Bath additive for improving or preventing cognitive decline

Abstract

To provide a bath agent for improving cognitive functions or preventing cognitive decline.SOLUTION: The present invention provides a bath agent for improving cognitive functions or preventing cognitive decline which contains 1,8-cineole and is foamable.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a bath agent for improving or suppressing decline of cognitive function.

Background Art

[0002] Cognitive function varies among individuals and declines with aging. It is said that one in five people aged 65 or older will suffer from dementia in 2025. Once dementia develops, it is difficult to be completely cured except in some cases. Between healthy people and those with dementia, there is a stage called mild cognitive impairment (MCI). If MCI is left untreated, the symptoms progress to dementia at an annual average rate of about 10%. However, since cognitive function can be restored or the onset of dementia can be prevented by effective intervention at this stage, there is a growing interest in methods for improving and suppressing decline of cognitive function. In addition, not only for the elderly, but also for efficient learning and performance of tasks, methods for improving cognitive function are demanded.

[0003] [[ID=1-6]]On the other hand, 1,8-cineole (also known as eucalyptol), which is a kind of monoterpene, is the main component of the essential oil of eucalyptus, which is one of the herbs, and is known as a component of fragrances and cosmetics (for example, Patent Documents 1 and 2).

[0004] The efficacy of 1,8-cineole has also been studied. For example, in Patent Document 3, although a composition containing terpineol, 1,8-cineole and camphor improved cerebral blood flow by olfactory stimulation, it was reported that inhalation of only 1,8-cineole did not improve cerebral blood flow.

Prior Art Documents

Patent Documents

[0005] [[ID=XX]] [[ID=XX]]

Patent Document 1

Patent Document 2

Patent Document 3

[0006] The inventors had previously investigated the effects of exposure to the scent of 1,8-cineole on memory (short-term memory) and executive function (recall ability), but did not find any particular effect on improving memory or executive function under normal conditions (25°C, 50% humidity). However, they unexpectedly discovered that exposure to the scent in the form of a bath additive could significantly improve cognitive function.

[0007] The object of the present invention is to provide a bath additive for improving or suppressing the decline of cognitive function. [Means for solving the problem]

[0008] In other words, the bath additive for improving or suppressing cognitive decline of the present invention is characterized by containing 1,8-cineole and being effervescent.

[0009] The bath additive for improving or suppressing cognitive decline of the present invention preferably contains 0.2% by mass or more of 1,8-cineole.

[0010] The bath additive for improving or suppressing cognitive decline of the present invention preferably contains 20 to 69% by mass of carbonate and 30 to 79% by mass of organic acid.

[0011] The bath additive for improving or suppressing cognitive decline of the present invention is preferably used to improve or suppress cognitive decline in elderly people aged 65 or older.

[0012] The bath additive for improving or suppressing cognitive decline of the present invention is preferably used for the treatment or prevention of mild cognitive impairment (MCI). [Effects of the Invention]

[0013] According to the present invention, a bath additive for improving or suppressing the decline of cognitive function can be provided. [Brief explanation of the drawing]

[0014] [Figure 1] This chart shows the changes in MPI scores of elderly individuals with MCI (mild cognitive impairment) as evaluated in Example 1. [Figure 2] This chart shows the changes in the MPI scores of general elderly individuals evaluated in Example 1. [Modes for carrying out the invention]

[0015] The improvement in cognitive function observed with the present invention was an unexpected result based on the results obtained from exposure to the scent of 1,8-cineole under normal environmental conditions. Although the detailed mechanism is not clear, considering the differences from normal environmental conditions, it is thought that the temperature and humidity during bathing contributed to the improvement in cognitive function. Furthermore, by using an effervescent bath additive, it is possible to efficiently reach the spatial concentration of 1,8-cineole that yields the cognitive improvement effect, even though it is used as a bath additive that is diluted or dissolved in water.

[0016] From the viewpoint of efficiently inhaling 1,8-cineole, the spatial concentration of 1,8-cineole is preferably 0.010 ppm or higher, more preferably 0.012 ppm or higher, even more preferably 0.020 ppm or higher, even more preferably 0.050 ppm or higher, and even more preferably 0.060 ppm or higher. The spatial concentration of 1,8-cineole can be calculated from a calibration curve obtained by measuring the odor intensity using an odor sensor XP-329m (manufactured by Shin-Cosmos Electric Co., Ltd.) and separately measuring 1,8-cineole at a known spatial concentration.

[0017] With the bath additive for improving or suppressing cognitive decline of the present invention, by exposing the face and head to the scent of 1,8-cineole during bathing or in the bathroom, the subject can inhale the scent of 1,8-cineole through their nose and mouth.

