Composition for improving muscle flexibility

Abstract

The purpose of this invention is to provide a composition for improving muscle flexibility. This invention relates to a composition for improving muscle flexibility, which contains quercetin and / or its glycosides.

Description

[Technical Field]

[0001] This invention relates to a composition for improving muscle flexibility. Additionally, this invention relates to the use of quercetin and / or its glycosides, etc., for improving muscle flexibility. [Previous Technology]

[0002] In Japan, a super-aged society, medical advancements are leading to an increasing proportion of the elderly population. However, on the other hand, extending healthy life expectancy and improving quality of life (QOL) are becoming challenges. One reason for the shortening of healthy life expectancy is the need for care due to motor organ dysfunction, a condition considered high-risk, namely motor disorder syndrome. With increasing age, motor function declines due to motor organ diseases, such as pain, decreased muscle strength, reduced endurance, and slower movement. These problems interact and create a vicious cycle. As a result, daily activities become impossible, leading to a perceived need for care, making prevention increasingly important.

[0003] It is known that motor function is not simply proportional to muscle mass; muscle flexibility and other factors are also related to motor function. Therefore, not only increasing muscle mass but also improving muscle flexibility is considered important for inhibiting or improving a decline in motor function.

[0004] Quercetin is a type of flavonoid, found directly or in the form of glycosides in many plants such as onions. Literature reports that the physiological activities of quercetin or its glycosides include PPARγ activation (e.g., Patent Document 1). [Prior Art Documents] [Patent Documents]

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-8117 [Summary of the Invention]

[0006] [The problem that the invention aims to solve]

[0007] For example, if muscle flexibility decreases, the muscle becomes less flexible. Components that improve muscle flexibility are effective, for example, in inhibiting or improving decreased motor function.

[0008] The object of this invention is to provide a composition for improving muscle flexibility. [Means for solving the problem]

[0009] The inventors have discovered that quercetin and / or its glycosides of one of the flavonols are effective in improving muscle flexibility.

[0010] That is, the present invention includes, but is not limited to, the following muscle flexibility improvement components. [1] A muscle flexibility improvement component containing quercetin and / or its glycosides. [2] The component of [1] above is used for one or more of reducing muscle stiffness, inhibiting the increase of muscle stiffness, improving muscle flexibility, and improving muscle elasticity. [3] The component of [1] or [2] above is used in combination with exercise. [4] The component of any one of [1] to [3] above, wherein the muscle is a thigh muscle. [5] The component of any one of [1] to [4] above is a food, beverage, cosmetic, or quasi-pharmaceutical. [6] The use of quercetin and / or its glycosides to improve muscle flexibility. [Effects of the Invention]

[0011] According to the present invention, a composition for improving muscle flexibility can be provided.

Implementation Method

[0013] The muscle flexibility improving composition of the present invention contains quercetin and / or its glycosides. Hereinafter, the muscle flexibility improving composition of the present invention will also be referred to simply as the composition of the present invention. The composition of the present invention typically contains quercetin and / or its glycosides as active ingredients.

[0014] In this specification, "quercetin" refers to quercetin, a flavonol compound belonging to the polyphenol family. In this invention, "quercetin glycoside" refers to the glycoside of the aforementioned quercetin, specifically, a general term for a series of compounds in which one or more sugars are bonded to the 3-position of quercetin via a hydroxyglycosidic bond. Quercetin glycosides are compounds represented by the following general formula. In the following general formula, (X)n represents a sugar chain. X represents a sugar (monosaccharide), and n is an integer of 1 or more. Quercetin glycosides may be one compound or two or more compounds.

[0015]

