CN112237588B

CN112237588B - Application of oyster mushroom polysaccharide selenoside-III anticancer active ingredient in preparation of medicine for resisting prostate cancer

Info

Publication number: CN112237588B
Application number: CN202011253503.1A
Authority: CN
Inventors: 钟世安; 张云山; 刘慧�; 张卓敏; 邓志伟; 沈剑
Original assignee: Hunan Wanzhen Biotechnology Co ltd
Current assignee: Hunan Wanzhen Biotechnology Co ltd
Priority date: 2020-02-17
Filing date: 2020-11-11
Publication date: 2023-07-21
Anticipated expiration: 2040-11-11
Also published as: CN112237588A

Abstract

The invention belongs to the technical field of drug development, and particularly discloses oyster mushroom polysaccharide selenoside-III; the invention discloses an oyster mushroom polysaccharide selenoside-III anticancer drug with the effect of resisting prostate cancer and a preparation method thereof. The oyster mushroom polysaccharide selenoside-III anticancer drug can specifically kill prostate cancer cells and promote metabolism and proliferation of normal cells. Provides a feasible scheme for treating the prostate cancer.

Description

Application of oyster mushroom polysaccharide selenoside-III anticancer active ingredient in preparation of medicine for resisting prostate cancer

Technical Field

The invention relates to the technical field of medicines, in particular to an oyster mushroom polysaccharide selenoside-III anticancer active ingredient with high anticancer effect and low toxic and side effect.

Technical Field

Prostate cancer is one of the most common malignant tumors in men, and the incidence is related to regions and races, and in the western world, prostate cancer is still the most common malignant tumor in men at present, with the incidence being the first. In China, in a relatively low-incidence area of prostate cancer, but in recent years, along with the development of social economy of China and the change of eating habits of people, the tumor spectrum has gradually changed, the incidence rate of the prostate cancer is gradually increased year by year, and the physical and mental health of men is seriously threatened. Research on anticancer drugs with special effects on prostate cancer is not sustained.

Most of prostate cancer patients have no obvious clinical symptoms, so that a plurality of patients have advanced stage, most of progressive tumors have more or less metastatic cell clusters, and local treatment means such as surgery, radiotherapy and the like cannot radically treat the tumors in theory, so that the purposes of diagnosis, stage division and tumor reduction can be achieved. Therefore, it is an urgent need to develop a drug which has a specific killing effect on prostate cancer and at the same time has no damaging effect on normal cells.

Disclosure of Invention

The invention aims to provide an oyster mushroom polysaccharide selenoside-III anticancer active ingredient (also called polysaccharide selenoside-III) with high anticancer effect and low toxic and side effects and application thereof in preparing an anti-prostate cancer medicament.

The second aim of the invention is to provide an anti-prostate cancer drug containing the oyster mushroom polysaccharide selenoside-III anti-cancer active ingredient.

The prior art discloses extraction modes and oxidation-resistant effects of oyster mushroom polysaccharide selenosides, but the prior art rarely relates to the oxidation-resistant effects of oyster mushroom polysaccharide selenosides. In fact, the present inventors have found that crude oyster mushroom polysaccharide (a mixture of various active ingredients) extracted from oyster mushrooms has substantially no anticancer activity. However, in the background of research in which crude oyster mushroom polysaccharide is known to have no anticancer activity, there is no motivation in the industry to screen anticancer components therefrom, however, the present inventors have unexpectedly found, through intensive research, that oyster mushroom polysaccharide selenoside-iii isolated from the crude oyster mushroom polysaccharide unexpectedly has good anti-prostate cancer activity, is not damaging to normal cells, and even has good metabolism-promoting and proliferation-promoting effects on normal cells, so the following technical scheme is provided:

an application of oyster mushroom polysaccharide selenoside-III as anticancer active component in preparing medicine for treating prostatic cancer is provided.

The oyster mushroom polysaccharide selenoside-III is a novel polysaccharide compound modified with organic selenium, and the polysaccharide compound is obtained by connecting monosaccharide units in glucose, galactose, mannose, glucuronic acid, galacturonic acid, xylose, glucosamine, fucose, arabinose, ribose and rhamnose through glycosidic bonds;

the content of glucose in the hydrolyzed polysaccharide compound is more than 80%, and the content of galactose, mannose and glucuronic acid is more than 1%; the content of each of galacturonic acid, xylose, glucosamine, fucose, arabinose, ribose and rhamnose is not higher than 1%;

preferably, the content of glucose in the hydrolyzed heteropolysaccharide compound is 82-84%, the content of galactose is 3-5%, the content of mannose is 2.5-3.5%, and the content of glucuronic acid is 1-2%; the content of each of galacturonic acid, xylose, glucosamine, fucose, arabinose, ribose and rhamnose is not higher than 1%.

