves and strawberry leaf extract separately, or they may be mixed in any proportion.

[0030] Among these, the strawberry leaf processed product of the present invention is preferably a strawberry leaf extract. Strawberry leaf extract can be obtained by extracting strawberry leaves according to conventional methods. The extraction method is not particularly limited as long as it does not impair the effects of the present invention, and any appropriate method can be arbitrarily selected and used depending on the purpose. For example, a preferred method involves contacting young strawberry leaves, either as they are or processed products such as crushed, dried, or pulverized leaves, with an extraction solvent to extract the components contained in the young strawberry leaves.

[0031] The extraction solvent may contain additives, provided that they do not impair the effects of the present invention. Examples include pH adjusters and viscosity adjusters.

[0032] When obtaining strawberry leaf extract by solvent extraction, the extraction solvent should be one that can extract the active ingredients contained in the strawberry leaves. Specific examples include water, lower alcohols (methanol, ethanol, propanol, isopropanol, butanol, etc.), polyhydric alcohols (butylene glycol, propylene glycol, sorbitol, glycerin, etc.), aromatic alcohols (benzyl alcohol, phenoxyethanol, phenethyl alcohol, etc.), ketones (acetone, methyl ethyl ketone, etc.), ethers (diethyl ether, tetrahydrofuran, propyl ether, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), hydrocarbons (hexane, heptane, etc.), alkyl halides (chloroform, etc.), acetonitrile, etc. Furthermore, the water used as the extraction solvent is optional as long as it does not impair the effects of the present invention, and examples include tap water, distilled water, mineral water, etc. These extraction solvents can be used individually or as a mixture of two or more. When using a mixture of two or more solvents as an extraction solvent, the mixing ratio can be adjusted as appropriate.

[0033] The extraction solvent may contain additives, provided that they do not impair the effects of the present invention. Examples include pH adjusters and viscosity adjusters.

[0034] A preferred example of a strawberry leaf extract is a solvent extract obtained using one or more extraction solvents selected from the group consisting of water, lower alcohols, polyhydric alcohols, and aromatic alcohols. In this case, specific examples of extraction solvents include water, ethanol, isopropyl alcohol, butylene glycol, propylene glycol, benzyl alcohol, and phenethyl alcohol. These can be used individually or as a mixture of two or more, and when a mixture of two or more solvents is used as an extraction solvent, the mixing ratio can be adjusted as appropriate.

[0035] In particular, from the standpoint of environmental and biological safety and manufacturing costs, a preferred example of strawberry leaf extract is a solvent extract of strawberry leaf using a mixed solvent of water and ethanol. When using a mixed solvent of water and ethanol as the extraction solvent, the mixing ratio of water and ethanol should be adjusted as appropriate within the range that allows for the extraction of the active ingredients contained in young strawberry leaves. For example, when the mixed solvent of water and ethanol is 100% by volume, the proportion of ethanol is 0.1 to 99% by volume.

[0036] There are no particular restrictions on the amount of extraction solvent relative to the raw material, young strawberry leaves, but it is usually about 1 to 100 times the weight of the young strawberry leaves.

[0037] Any method that can extract solvent extracts from young strawberry leaves is acceptable, as long as it can extract the active ingredients contained in the young strawberry leaves. A suitable method for producing strawberry leaf extract is to bring strawberry leaves into contact with an extraction solvent and stir for a certain period of time until the active ingredients are sufficiently extracted from the strawberry leaves into the extraction solvent. The extraction time is selected appropriately considering the type of extraction solvent and the ratio of strawberry leaves to the extraction solvent. For example, if the extraction solvent is a mixture of water and ethanol, the extraction time can range from 1 to 24 hours.

[0038] The extraction process is carried out at room temperature to avoid quality degradation, but it can be performed under heated conditions to increase extraction efficiency. Additionally, if necessary, solvent removal may be performed by reduced-pressure concentration or freeze-drying to increase the proportion of active ingredients in the strawberry leaf extract.

[0039] Furthermore, filtration or centrifugation may be performed to remove residue from the extract. The obtained extract may be used as is, or it may be subjected to treatments such as dilution, concentration, drying, and purification according to conventional methods. If necessary, the solvent may be removed by concentration and drying methods such as vacuum concentration, freeze-drying, or spray drying.

[0040] [2. Components of processed strawberry leaves] The strawberry leaves used as raw materials for the strawberry leaf processed product of the present invention contain casuarictin and strictinin. Furthermore, in this specification, the term "casuarictin" includes not only casuarictin but also its polymers.

[0041] Casuarictin has the molecular formula C 41 H 28 O 26 It is represented as follows, has a molecular weight of 936.649, and is a type of polyphenol represented by the following structural formula (1).

