JP2014043406A - Agent having blood pressure elevation-suppressing action from post-fermented tea, and drink or food product and medicament comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agent allowing inhibition of angiotensin-converting enzyme action for indirect relaxation of vascular smooth muscle, having an action of suppressing blood pressure elevation by direct action on the vascular smooth muscle for relaxation of the vascular smooth muscle, permitting daily administration due to its safety, and being capable of continuously suppressing blood pressure elevation.SOLUTION: A blood pressure elevation-suppressing agent has, as an active ingredient, an ethyl acetate extract of a substance obtained by extracting a post-fermented tea with hot water.

Description

  The present invention relates to an agent having an antihypertensive action, a food and drink containing the agent, and a medicine.

In recent years, Japan is facing a serious aging society, and there is a tendency to increase the number of patients with lifestyle-related diseases associated with hypertensive diseases due to westernization of dietary habits. It is estimated that the number of hypertensive patients, including those who have not started treatment, is approximately 40 million (edited by the Japanese Society for Hypertension 2009, edited by the Japanese Society of Hypertension, Hypertension Treatment Guidelines, published by the Japanese Society of Hypertension).
Currently, antihypertensive drugs such as diuretics, calcium antagonists, sympathetic nerve inhibitors, vasodilators and angiotensin converting enzyme inhibitors are widely used as antihypertensive drugs, but renal function deterioration, angioedema, sugars and lipids Adverse effects such as adverse metabolic effects and burden on the heart have been reported.
On the other hand, with an increase in health-oriented and safety-oriented, foods that are said to have a positive effect on health and foods for specified health use (so-called “special insurance”) have attracted attention. Teas that have been drunk for a long time are said to contain various active ingredients. By activating vascular relaxation factors (NO, EDHF, etc.) derived from vascular endothelium, blood vessel smooth muscles are relaxed to lower blood pressure. It has been recognized that tea-derived components such as tochu tea glycosides, peptides that inhibit angiotensin-converting enzymes involved in increasing blood pressure, and aminobutyric acid (GABA) that exhibit blood pressure lowering effects are effective in lowering blood pressure. Yes. In addition to this, tea is also known to have various effects such as body fat reduction and arteriosclerosis prevention.
For example, as a utilization of fermented tea, Patent Document 1 discloses an oxidation-inhibiting and cholesterol-inhibiting composition comprising, as an active ingredient, an aqueous solvent extract obtained by anaerobic fermentation after aerobic fermentation of tea. Has been.
Patent Document 2 discloses a composition for diabetes containing fermented tea extract residue obtained by extracting fermented tea with an aqueous liquid and further extracting the obtained extract with an organic solvent as an active ingredient. .
However, an agent for suppressing blood pressure elevation using an organic solvent extract as an active ingredient of post-fermented tea extracted with hot water, and a food and drink or a medicine containing the agent have not been known.

JP 2007-314508 A JP 2012-31078 A

  As mentioned above, the antihypertensive agent widely used in the treatment of hypertension has many reports of adverse effects such as kidney function deterioration, angioedema, adverse effects on blood glucose and metabolic lipids and burden on the heart, There is a need for a safe composition that does not cause side effects and has an antihypertensive action.

That is, the object of the present invention is to directly relax the vascular smooth muscle via vascular endothelial cells or other factors derived therefrom, such as inhibition of angiotensin converting enzyme (ACE) action. An object of the present invention is to provide a safe agent that has an action of relaxing vascular smooth muscle by working and has no side effects, and a food and drink and a medicine containing the agent.

The present inventors searched for a substance having the above characteristics to solve the above problems, and found that an ethyl acetate extract obtained by extracting post-fermented tea with hot water exhibits the above characteristics. Post-fermented tea refers to tea obtained by killing tea (Camellia sinensis) and undergoing a post-fermentation process using microorganisms. For example, raw tea leaves are roasted or steamed and then aerobically fermented. Pu-eru tea, and ganishi tea that has been aerated aerobically after steaming raw tea and then anaerobically fermented.
In addition, traditional Japanese aerobic fermented batterbatter tea (Toyama), Tengu black tea (Ehime), which has the same manufacturing method as Soseki tea, and Awabancha (Tokushima), which has only anaerobic fermentation, have been passed down.

  That is, the agent for suppressing blood pressure elevation according to the present invention contains, as an active ingredient, an ethyl acetate extract obtained by extracting post-fermented tea with hot water.

