JPS6213327B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an antitumor agent whose active ingredient is a water-insoluble fraction obtained by separation from an autolysed product of brewer's yeast. In recent years, antitumor polysaccharides have been isolated from a wide variety of materials ranging from microorganisms to higher plants, but the structures, physicochemical properties, and antitumor effects of these polysaccharides are not always clear. Regarding the antitumor components isolated from yeast, which is the target of the present invention, there have been reports on the antitumor properties of zymosan, mannan, and hydroglucan, but these polysaccharides are All of them are obtained by separating and purifying them as bacterial cell constituents by chemical means. As a result of investigating the collection of antitumor components from yeast cells, the present inventors found that the water-insoluble fraction obtained by removing the water-soluble extract from the autolysed product of beer yeast was purified by any chemical means. The present inventors have discovered that it exhibits excellent antitumor properties even without the use of sterilization, and have thus completed the present invention. Therefore, an object of the present invention is to provide an antitumor agent containing a water-insoluble fraction obtained from an autolysed product of brewer's yeast as an active ingredient. The present invention will be explained in detail below. As mentioned above, the antitumor agent of the present invention contains as an active ingredient a substance consisting of a water-insoluble fraction obtained by removing a water-soluble extract from an autolysed product of brewer's yeast. The main component is polysaccharide consisting of at least glucan, mannan and glycogen, and in addition contains protein.
In addition, the acid hydrolyzate exhibits a reducing sugar reaction and is particularly characterized by containing a relatively large amount of nitrogen as shown in the analytical values below. It is assumed that the protein component is complexly bound to the polysaccharide. Next, the compositional analysis values of the water-insoluble fraction (dry product) will be illustrated. (Weight%) Loss on drying 10.9 Residue on ignition 1.5 Total phosphorus 0.4 Total nitrogen 4.0 Crude protein 25.0 Total reducing sugar 49.5 Glycogen 24.9 Glucan 14.8 Mannan 13.9 (Note) (1) Total reducing sugar is obtained by hydrolyzing the sample with hydrochloric acid. It was quantified by the Somogyi method and expressed in terms of glycose. (2) Glycogen, glucan, and mannan were quantified by the Anthrone method after fractionation. The water-insoluble fraction in the present invention is produced, for example, by the following procedure. Brewer's yeast, such as Saccharomyces carlsbergensis
hop bitter substances and other impurities are removed by adding a de-bittering detergent to hops (Carlsbergensis), and then purified by repeated washing with water. The aqueous suspension of pure yeast obtained is then heated in an acidic region at an appropriate temperature, e.g. 45 to 55°C. It usually autolyzes for 18 to 24 hours, sometimes for 2 to 3 days. Next, the water-soluble extract in the resulting autolysis fluid is removed by means such as centrifugation or filtration, and the resulting water-insoluble fraction is dried. The yield is 25-45% by weight on dry matter. Next, the results of testing the antitumor activity of the water-insoluble fraction of the present invention (hereinafter referred to as the drug) obtained as described above against Ehritz's ascites tumor and incidental mammary tumor in mice are shown below. . (A) Test on Ehritzch ascites tumor: Ehritzch ascites tumor cells (1.5-1.7) x ¹⁰⁶
After 24 hours of subcutaneous injection into the left inguinal region of male DDD, ddk, ICR/JCR mice (10 mice per group),
Various doses of this drug shown below were administered for 10 days over 15 days.
It was injected subcutaneously into the right (contralateral site) or left (same site) groin. The results were as shown in Table 1 below.

[Table] From the above table, when this drug was administered at 0.1 to 10 mg/time, the survival period was significantly prolonged in the 1 to 10 mg administration group compared to the control group, and a survival effect was observed.

[Table] As shown in Table 2 above, the groups receiving 5 and 10 mg of this drug had significantly more tumor regression than the control group, and the average tumor diameter was also smaller. Furthermore, a life-prolonging effect was also observed with administration of 5.0 to 10.0 mg. In addition, when comparing Tables 1 and 2 above, it is understood that the antitumor effect of this drug is stronger when injected into the ipsilateral site where the tumor is present. Next, the antitumor effect of oral administration of this drug was tested. The test was conducted using Ehritzch ascites tumor cells.
1.7×10 ⁶ ICL/JCR, male mice (1 for 10 mice)
The test mice were injected subcutaneously into the left inguinal region of the mice (group), while the test mice received synthetic feed supplemented with this drug at a rate of 1, 5, 10, and 20%, respectively, 15 days before the injection and on the day of the injection. The antitumor effect was observed after oral administration of 5g daily. As a result, all patients in the control group died from tumors, but regression of tumors was observed in the group treated with this drug, and tumor growth inhibitory effects were observed even when administered orally. (B) Test for incidental mammary tumors: 25.5 × 10 ⁶ tumor cells from SMT-C ₃ H female mice were
A C ₃ H male mouse was injected subcutaneously into the left inguinal region, and from the next day, 5 mg of this drug was injected subcutaneously into the left inguinal region (ipsilateral site) for 10 days, and the subsequent progress was observed. The results were as shown in Table 3 below.

[Table] From the above table, it can be seen that all patients in the control group died from tumors, but in the group treated with this drug, the tumors regressed and the survival period was prolonged. It was also observed that tumor growth was suppressed when simultaneously injected into the right inguinal region (opposite site). In addition, although the animals used in the above experiment (B) and the tumor are of the same species, the antitumor agent of the present invention has the property of developing resistance to tumors even when administered to mice with congenital tumors. It should be noted that Regarding the acute toxicity of the antitumor agent of the present invention, this drug was intraperitoneally administered to a group of 10 male DD mice weighing 10 to 20 g, and the number of live and dead mice after 1 week was determined by REED-MCNCH. According to the results calculated using the method, the results were as follows. LD ₅₀ = 1335 (1128.5-1579.5) mg/Kg (P<0.05)

Claims (1)

[Claims] 1 Consists of a water-insoluble fraction obtained by removing a water-soluble extract from an autolysed product of brewer's yeast, and contains polysaccharides consisting of at least glucan, mannan, and glycogen as a main component, further contains protein, and is acid-hydrolyzable. An antitumor agent whose active ingredient is a substance that exhibits a reducing sugar reaction.