[0042] [ka]

[0043] Furthermore, a polymer of causallicin is a type of polyphenol formed by the dehydration condensation of two or more of the above-mentioned causallicin molecules. Typically, it consists of several dozen causallicin molecules linked together, and the degree of polymerization is not particularly important; it is sufficient if it consists of two or more units, with causallicin as one unit.

[0044] There are no specific limitations on the molecular weight of the casuarictin polymer, but the average molecular weights are 15,000 or less, 12,000 or less, and 10,000 or less.

[0045] Next, strictinin has the molecular formula C 27 H 22 O 18 It is represented as follows, has a molecular weight of 634.455, and is a type of polyphenol represented by the following structural formula (2).

[0046] [ka]

[0047] As described above, the strawberry leaf processed product of the present invention is a strawberry leaf processed product comprising dried strawberry leaves and / or extracts. The strawberry leaf processed product of the present invention preferably contains casuarictin and strictinin derived from the strawberry leaf used as the raw material. The amounts of casuarictin and strictinin may be any proportion, as long as the objective of the present invention is not impaired.

[0048] The following describes the content of causallicin and strictinin in processed strawberry leaf products (dried strawberry leaf product, strawberry leaf extract). The causallicin and strictinin content shown below is expressed per gram of dried strawberry leaf product or strawberry leaf extract, and therefore the unit "mg / g" is used. Furthermore, in this specification, the term "casuarictin content" refers to the content of casuarictin and its polymers.

[0049] When the processed strawberry leaf product is dried strawberry leaf product, the causallicin content in the dried strawberry leaf product is 6.0 mg / g or more, preferably 8.0 mg / g or more, 9.0 mg / g or more, 10.0 mg / g or more, or 12.0 mg / g or more, and the strictinin content in the dried strawberry leaf product is 1.5 mg / g or more, preferably 2.0 mg / g or more, 2.5 mg / g or more, 3.0 mg / g or more, 4.0 mg / g or more, or 5.0 mg / g or more. The content of causallicin and strictinin in the dried strawberry leaf material was measured by LC-MS, as described in the examples below.

[0050] When the processed strawberry leaf product is a strawberry leaf extract, the content of causallicin and strictinin in the strawberry leaf extract depends on the type and amount of extraction solvent used. To achieve the effects of the present invention, the content of causallicin and strictinin can be appropriately selected and adjusted by choosing the type and amount of extraction solvent used. The causallicin content in the strawberry leaf extract is 16.0 mg / g or more, preferably 20.0 mg / g or more, 25.0 mg / g or more, 28.0 mg / g or more, or 30.0 mg / g or more. The strictinin content in the strawberry leaf extract is 5.0 mg / g or more, preferably 7.0 mg / g or more, 9.0 mg / g or more, 10.0 mg / g or more, or 12.0 mg / g or more. The amounts of causallicin and strictin in the strawberry leaf extract were measured by LC-MS, as described in the examples below.

[0051] [3. Compositions containing processed strawberry leaves and their applications] The composition of the present invention is a composition containing the strawberry leaf processing product of the present invention. The strawberry leaf processed product of the present invention may be used as is, or it may be combined with other ingredients that do not impair the effects of the present invention to form a composition containing the strawberry leaf processed product. Other ingredients may be any ingredients that are safe for human use, and will be determined appropriately considering the form of use (medicinal, topical, or oral) as described later. The proportions of other components can be appropriately selected and determined according to the purpose, as long as they do not impair the effects of the present invention.

[0052] Furthermore, the composition of the present invention may also contain, to the extent that it does not impair the objectives of the present invention, other strawberry-derived components besides young strawberry leaves, such as mature strawberry leaves (dried or extracted) or runners (dried or extracted).

[0053] As described in the examples below, the compositions of the present invention have antioxidant, tyrosinase inhibitory, elastase inhibitory, IL-1α production inhibitory, and IL-8 production inhibitory effects, and can therefore be used as compositions for at least one application selected from antioxidant, tyrosinase inhibitory, elastase inhibitory, IL-1α production inhibitory, and IL-8 production inhibitory effects. Furthermore, the compositions of the present invention can be used in any form depending on their purpose. That is, they can be used as pharmaceutical compositions, as well as compositions for external skin application that do not fall under the category of pharmaceutical compositions (such as cosmetic compositions), and oral compositions (such as supplements and functional foods).

[0054] When using the composition of the present invention as an antioxidant composition, the amount of processed strawberry leaf extract contained is appropriately determined within a range that allows for the intake of the necessary amount, taking into consideration the type and degree of symptoms involving oxidation (oxidative stress), the form of the composition of the present invention, and the method of use.

[0055] When the composition of the present invention is used as a tyrosinase inhibitory composition, the amount of processed strawberry leaf product contained is appropriately determined within a range that allows for the intake of the necessary amount, taking into consideration the type and degree of symptoms involving tyrosinase, the form of the composition of the present invention, and the method of use.