[0016] The sugar constituting the sugar chain, represented by X, is glycosidically bonded to quercetin, and is such as glucose, rhamnose, galactose, glucuronic acid, etc., preferably glucose or rhamnose. Furthermore, n is not particularly limited as long as it is 1 or more, and is preferably 1 to 16, more preferably 1 to 8. When n is 2 or more, the X portion can be formed from one sugar or from multiple sugars. In other words, when n is 2 or more, (X)n can be a sugar chain formed from one sugar or a sugar chain formed from multiple sugars. The quercetin glycosides of this invention also include compounds obtained by treating existing quercetin glycosides with enzymes or the like to transfer their sugars. Specifically, the quercetin glycosides mentioned in this invention include rutin, enzyme-treated rutin (enzyme-treated rutin), quercetin, isoquercetin, etc. In this invention, using enzyme-treated rutin as the quercetin glycoside is particularly preferred. Suitable examples of enzymatic treatment of rutin include isoquercitrin obtained by treating isoquercitrin with rutinase to remove the rhamnose sugar chain, compounds obtained by treating isoquercitrin with a glycotransferase to obtain isoquercitrin compounds with sugar chains formed by 1 to 7 glucose molecules bonded to the isoquercitrin, and mixtures thereof as the main components. Among these, compounds in which the quercetin glycoside is bonded to 1 to 8 glucose molecules at the 3-position of quercetin (e.g., isoquercitrin, glycosides of isoquercitrin bonded to 1 to 7 glucose molecules) are preferred. The ingested quercetin glycoside is cleaved in the intestine, becoming a glycoside (quercetin), and then absorbed into the body.

[0017] In this invention, there are no particular limitations on the source or method of preparation used to obtain quercetin and / or its glycosides. For example, plants rich in quercetin and / or its glycosides are known to include buckwheat, locust tree, capernaum, apple, tea, onion, grape, broccoli, jute, raspberry, blueberry, cranberry, cactus, leafy vegetables, and citrus fruits, from which quercetin and / or its glycosides can be obtained. The quercetin and / or its glycosides used in this invention can be any substance that increases the quercetin and / or its glycoside content by concentrating or purifying extracts from the aforementioned plants and other natural sources, as long as the effects of this invention are achieved. For example, a concentrate or purified extract containing quercetin and / or its glycosides can be used. Known methods can be employed for concentration or purification. In this invention, purified or isolated quercetin and / or its glycosides can also be used. Quercetin and / or its glycosides may also be chemically synthesized.

[0018] Quercetin and / or its glycosides are compounds with a history of consumption, found in natural products and food products. Therefore, from a safety point of view, quercetin and / or its glycosides are considered to be of little concern even with daily intake. According to the present invention, a composition for improving muscle flexibility containing substances with high safety as active ingredients can be provided.

[0019] In this invention, muscle flexibility refers to the ease with which muscles can contract and relax. Literature reports that muscle flexibility decreases with age (e.g., Muscle Nerve. 2017 Mar55(3)305-315.). Improving muscle flexibility can also be referred to as improving muscle firmness (muscle hardness). In this invention, improving muscle flexibility includes inhibiting the decrease in muscle flexibility, maintaining muscle flexibility, and enhancing muscle flexibility (increasing flexibility). Improving muscle firmness (muscle hardness) includes inhibiting the increase in muscle firmness, maintaining muscle firmness, and reducing muscle firmness. Muscle flexibility can be measured using shear wave elastography, which uses the shear wave velocity of the muscle as an indicator for evaluation. Shear wave elastography is a type of ultrasound elastography that uses acoustic pulses to generate vibrations within a living organism. The propagation velocity distribution of the generated shear waves is then measured to assess tissue stiffness (Makoto Yamakawa, Journal of the Society for Biological Mechanisms, Vol. 40, No. 2 (2016), 73-78, especially page 74, right column, lines 10-12). Lower shear wave velocities generally indicate higher muscle flexibility (more supple muscles), while higher velocities generally indicate lower muscle flexibility (harder muscles). For example, comparing the ingestion of a test substance with the absence of the test substance, if the muscle shear wave velocity decreases or its increase is inhibited, it can be assessed that the test substance enhances muscle flexibility or inhibits its decrease. Therefore, substances that can reduce muscle shear wave velocity or inhibit its increase can be said to improve muscle flexibility. In this invention, the flexibility of muscles can be confirmed by the shear wave velocity of the muscles, preferably by the shear wave velocity of muscles under stress.

[0020] For example, the shear wave velocity of the thigh muscles in a fully flexed knee position (kneeling (bent-knee sitting)) increases with age. As shown in the following examples, when comparing the intake of quercetin glycosides with the absence of intake, the increase in the shear wave velocity of the thigh muscles in a fully flexed knee position is inhibited. Therefore, quercetin and / or its glycosides have the effect of improving muscle flexibility. Quercetin and / or its glycosides can be used to improve muscle flexibility. In one embodiment, quercetin and / or its glycosides can be used to inhibit the increase or decrease the shear wave velocity of muscles.