  By using ethyl acetate as the organic solvent used for extraction, more active ingredients can be extracted, and the blood pressure increase suppressing effect is further enhanced.

  Moreover, the food / beverage products and medicine of this invention contain the said blood pressure rise inhibitor.

  The agent of the present invention is an extract of tea that has been aerobically fermented after steaming, or tea that has been aerobically fermented and then anaerobically fermented. Ingestion is also possible. In addition, it not only inhibits the action of ACE and indirectly relaxes vascular smooth muscle, but also acts directly on vascular smooth muscle to relax vascular smooth muscle, so it has an excellent blood pressure rise inhibiting effect It is effective for prevention, progression inhibition and treatment of cerebrovascular disorders such as stroke and cerebral infarction, heart diseases such as heart failure and myocardial infarction, and kidney diseases such as nephrosclerosis and renal failure. Therefore, the agent, food / beverage product, and medicine of the present invention are extremely effective for adapting to the recent health orientation.

The chart schematic diagram of a tension measurement experiment is shown. The result of having measured the vascular smooth muscle relaxation effect | action of each organic solvent extract of Puer tea and garnet tea in the endothelium removal vascular smooth muscle of a rat femoral artery is shown. The representative chart of the tension | tensile_strength measurement experiment which added the ethyl acetate fraction extract of puer tea and garnet tea, and GABA containing green tea in the endothelium removal blood-vessel smooth muscle sample of a rat femoral artery is shown. The result of comparing the vascular smooth muscle relaxation effect of ethyl acetate fraction extracts of hydralazine hydrochloride, GABA-containing green tea, and meteorite tea in the endothelium-removed vascular smooth muscle preparation of rat femoral artery is shown. The blood pressure lowering effect by the continuous administration of the ethyl acetate fraction extract of Pu'er tea and Soseki tea to the male hypertensive rat (SHR) by noninvasive blood pressure measurement is shown. The blood pressure-lowering effect | action with time by the single administration of the ethyl acetate fraction extract of Pu'er tea and agate stone tea with respect to the male hypertensive rat (SHR) by noninvasive blood pressure measurement is shown. The blood pressure lowering effect of Soseki tea ethyl acetate fraction extract on normal Wistar rats by open blood pressure measurement is shown. The result of having compared the vascular smooth muscle relaxation effect of various post-fermented tea ethyl acetate fraction extracts in the endothelium removal vascular smooth muscle preparation of a rat femoral artery is shown. The result of having compared the ACE action inhibitory ability of various post-fermented tea ethyl acetate fraction extracts is shown.

The antihypertensive agent of the present invention comprises, as an active ingredient, an ethyl acetate extract obtained by extracting post-fermented tea with hot water.
Hereinafter, the manufacturing method of the agent of this invention is demonstrated.

The kind etc. of the tea used as the raw material of the composition of this invention are not restrict | limited, A general thing can be used. For example, tea mainly includes shrubs (scientific name: Camellia sinensis) and teas (scientific name: C. sinensis var. Assamica), either of which may be used. Above all,
Shrub tea common in Japan can be used without particular limitation.

  In the present invention, the tea is steamed (steamed) and then fermented in one or two stages. Steaming may be performed only with leaves, but may be performed for each branch. This is because it becomes easier to remove the leaves from the branches after cooking, and it takes less time than separating them immediately after collection.

  Steaming may be performed according to general conditions, and steam or steam may be passed through the tea layer. For example, it is carried out by closely packing tea leaves or tea leaves and branches into a container such as a steamer that can pass water vapor from the bottom, boiling water underneath, and passing water vapor or steam through the container. The steaming time may be set to such an extent that it can be subsequently fermented as it is, but for example, it can be 1 to 4 hours, preferably 2 to 3 hours, after the water boils. In practice, the time is adjusted while checking the state of the tea leaves and the color of the juice.

  In addition, since it is thought that the active ingredient is also contained in the steamed steam, you may use this as a water | moisture content required in a fermentation process.