[0056] When the composition of the present invention is used as an elastase inhibitory composition, the amount of processed strawberry leaf extract contained is appropriately determined within a range that allows for the intake of the necessary amount, taking into consideration the type and degree of symptoms involving elastase, the form of the composition of the present invention, and the method of use.

[0057] When the composition of the present invention is used as a composition for suppressing IL-1α production, the amount of processed strawberry leaf product contained is appropriately determined within a range that allows for the intake of the necessary amount, taking into consideration the type and degree of symptoms related to IL-1α production, the form of the composition of the present invention, and the method of use.

[0058] Furthermore, when the composition of the present invention is used as a composition for suppressing IL-8 production, the amount of processed strawberry leaf product contained therein is appropriately determined within a range that allows for the intake of the necessary amount, taking into consideration the type and degree of symptoms related to IL-8 production, the form of the composition of the present invention, and the method of use.

[0059] (Pharmaceutical composition) One preferred form of the composition of the present invention is a pharmaceutical composition (hereinafter sometimes referred to as "the pharmaceutical composition of the present invention") comprising an effective amount of processed strawberry leaves together with a pharmaceutically acceptable base material.

[0060] In this specification, "pharmaceutical composition" means an agent useful for at least one of the following: prevention, treatment, or improvement of symptoms of a target disease. Furthermore, in this specification, "pharmaceutical composition" includes not only pharmaceuticals but also quasi-drugs.

[0061] The pharmaceutical composition of the present invention may contain other drugs or any pharmacologically acceptable components in addition to the processed strawberry leaf product, as long as they do not impair its efficacy.

[0062] The pharmaceutical composition of the present invention is useful for at least one of the prevention, treatment, or improvement of symptoms of diseases involving oxidation (oxidative stress), tyrosinase, elastase, IL-1α production, and IL-8 production. Specifically, "prevention" includes suppressing and delaying the onset of the disease or symptoms. Furthermore, "treatment" includes improving and achieving remission of the pathological condition of the disease or symptoms, as well as suppressing the progression of the disease or symptoms.

[0063] The diseases or symptoms to which the antioxidant, tyrosinase inhibitory, elastase inhibitory, IL-1α production inhibitory, and IL-8 production inhibitory effects of the pharmaceutical composition of the present invention are involved are not limited, but specific examples include arteriosclerosis, cardiovascular disease, diabetes, cancer, inflammatory diseases, and rheumatoid arthritis.

[0064] The pharmaceutical composition of the present invention only needs to contain a processed strawberry leaf product, and can be any form of drug. The pharmaceutical composition of the present invention can take the form of tablets, pills, granules, powders, liquids, suspensions, syrups, or capsules. The form of the pharmaceutical composition of the present invention is not particularly limited; it may be solid or liquid, or solid and liquid. The method of administration may be oral or parenteral. Preferred embodiments of the pharmaceutical composition of the present invention include oral preparations and topical skin preparations.

[0065] The pharmaceutical composition of the present invention can also be applied to animals other than humans. Therefore, it can also be used as a pharmaceutical composition for animals.

[0066] The amount of the pharmaceutical composition of the present invention to be taken is not particularly limited as long as it is an amount that can exert the effects of the present invention, and is appropriately determined according to the gender, weight, health condition, etc. of the person taking it. The amount may be taken in one dose or divided into several doses per day. Furthermore, from the viewpoint of prevention, treatment, and improvement of symptoms of the target disease, it is preferable to take the pharmaceutical composition of the present invention continuously.

[0067] <Forms other than pharmaceutical compositions> As mentioned above, processed strawberry leaf extract may be incorporated into products other than pharmaceuticals and quasi-drugs. Preferred examples of such forms include compositions for topical application to the skin and compositions for oral use.

[0068] (Composition for external use on the skin) One preferred form of the composition of the present invention is a topical skin composition containing a processed strawberry leaf product (hereinafter sometimes referred to as "the topical skin composition of the present invention").

[0069] The following describes a cosmetic composition, which is a typical example of a topical skin composition of the present invention, but the topical skin composition of the present invention is not limited to a cosmetic composition.

[0070] The topical skin composition of the present invention has excellent antioxidant, tyrosinase inhibitory, elastase inhibitory, IL-1α production inhibitory, and IL-8 production inhibitory effects, and as described above, can prevent or improve symptoms related to oxidation (oxidative stress), tyrosinase, elastase, IL-1α production, and IL-8 production. For example, it can provide cosmetic effects against decreased skin firmness and elasticity, skin hydration, wrinkle formation, and skin redness.

