U.S. patent application number 12/088276 was filed with the patent office on 2009-05-21 for glucagon-like peptide-1 secretagogue, glucagon-like peptide-1 secretagogue food or drink, inhibitor of postprandial rise in blood glucose, and inhibitory food or drink of postprandial rise in blood glucose.
This patent application is currently assigned to MORINAGA MILK INDUSTRY CO., LTD.. Invention is credited to Yousuke Itoh, Kouji Nomaguchi, Muneo Yamada.
Application Number | 20090131316 12/088276 |
Document ID | / |
Family ID | 37899833 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090131316 |
Kind Code |
A1 |
Itoh; Yousuke ; et
al. |
May 21, 2009 |
GLUCAGON-LIKE PEPTIDE-1 SECRETAGOGUE, GLUCAGON-LIKE PEPTIDE-1
SECRETAGOGUE FOOD OR DRINK, INHIBITOR OF POSTPRANDIAL RISE IN BLOOD
GLUCOSE, AND INHIBITORY FOOD OR DRINK OF POSTPRANDIAL RISE IN BLOOD
GLUCOSE
Abstract
The invention relates to a GLP-1 secretagogue and an inhibitor
of postprandial rise in blood glucose, containing .kappa.-casein as
an active ingredient, and a food or drink for promoting GLP-1
secretion and an inhibitory food or drink of postprandial rise in
blood glucose, containing a milk-derived casein protein wherein
.kappa.-casein accounts for 60% by mass or more of the milk-derived
casein.
Inventors: |
Itoh; Yousuke;
(Yokohama-shi, JP) ; Nomaguchi; Kouji; (Ebina-shi,
JP) ; Yamada; Muneo; (Yokosuka-shi, JP) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER, 441 VINE STREET
CINCINNATI
OH
45202
US
|
Assignee: |
MORINAGA MILK INDUSTRY CO.,
LTD.
Tokyo
JP
|
Family ID: |
37899833 |
Appl. No.: |
12/088276 |
Filed: |
September 29, 2006 |
PCT Filed: |
September 29, 2006 |
PCT NO: |
PCT/JP2006/319551 |
371 Date: |
March 27, 2008 |
Current U.S.
Class: |
514/1.1 ;
530/360 |
Current CPC
Class: |
A23J 1/202 20130101;
A61P 3/10 20180101; A23L 33/19 20160801; A61K 38/17 20130101; A61P
43/00 20180101; A23L 2/52 20130101; A61P 5/50 20180101; A61P 3/08
20180101; A23V 2002/00 20130101; A61K 38/26 20130101; A61K 38/012
20130101; A23V 2002/00 20130101; A23V 2200/328 20130101; A23V
2250/54246 20130101 |
Class at
Publication: |
514/12 ;
530/360 |
International
Class: |
A61K 38/17 20060101
A61K038/17; C07K 14/47 20060101 C07K014/47 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2005 |
JP |
2005-288338 |
Claims
1. A glucagon-like peptide-1 secretagogue, comprising
.kappa.-casein as an active ingredient.
2. A glucagon-like peptide-1 secretagogue food or drink, comprising
a milk-derived casein protein, wherein .kappa.-casein accounts for
60% by mass or more of the milk-derived casein protein.
3. The glucagon-like peptide-1 secretagogue food or drink according
to claim 2, further comprising a carbohydrate.
4. An inhibitor of postprandial rise in blood glucose, comprising
.kappa.-casein as an active ingredient.
5. An inhibitory food or drink of postprandial rise in blood
glucose, comprising a milk-derived casein protein, wherein
.kappa.-casein accounts for 60% by mass or more of the milk-derived
casein protein.
6. The inhibitory food or drink of postprandial rise in blood
glucose according to claim 5, further comprising a carbohydrate.
Description
TECHNICAL FIELD
[0001] The present invention relates to a glucagon-like peptide-1
secretagogue and a glucagon-like peptide-1 secretagogue food or
drink, containing .kappa.-casein as an active ingredient. Moreover,
the present invention relates to an inhibitor of postprandial rise
in blood glucose or an inhibitory food or drink of postprandial
rise in blood glucose, containing .kappa.-casein as an active
ingredient.
[0002] Priority is claimed on Japanese Patent Application No.
2005-288338, filed Sep. 30, 2005, the contents of which are
incorporated herein by reference.
BACKGROUND ART
[0003] Diabetes mellitus is one of the most typical metabolic
diseases from which 200 million people are currently suffering in
the world. The number of diabetic patients is predicted to exceed
300 million people in the year 2025, and is considered to be
particularly increased in the South-East Asian region and the
Western Pacific region where the entire populations are increasing.
Also, in Japan, currently the diabetic population including
patients on the borderline is considered to exceed 15 million
people, and there is concern of further increase in the future.
[0004] Diabetes mellitus is largely classified into two types.
Insulin-dependent diabetes mellitus (IDDM), referred to as type 1,
is a disease in which pancreatic .beta. cells are progressively
destroyed by the immune system to cause a loss of insulin-producing
cells, and this constitutes 5 to 10% of the entire diabetic
population. Non-insulin-dependent diabetes mellitus (NIDDM),
referred to as type 2, occurs as a result of defective
responsiveness of tissues to insulin (insulin resistance) in the
intake of glucose under the presence of a normal to high level of
insulin, which also leads to the exhaustion of .beta. cells. At
present, type 2 diabetic patients constitutes 90 to 95% of the
entire diabetic patients.