The tea that has been subjected to the pretreatment is then subjected to a fermentation treatment.
Aerobic fermentation is performed as the first stage fermentation process. Specifically, it is carried out by leaving tea leaves under high humidity. For example, it is carried out by putting tea leaves in a container, spraying water or steam to maintain the humidity, applying a cover, and allowing to stand at room temperature for about 5 to 10 days. Meanwhile, it is necessary to maintain an appropriate temperature and humidity, and the fermentation conditions are appropriately adjusted while confirming the state of the tea leaves. In addition, when aerobic fermentation is performed, an appropriate pressure may be applied by pressing with hands or by stepping with feet. Further, aerobic bacteria or fungi suitable for aerobic fermentation may be added, but even when these are not added, the fermentation proceeds by the tea leaf oxidase, naturally occurring bacteria, and the like.

  Thus, Pu'er tea can be mentioned as post-fermented tea produced by performing one-stage aerobic fermentation of tea leaves.

  Subsequently, anaerobic fermentation is performed as a second stage fermentation process as necessary. The conditions for anaerobic fermentation are not particularly limited, and can be performed using a known method. For example, traditionally, aerobically fermented tea leaves are packed tightly into a container while applying pressure, and finally the container is covered with pressure to block contact with outside air. To do anaerobic fermentation. At this time, the above-mentioned steam may be sprayed or added to such an extent that the tea leaves are immersed. Furthermore, although bacteria for performing anaerobic fermentation may be added, anaerobic fermentation may be allowed to proceed without being added.

  After anaerobic fermentation, the tea leaves are agglomerated due to pressure, so it is preferable to cut them to a suitable size. This is because the subsequent drying of the tea leaves proceeds smoothly.

  Tea leaves may be dried mechanically, but can also be dried in the sun. Also, the degree of drying is not particularly limited, but it is necessary to dry to the extent that it does not rot at least during storage.

  Thus, as a post-fermented tea manufactured by performing anaerobic fermentation after performing an aerobic fermentation, the garnet tea traditionally manufactured in Kochi Prefecture can be mentioned. Soseki tea has been studied for its antioxidant activity so far, and further research has been conducted on elucidation of other functions and health promotion effects.

  In one aspect of the composition of the present invention, the tea leaves fermented as described above are extracted with hot water, and the obtained hot water extract is further extracted with ethyl acetate as an active ingredient.

  As an extraction method using hot water, for example, 50 g of tea leaves that have undergone the fermentation process are added to 500 mL of DDW, and extracted with hot water at 100 to 120 ° C. for about 1 minute to 1 hour. During such extraction, the mixture may be stirred or allowed to stand, or may be continuously heated or heated to reflux.

  The extraction method using ethyl acetate is not particularly limited, and can be performed by a conventional method. For example, ethyl acetate is added to the extract obtained by the hot water extraction, and the mixture is separated into an ethyl acetate phase and an aqueous phase with stirring to obtain an ethyl acetate extract. Before performing the ethyl acetate extraction, the hot water extract may be treated with hexane to remove the hexane extraction fraction and then the ethyl acetate extraction.

  The obtained ethyl acetate extract is preferably subjected to an operation for removing ethyl acetate. Further, further extraction / purification may be performed as long as the blood pressure increase suppressing action is not impaired.

  The extract may be taken as it is, but may be taken after lyophilization or the like.

  Since the agent of the present invention exhibits an antihypertensive action, hypertension and complications caused by hypertension, for example, cerebrovascular disorders such as stroke and cerebral infarction, heart diseases such as heart failure and myocardial infarction, and It is effective for prevention, progression inhibition and treatment of kidney diseases such as nephrosclerosis and renal failure.

  The agent of this invention can also be mix | blended with food-drinks (health food, functional food, etc.). This is because the agent of the present invention contains an extract obtained from one-stage fermentation or two-stage fermentation of tea and is considered safe and free from side effects. When used as a food or drink, the extract may be added to a normal food or drink (tea, juice, yogurt, etc.). In addition, excipients, extenders, binders, thickeners (stabilizers), emulsifiers, colorants, fragrances, food additives, seasonings, nutritional supplements (vitamins, calciums, proteins, chitosan and lecithin Etc.) and sweeteners may be added.

  Moreover, it is preferable that it is 0.001 to 5 weight%, and, as for the quantity of the ethyl acetate extract contained in food-drinks, it is more preferable that it is 0.01 to 1 weight%.