[0021] By improving muscle flexibility, the suppleness and elasticity of muscles can be improved. In one embodiment, the components of the present invention can be used to reduce muscle stiffness, inhibit the increase of muscle stiffness, improve muscle flexibility, and improve muscle elasticity in one or more ways. By improving muscle flexibility, effects such as increased muscle strength, increased walking ability, improved balance, and improved agility can be obtained (e.g., Ultrasound Med Biol. 2020 Nov 46(11):2891-2907.). In addition, by improving muscle flexibility, the flexibility of cutaneous muscles (e.g., facial muscles) can be improved. As a result, improved skin elasticity can be expected.

[0022] In one embodiment, the composition of the present invention is preferably used in combination with exercise. The composition of the present invention is suitable for use in combination with exercise to improve muscle flexibility. When using the composition of the present invention in combination with exercise, it is sufficient to take or administer the composition of the present invention in conjunction with exercise for a certain period of time; the amount of exercise, the timing of taking or administering the composition of the present invention, etc., are not particularly limited. If quercetin and / or its glycosides are taken or administered in combination with exercise, the effect of improving muscle flexibility is more likely to be obtained. The composition of the present invention, by being used in combination with exercise, is more likely to exert the effect of improving muscle flexibility. The type of exercise is not particularly limited, and examples include, for instance, daily exercise, aerobic exercise, strength training (e.g., resistance training), flexibility exercises (stretching), etc. Exercise can be performed in one or more combinations. In one embodiment, the above-mentioned exercise is preferably a combination of strength training and flexibility exercises, or strength training, more preferably a combination of resistance training and flexibility exercises, or resistance training, more preferably a combination of resistance training and flexibility exercises. In this case, flexibility exercises can be performed either before or after resistance exercises, or both. Resistance exercises refer to exercises that apply a certain load to the muscles. The method of applying the load is not particularly limited and can utilize, for example, barbells, exercise machines, appropriate weights, water, chest expanders, rubber tubing, etc. Examples of resistance exercises include leg extensions, thigh presses, leg curls, chest presses, squats, barbell bench presses, dumbbell lateral raises, rows, calf raises, sit-ups, etc. Resistance exercises can be performed one type or in combination of two or more. Examples of aerobic exercises include jogging, walking, gymnastics, aerobic dance, etc. Quercetin and / or its glycosides can be used to promote or enhance the improvement in muscle flexibility resulting from exercise. In one embodiment, the components of this invention can be used to promote or enhance the improvement in muscle flexibility resulting from exercise.

[0023] The frequency and duration of the above-mentioned exercises can be set as follows: for example, more than 1 day a week, once a day for more than 5 minutes (preferably more than 30 minutes); more than 2 days a week, once a day for more than 5 minutes (preferably more than 30 minutes); preferably more than 3 days a week, once a day for more than 5 minutes (preferably more than 30 minutes). Alternatively, the frequency and / or duration of the above-mentioned exercises can be determined according to the individual, the type of exercise, and / or the combination of exercises. For example, in the case of aerobic exercise, it can be 2 to 5 days a week, once a day for about 10 to 60 minutes. In the case of resistance exercise, it can be 1 to 3 days a week, once a day for about 10 to 60 minutes; in the case of flexibility exercise, it can be 1 to 7 days a week (e.g., 1 to 3 days), once a day for about 5 to 30 minutes.

[0024] The intensity of the exercise that can be combined with the components of the present invention is preferably 2.0 METs (e.g., walking / very slow / number 17151) or more, preferably 2.3 METs (e.g., stretching / comfortable / number 02101) or more, and even more preferably 3.5 METs (e.g., resistance weight training / number 02054) or more. Furthermore, the intensity of the resistance exercise is preferably 80% or less (preferably 30% or more) of the maximum lifting weight (1RM), and preferably 60% or less (preferably 30% or more). The exercise load is preferably determined according to the individual. (The intensity of exercise is based on the revised version of the Metabolic Equivalent Scale for Physical Activity (National Institute of Health and Nutrition, Germany, 2012) and MedSci Sports Exerc. 2009 Mar; 41(3):687-708. The above "number" is the number recorded in the revised version of the Metabolic Equivalent Scale for Physical Activity (National Institute of Health and Nutrition, Germany, 2012)).