[0005] Currently, treatments such as insulin replacement therapy
are performed against the dysfunction of .beta. cells in the type 1
and the advanced-stage type 2 diabetes. However, there are problems
in that the postprandial blood glucose level does not return to
normal depending on the symptom, and the like. Moreover, the
concerned treatments must be performed while avoiding
hyperglycemia, hypoglycemia, metabolic acidosis, and ketosis, and
need to be carefully programmed.
[0006] Furthermore, with respect to type 2 diabetes, treatments
using drugs which promote the insulin production or secretion from
the .beta. cells, or drugs which improve the insulin resistance,
are generally performed. However, these drugs promote the insulin
production or secretion irrespective of the blood glucose level,
and thus the blood glucose level should be controlled by diet so as
not to fall into a hypoglycemic state or the like. There are also
drawbacks of having side effects such as abdominal bloating,
meteorism, increased flatulence, loose stools, diarrhea, and
abdominal pain. Moreover, in cases of the insulin resistance
improvers, it is reported that, as a result of the examination of
their effects by hemoglobin Alc (HAlc) values or the like, the
symptoms are not satisfactorily improved (Non-patent Document 1),
and that side effects such as heart failure may possibly be induced
by long term usage.
[0007] On the other hand, glucagon-like peptide-1 (GLP-1), a
hormone secreted from L cells which are scattered in the
gastrointestinal tract, is confirmed to have effects such as
promoting a strong insulin secretion, stimulating the satiety
center, and suppressing the gastrointestinal peristalsis,
stimulated by food (Non-patent Document 2). These effects are all
considered to be associated with inhibitory effects on rapid
increase in the blood glucose level caused by food intake.
[0008] The effects of this GLP-1 stop working when the blood
glucose level drops to 60 mg/dL or less, and thus it can be said
that therapies using GLP-1 are more readily capable of controlling
the blood glucose level as compared to conventional insulin
therapies or the like (Non-patent Document 3). Further, GLP-1 has
important functions such as an ability to promote the
differentiation and proliferation of .beta. cells to protect the
pancreas, an ability to inhibit gluconeogenesis in the liver, an
ability to improve the insulin resistance in cells, or an ability
to improve peripheral glucose disposal (Non-patent Documents 4 and
5).
[0009] Therefore, many pharmaceutical manufacturers are dedicated
to research with the expectation of a therapeutic effect of GLP-1
on type 2 diabetes. However, GLP-1 is extremely unstable in vivo,
and thus it is required for example to optimize the administration
method and the administration route, and to search for functional
analogues which are highly stable in vivo. Practical implementation
is still on the way at the present stage.
[0010] Therefore, research is being conducted not only on the
direct administration of GLP-1 but also on the substances which
promote the GLP-1 release in vivo, and naturally-derived components
which have a GLP-1 release promoting effect are known.
[0011] For example, Patent Document 1 discloses that acid caseins
and the like have a promoting effect on GLP-1 secretion. FIG. 1 of
the Patent Document 1 shows results of the examination on the
promoting effect on GLP-1 secretion by an in vitro test method.
According to these, the promoting effect on GLP-1 secretion of acid
caseins is approximately twice as compared to the control.
Moreover, the promoting effect on GLP-1 secretion of acid-soluble
proteins of casein micelles is approximately six times as compared
to the control.
[0012] Moreover, Patent Document 2 discloses that a casein
glycomacropeptide (CGMP) has a promoting effect on GLP-1 secretion.
CGMP is a peptide obtained by cleaving the bond between
phenylalanine 105 and methionine 106 of .kappa.-casein with
chymosin. FIG. 1 and FIG. 2 of Patent Document 2 show results of
the examination on the promoting effect on GLP-1 secretion by an in
vitro test method. According to them, the promoting effects on
GLP-1 secretion of CGMP calcium salt and CGMP sodium salt are
approximately twice to three times as compared to the control.
[0013] Since these components are naturally-derived and highly
safe, it is expected that the administration thereof into diabetic
patients including patients on the borderline can lead to the
control of the postprandial blood glucose level without causing
hypoglycemia.
[0014] (Patent Document 1) European Patent Application, Publication
No. 1367065
[0015] (Patent Document 2) PCT International Publication No. WO
01/37850 Pamphlet
[0016] (Non-patent Document 1) Ghazzi et al., Diabetes, Vol. 46,
No. 3, p. 433-439 (1997)
[0017] (Non-patent Document 2) Wettergren A, et al., Digestive
Diseases and Sciences (Dig Dis Sci), Vol. 38, p. 665-673 (1993)
[0018] (Non-patent Document 3) Nauck et al., Diabetologia, Vol. 36,
p. 741-744 (1993)
[0019] (Non-patent Document 4) M. L. Vellanueva et al.,
Diabetologia, Vol. 37, p. 1163 (1994)
[0020] (Non-patent Document 5) D. J. Drucker, Diabetes, Vol. 47, p.
159 (1998)
DISCLOSURE OF INVENTION
Problems to be Solved by the Invention
[0021] However, components described in Patent Documents 1 and 2
have only two to three times higher, at most approximately six
times higher promoting effect on GLP-1 secretions, as compared to
the control. A large amount of these components must be consumed to
obtain a certain degree of effect. According to Patent Document 2,
the preferable dose of CGMP should desirably be 5 to 10 g per 100 g
of food.
[0022] Moreover, the acid-soluble proteins of casein micelles
described in Patent Document 1 are proteins obtained such that a
whey is removed from milk through calcium precipitation to obtain
casein micelles, and then these casein micelles are dissolved with
an acid. Only a very small amount of these proteins can be obtained
from milk. Although the promoting effect on GLP-1 secretion thereof
is about six times as compared to the control and is slightly
higher than that of acid caseins, it is difficult to produce a
necessary amount for practical use.