[0071] The topical skin composition of the present invention can be formulated with conventional cosmetic base materials to form a desired dosage form. While there are no particular limitations on its form, examples include lotions, emulsions, gels, creams, packs, hair tonics, hair cream foundations, aqueous ointments, and sprays. Furthermore, in the present invention, the term "cosmetic composition" also includes bath compositions such as bath additives, body soaps, and shampoos.

[0072] Furthermore, the topical skin composition of the present invention may contain any ingredients commonly used in cosmetics, topical skin medicines, and bath products, as long as they do not impair the effects of the present invention. Specific examples of such optional ingredients include thickeners / gelling agents, antioxidants, UV absorbers, colorants, chelating agents, preservatives, pH adjusters, fragrances, and beeswax. The proportions of these optional ingredients can be appropriately selected and determined according to their purpose.

[0073] The proportion of processed young strawberry leaves incorporated into the topical skin composition is arbitrary, but the proportion should be selected within a range that allows for the contribution of at least one of the following effects: antioxidant effect, tyrosinase inhibitory effect, elastase inhibitory effect, IL-1α production inhibitory effect, or IL-8 production inhibitory effect.

[0074] The topical skin composition of the present invention can also be applied to animals other than humans. Therefore, it can also be used as a topical skin composition for animals.

[0075] (Oral composition) One preferred form of the composition of the present invention is an oral composition containing a processed strawberry leaf product (hereinafter sometimes referred to as "the oral composition of the present invention"). The oral composition of the present invention has excellent antioxidant, tyrosinase inhibitory, elastase inhibitory, IL-1α production inhibitory, and IL-8 production inhibitory effects, and is therefore suitable for use in functional foods, supplements, and the like.

[0076] The following describes typical examples of the oral compositions of the present invention, such as functional foods, supplements, and food additives. However, the oral compositions of the present invention are not limited to functional foods, supplements, or food additives.

[0077] The amount of the oral composition of the present invention to be taken is not particularly limited as long as it is an amount that can exert the effects of the present invention, and is appropriately determined according to the form of the oral composition of the present invention, the gender, weight, health condition, etc. of the person taking it. The amount may be taken in one dose or divided into several doses per day. Furthermore, in order to obtain the effects or efficacy of the oral composition of the present invention, it is preferable to take the oral composition of the present invention continuously.

[0078] The composition of the present invention can be easily consumed orally on a daily basis by mixing it with various foods and beverages to create a functional food, making it easy to consume over the long term. In this context, "functional foods" refers to foods and / or beverages consumed for the purpose of maintaining health, in addition to general foods. This concept includes health functional foods (foods for specified health uses, nutrient function foods, or foods with functional claims), health foods, nutritional supplements, and nutritional health foods. Among these, health functional foods such as foods for specified health uses, nutrient function foods, and foods with functional claims are preferred forms of functional foods. When commercializing a product as a functional food, various additives used in food, specifically colorants, preservatives, thickeners and stabilizers, antioxidants, bleaching agents, antibacterial and antifungal agents, acidulants, seasonings, emulsifiers, fortifiers, processing agents, flavorings, etc., may be added.

[0079] There are no particular limitations on the types of foods and beverages that qualify as functional foods. For example, foods include dried powders, sausages, ham, processed seafood products, jellies, candies, and chewing gum. Beverages include various types of tea, green juice drinks, soft drinks, alcoholic beverages, and nutritional drinks.

[0080] Furthermore, the oral composition of the present invention can also be used in the form of a supplement. The form of the supplement is not particularly limited and may be any form such as tablets, powders, granules, capsules, sugar-coated tablets, films, lozenges, chewables, solutions, emulsions, suspensions, etc. The supplement of the present invention may contain any ingredients commonly used as supplements, in addition to the composition of the present invention. Examples of such ingredients include amino acids, peptides; vitamins such as vitamin E, vitamin C, vitamin A, vitamin B, and folic acid; minerals; sugars; inorganic salts; citric acid or its salts; tea extract; oils and fats; tonic ingredients such as propolis, royal jelly, and taurine; herbal extracts such as ginger extract and ginseng extract; herbs; collagen, etc.

[0081] The proportion of processed young strawberry leaves included in functional foods and supplements is arbitrary, but the proportion should be selected within a range that contributes to at least one of the following effects: antioxidant effect, tyrosinase inhibitory effect, elastase inhibitory effect, IL-1α production inhibitory effect, or IL-8 production inhibitory effect.

[0082] When the oral composition of the present invention is used as a health functional food, the effects or benefits provided by the strawberry leaf processed product according to the present invention may be displayed on the product. For example, this could be displayed on the product itself, packaging, container, or other contents, or on advertisements thereof.

[0083] Furthermore, examples of claims regarding the effects or benefits that may be attached to the product during its commercialization include: "maintains skin elasticity," "improves skin firmness," "prevents loss of skin firmness," "prevents wrinkles," "retains skin moisture," and "improves redness associated with inflammation."

