ERYTHROCYTE FUNCTION IMPROVING AGENT

Abstract

An object of the present invention is to provide an agent for improving red blood cell function which has both high antioxidant action and high ability to migrate into red blood cells, and can effectively protect red blood cells against oxidative stress. Cucurbitaxanthin A and/or a derivative thereof has an ability to migrate into red blood cells significantly higher than that of the other carotenoids reported to migrate into red blood cells, and can effectively protect red blood cells against oxidative stress, and thus, is effective as an agent for improving red blood cell function.

Claims

1. A method of improving red blood cell function comprising the step of administering, to an individual in need of improvement of red blood cell function, cucurbitaxanthin A and/or a derivative thereof in an amount effective for improving red blood cell function.

2. The method of improving red blood cell function according to claim 1, wherein cucurbitaxanthin A and/or a derivative thereof is derived from paprika.

3. The method of improving red blood cell function according to claim 1, wherein cucurbitaxanthin A and/or a derivative thereof is administered in a form of a food or beverage product.

4. The method of improving red blood cell function according to claim 1, wherein cucurbitaxanthin A and/or a derivative thereof is administered in a form of a pharmaceutical preparation.

5. The method of improving red blood cell function according to claim 1, wherein red blood cells are protected against oxidative stress by improvement of red blood cell function.

6. The method of improving red blood cell function according to claim 1, wherein oxygen-carrying capacity of red blood cells is improved by improvement of red blood cell function.

7. The method of improving red blood cell function according to claim 1, wherein oxidative damage to red blood cells is suppressed by improvement of red blood cell function.

8. The method of improving red blood cell function according to claim 1, wherein physical function is improved by improvement of red blood cell function.

9. The method of improving red blood cell function according to claim 1, wherein physical function is recovered during or after exercise by improvement of red blood cell function.

10. The method of improving red blood cell function according to claim 1, wherein cardiopulmonary function is improved by improvement of red blood cell function.

11. The method of improving red blood cell function according to claim 1, wherein brain function is maintained or improved by improvement of red blood cell function.

12. The method of improving red blood cell function according to claim 1, wherein dementia is prevented or treated by improvement of red blood cell function.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0068] FIG. 1 shows exemplary structures of carotenoids having 3,6-epoxy end groups or 5-membered ring end groups, as well as a carotenoid without these end groups.

[0069] FIG. 2 is a bar graph showing the total amount of each of the carotenoids ingested over 4 weeks in Example 1.

[0070] FIG. 3 is a bar graph showing the results of measurement of the migration ratio (%) into red blood cells of the amount of each of the carotenoids in Example 1.

DESCRIPTION OF EMBODIMENTS

[0071] The agent for improving red blood cell function of the present invention contains cucurbitaxanthin A and/or a derivative thereof as an active ingredient. The agent for improving red blood cell function of the present invention will be hereinafter described.

[0072] Active Ingredient

[0073] In the agent for improving red blood cell function of the present invention, cucurbitaxanthin A and/or a derivative thereof is used as an active ingredient.

[0074] Cucurbitaxanthin A, which has 3,6-epoxy end groups at the ends, is a carotenoid having antioxidant action, also referred to as (3S,3′R,5R,6R)-3,6-epoxy-5,6-dihydro-β,β-carotene-3′,5-diol.

[0075] Specific examples of derivatives of cucurbitaxanthin A include fatty acid esters of cucurbitaxanthin A. Specific examples of fatty acid esters of cucurbitaxanthin A include esters of saturated or saturated fatty acids containing 12 to 22 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid.

[0076] It is known that cucurbitaxanthin A and/or a derivative thereof is contained in natural products, for example, plants of the genus Capsicum such as paprika and plants of the genus Cucurbitaceae such as pumpkins. In the present invention, it is preferred to use cucurbitaxanthin A and/or a derivative thereof extracted from these natural products; however, cucurbitaxanthin A and/or a derivative thereof chemically or enzymatically synthesized or semi-synthesized may also be used.

[0077] In the agent for improving red blood cell function of the present invention, either one of cucurbitaxanthin A and a derivative thereof may be used alone, or a combination thereof may be used, as the active ingredient; however, a preferred example is cucurbitaxanthin A.

[0078] Cucurbitaxanthin A and/or a derivative thereof used in the present invention may not necessarily be a purified product, and may be a mixture containing carotenoids other than cucurbitaxanthin A and/or a derivative thereof. For example, paprika oleoresin derived from paprika contains a high concentration of cucurbitaxanthin A, and therefore, paprika oleoresin can be used as the active ingredient in the present invention.

[0079] The Dose of Cucurbitaxanthin A and/or a Derivative Thereof

[0080] The dose of the agent for improving red blood cell function of the present invention may be an amount effective for improving red blood cell function, and may be set as appropriate in accordance with the type or form, the use, the expected effects, the mode of administration, and the like of the product to be used. For example, the daily amount of ingestion or administration of cucurbitaxanthin A and/or a derivative thereof for an adult may be set to 0.001 to 20 mg, preferably 0.002 to 18 mg, and more preferably 0.005 to 15 mg.