[0025] In this invention, the muscle for which muscle flexibility is improved can include skeletal muscle and cutaneous muscle, but is preferably skeletal muscle. In this invention, the location of the muscle for which muscle flexibility is improved is not particularly limited, but the muscles of the thigh are preferred. In one embodiment, the composition of this invention is suitable for improving the flexibility of the thigh muscles.

[0026] The composition of the present invention can be used for either therapeutic or non-therapeutic purposes. Non-therapeutic means excluding medical procedures, i.e., surgery, treatment, or diagnosis of a person. The composition of the present invention can be formulated as a food product, cosmetic, pharmaceutical, quasi-pharmaceutical, feed, etc. The composition of the present invention itself can be a food product, cosmetic, pharmaceutical, quasi-pharmaceutical, feed, etc., used to improve muscle flexibility, or it can be a material or preparation incorporated therein. One example of the muscle flexibility improving composition of the present invention is that it can be provided in the form of an agent, but this is not limited to this form. The agent can be directly formulated into a composition, or it can be provided as a composition containing the agent. In one embodiment, the muscle flexibility improving composition of the present invention can also be called a muscle flexibility improving agent. The composition of the present invention can be either an oral composition or a non-oral composition. By orally ingesting or administering the composition of the present invention to a subject, or by non-oral administration, the muscle flexibility of the subject can be improved. Oral formulations may include food products, oral pharmaceuticals, oral quasi-pharmaceuticals, and animal feed; preferably, they should be food products or oral quasi-pharmaceuticals. Non-oral formulations may include cosmetics, non-oral pharmaceuticals, and non-oral quasi-pharmaceuticals; preferably, they should be cosmetics or non-oral quasi-pharmaceuticals.

[0027] The composition of the present invention may contain any additives and any ingredients other than quercetin and / or its glycosides, provided that the effects of the present invention are not impaired. These additives and ingredients may be selected according to the form of the composition, and substances generally applicable to food and beverage products, cosmetics, pharmaceuticals, quasi-pharmaceuticals, and animal feed may be used. When the composition of the present invention is manufactured into food and beverage products, cosmetics, pharmaceuticals, quasi-pharmaceuticals, animal feed, etc., the manufacturing method is not particularly limited and can be manufactured using conventional methods.

[0028] For example, when the components of the present invention are formulated into food and beverage products, various food and beverage products can be formulated by combining quercetin and / or its glycosides with ingredients that can be used in food and beverage products (e.g., food materials, food additives used as necessary). Food and beverage products are not particularly limited, and examples include general food and beverage products, health foods, health drinks, functionally labeled foods, foods for specific health purposes, health supplements, and food and beverage products for patients. The aforementioned health foods, functionally labeled foods, foods for specific health purposes, and health supplements can be used in various formulations, such as granules, tablets, pellets, powders, capsules, chewable tablets, dry syrups, syrups, liquids, beverages, and liquid foods.

[0029] When the components of the present invention are made into cosmetics, quercetin and / or its glycosides may be blended with carriers, additives, etc., permissible in cosmetics. The product form of the cosmetic is not particularly limited.

[0030] When the components of the present invention are formulated into pharmaceuticals or quasi-pharmaceuticals, for example, by incorporating pharmacologically permissible supports, additives, etc., into quercetin and / or its glycosides, pharmaceuticals or quasi-pharmaceuticals in various dosage forms can be formulated. Such supports, additives, etc., can be any one or more of the following, as long as they are usable in pharmaceuticals or quasi-pharmaceuticals and are pharmacologically permissible: excipients, binders, disintegrants, lubricants, antioxidants, colorants, etc. The administration (ingestion) forms of pharmaceuticals or quasi-pharmaceuticals can include oral or non-oral (dermal, mucosal, enteric, injectable, etc.) administration. When formulating the components of the present invention into pharmaceuticals or quasi-pharmaceuticals, it is preferable to formulate them into oral (oral administration) pharmaceuticals or quasi-pharmaceuticals. Dosage forms used for oral administration can include liquids, tablets, powders, granules, pellets, sugar-coated tablets, capsules, suspensions, emulsions, chewable tablets, etc. Dosage forms used for non-oral administration include injections, intravenous drips, and topical skin preparations (patch, emulsion, ointment, etc.). Pharmaceuticals can be for non-human or non-animal use.