[0084] Furthermore, the compositions of the present invention can be used as food additives, either on their own or with other components added. The other components are not particularly limited, as long as they are suitable for use as food additives. The beverages and foods to which the food additives are added are also arbitrary and not particularly limited.

[0085] The proportion of the composition of the present invention incorporated into a food additive is arbitrary, but the proportion is selected within a range that can contribute to at least one of the following: antioxidant activity, tyrosinase inhibition, elastase inhibition, IL-1α production inhibition, and IL-8 production inhibition.

[0086] The oral composition of the present invention can also be applied to animals other than humans. Therefore, it can also be used as an oral composition for animals, such as pet food. [Examples]

[0087] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In addition, the "%" shown in the mixed solvents of the examples refers to "volume %" unless otherwise specified. Also, when the extraction solvent is a mixed solvent, the balance of water is omitted. For example, when "50% ethanol" is written, it means a mixed solvent of 50 volume % ethanol and 50 volume % water.

[0088] 1. Classification of strawberry leaves The strawberry leaves (whole leaves) used are as follows: Figure 1(a) shows a photograph of the entire strawberry leaf, and Figure 1(b) shows a close-up photograph of the area near the base of the entire strawberry leaf. • Variety: Ichigo-san (cultivated at the Saga Prefectural Agricultural Experiment Station) • Cultivation period: 6 months • Target parts: Leaf blade and petiole

[0089] As shown in Table 1, strawberry leaves (whole leaves) were classified according to their maturity into small (15cm or less), medium (over 15cm and under 30cm), large (over 30cm and under 40cm), and extra-large (over 40cm). Of these, small and medium strawberry leaves were designated as young strawberry leaves, while large and extra-large strawberry leaves were designated as mature strawberry leaves. Photographs of each classified strawberry leaf are shown in Figure 2. Note that "size" in Table 1 refers to the combined length of the leaf blade and petiole in a strawberry leaf.

[0090] [Table 1]

[0091] 2. Method and evaluation of dried strawberry leaves Each type of dried strawberry leaf was prepared using the following method, and the total polyphenol content and antioxidant activity were evaluated. Hereinafter, the dried strawberry leaves of small, medium, large, and extra-large sizes will be collectively referred to as "dried whole strawberry leaves," and when distinguishing between them, they may be referred to as "dried small strawberry leaves," "dried medium strawberry leaves," "dried large strawberry leaves," and "dried extra-large strawberry leaves," respectively. Furthermore, when the product is labeled as "dried young strawberry leaves," it refers to a mixture of dried small strawberry leaves and dried medium strawberry leaves.

[0092] (Method for producing dried whole strawberry leaves) After washing the entire strawberry leaves with tap water, they were dried in a dryer (45°C) for 18 hours. After drying, they were ground using a Force Mill FM-1 and a Ball Mill TI-100 to obtain dried whole strawberry leaf material (dried and ground material).

[0093] (Methods for producing each type of dried strawberry leaf product) Each strawberry leaf, classified according to Table 1 above, was individually washed with tap water and then dried in a dryer (45°C) for 18 hours. After drying, it was ground using a Force Mill FM-1 and a Ball Mill TI-100 to obtain dried strawberry leaf products (dried and ground products).

[0094] Furthermore, the fresh weight (g) before drying and the dry weight (g) after drying were measured for each classified strawberry leaf. The solid content percentage (%) was also calculated from the measured fresh and dry weights. The results are shown in Table 2.

[0095] [Table 2]

[0096] (Total polyphenol content and antioxidant activity) The total polyphenol content and antioxidant activity were measured using "dried young strawberry leaves" and "dried whole strawberry leaves" produced by the above method. Furthermore, the "dried young strawberry leaves" were manufactured using young strawberry leaves (small and medium-sized strawberry leaves) and the same method as described above (method for manufacturing dried whole strawberry leaves).

[0097] First, measurement samples were prepared using dried strawberry young leaves and dried whole strawberry leaves obtained by the above manufacturing method. To the dried young strawberry leaves or dried whole strawberry leaves obtained, 100 times the weight of AWA (acetone / water / acetic acid = 70:29.5:0.5) was added and stirred for 30 minutes. The supernatant was then obtained by centrifugation (3000 rpm, 10 minutes). The obtained supernatant was used as a sample for measuring the total polyphenol content and antioxidant activity.

[0098] (Measurement of total polyphenol content) The total polyphenol content was measured using a modified version of the Folin-Ciocalteu method. 10 μL of the sample solution (young strawberry leaves, whole strawberry leaves) was added to a 96-well microplate, 75 μL of a 10-fold diluted Folin-Ciocalteu reagent was added, and the mixture was stirred. The plate was then left to stand at room temperature for 5 minutes. Furthermore, 75 μL of 2 wt% sodium carbonate solution was added and stirred. After standing at room temperature for 15 minutes, the absorbance at 750 nm was measured using a microplate reader. A calibration curve was created using gallic acid as the standard substance, and the total polyphenol content was calculated either per dry weight of the extract or per gallic acid equivalent per extract. The results are shown in Table 3.