[0081] Use

[0082] The agent for improving red blood cell function of the present invention is used for the purpose of improving the function of red blood cells, because the agent for improving red blood cell function can exhibit the protective action against oxidative stress of red blood cells, and improve the function of red blood cells, through efficient migration of cucurbitaxanthin A and/or a derivative thereof into red blood cells.

[0083] The protective action against oxidative stress of red blood cells is also effective for improving the oxygen-carrying capacity of red blood cells through improvement of arterial blood oxygen saturation, suppressing oxidative damage to red blood cells, and stabilizing red blood cells, for example. Thus, the agent for improving red blood cell function of the present invention can also be used as an agent for protecting red blood cells against oxidative stress, an agent for improving oxygen-carrying capacity of red blood cells, an agent for suppressing oxidative damage to red blood cells, and an agent for stabilizing red blood cells, for example.

[0084] Further, the improvement of the oxygen-carrying capacity of red blood cells is effective for improving physical function, and is particularly also effective for recovering physical function during or after exercise. Thus, the agent for improving red blood cell function of the present invention can also be used as an agent for improving physical function, an agent for improving cardiopulmonary function, and an agent for recovering physical function during or after exercise, for example. Further, the improvement of the oxygen-carrying capacity of red blood cells is also effective for maintaining or improving the function of brain, which is a tissue that requires a large amount of oxygen. Thus, the agent for improving red blood cell function of the present invention can also be used as an agent for maintaining or improving brain function.

[0085] The improvement of the oxygen-carrying capacity of red blood cells is also effective for preventing or treating a disease caused in part by a decrease in oxygen-carrying capacity of red blood cells. Thus, the agent for improving red blood cell function of the present invention can also be used as an agent for preventing or treating a disease caused in part by a decrease in oxygen-carrying capacity of red blood cells. Specific examples of diseases caused in part by a decrease in oxygen-carrying capacity of red blood cells include dementia such as Alzheimer-type dementia, arteriosclerosis, hypertension, diabetes, hyperlipidemia, cataract, and apoplexy.

[0086] Forms of Use of the Agent for Improving Red Blood Cell Function

[0087] There is no particular limitation to the mode of administration of the agent for improving red blood cell function of the present invention, as long as it is absorbed into a living organism, and examples of modes of administration include oral, enteral, transvenous, transarterial, subcutaneous, and intramuscular administration. Of these modes of administration, a preferred example is oral administration, from the standpoint of causing cucurbitaxanthin A and/or a derivative thereof to be easily and efficiently migrated into red blood cells.

[0088] The agent for improving red blood cell function of the present invention is incorporated into a product that needs to be provided with the action of improving the function of red blood cells. There is no particular limitation to the product into which the agent for improving red blood cell function of the present invention can be incorporated, and examples of products include food or beverage products and pharmaceutical preparations.

[0089] The dosage form of the product into which the agent for improving red blood cell function of the present invention is incorporated may be any of solid, semi-solid, liquid, and like dosage forms, and is set as appropriate in accordance with the type or use of the product. The product into which the agent for improving red blood cell function of the present invention is incorporated may contain food raw materials, food additives, nutritional components, pharmacologically acceptable bases, pharmacologically acceptable additives, pharmacological components, and the like, within a range where the effects of the present invention are not impaired. The product into which the agent for improving red blood cell function of the present invention is incorporated may also contain components that can improve the function of red blood cells, other than the agent for improving red blood cell function of the present invention. Examples of such components include lutein, zeaxanthin, β-cryptoxanthin, and astaxanthin.

[0090] When the agent for improving red blood cell function of the present invention is used in the field of food or beverage products, cucurbitaxanthin A and/or a derivative thereof as is or in combination with other food raw materials or additive components may be prepared into a desired form, and provided as a food or beverage product that achieves the effect of improving red blood cell function. Examples of such food or beverage products include, in addition to general food or beverage products, foods for specified health uses, nutritional supplements, functional foods, and foods for sick people. Specific examples of forms of these food or beverage products include, but are not particularly limited to, main dishes such as bread and noodles; side dishes such as cheese, ham, vienna sausages, and processed seafood products; confectionery such as gums, chocolates, soft candies, hard candies, biscuits, cookies, crackers, deep-fried rice crackers (“okaki” in Japanese), rice crackers (“senbei” in Japanese), and puffed snacks; chilled deserts such as ice creams, soft serve ice creams, sorbets, and frozen desserts; supplements such as tablets, granules, powders, capsules, and soft capsules; and beverages such as soft drinks, milk beverages, lactic acid bacteria beverages, carbonated beverages, fruit juices, vegetable juices, vegetable or fruit beverages, powdered beverages, jelly drinks, coffee beverages, tea beverages, green tea beverages, sport drinks, nutritional beverages, energy drinks, non-alcoholic beverages, and alcoholic beverages. The above-described foods for sick people can be provided for patients who require improvement of red blood cell function.