Moreover, the agent of this invention can also be used as a pharmaceutical for suppressing a blood pressure rise. When used as a medicine, the ethyl acetate extract may be used as it is, or may be used in combination with a pharmaceutically acceptable pharmaceutical carrier. Pharmaceutically acceptable pharmaceutical carriers include excipients, binders, disintegrants, lubricants, stabilizers, flavoring agents, diluents, surfactants, solvents for injections, etc. It is done. Moreover, unless the effect of this invention is impaired, you may use together the agent of this invention, the other agent for suppressing a blood pressure rise, etc. together.

  When used as a medicine, the dosage is not particularly limited as long as it is an effective amount for suppressing an increase in blood pressure, and may be an amount that does not cause abnormalities due to excessive intake or constitutional problems. The preferred dosage is 0.00001 to 1 / kg body weight / day, with the amount of ethyl acetate extract obtained from 1 g of tea leaves being 1, preferably 0.0001 to 0.5 / kg body weight / day. It is more preferable that it is 0.001-0.1 / kg body weight / day. Can be taken once a day or divided into multiple doses.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and may be implemented with appropriate modifications within a range that can meet the gist of the present invention. All of which are within the scope of the present invention.

[Production Example 1] Production of extract of the present invention An ethyl acetate extract of post-fermented tea as an extract raw material was produced as follows.
50 g of Soseki tea leaves were added to 500 mL of DDW, heated at 120 ° C. for 20 minutes, and the tea leaves were filtered to obtain an extract. An equal amount of hexane was added to the resulting extract and stirred at room temperature for 3 hours. A hexane phase and an aqueous phase were separated using a separatory funnel, an equal amount of ethyl acetate was added to the aqueous phase, and the mixture was stirred at room temperature for 12 hours. The ethyl acetate phase and the aqueous phase were separated using a separatory funnel, and the ethyl acetate phase was completely dried by an evaporator. After measuring the dry weight of the ethyl acetate phase, it was dissolved in DDW so as to be 10 mg / ml to obtain an ethyl acetate extract.
Moreover, the ethyl acetate extract was obtained also about puer tea tea leaves on the same conditions and processes.

[Test Example 1] Measurement of vascular smooth muscle relaxant action of each solvent fraction extract of Puer tea and Meteorite tea Using a vascular smooth muscle specimen from which the endothelial cells of rat femoral artery were removed, the fine tension of vascular smooth muscle was measured. Iizuka et al. (Iizuka et al., InsP3, but not novel Ca ²⁺ releasers, contributes to agonist-initiated contraction in rabbit airway smooth muscle, J. Physiol., 1998 Sep 15; 511 (Pt 3): 915-33 ), The vascular smooth muscle relaxation action of each solvent fraction extract of Puer tea (one-stage fermented tea) and Goseki tea (two-stage fermented tea) was measured.
First, rat femoral artery smooth muscle was used as vascular smooth muscle tissue. The excised femoral artery was cut into strips, vascular endothelial cells and connective tissue were removed, and the femoral artery was set in a tension measuring device. Normal extracellular fluid (NES) was used to relax vascular smooth muscle tissue. In addition, high potassium extracellular fluid (KES) containing 155 mM potassium was used for contraction. The vascular smooth muscle tissue was relaxed and contracted by the following procedure, and the tension at each time point 1 to 4 in the chart shown in FIG. 1 was measured.
(1) In order to stabilize the tension of the smooth muscle tissue, the extracellular fluid was changed to KES and contracted for 3 minutes, and then changed to NES and relaxed. This operation was repeated three times for complete relaxation. The tension at this point is defined as “1. Reference”.
(2) When the extracellular fluid was replaced with KES and the sustained contraction of smooth muscle was stabilized, 4 μL or 12 μL of each solvent fraction extract (10 mg / ml) was added to the extracellular fluid, and the change in tension was observed. . The tension at the time when the sustained shrinkage is stabilized is defined as “2. Pre-shrinkage”, and the tension after addition of each solvent fraction extract is defined as “3. Relaxation”.
(3) The extracellular fluid was replaced with another KES to which each solvent fraction extract was not added, and the change in tension was observed. The tension at this point is referred to as “4.
(4) (2) and (3) were performed on each solvent fraction extract, and the change in tension was observed.
The T value representing the change in the tension of the smooth muscle tissue was calculated based on the following formula.

T value = ([3. Relaxation] − [1. Reference value]) / {([2. Pre-contraction] + [4. Post-contraction]) / 2− [1. Reference value]}

When the T value is 1 or more, it means that there is a contraction effect, and when it is 1 or less, it means that there is a relaxation effect.
The results are shown in FIG.