[0023] Accordingly, various types of naturally-derived components
having the GLP-1 release promoting effect are known, but all are
poor in practicability.
[0024] The present invention addresses the abovementioned problems
with an object of providing a GLP-1 secretagogue and an inhibitor
of postprandial rise in blood glucose which have a high promoting
effect on GLP-1 secretion and therefore a high inhibitory effect on
postprandial rise in blood glucose, and are practically capable of
providing a sufficient amount of an active ingredient, with use of
a safe and naturally-derived component.
[0025] Moreover, another object is to provide a food or drink for
promoting GLP-1 secretion and an inhibitory food or drink of
postprandial rise in blood glucose which have a high promoting
effect on GLP-1 secretion and therefore a high inhibitory effect on
postprandial rise in blood glucose, and are capable of mass
production as a food or drink.
Means for Solving the Problems
[0026] In order to achieve the abovementioned objects, the present
invention employs the following constructions.
(1) A glucagon-like peptide-1 secretagogue, containing
.kappa.-casein as an active ingredient. (2) A glucagon-like
peptide-1 secretagogue food or drink, containing a casein protein
derived from milk (milk-derived casein protein), wherein
.kappa.-casein accounts for 60% by mass or more of the milk-derived
casein protein. (3) The glucagon-like peptide-1 secretagogue food
or drink according to (2), further containing a carbohydrate. (4)
An inhibitor of postprandial rise in blood glucose, containing
.kappa.-casein as an active ingredient. (5) An inhibitory food or
drink of postprandial rise in blood glucose, containing a
milk-derived casein protein, wherein .kappa.-casein accounts for
60% by mass or more of the milk-derived casein protein. (6) The
inhibitory food or drink of postprandial rise in blood glucose
according to (5), further containing a carbohydrate.
EFFECTS OF THE INVENTION
[0027] The GLP-1 secretagogue of the present invention contains
.kappa.-casein being a milk component as an active ingredient, and
thus is highly safe. Moreover, since the promoting effect on GLP-1
secretion is extremely high and a large amount of .kappa.-casein
serving as the active ingredient can be obtained, the
practicability is high.
[0028] Since the food or drink for promoting GLP-1 secretion of the
present invention contains .kappa.-casein being a milk component at
a higher ratio as compared to normal milk, the promoting effect on
GLP-1 secretion is extremely high. Moreover, since mass production
is possible, the practicability is high. Furthermore, since the
.kappa.-casein by itself serves as a nutrient, the food or drink is
excellent as a medical diet for diabetic patients who need to take
nutrients while controlling the blood glucose level.
[0029] The inhibitor of postprandial rise in blood glucose of the
present invention contains .kappa.-casein being a milk component as
an active ingredient, and thus is highly safe. Moreover, the blood
glucose level is suppressed by the promoting effect on GLP-1
secretion of .kappa.-casein, and thus hypoglycemia is not induced.
Furthermore, since the inhibitory effect on postprandial rise in
blood glucose is extremely high and a large amount of
.kappa.-casein serving as the active ingredient can be obtained,
the practicability is high.
[0030] Since the inhibitory food or drink of postprandial rise in
blood glucose of the present invention contains .kappa.-casein
being a milk component at a much higher ratio as compared to normal
milk, the inhibitory effect on postprandial rise in blood glucose
is extremely high. Moreover, the blood glucose level is suppressed
by the promoting effect on GLP-1 secretion of .kappa.-casein, and
thus hypoglycemia is not induced. Moreover, since mass production
is possible, the practicability is high. Furthermore, since the
.kappa.-casein by itself serves as a nutrient, the food or drink is
excellent as a medical diet for diabetic patients who need to take
nutrients while controlling the blood glucose level.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a graph showing test results of Test Example
1.
[0032] FIG. 2 is a graph showing test results of Test Example
2.
BEST MODE FOR CARRYING OUT THE INVENTION
[0033] Preferred embodiments of the present invention will be
explained in more detail. However, the present invention is not to
be limited to the following preferred embodiments, and may be
freely modified within the scope of the present invention.
(GLP-1 Secretagogue)
[0034] The GLP-1 secretagogue of the present invention contains
.kappa.-casein as an active ingredient. In the present invention,
the phrase "contains .kappa.-casein as an active ingredient" means
to contain an effective amount of .kappa.-casein capable of
providing an intended effect (a promoting effect on GLP-1 secretion
in the case of the GLP-1 secretagogue, or an inhibitory effect on
postprandial rise in blood glucose in the case of an inhibitor of
postprandial rise in blood glucose that will be described later).
Moreover, in the present invention, the phrase "promoting GLP-1
secretion" means to promote the secretion of GLP-1 by cells that
have a GLP-1 secretional capacity.
[0035] .kappa.-casein is a protein contained in milk. That is to
say, milk proteins are present in casein micelles and whey, and are
classified into caseins and whey proteins. When skim milk obtained
by removing fat from milk is added with an acid at 20.degree. C. to
adjust to pH 4.6, the precipitated part is casein and proteins
contained in the supernatant liquid are whey proteins.
[0036] Casein is further fractioned into .alpha.s-casein,
.beta.-casein, .kappa.-casein, and a small amount of
.gamma.-casein. .kappa.-casein is one of the most rapidly migrating
casein components (.alpha.-casein) in the moving boundary
electrophoresis that is soluble with 0.4M CaCl.sub.2 (4.degree. C.,
pH 7.0). .kappa.-casein is easily soluble with water as compared to
.alpha.s-casein and .beta.-casein, and thus is easy to handle for
use as a food ingredient. .kappa.-casein accounts for about 10% by
mass of milk proteins.