The research of the invention discovers that the oyster mushroom polysaccharide selenoside-III has excellent anticancer activity, and furthermore, the oyster mushroom polysaccharide selenoside-III has no damage to normal cells, and even has good metabolism and proliferation promoting effects on the normal cells.

For the anticancer drug, the normal cells are not damaged while inhibiting and killing cancer cells. However, the inventor further conducts intensive research on oyster mushroom polysaccharide selenoside-III, and discovers that the oyster mushroom polysaccharide selenoside-III not only has good anticancer activity, but also has no damage to normal cells, and even has good metabolism and proliferation promoting effects on the normal cells.

The monosaccharide composition analysis shows that the glucose content of the oyster mushroom polysaccharide selenoside-III after hydrolysis is more than 80%, the galactose, mannose and glucuronic acid content is more than 1%, and the monosaccharide composition is obviously different from the polysaccharide or polysaccharide derivative of the existing oyster mushroom source, so that the oyster mushroom polysaccharide selenoside-III is a newly obtained substance.

Preferably, the molecular weight of the oyster mushroom polysaccharide selenoside-III anticancer active ingredient is 13000-18000.

Preferably, the organic selenium is modified in the polysaccharide compound by se=o and Se-C-O;

preferably, the selenium content is 24-26 mug/g.

The invention also provides a preparation method of the oyster mushroom polysaccharide selenoside-III anticancer active ingredient, which comprises the steps of degreasing selenium-enriched oyster mushroom powder by an alcohol water solution, extracting by water, precipitating by alcohol, deproteinizing to obtain crude polysaccharide (also called as oyster mushroom crude polysaccharide in the invention);

separating the crude polysaccharide by a cellulose exchange column, wherein the separation process comprises the following steps of sequentially carrying out distilled water elution, 0.05-0.15 mol/L sodium chloride solution elution, 0.25-0.35 mol/L sodium chloride solution elution and 0.45-0.55 mol/L sodium chloride solution elution;

collecting 0.25-0.35 mol/L sodium chloride solution as target eluent, desalting, concentrating, purifying by sephadex column to obtain oyster mushroom polysaccharide selenoside-III.

According to the preparation method, the oyster mushroom polysaccharide selenoside-III anticancer active ingredient with excellent anticancer activity and no obvious damage to cells can be unexpectedly obtained through the special elution mechanism.

The degreasing process of the alcohol aqueous solution comprises the following conditions: the alcohol-water solution is ethanol water solution, and the volume fraction of the ethanol is 75-85%; reflux degreasing;

degreasing an alcohol aqueous solution, performing solid-liquid separation, and dispersing and extracting the precipitate in water; the temperature of the water extraction is 80-90 ℃;

extracting with water to obtain extractive solution, concentrating, adding ethanol, precipitating with ethanol, and separating solid from liquid to obtain ethanol precipitate;

deproteinizing the alcohol precipitate to obtain crude polysaccharide.

Preferably, the cellulose exchange column is a DEAE-52 cellulose ion exchange column.

Preferably, the target eluent is desalted by dialysis means.

Preferably, the sephadex column is a G-100 sephadex column.

Preferably, the use is for the preparation of an anti-prostate cancer drug that specifically apoptosis PC-3 cells.

Further preferred, said application is characterized in that: the preparation method is used for preparing the polypeptide which specifically causes apoptosis of PC-3 cells, has no damage to normal cells, and even has good metabolism promoting and proliferation promoting effects on the normal cells.

The oyster mushroom polysaccharide selenoside-III prepared by the invention can effectively kill cancer cells, has no damage to normal cells, has good metabolism promoting and proliferation promoting effects on normal cells, and has great significance for the development of the anticancer field in the research of the oyster mushroom polysaccharide serving as an anticancer active ingredient.

The normal cells are preferably human normal hepatocytes L02.

For example, the polysaccharide selenoside-III anticancer active ingredient has the survival rate of 100% -60% when the concentration of the polysaccharide selenoside-III anticancer active ingredient is 0-600 mug/mL. When the concentration of the polysaccharide selenoside-III anticancer active ingredient is 600 mug/mL, the survival rate of cancer cells is 59-62%, and the tumor inhibition rate is 38% -41%.

The invention also provides a medicament which specifically promotes PC-3 apoptosis, has no damage to normal cells, and even has good metabolism promoting and proliferation promoting effects on the normal cells, and comprises a pharmaceutically effective amount of the oyster mushroom polysaccharide selenoside-III anticancer active ingredient.