  As is apparent from FIG. 2, the extract of the present invention has an excellent vascular smooth muscle relaxing action as compared with extracts obtained using other tea leaves or other solvents. It was. In particular, an extract obtained by using ethyl acetate as an extraction solvent (ethyl acetate fraction extract) has a particularly excellent vascular smooth muscle relaxation action compared to extracts obtained using other solvents. It became clear.

[Test Example 2] Measurement of vascular smooth muscle relaxing action of ethyl acetate fraction extract of Pu'er tea and meteorite tea Using the endothelium-removed vascular smooth muscle of rat femoral artery, ethyl acetate fraction extract of Pu'er tea, acetic acid of meteorite tea Specifically, the vascular smooth muscle relaxing action when accumulating ethyl fraction extract and GABA-containing green tea (product name: Natural Care, Taisho Pharmaceutical Co., Ltd.) was measured by the method of Iizuka et al. To the vascular smooth muscle of the femoral artery, 4 μl each of puer tea and meteorite tea ethyl acetate extract (10 mg / ml) was added cumulatively every 5 minutes. Meanwhile, 4 μl of GABA-containing green tea (natural care) was added and administered. The results are shown in FIG.

  As can be seen from FIG. 3, vascular smooth muscle relaxes in a concentration-dependent manner when puer tea and garnet tea ethyl acetate fraction extracts are administered, but vascular smoothness occurs when GABA-containing green tea is administered. There was no muscle relaxation. From these results, it is considered that the ethyl acetate fraction extract of Pu'er tea and Soseki tea acts directly on the vascular smooth muscle and exhibits its relaxing action.

[Test Example 3] Comparison of vascular smooth muscle relaxing action with hydralazine hydrochloride The vascular smooth muscle relaxing action of hydralazine hydrochloride, which is an antihypertensive agent acting directly on peripheral blood vessels, and ethyl acetate fraction extract of Meishiishi tea is the same as in Test Example 1. Measurements were made according to the procedure and compared. Although the mechanism of action of hydralazine hydrochloride is unknown, it is known as a hypotensive agent that lowers blood pressure by dilating peripheral blood vessels by relaxing arterial smooth muscle in the clinic.

  As is apparent from FIG. 4, the ethyl acetate fraction extract of the meteorite tea of the present invention has an excellent vascular smooth muscle relaxing action compared to hydralazine hydrochloride and GABA-containing green tea (product name: Natural Care, Taisho Pharmaceutical). It became clear that

[Test Example 4] Non-invasive blood pressure measurement by continuous administration test In order to verify the blood pressure increase-inhibiting action in animals, non-invasive blood pressure measurement by a continuous administration test using male hypertensive rats (SHR) was performed. It was. Specifically, the sample used was a puer tea (one-stage fermented tea) and garnet tea (two-stage fermented tea) ethyl acetate fraction extract, GABA-containing green tea (product name: Natural Care, Taisho Pharmaceutical), and DDW as a control. Was carried out by the following method. Each group of 6 SHR was orally administered with hot water extract (10 mg) using a gastric sonde from the 6th week of age, and from the 13th week of age, each of the ethyl acetate fractions of Puer tea and Soseki tea. 1 mg each of extract, GABA-containing green tea and DDW was orally administered. Blood pressure measurement was performed in the morning using a non-invasive automatic blood pressure measurement device BP-98A (manufactured by Softron Co., Ltd.) with a tail-cuff method at a holding temperature of 38 ° C. for each systolic and diastolic blood pressure per group The measurement was performed three times per time. The results are shown in FIG.

  As is clear from FIG. 5, systolic blood pressure was significantly decreased with respect to the control and GABA-containing green tea in the group to which the ethyl acetate fraction extract of Puer tea or Soseki tea was administered from the 13th week.

[Test Example 5] Non-invasive blood pressure measurement by single-dose test Non-invasive blood pressure measurement by single-dose test using spontaneously hypertensive rats (SHR) in order to verify the blood pressure increase inhibitory effect in animals Went. Specifically, using the ethyl acetate fraction extract of puer tea (one-stage fermented tea) and ganishi tea (two-stage fermented tea) as samples, the following method was used. In each group of 4 21-week-old SHR, systolic and diastolic blood pressure before sample administration were measured 6 times each with a BP-98A sphygmomanometer (manufactured by Softron Co., Ltd.). Subsequently, 1 mg each of ethyl acetate fraction extract of Pu'er tea and Soseki tea was orally administered by stomach sonde, and systolic blood pressures at 4, 8, 24 and 28 hours after the administration were measured. The results are shown in FIG.