[0037] .kappa.-casein differs from CGMP which is a decomposition
product of .kappa.-casein.
[0038] .kappa.-casein can be purified from raw milk, skim milk,
casein, sodium caseinate, acid casein, or the like through
well-known steps such as centrifugal separation, pH adjustment with
an acid, and addition of urea, sulfuric acid, or calcium.
[0039] For example, a cream phase is removed from raw milk through
centrifugal separation to obtain skim milk, and then the pH is
adjusted to 4.6 so as to precipitate caseins. Then, the whey
fraction is removed through centrifugal separation to obtain the
casein fraction. Next, the separated casein fraction is redissolved
at pH 8.0, and then is added with calcium chloride, followed by the
removal of a generated precipitation through centrifugal separation
and collection of the supernatant. This supernatant is subjected to
dialysis and subsequent freeze-drying to thereby obtain proteins
having .kappa.-casein as a main component.
[0040] For use in oral intake, the calcium precipitation method is
preferably used. For use as a food ingredient, highly purified
.kappa.-casein is preferably used for facilitating the adjustment
of the addition amount.
[0041] The present inventors have found that .kappa.-casein has an
extremely high promoting effect on GLP-1 secretion. GLP-1 is a
hormone secreted from L cells which are scattered in the
gastrointestinal tract and has effects of promoting strong insulin
secretion, stimulating the satiety center, suppressing the
gastrointestinal peristalsis, and so forth. These effects are all
associated with inhibitory effects on rapid increase in the blood
glucose level caused by food intake. Moreover, the effects of this
GLP-1 stop working when the blood glucose level drops to 60 mg/dL
or less, and thus therapies by promoting the GLP-1 secretion are
safer and more readily capable of controlling the blood glucose
level, as compared to conventional insulin therapies or the
like.
[0042] Further, GLP-1 has important abilities such as an ability of
promoting the differentiation and proliferation of .beta. cells to
protect the pancreas, an ability of inhibiting gluconeogenesis in
the liver, an ability of improving the insulin resistance in cells,
or an ability of improving peripheral glucose disposal. These
effects are all associated with inhibitory effects on rapid
increase in the blood glucose level caused by food intake.
Therefore, GLP-1 is effective for the prevention or the treatment
of diabetes.
[0043] The GLP-1 secretagogue of the present invention may be, for
example, a medical composition, or may be a component to be added
to a food or drink.
[0044] In the case of a medical composition, administration thereof
can be performed into a human or an animal orally, through tubes,
or enterally, for example. Various dosage forms being forms of
general medical formulations can be selected in accordance with
these administration methods and the purpose of the treatment.
Representative examples thereof may include a tablet, a pill, a
powder, a liquid formulation, a suspension, an emulsion, granules,
and a capsule.
[0045] There is no specific limitation on the additive which can be
used for preparing formulations, and additives that are generally
used for medical compositions such as an excipient, a binder, a
disintegrator, a lubricant, a stabilizer, a flavoring agent, a
diluent, and a solvent for injection may be used.
[0046] Examples of the excipient include: sugar derivatives such as
lactose, white sugar, glucose, mannitol, and sorbitol; starch
derivatives such as corn starch, potato starch, .alpha.-starch,
dextrin, and carboxymethyl starch; cellulose derivatives such as
crystalline cellulose, hydroxypropylcellulose,
hydroxypropylmethylcellulose, carboxymethylcellulose, and
carboxymethylcellulose calcium; Arabian gum; dextran; pullulan;
silicate derivatives such as light anhydrous silicic acid,
synthetic aluminum silicate, and magnesium aluminometasilicate;
phosphate derivatives such as calcium phosphate; carbonate
derivatives such as calcium carbonate; and sulfate derivatives such
as calcium sulfate.
[0047] Examples of the binder include, in addition to the above
excipients: gelatin; polyvinylpyrrolidone; and macrogol.
[0048] Examples of the disintegrator include, in addition to the
above excipients: chemically modified starch or cellulose
derivatives such as croscarmellose sodium, sodium carboxymethyl
starch, and crosslinked polyvinylpyrrolidone.
[0049] Examples of the lubricant include: talc; stearic acid; metal
stearates such as calcium stearate and magnesium stearate;
colloidal silica; waxes such as VEEGUM and spermaceti; boric acid;
glycol; carboxylic acids such as fumaric acid and adipic acid;
sodium carboxylates such as sodium benzoate; sulfates such as
sodium sulphate; leucine; lauryl sulfates such as sodium lauryl
sulfate and magnesium lauryl sulfate; silicic acids such as
anhydrous silicic acid and silicic acid hydrate; and starch
derivatives.
[0050] Examples of the stabilizer include: parahydroxybenzoate
esters such as methylparaben and propylparaben; alcohols such as
chlorobutanol, benzyl alcohol, and phenylethyl alcohol;
benzalkonium chloride; acetic anhydride; and sorbic acid.
[0051] Examples of the flavoring agent include sweeteners,
acidifiers, and perfumes.
[0052] Examples of the solvent for injection include water,
ethanol, and glycerin.
[0053] The GLP-1 secretagogue of the present invention may be
contained in a food or drink so as to make a food or drink for
promoting GLP-1 secretion. The form of the GLP-1 secretagogue to be
contained in a food or drink is not specifically limited, and may
solely consist of proteins having .kappa.-casein as a main
component, or may contain another ingredient which is permitted to
be contained in a food or drink, in addition to .kappa.-casein.