[0031] When the components of the present invention are made into feed, it is sufficient to simply incorporate quercetin and / or its glycosides into the feed. The feed also includes feed additives. Examples of feeds include livestock feeds used for cattle, pigs, chickens, sheep, horses, etc.; small animal feeds used for rabbits, rats, mice, etc.; and pet food used for dogs, cats, birds, etc.

[0032] The content of quercetin and / or its glycosides in the composition of the present invention is not particularly limited and can be set according to their form, etc. The content of quercetin and / or its glycosides in the composition of the present invention, for example, in terms of quercetin conversion value, is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and preferably 80% by weight or less, more preferably 50% by weight or less. In one particular state, the content of quercetin and / or its glycosides, in terms of quercetin conversion value, is preferably 0.01 to 80% by weight, more preferably 0.1 to 50% by weight in the composition of the present invention. The content of quercetin and / or its glycosides can be determined by known methods, such as HPLC (high performance liquid chromatography).

[0033] The composition of the present invention is generally ingested or administered to a subject. The administration route of the composition of the present invention is not particularly limited, and it can be ingested or administered by a suitable method depending on its form. In one embodiment, oral ingestion (oral administration) of the composition of the present invention is preferred. The amount administered (also referred to as the intake amount) of the composition of the present invention is not particularly limited, as long as it is an amount that achieves the effect of improving muscle flexibility (also referred to as the effective amount), and can be appropriately set according to the administration form, administration method, etc.

[0034] In one formulation, when a person (adult) ingests or is given the composition of the present invention, the dosage of quercetin and / or its glycosides, converted to quercetin values, is preferably 0.3 mg or more per 60 kg of body weight per day, more preferably 1.0 mg or more, even more preferably 10 mg or more, and preferably less than 4000 mg, more preferably less than 2000 mg, even more preferably less than 1000 mg. In one formulation, the dosage of quercetin and / or its glycosides, converted to quercetin values, for a person (adult), is preferably 0.3 to 4000 mg per 60 kg of body weight per day, more preferably 1.0 to 2000 mg, even more preferably 1.0 to 1000 mg, and particularly preferably 10 to 1000 mg. It is preferable to divide the above-mentioned amount into one or more times per day, for example, once or several times a day (e.g., 2 to 3 times). In one embodiment, it is preferable to administer the above-mentioned amount of quercetin and / or its glycosides orally to a human. In one embodiment of the present invention, the composition of the present invention can be used to administer the above-mentioned amount of quercetin and / or its glycosides to a human per 60 kg body weight per day.

[0035] The composition of the present invention is preferably ingested or administered continuously. By continuously ingesting or administering quercetin and / or its glycosides, a significant improvement in muscle flexibility can be expected. In one embodiment, it is preferable to continuously ingest or administer the composition of the present invention for more than one week, more preferably for more than four weeks, and even more preferably for more than eight weeks.

[0036] The components of the present invention can be used to prevent or improve conditions or diseases that can be prevented or improved by improving muscle flexibility. Such conditions or diseases may include conditions or diseases caused by decreased muscle flexibility, etc. Such conditions or diseases may include, for example, sarcopenia, myogenic diseases including muscular dystrophy, neurological disorders including cerebral palsy, Parkinson's disease, stroke, etc. (Ultrasound Med Biol. 2020 Nov; 46(11): 2891-2907.). In one embodiment, the components of the present invention can be used to prevent or improve muscle abnormalities (e.g., muscle stiffness) caused by conditions or diseases such as sarcopenia, myogenic diseases including muscular dystrophy, neurological disorders including cerebral palsy, Parkinson's disease, stroke, etc. In this specification, prevention of conditions or diseases includes preventing the onset of conditions or diseases, delaying the onset of onset, reducing the incidence rate, reducing the risk of onset, etc. Improvement of a condition or disease includes allowing the subject to recover from the condition or disease, alleviating the symptoms of the condition or disease, improving the symptoms of the condition or disease, delaying the progression of the condition or disease, etc.