[0099] (Measurement of antioxidant activity) Antioxidant activity was measured using reactive oxygen species absorption capacity (ORAC) as an indicator. ORAC was measured in accordance with the H-ORAC analysis standard procedure of the National Agriculture and Food Research Organization (NARO) Food Research Institute. A blank (phosphate buffer) and the above-mentioned measurement samples (young strawberry leaves, whole strawberry leaves) diluted in phosphate buffer, or 35 μL of Trolox, were dispensed into a 96-well microplate, and 115 μL of 100.7 nmol / L fluorescein sodium salt solution was added to each well. After a 10-minute pre-incubation, 50 μL of 31.7 mmol / L AAPH was added and stirred, and the fluorescence intensity was measured using a fluorescence microplate reader (TECAN, Infinite200PRO). ORAC values ​​were calculated by determining the area under the fluorescence intensity decay curve and then determining the Trolox equivalent per dry weight of the sample or per extract from the calibration curve. The results are shown in Table 3.

[0100] [Table 3]

[0101] As shown in Table 3, the polyphenol content of dried strawberry leaves was 177.62 mg GA equiv. / g-DW, and the antioxidant activity was 1.64 mmol Trolox equiv. / g-DW. The polyphenol content of dried whole strawberry leaves was 71.74 mg GA equiv. / g-DW, and the antioxidant activity was 0.88 mmol Trolox equiv. / g-DW.

[0102] 3. Method and evaluation of strawberry young leaf extract and strawberry whole leaf extract Strawberry young leaf extract and strawberry whole leaf extract were produced using the following method, and the total polyphenol content and each functionality were evaluated.

[0103] (Method for producing strawberry leaf extract) The above-mentioned dried strawberry leaves were mixed with 20 times their weight in 50% (v / v) aqueous ethanol, and the mixture was stirred at room temperature for 4 hours to extract the components contained in the strawberry leaves. The obtained extract was centrifuged (10,000 g, 30 minutes) to collect the supernatant, which was then dried to obtain strawberry leaf extract (dried powder).

[0104] (Method for producing whole strawberry leaf extract) The components contained in the whole strawberry leaves were extracted by adding 20 times the weight of 50% (v / v) aqueous ethanol to the whole strawberry leaves dried as described above (method for producing whole strawberry leaves dried), and stirring at room temperature for 4 hours. The obtained extract was centrifuged (10,000 g, 30 minutes) to collect the supernatant, which was then dried to obtain whole strawberry leaf extract (dried powder).

[0105] (Total polyphenol content) First, the total polyphenol content and antioxidant activity were measured using the strawberry young leaf extract and strawberry whole leaf extract produced by the method described above. The total polyphenol content and antioxidant activity were measured using the same method as described in "2. Method and Evaluation of Dried Products" (Measurement of Total Polyphenol Content). The results are shown in Table 4.

[0106] [Table 4]

[0107] As shown in Table 4, the polyphenol content of the strawberry leaf extract was 319.8 mg GA equiv. / g-extract. The polyphenol content in the whole strawberry leaf extract was 145.9 mg GA equiv. / g-extract.

[0108] (Evaluation of functionality) Next, the functionality of the strawberry young leaf extract and strawberry whole leaf extract produced by the above method was evaluated using the following method. The functional evaluation included "antioxidant activity," "tyrosinase inhibitory activity," "human fibroblast elastase inhibitory activity," and "inhibition rate of IL-1α and IL-8 production."

[0109] (Antioxidant activity) The antioxidant activity was measured using the same method as described in "2. Method and Evaluation of Dried Products" above (Measurement of Antioxidant Activity). The results are shown in Table 5.

[0110] (Tyrosinase inhibitory activity) 1) 8.25 μL of tyrosinase (500 U / mL) was added to 150 μL of 0.1 M phosphate buffer (pH 6.5). 2) 83.2 μL of 2.5 mM-DOPA aqueous solution was mixed with 8.25 μL of strawberry young leaf extract or strawberry whole leaf extract to achieve the desired concentration. 3) The solution obtained in 2) above was added to the solution obtained in 1) above, and the absorbance (475 nm) was measured after 15 minutes of reaction at 25°C. 4) Furthermore, samples with 8.25 μL of the sample solvent added instead of the sample extract, and samples with 8.25 μL of 0.1 M phosphate buffer added instead of tyrosinase, were treated under the same conditions, and the tyrosinase inhibitory activity was calculated by measuring the absorbance. The results are shown in Table 6.