[0054] The effective dose of the GLP-1 secretagogue of the present
invention varies depending on the degree of the diabetic symptom,
the age of the patient, and so forth in the case of the oral
administration (which is also the same in the case of the addition
to a food or drink), although 5 to 500 mg/kg/day is preferable, and
25 to 150 mg/kg/day is more preferable as the amount of the active
ingredient (.kappa.-casein).
(Food or Drink for Promoting GLP-1 Secretion)
[0055] The food or drink for promoting GLP-1 secretion of the
present invention contains a milk-derived casein protein, wherein
.kappa.-casein accounts for 60% by mass or more of the milk-derived
casein protein. In dairy products containing normal milk or a
milk-derived casein protein, the proportion of .kappa.-casein in
the casein protein is about 13% by mass.
[0056] On the other hand, since the food or drink for promoting
GLP-1 secretion of the present invention contains a lot of
.kappa.-casein at 60% by mass or more, the food or drink can be
used as an active ingredient to demonstrate similar effects to
those of the GLP-1 secretagogue.
[0057] There is no specific limitation on the .kappa.-casein
content in the food or drink for promoting GLP-1 secretion of the
present invention. Preferably, .kappa.-casein is contained at an
amount to a degree which allows a reasonable intake of the
abovementioned dose for the effective GLP-1 secretion promotion per
day, and normally, .kappa.-casein is contained at an amount of 0.05
to 2.5% by mass.
[0058] For example, if a patient weighing 50 kg takes a food or
drink for promoting GLP-1 secretion which contains 1.5 g of
.kappa.-casein in 100 g of the food or drink, the dose would be 30
mg/kg. This is comparable to the preferable effective dose of the
GLP-1 secretagogue per day, and is capable of demonstrating similar
effects to those of the GLP-1 secretagogue, at an amount allowing a
reasonable intake as a food or drink.
[0059] Moreover, since the .kappa.-casein by itself serves as a
nutrient, the above food or drink is suitable for a medical diet or
an enteral nutrition food, for diabetic patients who need to take
nutrients while controlling the blood glucose level, and functional
foods (food for specified health use, food for special dietary use
such as foods for patients, and food for health).
[0060] The food or drink for promoting GLP-1 secretion of the
present invention may be produced using, as raw materials, the
GLP-1 secretagogue and other ingredients which are permitted to be
contained in a food or drink, or may be produced by formulating the
GLP-1 secretagogue of the present invention in an already-known
food or drink containing other ingredients.
[0061] Regarding other ingredients to be contained in the food or
drink for promoting GLP-1 secretion, any ingredient which is
approved for use for foods/drinks by food regulations such as the
Food Sanitation Law may be used without any specific limitations so
long as the promoting effect on GLP-1 secretion is not
deteriorated. For example, carbohydrates such as dextrin and
starch; proteins such as gelatin, a soybean protein, and a corn
protein; amino acids such as alanine, glutamine, and isoleucine;
polysaccharides such as cellulose and Arabian gum; and oils and
fats such as soybean oil and medium chain triglyceride, may be
contained. In particular, if a carbohydrate is contained, the
effect of the present invention is of great significance since it
enables the intake of nutrients while controlling the blood glucose
level.
[0062] The form of the food or drink for promoting GLP-1 secretion
is not specifically limited. Examples thereof include: drinks such
as coffee, tea, soft drinks, carbonated drinks, nutrient drinks,
fruit drinks, lactic acid drinks (including concentrated stock
solutions and powders for preparation of these drinks); frozen
desserts such as ice cream, sorbet, and chipped ice; noodles such
as buckwheat noodle, Japanese wheat noodle, Chinese vermicelli,
Chinese dumpling wrap, Chinese shao mai skins, Chinese noodle, and
instant noodle; confectioneries such as sweet drops, chewing gum,
candies, gum, chocolate, sweet tablets, snack food, biscuits,
jelly, jam, cream, and baked confectioneries; processed foods of
seafood/meat such as steamed fish paste, ham, and sausage; dairy
products such as processed milk and fermented milk; oils and fats
and processed foods thereof such as salad oil, oil for deep fry,
margarine, mayonnaise, shortening, whipped cream, and dressing;
seasonings such as sauce and gravy; and soups, stews, salads,
delicatessens, pickles, and bread.
[0063] The food or drink for promoting GLP-1 secretion of the
present invention is preferably labeled with the usage instruction
showing the purpose of GLP-1 secretion promotion. Specifically, for
example, the food or drink is preferably marketed as "a food or
drink for promoting GLP-1 secretion which contains .kappa.-casein
as an active ingredient".
[0064] Here, the term "label" means all manners for informing
consumers about the above usage instruction, and any label which
suggests or implies the above usage instruction may fall under the
"label" of the present invention irrespective of the purpose of the
label, the content of the label, the type of the object/media of
the label, and the like. Examples thereof include acts of
indicating the above usage instruction on goods according to the
food or drink for promoting GLP-1 secretion of the present
invention or casings thereof, acts of assigning, delivering,
display for the purpose of assignment or delivery, importing, or
providing through an electronic telecommunication line of such
goods or casings thereof having the indication of the above usage
instruction, acts of displaying or circulating a goods-related
advertisement, price list, or trade document having the indication
of the above usage instruction, or providing information on such
contents having the indication of the above usage instruction
through an electromagnetic method (such as the Internet).
[0065] Preferable labels are labels approved by the government or
the like (for example, labels approved on the basis of various
constitutions established by the government and executed in a form
on the basis of such an approval), and particularly labels on
casings, packages, catalogs, pamphlets, promotional materials for
on-site sales such as POP, or other documents are preferable.
