JP3572103B2 - Secondary bile acid lowering agent - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a secondary bile acid lowering agent that suppresses the production of secondary bile acids in the intestine.
[0002]
[Prior art]
In recent years, the number of colorectal cancer patients has increased in Japan, and the proportion of colorectal cancer deaths among various cancer deaths has also increased. It is thought that the cause is that the amount of a substance having a carcinogenic effect produced in the intestine has increased with the westernization of the diet.
[0003]
One of the substances produced in the intestine and thought to be involved in carcinogenesis is secondary bile acid (SB Reddy et al., Cancer Res., Vol. 37, p. 3238-3242 (1977)). ). Secondary bile acids are primary bile acids, i.e., bile acids secreted from the liver into the intestinal tract, altered by the action of some intestinal bacteria, and deoxycholic acid and lithocholic acid, which are not present in primary bile acids. , Ursodeoxycholic acid and the like. Therefore, if the production of secondary bile acids can be suppressed by a substance which can be orally ingested on a daily basis, it is considered to be very effective in preventing colorectal cancer. However, such substances are not yet known.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a secondary bile acid lowering agent which is highly safe, can be taken orally on a daily basis, and is effective in suppressing the production of secondary bile acids in the intestine.
[0005]
[Means for Solving the Problems]
The secondary bile acid lowering agent successfully provided by the present invention has the general formula Gal- (Gal) n-Glc (where Gal is a galactose residue, Glc is a glucose residue, and n is 1 to 4). The galacto-oligosaccharide represented by the following formula is used as an active ingredient.
(Hereinafter, when referred to as galactooligosaccharide, it means an oligosaccharide represented by the above general formula.)
[0006]
The galacto-oligosaccharide constituting the secondary bile acid lowering agent of the present invention is an oligosaccharide known, for example, from JP-A-2-299582, JP-B-58-20266, and the like. Lactose is treated with β-galactosidase. To give a transfer reaction.
[0007]
When this galacto-oligosaccharide is produced from lactose, β-galactosidase used in the transfer reaction includes Streptococcus thermophilus, Lactobacillus bulgaricus, Cryveromyces fragilis, Cryveromyces lactis, Aspergillus oryzae, Bacillus circulans, and Brera singularis. And β-galactosidase produced by Cryptococcus laurentii, Lipomaces lipofa, Sterigmatomyces eliviae, Rhodotorula minuta, Silobasidium magnum and the like. Above all, β-galactosidase derived from Bacillus circulans has a feature of providing galactooligosaccharides in high yield, and is preferred. As β-galactosidase, those present in microbial cells may be used as they are.
[0008]
As the raw material lactose, those marketed for food can be used as they are. In addition to lactose, milk containing milk sugar, milk powder, cheese whey and the like may be used.
[0009]
The lactose β-galactosidase treatment is desirably performed by adding the enzyme to a lactose solution having a concentration of about 4.5 to 80% w / v and a temperature of about 5 to 80 ° C. At this time, from lactose, transfer disaccharides such as Gal-β (1-2) -Glc, Gal-β (1-3) -Glc and Gal-β (1-6) -Glc, as well as galactooligosaccharides, Glucose and galactose are also produced by the decomposition, but the amounts of the produced amounts vary with time. Therefore, by selecting the reaction time, a reaction product mainly composed of galactooligosaccharide can be obtained.
[0010]
The reaction product can be used as it is for the secondary bile acid lowering agent of the present invention. It is desirable to separate the resulting monosaccharides and unreacted lactose. The transfer disaccharide is considered to be effective in lowering the secondary bile acid, though not so much as galacto-oligosaccharide. Therefore, it is advantageous to include the galacto-oligosaccharide together with the galacto-oligosaccharide in the secondary bile acid lowering agent without separation.
[0011]
Heretofore, galactooligosaccharides have been known to promote the growth of bifidobacteria in the intestine, but have not been known to be effective in suppressing the production of secondary bile acids.
[0012]
If the galactooligosaccharide or the product of the above-mentioned transfer reaction containing the same is formulated by a conventional method into a dosage form suitable for oral ingestion, such as powders, granules, syrups and tablets, the secondary bile acid lowering agent of the present invention can be obtained. Is obtained. For formulation, commonly used excipients (eg, glucose, lactose), disintegrants (eg, starch, sodium alginate), binders (eg, gelatin), pigments, diluents, and the like, depending on the dosage form, should be used. Can be.
[0013]
Since the secondary bile acid-lowering agent of the present invention is mainly composed of galacto-oligosaccharide derived from lactose and has not been confirmed to be toxic, the dose when this is orally administered for the purpose of preventing colorectal cancer has been confirmed. While there is no strict limit, typical preferred doses are 0.1 to 10 g per dose, 0.1 to 20 g per day in total.