[0111] (Human fibroblast elastase inhibitory activity) 1) 25 μL of strawberry young leaf extract or strawberry whole leaf extract was added to a 96-well plate (each extract was adjusted to the specified concentration). 2) 50 μL of 5 mM Suc-Ala-Ala-Ala-pNA prepared in 0.1 M Tris-HCl buffer (pH 8.0) containing 1 mM MPMSF was added. 3) Human neonatal-derived fibroblasts were lysed, 25 μL of the prepared crude enzyme solution was added, and the mixture was reacted at 37°C for 2 hours in a light-shielded environment. 4) The absorbance at 405 nm was measured, and the elastase inhibitory activity was calculated. The results are shown in Table 6.

[0112] (Suppression rate of IL-1α and IL-8 production) 25 × 10⁶ human neonatal-derived epidermal keratinocytes in a 24-well culture plate. 4 Cells were seeded in wells and cultured in a 5% CO2 incubator at 37°C. After 24 hours of incubation, the culture medium was removed, washed twice with phosphate saline (-) (PBS(-)), and 500 μL of PBS(-) was added. This was irradiated with ultraviolet UVB to remove PBS(-), and a culture medium containing strawberry young leaf extract or strawberry whole leaf extract adjusted to the specified concentration was added and cultured in a 5% CO2 incubator at 37°C. After 48 hours of incubation, the amounts of IL-1α and IL-8 in the culture supernatant were measured by enzyme immunoassay, and their respective production levels were calculated. The results are shown in Table 6.

[0113] [Table 5]

[0114] [Table 6]

[0115] As shown in Table 5, the antioxidant activity of the strawberry young leaf extract was 3.47 mmol Trolox equiv. / g-extract, and the antioxidant activity of the strawberry whole leaf extract was 2.43 mmol Trolox equiv. / g-extract.

[0116] As shown in Table 6, the tyrosinase inhibitory activity of whole strawberry leaf extract at a concentration of 0.1% was 49%, while the tyrosinase inhibitory activity of young strawberry leaf extract at a concentration of 0.1% was 60%, indicating that young strawberry leaf extract exhibited stronger tyrosinase inhibitory activity than whole strawberry leaf extract.

[0117] As shown in Table 6, the elastase inhibitory activity of whole strawberry leaf extract at a concentration of 0.1% was 51%, while the elastase inhibitory activity of young strawberry leaf extract at a concentration of 0.1% was 84%, indicating that young strawberry leaf extract exhibited stronger elastase inhibitory activity than whole strawberry leaf extract.

[0118] As shown in Table 6, the IL-1α production inhibition rate of whole strawberry leaf extract at a concentration of 0.005% was 70%, while the IL-1α production inhibition rate of young strawberry leaf extract at a concentration of 0.005% was 75%, confirming that young strawberry leaf extract is more effective than whole strawberry leaf extract in inhibiting IL-1α production. Furthermore, while the IL-8 production inhibition rate of whole strawberry leaf extract at a concentration of 0.005% was 47%, the IL-8 production inhibition rate of young strawberry leaf extract at a concentration of 0.005% was 75%, confirming that young strawberry leaf extract has a superior effect on inhibiting IL-8 production compared to whole strawberry leaf extract.

[0119] 4. Evaluation of the components contained in each strawberry leaf extract. The components contained in each strawberry leaf extract were evaluated using strawberry leaf extracts (small, medium, large, and extra-large) produced by the following method.

[0120] (Method of producing each strawberry leaf extract) To each of the dried strawberry leaves obtained using the method described above (method for producing dried strawberry leaves), 20 times the weight of 50% (v / v) aqueous ethanol was added and the mixture was stirred at room temperature for 4 hours to obtain strawberry leaf (small, medium, large, extra-large) extracts containing the components of each strawberry leaf. The supernatant was then collected by centrifugation (10,000g, 30 minutes), and the dried powder was used for the following evaluations.

[0121] 4-1. High-performance liquid chromatography-mass spectrometry Strawberry leaf extracts (small, medium, large, and extra-large) prepared by the method described above were subjected to high-performance liquid chromatography-mass spectrometry (LC-MS). The LC-MS conditions are shown in Table 7. Each strawberry leaf extract was analyzed using MS / MS mode (negative ion mode) to detect precursor ion fragments. Only the spectrum at m / z 300.9986 attributed to ellagic acid was extracted from the MS / MS spectrum. By creating a chromatogram, the content of ellagtannins, which contain ellagic acid within their molecules, was visualized, and the amount of ellagtannins was measured from the total peak area of ​​the extracted chromatogram. The measurement results are shown in Figure 3.