[0066] Moreover, examples thereof also include labels as food for
health, functional food, enteral nutrition food, food for special
dietary use, nutrient functional food, and quasi drugs, and other
labels approved by the Ministry of Health, Labor and Welfare such
as food for specified health use and labels approved by like
constitutions. Examples of the latter labels include labels as food
for specified health use, labels as food for specified health use
with conditions, labels indicating that the body structure and
function are affected, labels indicating a decrease in the risk of
disease. More in detail, labels as food for specified health use
regulated by Enforcement Regulation of Health Promotion Law (Apr.
30, 2003, ordinance No. 86 of the Ministry of Health, Labor and
Welfare of Japan) (in particular, labels of the usage instruction
for health care) and like labels can be enumerated as typical
examples.
[0067] Phrases and words used for such labels are not limited to
the terms of "for promoting glucagon-like peptide-1 secretion" and
"for promoting GLP-1 secretion" only but may be any other terms
which indicate the promoting effect on GLP-1 secretion.
(Inhibitor of Postprandial Rise in Blood Glucose)
[0068] The inhibitor of postprandial rise in blood glucose of the
present invention contains .kappa.-casein as an active ingredient,
and has a similar construction to that of the GLP-1 secretagogue of
the present invention. As described above, GLP-1 has an inhibitory
effect on postprandial rise in blood glucose. Accordingly, the
inhibitor of postprandial rise in blood glucose of the present
invention which contains .kappa.-casein having a high promoting
effect on GLP-1 secretion as an active ingredient, has a high
inhibitory effect on postprandial rise in blood glucose.
[0069] Moreover, as described above, GLP-1 is safe and readily
capable of controlling the blood glucose level. Furthermore, GLP-1
has various abilities associated with the inhibitory effects on
rapid increase in the blood glucose level caused by food intake.
Therefore, GLP-1 is effective for the prevention or the treatment
of diabetes.
[0070] Accordingly, the inhibitor of postprandial rise in blood
glucose of the present invention based on the promoting effect on
GLP-1 secretion is useful for the prevention or the treatment of
diabetes.
(Inhibitory Food or Drink of Postprandial Rise in Blood
Glucose)
[0071] The inhibitory food or drink of postprandial rise in blood
glucose of the present invention contains a milk-derived casein
protein, wherein .kappa.-casein accounts for 60% by mass or more of
the milk-derived casein protein. Moreover, if a carbohydrate is
further contained, the effect of the present invention is of great
significance since it enables the intake of nutrients while
controlling the blood glucose level. The inhibitory food or drink
of postprandial rise in blood glucose of the present invention has
a similar construction to that of the food or drink for promoting
GLP-1 secretion of the present invention.
[0072] Since the inhibitory food or drink of postprandial rise in
blood glucose of the present invention contains a lot of
.kappa.-casein at 60% by mass or more as an active ingredient
thereof, the food or drink exhibits similar effects to those of the
inhibitor of postprandial rise in blood glucose.
[0073] Similarly to the food or drink for promoting GLP-1 secretion
mentioned above, the inhibitory food or drink of postprandial rise
in blood glucose of the present invention is preferably labeled
with the usage instruction showing the purpose of inhibiting
postprandial rise in blood glucose. Specifically, for example, the
food or drink is preferably marketed as "an inhibitory food or
drink of postprandial rise in blood glucose which contains
.kappa.-casein as an active ingredient".
[0074] Phrases and words used for such labels are not limited to
terms "for inhibiting postprandial rise in blood glucose" only but
may be any other term which indicates the inhibitory effect on
postprandial rise in blood glucose.
EXAMPLES
Test Example 1
1. Preparation of Test Samples
[0075] Skim milk powder (manufactured by Morinaga Milk Industry
CO., LTD.), a glycomacropeptide (manufactured by Arla Foods
Ingredients amba, GMP), casein (manufactured by Fonterra
Co-operative Group Ltd., Alacid 720), .alpha.s-casein (manufactured
by Sigma-Aldrich Corp., purity of 70% by mass), .beta.-casein
(manufactured by Sigma-Aldrich Corp., purity of 90% by mass), and
.kappa.-casein (manufactured by Sigma-Aldrich Corp., purity of 80%
by mass) were each dissolved in Krebs-Ringer-HEPES buffer to
prepare test samples at a concentration of 10 mg/mL or 50 mg/mL as
the total protein content. Krebs-Ringer-HEPES buffer was used as a
control.
2. Preparation of Differentiated Human Gastrointestinal-Derived
Cell Line
[0076] A human gastrointestinal-derived cell line NCI-H716
(CCL-251) was purchased from American Type Culture Collection
(ATCC). The purchased cell line was cultured in an RPMI1640 medium
(manufactured by Sigma-Aldrich Corp., R8758) in which 10 mM HEPES
buffer (manufactured by Sigma-Aldrich Corp., H0887), 1 mM sodium
pyruvate (manufactured by Sigma-Aldrich Corp., S8636), 13.9 mM
glucose, 10% by volume of fetal bovine serum, 100 U/mL penicillin,
and 100 .mu.g/mL streptomycin (manufactured by Invitrogen
Corporation., 15140-122) are formulated at each final
concentrations, at 37.degree. C. in an atmosphere with 5% by volume
of carbon dioxide.