[0037] The recipient (also referred to as the object of administration) of the composition of the present invention is not particularly limited. It is preferably a human or non-human mammal, but more preferably a human. In one embodiment, the object of administration may include individuals who need or wish to improve muscle flexibility, individuals who need or wish to prevent or improve conditions or diseases caused by decreased muscle flexibility, etc. Decreased muscle flexibility may be due to aging, or may be due to aging in middle-aged or elderly individuals. In one embodiment, the object of administration in the present invention may include middle-aged and elderly individuals. Middle-aged and elderly individuals include the elderly. Among middle-aged and elderly individuals, the elderly are preferred. In the present invention, middle-aged and elderly individuals may be, for example, people aged 40 or older. The elderly may be, for example, people aged 60 or older or 65 or older. In one embodiment, the composition of the present invention is suitable for use as a composition for improving muscle flexibility in middle-aged and elderly individuals. The object of administration of the composition of the present invention may be a healthy person, such as a healthy middle-aged or elderly person. The composition of the present invention may also be used on healthy individuals, for example, for the purpose of preventing or improving conditions or diseases that can be prevented or improved by improving muscle flexibility.

[0038] The components of the present invention may also be labeled with a function performed by improving muscle flexibility. The muscle flexibility improvement components of the present invention may also be labeled with one or more functions such as "making muscles soft," "making muscles elastic," "improving muscle elasticity," and "making the body flexible." Furthermore, in another embodiment, the components of the present invention may also be labeled with one or more functions such as "muscle elasticity," "muscle firmness," "elasticity," "softness," and "bouncyness." The labeling of these functions may also state that the function is obtained by improving muscle flexibility. In one embodiment, the components of the present invention are preferably food or beverages with the above-mentioned labels. Additionally, the above labels may be labels indicating the purpose of obtaining the above-mentioned functions. These labels may be affixed to the component itself or to the container or packaging of the component.

[0039] The present invention also includes the following methods and uses. A method for improving muscle flexibility, comprising administering quercetin and / or its glycosides. A use of quercetin and / or its glycosides for improving muscle flexibility. The above methods and uses may be therapeutic or non-therapeutic. Administering (ingesting) quercetin and / or its glycosides can improve muscle flexibility. Quercetin and / or its glycosides, by improving muscle flexibility, can improve muscle suppleness and / or muscle elasticity. In one embodiment, quercetin and / or its glycosides may be used in one or more of the group consisting of reducing muscle stiffness, inhibiting the increase of muscle stiffness, improving muscle suppleness, and improving muscle elasticity. Quercetin and / or its glycosides, for example, by improving muscle flexibility, may be used to prevent or improve conditions or diseases that can be prevented or improved.

[0040] Quercetin and / or its glycosides are preferably used in combination with exercise to improve muscle flexibility. In this invention, it is preferred to ingest or administer quercetin and / or its glycosides in combination with exercise. The muscles are the same as described above, with thigh muscles being preferred. The appropriate form of exercise is the same as described above.

[0041] In the above method and use, it is preferable to administer quercetin and / or its glycosides to the subject (so that the subject can ingest them) once a day or more, for example, once a day to several times a day (for example, 2 to 3 times). Quercetin and / or its glycosides are as described above.

[0042] In the above method and use, only an effective amount of quercetin and / or its glycosides that can achieve the effect of improving muscle flexibility is used. The appropriate dosage, target, and method of administration of quercetin and / or its glycosides are the same as those of the muscle flexibility improvement composition of the present invention described above. The above use is preferably in humans or non-human mammals, but more preferably in humans. Quercetin and / or its glycosides can be administered directly or in the form of a composition containing them. For example, the composition of the present invention described above can be used. Oral administration (ingestion) of quercetin and / or its glycosides is preferred.

[0043] Quercetin and / or its glycosides can be used in the manufacture of food products, cosmetics, pharmaceuticals, quasi-pharmaceuticals, feed, etc., for improving muscle flexibility. In one embodiment, the present invention further includes the use of quercetin and / or its glycosides in the manufacture of a composition for improving muscle flexibility. The composition for improving muscle flexibility and suitable embodiments thereof are the same as those of the compositions of the present invention described above. Furthermore, all academic and patent documents described in this specification are incorporated herein by reference. [Examples]

[0044] The present invention will be further described in detail below by way of embodiments, but this will not limit the scope of the present invention.