[0018] In the present invention, the cognitive function is not particularly limited, and examples thereof include attention, concentration, judgment, memorization ability (short-term memory), working memory, execution ability (ability to remember), and the like. Among these, the present invention is particularly preferably used for improving or suppressing the decline of memorization ability (short-term memory) and / or working memory.

[0019] The target for improving or suppressing the decline of the cognitive function is not particularly limited, and it may be an elderly person (for example, 65 years old or older), or may be a person other than the elderly. Further, it may be used for the treatment or prevention of mild cognitive impairment (MCI) or dementia. Further, it may be other than humans, for example, a non-human mammalian animal.

[0020] Hereinafter, the bath agent for improving or suppressing the decline of the cognitive function of the present invention will be described in detail.

[0021] [Bath agent for improving or suppressing the decline of cognitive function] The bath agent for improving or suppressing the decline of the cognitive function of the present invention contains 1,8-cineole and has foaming properties. The 1,8-cineole is not particularly limited as long as it can generate the fragrance of 1,8-cineole. For example, a single compound of 1,8-cineole may be used, or an extract such as an essential oil containing 1,8-cineole may be used. The essential oil, also called an essential oil, is a natural liquid present in the flowers, leaves, wood parts, fruit peels, tree barks, roots, seeds, etc. of plants, and the fragrance components of the plants are condensed therein. The single compound may be organically synthesized or purified from natural products such as essential oils. Examples of the essential oil containing 1,8-cineole include essential oils such as eucalyptus, rosemary, Spanish sage, lavintsara, getto, and brushwood.

[0022] The content of 1,8-cineole is not particularly limited as long as it can generate the aroma of 1,8-cineole. For example, it may be 0.01 to 10% by mass, preferably 0.05 to 5% by mass, and more preferably 0.2 to 2% by mass. From the perspective of efficiently increasing the spatial concentration of 1,8-cineole, a higher content of 1,8-cineole is preferred. However, even if the content is low, the aroma generation efficiency can be increased by methods such as heating or increasing the usage amount of the composition.

[0023] The bath agent for improving or suppressing the decline of the cognitive function of the present invention may contain various known and commonly used components. For example, components commonly used in cosmetics, food and beverages, quasi-drugs or pharmaceuticals, such as fragrances, pigments, oily components, disintegrants, moisturizing components, surfactants, polyhydric alcohols, anti-inflammatory agents, vitamins, gold flake materials, preservatives, sequestering agents, crude drug extracts, water, foaming agents, etc., can be blended.

[0024] The bath agent for improving or suppressing the decline of the cognitive function of the present invention is a foaming bath agent that foams when diluted or dissolved in water, and can efficiently increase the spatial concentration of 1,8-cineole. Since the bath agent is usually diluted with a large amount of water during use, the 1,8-cineole becomes diluted. Also, usually the content of the fragrance contained in the bath agent is limited. Moreover, since the face and head can be exposed to the aroma of 1,8-cineole in a short time, it is preferable to efficiently increase the spatial concentration of 1,8-cineole. Also, the foaming bath agent may be a bath agent that foams on the surface of water or a bath agent that foams on the bottom of water. However, from the perspective of increasing the spatial concentration and absorption efficiency, a bath agent that foams on the surface of water is preferred.

[0025] For foaming agents to impart effervescence, it is preferable to combine a carbonate and an organic acid. Examples of carbonates include sodium carbonate, sodium bicarbonate, sodium sesquicarbonate, potassium carbonate, potassium bicarbonate, magnesium carbonate, ammonium carbonate, and calcium carbonate, and one or more of these may be used. Among these, sodium carbonate and sodium bicarbonate are preferably used from the viewpoint of ease of availability. Examples of organic acids include malic acid, succinic acid, fumaric acid, citric acid, tartaric acid, malonic acid, pyrrolidone carboxylic acid, monosodium citrate, monosodium succinate, monosodium fumarate, adipic acid, tartaric acid, benzoic acid, salicylic acid, glutaric acid, glycolic acid, lactic acid, glyceric acid, and pyruvic acid, and one or more of these may be used. Among these, malic acid, fumaric acid, succinic acid, and citric acid are preferred because they have excellent reactivity with carbonates.

[0026] The carbonate content is preferably 20-69% by mass, more preferably 40-60% by mass. The organic acid content is preferably 30-79% by mass, more preferably 30-60% by mass. This is because the above ranges provide good solubility and sufficient foaming power.

[0027] Furthermore, when the bath additive for improving or suppressing cognitive decline of the present invention contains fragrances other than 1,8-cineole, the proportion of 1,8-cineole per total amount of fragrance is not particularly limited, but is preferably 5% by mass or more, and more preferably 10% by mass or more. The proportion of 1,8-cineole may be higher, and may be 40-100% by mass, more preferably 50-100% by mass, or even more preferably 60-100% by mass per total amount of fragrance.