[0122] [Table 7]

[0123] As shown in Figure 3, the ellagutannin content in young strawberry leaves (small and medium) was higher in the order of small > medium. On the other hand, the ellagutannin content in mature strawberry leaves (large and extra-large) was lower compared to that of young strawberry leaves. The content of ellagtannins varied depending on the maturity of the strawberry leaves, with the highest levels occurring in the order of small > medium > large > extra-large.

[0124] 4-2. Quantitative determination of causallictin and strictinin Using the dried samples (dried strawberry leaves (small, medium, large, extra-large), dried whole strawberry leaves) and extract samples (extracts from small, medium, large, extra-large strawberry leaves, and extracts from whole strawberry leaves) obtained by the above manufacturing method, the causarictin and strictinin contained in each were quantified. Dried or extracted samples were subjected to LC-MS under the conditions shown in Table 7. Casuarictin and strictinin were quantified by LC-MS. The results are shown in Table 8.

[0125] [Table 8]

[0126] As shown in Table 8, the causarictin content in each dried product was 13.7 mg / g and 9.9 mg / g for young strawberry leaves (small) and medium-sized strawberry leaves, respectively. In comparison, the content was 5.2 mg / g and 2.0 mg / g for mature strawberry leaves (large) and 3.4 mg / g for whole strawberry leaves. Furthermore, the strictinin content in each dried product was 5.6 mg / g and 2.7 mg / g for young strawberry leaves (small) and medium-sized strawberry leaves, respectively. In comparison, the content was 1.3 mg / g and 0.8 mg / g for mature strawberry leaves (large) and 1.0 mg / g for whole strawberry leaves, respectively.

[0127] As shown in Table 8, the causarictin content in each extract was 34.4 mg / g and 27.6 mg / g for young strawberry leaves (small) and medium-sized strawberry leaves, respectively. In comparison, the content was 15.9 mg / g and 6.9 mg / g for mature strawberry leaves (large) and extra-large strawberry leaves, respectively, and 10.5 mg / g for whole strawberry leaves. Furthermore, the strictinin content in each extract was 16.4 mg / g and 8.2 mg / g for young strawberry leaves (small) and medium-sized strawberry leaves, respectively. In comparison, the content was 4.1 mg / g and 2.6 mg / g for mature strawberry leaves (large) and 3.1 mg / g for whole strawberry leaves, respectively.

[0128] 4-3. LC-MS Hierarchical Cluster Analysis Extract samples (strawberry leaf extracts (small, medium, large, and extra-large)) were subjected to LC-MS under the conditions shown in Table 7 above. The total ion chromatograms obtained by LC-MS were subjected to peak recognition and statistical analysis software (Compound Discoverer, Thermo Fisher Scientific), and hierarchical cluster analysis was performed based on the m / z attribute and retention time attribute of the identified peaks. The results are shown in Figure 4.

[0129] As shown in Figure 4, the groups of young strawberry leaves (small and medium) and mature strawberry leaves (large and extra-large) were clearly separated into distinct lineages, and it was confirmed that there were clear differences in the components contained in each group. [Industrial applicability]

[0130] The strawberry leaf processed product of the present invention has antioxidant, tyrosinase inhibitory, elastase inhibitory, IL-1α production inhibitory, and IL-8 production inhibitory effects, and compositions containing the strawberry leaf processed product of the present invention can be suitably applied as a topical skin composition or an oral composition.

Claims

1. It is an extract of young strawberry leaves, The aforementioned young strawberry leaves contain at least 6.0 mg / g of casuarictin and at least 1.5 mg / g of strictinin, based on dry matter. The aforementioned strawberry leaf extract is a solvent extract obtained by using one or more extraction solvents selected from the group consisting of water, lower alcohols, polyhydric alcohols, and aromatic alcohols. Strawberry leaf extract containing 16.0 mg / g or more of casuarictin and / or 5.0 mg / g or more of strictinin.

2. The strawberry leaf extract according to claim 1, wherein the strawberry leaf extract is a solvent extract using a mixed solvent of water and ethanol.

3. A composition containing the strawberry leaf extract described in claim 1 or 2.

4. The composition according to claim 3 for at least one use selected from antioxidant, tyrosinase inhibitor, elastase inhibitor, IL-1α production suppression, and IL-8 production suppression.

5. The composition according to claim 3, for external use on the skin.

6. The composition according to claim 3, which is for oral use.

7. A method for producing strawberry leaf extract, characterized by contacting dried strawberry leaves with an extraction solvent to extract components contained in the strawberry leaves, A method for producing the aforementioned strawberry leaf, wherein the strawberry leaf contains 6.0 mg / g or more of casuarictin and 1.5 mg / g or more of strictinin on a dry basis, and the extraction solvent is one or more extraction solvents selected from the group consisting of water, lower alcohols, polyhydric alcohols, and aromatic alcohols.

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