[0014]
【Example】
Example 1
Dissolve 25 kg of lactose in 20 liters of hot water, add 500 ml of 1M potassium phosphate buffer (pH 7.0) and 150,000 units of β-galactosidase biolacta (trade name, product of Daiwa Kasei Co., Ltd.) to 60 ° C. For 12 hours. Thereafter, the reaction solution is heated to inactivate the enzyme, activated carbon is added to decolorize the mixture, and the mixture is passed through a resin tower filled with a mixture of a cation exchange resin (Diaion PK218) and an anion exchange resin (PA316), followed by filtration. And concentrated to give a viscous sugar mixture. The saccharide composition of this saccharide mixture was as follows: galacto-oligosaccharides 38%, transfer disaccharides 20%, unreacted lactose 20%, monosaccharides 22%. The main component of the galactooligosaccharide was Gal-β (1-4) -Gal-β (1-4) -Glc.
[0015]
Example 2
The secondary bile acid lowering effect of galactooligosaccharide was confirmed by the following method. The galactooligosaccharide-containing saccharide mixture produced in Example 1 was used as it was.
[0016]
Test method: Group A subjects consisting of 8 healthy boys (36.1 ± 9.8 years old) and Group B subjects consisting of 9 healthy boys (39.7 ± 10.8 years old) were prepared. Was administered with 10 g of galactooligosaccharides, and 2.5 g of galactooligosaccharides in group B subjects, each dissolved in 10 ml of lemon water, and administered for 3 weeks after every breakfast. All subjects were kept under observation for three weeks before the start of galactooligosaccharide administration, three weeks during the administration, and three weeks after the end of the administration, and collected stool samples once a week, a total of nine times. In the meantime, ingestion of foods and drinks including dairy products, fermented foods and oligosaccharides, and taking of antibiotics and the like were prohibited. Dosing studies were performed in compliance with the Helsinki Convention. The stool sample was diluted and homogenized with a 10-fold amount of a phosphate buffer (0.05 M, pH 7), filtered through a gauze, and freeze-dried. After extracting the dried feces with ethanol at 70 ° C. for 2 hours, the centrifuged supernatant was dried under a nitrogen stream, the obtained dried product was dissolved in methanol, and a bile acid analysis system (separation column manufactured by JASCO Corporation) : Bilepak-11, immobilized enzyme color: Enzymepak-HSD). Cholic acid and chenodeoxycholic acid were quantified as primary bile acids, and deoxycholic acid, lithocholic acid and ursodeoxycholic acid were quantified as secondary bile acids. Primary and secondary bile acids were each determined in total and averaged over each period.
[0017]
The results are shown in FIGS. In both Group A and Group B, the administration of galactooligosaccharide significantly reduced the concentration of secondary bile acids in feces (FIGS. 1 and 2). During the entire test period, there was no effect of the galacto-oligosaccharide administration on the primary bile acid concentration (FIGS. 3 and 4). In addition, a non-parametric multiple comparison was performed for the significance test of the results, and it was determined that there was a significant difference at p <0.01.
[0018]
From the above results, it was found that administration of galactooligosaccharides reduced the concentration of secondary bile acids in human feces. This is considered to be due to the fact that galactooligosaccharides suppress the production of secondary bile acids in the human intestine.
[0019]
Example 3
A test was conducted in which 20 healthy male subjects were allowed to drink a solution prepared by dissolving 15 g of the galactooligosaccharide-containing saccharide mixture according to Example 1 in 70 ml of water after fasting overnight. When the abdominal condition of the subject was observed for 8 hours after administration, no symptoms such as abdominal pain and diarrhea were observed.
[0020]
【The invention's effect】
As described above, the secondary bile acid lowering agent of the present invention can extremely effectively reduce the intestinal concentration of secondary bile acids which are deeply involved in the development of colorectal cancer. Since the secondary bile acid-lowering agent of the present invention contains galacto-oligosaccharide obtained from lactose as a main component, the taste is also good, and it is considered that there is almost no adverse effect of continuous administration. It is also an advantage that it can be used daily for the prevention of colorectal cancer.
[Brief description of the drawings]
FIG. 1 is a graph showing quantitative values of secondary bile acids in feces of Group A subjects in Example 2.
FIG. 2 is a graph showing quantitative values of secondary bile acids in feces of a group B subject in Example 2.
FIG. 3 is a graph showing quantitative values of primary bile acids in feces of a group A subject in Example 2.
FIG. 4 is a graph showing the primary bile acid quantitative value of feces of a subject in group B in Example 2.

Claims (1)

A galacto-oligosaccharide represented by the general formula Gal- (Gal) n-Glc (wherein, Gal represents a galactose residue, Glc represents a glucose residue, and n represents an integer of 1 to 4). Secondary bile acid lowering agent.

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