[0028] Other fragrances besides 1,8-cineole and essential oils containing 1,8-cineole include, for example, natural fragrances such as yuzu oil, bergamot oil, orange oil, grapefruit oil, geranium oil, neroli oil, cedarwood oil, cabreuba oil, juniper berry oil, myrrh oil, vetiver oil, lime oil, thyme borneol oil, clove oil, jasmine oil, turpentine oil, and pine oil; terpene fragrances such as α-pinene, β-pinene, d-limonene, camphene, and terpinene; green leaf alcohol, sandalol, evanol, ambrinol, ambercore, citronellol, geraniol, nerol, linalool, tetrahydrolinalool, dihydromyrcenolic acid, ethyllinalool, isopulegol, menthol, terpineol, dihydroterpineol, farnesol, santalol, vetiverol, and β-f Examples include alcohol-based fragrances such as phenylethyl alcohol and pactanol; synthetic fragrances such as aldehyde C-8, aldehyde C-9, aldehyde C-10, aldehyde C-11, aldehyde C-12, leaf aldehyde, citronellal, citral, α-methylenecitronellal, isocyclocitral, dimethyltetrahydrobenzaldehyde, benzaldehyde, phenylacetaldehyde, α-amyl cinnamic aldehyde, α-hexyl cinnamic aldehyde, vanillin, ethyl vanillin, heliotropin, helional, cis-jasmone, dihydrojasmone, nectaril, damascone, ionone, iso-E-super, chalon, l-carbone, menthone, and other aldehyde / ketone fragrances; and blended fragrances that arbitrarily combine the aforementioned natural and synthetic fragrances.

[0029] The properties of the bath additive for improving or suppressing cognitive decline of the present invention are not particularly limited, but it is preferable that it be in a solid form such as granules, briquettes, tablets, powders, or flakes. Furthermore, it is preferable that the average particle diameter is 250 to 3000 μm. If the average particle diameter is 250 μm or more, it is less likely to foam rapidly on the surface of the water, the scattering of 1,8-cineole is suppressed, and the spatial concentration is easily maintained. If the average particle diameter is 3000 μm or less, the particles are less likely to sink, and the spatial concentration of 1,8-cineole is easily increased efficiently. In this specification, the average particle diameter is the average particle diameter measured by the following method. (Method for measuring average particle size) Classification is performed using an electromagnetic sieve shaker (model A-3 PRO). Six to seven sieves are used to divide the material between the upper and lower limits at a constant ratio. After measuring the weight of the sample on each sieve, the particle size at which the cumulative weight is 50% is taken as the average molecular diameter. The particle size at which the cumulative weight is 50% is calculated by linear interpolation from the mesh openings of the upper and lower sieves and the cumulative weight.

[0030] The method of using the bath additive for improving or suppressing cognitive decline of the present invention is to use it in a normal bath, for example, by adding it to bath water at 39-41°C.

[0031] The duration of exposure to the fragrance of 1,8-cineole using the bath additive for improving or suppressing cognitive decline of the present invention varies depending on the subject, but for example, it is 2 minutes or more, more than 5 minutes or more, and more than 10 minutes or more per day.

[0032] The bath additive for improving or suppressing cognitive decline of the present invention may be used in combination with other bath additives, provided that the effects of the present invention are not impaired. [Examples]

[0033] [Example 1] The effectiveness of 1,8-cineole-containing bath additive use in general elderly individuals and elderly individuals with mild cognitive impairment was evaluated using a quasi-randomized, two-group parallel-group comparative trial, as described below.

[0034] <Preparation of bath additives> A 30g effervescent granule mixture containing 30% sodium carbonate, 7% sodium bicarbonate, 20% DL-malic acid, 20% fumaric acid, 21% sodium sulfate, 0.5% polyethylene glycol 6000, 0.3% polyvinylpyrrolidone, 0.2% glyceryl caprylate, and 1% 1,8-cineole was used as one serving of 1,8-cineole-containing bath additive. When 30g of the mixture was dissolved in 200L of hot water (40°C) in a bathtub, it was confirmed that the spatial concentration of 1,8-cineole in the bathroom reached 0.020ppm. The spatial concentration of 1,8-cineole reached a peak of 0.024ppm 10-30 seconds after dissolution, the average concentration after 2 minutes was 0.018ppm, and the average concentration after 5 minutes was 0.013ppm. Furthermore, spatial concentration was measured with the bathtub lid partially open, an odor sensor placed on top of the lid, and approximately at the position of a person's nose while bathing. In addition, for bath additives, the initial value was measured for 25 seconds with the lid on the sensor side closed, then the lid on the opposite side of the sensor was opened and the additive was added, stirred for a few seconds, and then the lid on the sensor side was partially opened and the measurement was taken again.