[0045] (Examples 1, 2, and Comparative Example 1) <Preparation of Test Foods> Using quercetin glycosides (SAN EMIQ P30, San-Ying Yuan FFI Co., Ltd.) and excipients, hard capsules (size of one capsule: 19.54 mm long diameter × 6.94 mm short diameter) were manufactured, producing quercetin glycoside-containing foods containing 200 mg or 500 mg of quercetin glycosides per 6 capsules (200 mg quercetin glycoside-containing food and 500 mg quercetin glycoside-containing food, respectively). SAN EMIQ P30 is a mixture of two or more quercetin glycosides with 1 to 7 glucose molecules added to quercetin. Hard capsules containing only excipients were manufactured as control foods for clinical testing. To prevent deterioration due to oxidation, the quercetin glycoside-containing food and the control food were packaged separately in aluminum bags of 6 capsules each, and the necessary quantity for clinical testing was prepared.

[0046] <Clinical Trial> A placebo-controlled, single-blind, parallel cohort comparison trial was conducted on healthy middle-aged and elderly individuals (without exercise habits) aged 50–74 years who had provided consent to participate in the trial. Participants were assigned to three groups: a group that exercised and consumed a control food (Comparative Example 1: Control Food Group), a group that exercised and consumed a food containing 200 mg of quercetin glycosides (Example 1: 200 mg Quercetin Glycosides Group), and a group that exercised and consumed a food containing 500 mg of quercetin glycosides (Example 2: 500 mg Quercetin Glycosides Group). Each group underwent exercise and test food intake intervention for 24 weeks. Exercise consisted of four lower limb-centered resistance exercises (leg extension, thigh press, leg curl, and chest press, performed 14 times each at 40% of maximum lifting weight (1RM), constituting one set, with 3 sets per day), performed 3 days per week. All exercises included warm-up and cooling-off stretching exercises before and after the main workout. Additionally, 1RM (one-response tolerance) was measured every 4 weeks, with the load weight adjusted for each subject individually. The test food (control food or food containing quercetin glycosides) was taken 6 capsules daily with sufficient water or warm water. Muscle flexibility was assessed using shear wave elastography on an Aixplorer (manufactured by Konica Minolta) to measure and quantify shear wave velocity. Lower shear wave velocity indicated higher muscle flexibility (softness), while higher shear wave velocity indicated lower muscle flexibility (hardness). The lateral quadriceps of the right thigh was analyzed in a fully flexed knee position (kneeling position). The state of the lateral quadriceps of the right thigh in this fully flexed knee position represents the state of stress (muscle being stretched).

[0047] <Analysis Results> The subjects analyzed at the end of the intervention were: control food group: 16 subjects, 200mg quercetin glycoside group: 16 subjects, and 500mg quercetin glycoside group: 16 subjects. In the 500mg quercetin glycoside group, one data point was corrupted, therefore the subjects analyzed for shear wave velocity at week 12 were 15 subjects. The mean (standard deviation in parentheses) of the shear wave velocity (m / s) is shown in Table 1. In Table 1, * indicates a significant difference compared to the control food group (*p<0.05, Dunnett's test). The results shown in Table 1 are rounded to the third decimal place. There was no significant difference in shear wave velocity among the three groups before intervention. Regarding changes before and after intervention, when comparing with the control food group, the change in shear wave at week 24 after intervention was significantly lower in the 200 mg quercetin glycoside group and the 500 mg quercetin glycoside group. Figure 1 shows the change in shear wave velocity at week 24 after intervention compared with the pre-intervention levels of exercise and test food intake.

[0048]

[0049] The shear wave velocity of muscles in a fully flexed knee position increases with age, indicating a decrease in muscle flexibility. A decrease in shear wave velocity in a fully flexed knee position was observed only in the group consuming quercetin glycosides, thus confirming the usefulness of quercetin and / or its glycosides for muscle flexibility. [Simplified Explanation of the Diagram]

[0012] [Figure 1] is a graph showing the change in shear wave velocity of muscles at week 24 after intervention, compared with before intervention and test food intake.

Claims

1. A composition for improving muscle flexibility, comprising quercetin and / or its glycosides.

2. The component of claim 1 is used for one or more of the following: reducing muscle stiffness, inhibiting the increase of muscle stiffness, improving muscle flexibility, and improving muscle elasticity.

3. Components of claim 1 or 2, which are used in combination with motion.

4. A component of any one of claims 1 to 3, wherein the muscle is a muscle of the thigh.

5. If any component of any of the claims 1 to 4 is a food, beverage, cosmetic or quasi-medicine.

6. The use of a quercetin and / or its glycoside for improving muscle flexibility.

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