  As is apparent from FIG. 6, when the Puer tea ethyl acetate fraction extract was administered, the blood pressure decreased about 10 mmHg after 4 hours compared to before administration, and the blood pressure lowering effect continued for about 8 hours thereafter. . In addition, when the ethyl acetate fraction extract of Goishi tea was administered, the blood pressure decreased by about 30 mmHg after 8 hours compared to before administration, and the blood pressure lowering action continued for more than 20 hours thereafter.

[Test Example 6] Open blood pressure measurement using normal Wistar rats Open blood pressure measurement using normal Wistar rats was performed. Specifically, a 24-week-old normal Wistar rat was anesthetized with urethane, and after securing the airway, a cannula placed in the carotid artery was connected to a disposable blood pressure transducer for animals, and the blood pressure change was changed to a voltage via a Quad Bridge amplifier. Converted to. Blood pressure was measured and recorded using the PowerLab system from ADINSTRUMENTS. The converted voltage was recorded on a computer as digital data at 1/100 second intervals by an AD converter PowerLab 4/25. The recorded data was calibrated to mmHg with reference to the actual pressure measured using a mercury sphygmomanometer. Soseki Tea's ethyl acetate fraction extract (10 mg / ml) diluted 1/1000 times, 1/100 times and 1/10 times with physiological saline, and the stock solution every 0.1 min. After administration, the systolic and diastolic blood pressure was measured for 10 minutes. The measured chart and data are shown in FIG.

  As can be seen from FIG. 7, when the extract with a dilution of 1/1000 times the lowest concentration was administered, the systolic blood pressure decreased by about 12 mmHg 10 minutes after administration, and with the extract diluted 1/100 times, about 16 mmHg. In the extract diluted 1/10, the blood pressure decreased by about 18 mmHg, and the blood pressure decreased as the extract concentration increased. In addition, when the stock solution was administered, a further decrease in blood pressure was not observed as compared with the case where the extract diluted 1/10 was administered. This is considered to be because the blood pressure lowering action reaches its peak when the concentration of the extract is about 1/100 to 1/10.

[Test Example 7] Comparison of smooth muscle relaxant action of post-fermented tea Soseki tea (Kochi Prefecture), Tengu black tea (Ehime Prefecture), Awaban tea (Tokushima Prefecture), Batabata tea (Toyama Prefecture) and Puer tea ethyl acetate content The extract was prepared in the same manner as in Production Example 1, and each vascular smooth muscle relaxing action was measured in the same procedure as in Test Example 1 for comparison.

  As is clear from FIG. 8, the ethyl acetate fraction extract of post-fermented teas other than meteorite tea and puer tea has the effect of relaxing the blood vessels by acting directly on vascular smooth muscle, as is the case with meteorite tea and puer tea. It became clear that.

[Test Example 8] Comparison of the ability of post-fermented tea to inhibit angiotensin converting enzyme (ACE) For each ethyl acetate fraction extract of Goishi tea, Puaru tea, Awaban tea, Batabata tea and Tengu black tea, ACE kit-WST (Dojin) The ACE inhibitory activity was measured using Chem. As a positive control, Alacepril used clinically was used, and the measurement was performed simultaneously.

As is clear from FIG. 9, it was found that the ethyl acetate fraction extract of post-fermented tea has inhibitory activity against ACE. In particular, it was found that ethyl acetate fraction extracts of Pu'er tea, Batabata tea and Tengu black tea have a relatively strong ACE inhibitory effect.

  As described above, an increase in blood pressure can be suppressed by administration of the extract of the present invention.

Claims (4)

  An antihypertensive agent comprising, as an active ingredient, an ethyl acetate extract of post-fermented tea extracted with hot water.   The antihypertensive agent according to claim 1, wherein the post-fermented tea is Goishi tea or Pu'er tea.   Food / beverage products containing the blood pressure rise inhibitor of Claim 1 or 2.   A medicament comprising the blood pressure increase inhibitor according to claim 1 or 2.