[0035] Furthermore, when the spatial concentration of 1,8-cineole was similarly measured for a non-foaming powdered bath additive (98.5% sodium sulfate by mass, 0.5% anhydrous silicic acid by mass, and 1% 1,8-cineole by mass), the maximum concentration of 1,8-cineole was reached 50-60 seconds after dissolution, the average concentration after 2 minutes was 0.009 ppm, and the average concentration after 5 minutes was also 0.009 ppm. From this, it can be seen that foaming bath additives not only show a faster rise in spatial concentration of 1,8-cineole but can also achieve higher spatial concentrations.

[0036] <Selection of subjects> Forty-three elderly individuals (65 years and older) with no history of sinusitis or other underlying medical conditions and no olfactory abnormalities were screened using Millennia Co., Ltd.'s Brain Health Check (registered trademark). Subjects with a Memory Performance Index (MPI) score between 0 and 49.8 were classified as MCI (Mild Cognitive Impairment) elderly, and those with a score of 50.2 or higher were classified as general elderly. At this point, five subjects were eliminated because a score could not be calculated, leaving 9 MCI elderly and 29 general elderly. After randomly assigning them to two groups, 4 MCI elderly were placed in the 1,8-cineole bath additive group and 5 in the unscented bath additive group, while 16 general elderly were placed in the 1,8-cineole bath additive group and 13 in the unscented bath additive group. One subject in the general elderly unscented bath additive group dropped out midway through the study.

[0037] <Evaluation of bath additive samples and their effectiveness> Each participant was provided with either a 1,8-cineole bath additive or an unscented bath additive. They were instructed to dissolve the additive in 200 liters of 39-40°C water in their home bathtub once a day and bathe for 10 minutes, continuing this for 8 weeks. During this period, cognitive function was assessed by repeating the Brain Health Check (registered trademark) test at 4 and 8 weeks. Figure 1 shows the test results for MCI (Mild Cognitive Impairment) elderly participants, and Figure 2 shows the test results for the general elderly group. The test results were evaluated using one-way ANOVA.

[0038] The results of the Brain Health Check (registered trademark) in Figures 1 and 2 show that the 1,8-cineole bathing habit is effective for both MCI (Mild Cognitive Impairment) elderly and the general elderly population. Furthermore, among the breakdown of the MPI score, working memory and short-term memory were particularly improved in both MCI elderly and the general elderly population with the 1,8-cineole bathing habit.

[0039] The following describes specific formulation examples of the bath additive for improving or suppressing cognitive decline according to the present invention, but the present invention is not limited to these.

[0040] <Bath additive> Ingredients Amount (mass%) Sodium carbonate 30.0% Sodium bicarbonate 7.0% DL-Malic Acid 20.0% Fumaric acid 20.0% Sodium sulfate 21.0% Polyethylene glycol 6000 0.5% Polyvinylpyrrolidone 0.3% Caprylic / Capric Glyceryl 0.2% 1,8-Cineole 1.0%

[0041] <Bath additive> Ingredients Amount (mass%) Fumaric acid 20.0% Malic acid 18.0% Sodium bicarbonate 21.0% Sodium carbonate 20.0% Sodium sulfate 18.58% Caprylic / Capric Glyceryl 0.2% EthylenediaminetetraPOE·POP 0.02% Soybean oil 0.3% Polyvinylpyrrolidone 0.2% Polyethylene glycol 6000 0.5% 1,8-Cineole 1.0%

[0042] <Bath additive> Ingredients Amount (mass%) Sodium carbonate 30.0% Sodium bicarbonate 7.0% DL-Malic Acid 20.0% Fumaric acid 20.0% Sodium sulfate 21.8% Polyethylene glycol 6000 0.5% Polyvinylpyrrolidone 0.3% Caprylic / Capric Glyceryl 0.2% 1,8-Cineole 0.2%

Claims

[Claim 1] A solid, effervescent bath additive for improving or inhibiting cognitive decline, having a 1,8-cineole content of 0.2 to 10% by mass, a carbonate content of 20 to 60% by mass, and an organic acid content of 30 to 60% by mass, The carbonate is at least one selected from the group consisting of sodium carbonate and sodium bicarbonate. The aforementioned organic acid is at least one selected from the group consisting of malic acid, fumaric acid, succinic acid, and citric acid. The 1,8-cineole is a single compound that is organically synthesized or purified from a natural product. A bath additive for improving or suppressing cognitive decline, characterized by its use in the treatment or prevention of mild cognitive impairment (MCI) in elderly people aged 65 or older.

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