[0077] The cultured cell line was collected through centrifugal
separation, and was resuspended into a DMEM medium (manufactured by
Sigma-Aldrich Corp.) containing 10% by volume of fetal bovine serum
at its final concentration, at 1.0.times.10.sup.6 cells/mL. Then,
the cell suspension was aliquoted at 250 .mu.L for each plate of
which the surface was treated with a matrigel manufactured by
Becton, Dickinson and Company, and was further cultured at
37.degree. C. in an atmosphere with 5% by volume of carbon dioxide
for 2 days, to allow differentiation into a cell line having the
GLP-1 secretional capacity.
3. Measurement of Promoting Effect on GLP-1 Secretion
[0078] The culture solution of the differentiated human
gastrointestinal-derived cell line that had been prepared in step
2, was replaced with 250 .mu.L of the test sample that had been
prepared in step 1, followed by culturing at 37.degree. C. in an
atmosphere with 5% by volume of carbon dioxide for 2 hours. Then,
the culture supernatant was collected through centrifugal
separation, and was added with a protease inhibitor cocktail
(manufactured by Nacalai Tesque, Inc.). The resultant mixture was
preserved at -80.degree. C. until measurement.
[0079] The sample that had been preserved at -80.degree. C. was
thawed. Then, the concentration of GLP-1 secreted in the culture
supernatant was measured. The GLP-1 concentration was measured
using the Glucagon-Like-Peptide-1 (GLP-1) (7-36) EIA kit
(manufactured by Phoenix Pharmaceuticals, Inc.).
4. Test Results
[0080] Test results (a test was performed three times for each
sample) are shown in Table 1 and FIG. 1. In Table 1, "versus
control" means a ratio to 0.055 that is the average value of the
measured results of the control. The standard deviation of the
control was 0.012 ng/mL.
[0081] As shown in Table 1, .kappa.-casein showed a 175 times
promoting effect on GLP-1 secretion at the concentration of 10
mg/mL and a 789 times effect at the concentration of 50 mg/mL, with
respect to the control. As shown in FIG. 1, these values are
remarkably higher as compared to casein and other fraction
components in casein (.alpha.s-casein and .beta.-casein). The
present test revealed that .kappa.-casein has a remarkably high
promoting effect on GLP-1 secretion.
TABLE-US-00001 TABLE 1 10 mg/mL 50 mg/mL Average Standard Average
Standard value deviation Versus value deviation Versus (ng/mL)
(ng/mL) control (ng/mL) (ng/mL) control Skim milk 0.304 0.045 5.53
1.51 0.210 27.5 powder GMP 0.265 0.043 4.82 0.573 0.130 10.1 Casein
1.94 0.300 35.3 6.75 0.890 123 .alpha.s-casein 2.41 0.380 43.9 10.1
1.60 184 .beta.-casein 1.64 0.140 29.9 7.21 0.900 131
.kappa.-casein 9.63 1.00 175 43.4 4.90 789
Test Example 2
1. Test Methods
[0082] Eighteen commercially available mice weighing 31 to 33 g
(Slc: ddy, provided from Japan SLC, Inc., 7-week-old male) were fed
for 14 days, and then no food was given for the following 20 hours.
Then, the weight and the blood glucose level were measured, and the
mice were divided into two groups: a .kappa.-casein administration
group; and a control group so that the respective groups had
equivalent average weights and blood glucose levels.
[0083] Then, the mice of the .kappa.-casein administration group
were forcibly and orally administered with a test liquid having 25
mg of .kappa.-casein and 2000 mg of soluble starch per kg of body
weight which were liquefied with sterile distilled water.
Meanwhile, the mice of the control group were forcibly and orally
administered with a test liquid having 2000 mg of soluble starch
per kg of body weight which were liquefied with sterile distilled
water.
[0084] Blood was collected from these mice through the caudal vein
at every 30 minutes from the preadministration of the test liquid
until 120 minutes postadministration, and the blood glucose level
(blood glucose level (mg/dL)) was respectively measured using the
blood glucose self-monitoring system "One Touch Ultra"
(manufactured by Johnson & Johnson K.K.).
2. Test Results
[0085] Table 2 shows the body weights of No. 1 to 9 mice of the
control group at the preadministration of the test liquid, and the
measured results of their blood glucose levels (mg/dL) at every 30
minutes from the preadministration of the test liquid (0 min) until
120 minutes postadministration (120 min). The average values and
the standard deviations of these body weights and respective blood
glucose levels are also shown.
[0086] Moreover, Table 3 shows the body weights of No. 1 to 9 mice
of the .kappa.-casein administration group at the preadministration
of the test liquid, and the measured results of their blood glucose
levels (mg/dL) at every 30 minutes from the preadministration of
the test liquid (0 min) until 120 minutes postadministration (120
min). The average values and the standard deviations of these body
weights and respective blood glucose levels are also shown.
TABLE-US-00002 TABLE 2 Body Control weight 0 min 30 min 60 min 90
min 120 min group (g) (mg/dL) (mg/dL) (mg/dL) (mg/dL) (mg/dL) 1
38.4 80 238 212 181 148 2 39.3 71 192 189 142 108 3 36.6 75 229 208
156 126 4 33.7 74 196 156 145 124 5 39.2 95 237 202 170 127 6 38.5
66 242 218 188 155 7 41.1 82 225 183 130 116 8 43.1 104 237 219 181
169 9 38.8 86 222 206 169 135 Average 38.7 81.4 224 199 162 134
Standard 2.63 12.0 18.4 20.2 20.2 19.6 deviation
TABLE-US-00003 TABLE 3 .kappa.-casein Body administration weight 0
min 30 min 60 min 90 min 120 min group (g) (mg/dL) (mg/dL) (mg/dL)
(mg/dL) (mg/dL) 1 41.7 85 201 202 168 132 2 38.9 74 175 159 121 91
3 38.6 93 208 182 151 116 4 35.9 65 178 182 143 72 5 40.0 69 179
170 129 102 6 33.9 70 152 123 98 67 7 37.6 89 207 176 148 124 8
41.7 102 226 200 154 114 9 37.9 88 182 167 124 99 Average 38.5 81.7
190 173 137 102 Standard 2.55 12.6 22.4 23.7 21.2 22.3
deviation
[0087] Moreover, FIG. 2 shows the average values of the blood
glucose levels shown in Table 2 and Table 3 plotted with respect to
time after the administration of the test liquid. The respective
horizontal bars indicate the mean values .+-.standard
deviations.