[0091] Further, when the agent for improving red blood cell function of the present invention is used in the field of food or beverage products, the agent for improving red blood cell function of the present invention, either alone or in combination with other components, can be provided as a food additive for use in improving red blood cell function.

[0092] When the agent for improving red blood cell function of the present invention is used for a food or beverage product, the amount of the agent for improving red blood cell function incorporated into the food or beverage product may be set as appropriate within a range where the above-described dose can be satisfied, in accordance with the type, form, and the like of the food or beverage product. For example, the amount of cucurbitaxanthin A and/or a derivative thereof may be in the range from 0.000001 to 20 mass %, preferably from 0.000002 to 18 mass %, and even more preferably from 0.000005 to 15 mass %.

[0093] When the agent for improving red blood cell function of the present invention is used in the field of pharmaceutical preparations, cucurbitaxanthin A and/or a derivative thereof, either alone or in combination with other pharmacological components, pharmacologically acceptable bases or additives, and the like, may be prepared into a desired dosage form, and provided as a pharmaceutical preparation for use in improving red blood cell function. Specific examples of such forms of pharmaceutical preparations include, but are not particularly limited to, pharmaceutical preparations for oral administration such as tablets, granules, powders, capsules, soft capsules, and syrups; and pharmaceutical preparations for systemic administration such as injections and infusions. Among the above, a preferred example is a pharmaceutical preparation for oral administration.

[0094] When the agent for improving red blood cell function of the present invention is used for a pharmaceutical preparation, the amount of the agent for improving red blood cell function incorporated into the pharmaceutical preparation may be set as appropriate within a range where the above-described dose can be satisfied, in accordance with the type, dosage form, and the like of the pharmaceutical preparation. For example, the amount of cucurbitaxanthin A and/or a derivative thereof may be in the range from 0.00001 to 80 mass %, preferably from 0.00002 to 75 mass %, and even more preferably from 0.0005 to 70 mass %.

EXAMPLES

[0095] The present invention will be specifically described hereinafter with examples; however, the present invention should not be construed as being limited to these examples.

Example 1

[0096] In this test, paprika carotenoids rich in carotenoids having 3,6-epoxy end groups or 5-membered ring end groups were orally administered to an adult male, and cucurbitaxanthin A, capsanthin, capsorubin, and capsanthin 3,6-epoxide were evaluated for their ability to migrate into red blood cells. A specific testing method was as described below.

[0097] Initially, 15 g of a paprika pigment emulsified preparation (PapriX; total amount of carotenoids: 10 mg/g) from Glico Nutrition Co., Ltd., 30 g of dextrin, 70 g of sugar, and 3 g of citric acid were dissolved in 1 L of water to prepare a test beverage containing the paprika carotenoids. The paprika pigment emulsified preparation contained 0.053 mass % of cucurbitaxanthin A, 0.40 mass % of capsanthin, 0.021 mass % of capsorubin, and 0.034 mass % of capsanthin 3,6-epoxide, and the test beverage contained 0.00079 mass % of cucurbitaxanthin A, 0.0060 mass % of capsanthin, 0.00031 mass % of capsorubin, and 0.00051 mass % of capsanthin 3,6-epoxide.

[0098] A healthy male in his forties continuously ingested 100 mL (200 ml/day) of the test beverage each in the morning and evening for four weeks. Before the beginning of the ingestion and after 4 weeks from the ingestion, blood was collected to obtain blood samples. Red blood cells were separated from the obtained blood samples, and the carotenoids (capsanthin 3,6-epoxide, cucurbitaxanthin A, capsanthin, and capsorubin) present in red blood cells were quantified by HPLC.

[0099] FIG. 2 shows the total amount of ingestion of each of the carotenoids through the ingestion of the test beverage for 4 weeks, and FIG. 3 shows the proportion of the amount of each of the carotenoids present in the red blood cells, relative to the total amount of ingestion of each of the carotenoids (migration ratio into red blood cells; %). The results confirmed that cucurbitaxanthin A has a markedly high ability to migrate into red blood cells. On the other hand, the carotenoids having 3,6-epoxy end groups or 5-membered ring end groups other than cucurbitaxanthin A (capsanthin, capsorubin, and capsanthin 3,6-epoxide) showed little migration into red blood cells.

[0100] Cucurbitaxanthin A is a carotenoid having 3,6-epoxy end groups, which has high antioxidant action, and has been believed from the conventional art to lack the ability to migrate into red blood cells. The results obtained in this test, however, revealed that cucurbitaxanthin A in fact has a markedly high ability to migrate into red blood cells, and can effectively protect red blood cells against oxidative stress, and thus, is effective for improving the function of red blood cells.