[0088] The significant difference between the .kappa.-casein
administration group and the control group was judged by t-test. In
FIG. 2, the mark * indicates a significant difference at p<0.05
and the mark ** indicates a significant difference at
p<0.01.
[0089] As shown in FIG. 2, the .kappa.-casein administration group
was confirmed to significantly inhibit the increase in blood
glucose level as compared to the control group, at all points of
30, 60, 90, and 120 mins postadministration.
[0090] From the above results, it was revealed that postprandial
rise in blood glucose can be inhibited by the intake of
.kappa.-casein.
[0091] Separately, the promoting effect on GLP-1 secretion of
respective samples was also measured at each time point, and
thereby it was confirmed to be correlated with the values of the
inhibitory effect on postprandial rise in blood glucose.
[0092] Next is a further detailed description of the present
invention with reference to Examples, but the present invention is
not to be construed as being limited to these Examples.
Example 1
[0093] 14 kg of commercially available casein (Alacid 720:
manufactured by Fonterra Co-operative Group Ltd.,) was added to 77
kg of distilled water, which was dissolved by adjusting to pH 8.0
with a 5.0 mass/volume % sodium hydroxide aqueous solution. Next, a
40 mass/volume % calcium chloride aqueous solution was added
thereto at the final concentration of 300 mM, and the mixture was
sterilized by heating at 85.degree. C. for 10 minutes. The
resultant solution was left standing for 1 hour, followed by
centrifugal separation at 5000 g. The supernatant was collected and
was subjected to ultrafiltration and subsequent freeze-drying, to
obtain about 900 g of a purified product of .kappa.-casein.
[0094] The obtained purified product was dissolved in a distilled
water, and the purity was confirmed through SDS-PAGE and using the
Zone Densitometry apparatus (ATTO'S Densitometry Software produced
by ATTO Corporation), which showed that the purity of
.kappa.-casein was 60% by mass or more.
[0095] The obtained .kappa.-casein was filled with 2.0 g for each
gelatin capsules No. 1 listed in the pharmacopeia of Japan (Aliment
Industry Co. Ltd.). The joint of the cap and the body of the
capsule was sealed with a gelatin to produce an inhibitor of rise
in blood glucose containing .kappa.-casein as an active
ingredient.
Example 2
[0096] Commercially available .kappa.-casein (manufactured by
Sigma-Aldrich Corp., purity of 80% by mass) was used to produce a
food having the composition shown in Table 4.
TABLE-US-00004 TABLE 4 (Liquid food) Blending amount (g)
.kappa.-casein 0.7 Dextrin 13.8 Vegetable oil 2.9 Granulated sugar
0.5 Soybean protein 3.3 Cellulose 0.4 pH adjuster 0.3 Magnesium
chloride 0.05 Emulsifier 0.1 Perfume 0.1 Thickening stabilizer 0.01
Total (dissolved in distilled water) 100 mL
INDUSTRIAL APPLICABILITY
[0097] The GLP-1 secretagogue of the present invention contains
.kappa.-casein being a milk component as an active ingredient, and
thus is highly safe. Moreover, since the promoting effect on GLP-1
secretion is extremely high and a large amount of .kappa.-casein
serving as the active ingredient can be obtained, the
practicability is high.
[0098] Since the food or drink for promoting GLP-1 secretion of the
present invention contains .kappa.-casein being a milk component at
an extremely high ratio as compared to normal milk, the promoting
effect on GLP-1 secretion is extremely high. Moreover, since mass
production is possible, the practicability is high. Furthermore,
since the .kappa.-casein by itself serves as a nutrient, the food
or drink is excellent as a medical diet for diabetic patients who
need to take nutrients while controlling the blood glucose
level.
[0099] The inhibitor of postprandial rise in blood glucose of the
present invention contains .kappa.-casein being a milk component as
an active ingredient, and thus is highly safe. Moreover, the blood
glucose level is suppressed by the promoting effect on GLP-1
secretion of .kappa.-casein, and thus hypoglycemia is not induced.
Furthermore, since the inhibitory effect on postprandial rise in
blood glucose is extremely high and a large amount of
.kappa.-casein serving as the active ingredient can be obtained,
the practicability is high.
[0100] Since the inhibitory food or drink of postprandial rise in
blood glucose of the present invention contains .kappa.-casein
being a milk component at an extremely high ratio as compared to a
normal milk, the inhibitory effect on postprandial rise in blood
glucose is extremely high. Moreover, the blood glucose level is
suppressed by the promoting effect on GLP-1 secretion of
.kappa.-casein, and thus hypoglycemia is not induced. Moreover,
since mass production is possible, the practicability is high.
Furthermore, since the .kappa.-casein by itself serves as a
nutrient, the food or drink is excellent as a medical diet for
diabetic patients who need to take nutrients while controlling the
blood glucose level.
* * * * *