Preferably, the specificity promotes PC-3 apoptosis, has no damage to normal cells, even has good metabolism promoting and proliferation promoting effects on normal cells, and also comprises auxiliary materials for preparing the oyster mushroom polysaccharide selenoside-III anticancer active ingredient into any pharmaceutically acceptable dosage form.

Any pharmaceutically acceptable dosage forms are, for example, powder injection, capsules, dripping pills, medicinal granules and the like.

The anticancer activity of the polysaccharide selenoside-III anticancer active ingredient can be quantitatively analyzed by a cck-8 method, and can also be visually analyzed by an AO/EB fluorescent staining method. Acridine Orange (AO) is a selective fluorescent cationic dye that can permeate cell membranes and can stain both living and dead cells. Observing under a fluorescence microscope, wherein acridine orange can penetrate through a complete cell membrane, and the cell nucleus of a living cell is dyed into uniform green fluorescence; the apoptotic cells are condensed or broken into fragments with different sizes due to the chromatin, and the acridine orange dyes the cell nucleus into yellow green bright green fluorescence; dead cells fluoresce orange, but the fluorescence is weak and even vanishes. Ethidium Bromide (EB) can only stain cells with incomplete cell membranes, AO is used in combination with EB to stain necrotic cells orange or orange red, but this also includes cells that resemble viable nuclear morphology and do not have chromatin condensation. Therefore, AO/EB staining kit can distinguish normal cells, apoptotic cells and necrotic cells. The polysaccharide selenoside-III anticancer active ingredient can be observed to specifically cause PC-3 cells to apoptosis by an AO/EB staining method, and has no obvious damage to normal cells.

Advantageous effects

1. The invention surprisingly discovers that the oyster mushroom polysaccharide selenoside-III not only has good anticancer activity, but also can solve the problem that the existing anticancer active ingredients hurt normal cells.

2. By the preparation method, the oyster mushroom polysaccharide selenoside-III with good anticancer activity and no obvious toxic or side effect on normal cells can be obtained.

Drawings

FIG. 1 is an infrared spectrum (758 cm) of a component of oyster mushroom polysaccharide selenoside-III ^-1 The peak at the position is Se=O characteristic peak, 660cm ^-1 The peak of (C) is Se-C-O bond

FIG. 2 is a Gel Permeation Chromatography (GPC) diagram of oyster mushroom polysaccharide selenoside-III component

FIG. 3 shows the elution curves of the fiber columns of crude selenium polysaccharide of oyster mushroom (three components eluted from aqueous sodium chloride solution with concentration of 0,0.1 and 0.3mol/L respectively, named as selenoside I, component II and component III respectively)

FIG. 4 shows the selenium content (ICP) of the oyster mushroom polysaccharide selenoside-III component

FIG. 5 elution profile (HPLC) of oyster mushroom polysaccharide selenoside-III hydrolysate and reference monosaccharides

FIG. 6 Transmission Electron Microscopy (TEM) of the polysaccharide selenoside-III

FIG. 7 shows survival of prostate cancer cells (PC-3) after incubation of oyster mushroom polysaccharide selenoside-III fraction

FIG. 8 is a fluorescent image of prostate cancer cells (PC-3) after AO/EB staining after incubation of the oyster mushroom polysaccharide selenoside-III fraction. (pictures were taken with high content, 40×)

FIG. 9 is a cell flow chart of prostate cancer cells (PC-3) after staining with annexin V-FITC/PI apoptosis detection kit after incubation of oyster mushroom polysaccharide selenoside-III

FIG. 10 shows a scratch test of prostate cancer cells (PC-3) after incubation with oyster mushroom polysaccharide selenoside-III

FIG. 11 survival of prostate cancer cells (PC-3) after incubation of crude oyster mushroom polysaccharide

FIG. 12 survival of Normal cells (L02) after incubation of oyster mushroom polysaccharide selenoside-III fraction

FIG. 13 is a fluorescent image of normal cells (L02) after AO/EB staining after incubation of the oyster mushroom polysaccharide selenoside-III fraction. (pictures were taken with high content, 40×)

FIG. 14 is a flow chart of L02 cells after incubation of polysaccharide selenoside-III and staining with annexin V-FITC/PI apoptosis detection kit

FIG. 15 is a scratch test of L02 cells after incubation with polysaccharide selenoside-III

FIG. 16 survival of Normal cells (L02) after incubation of crude oyster mushroom polysaccharide

Detailed Description

The following examples are intended to illustrate the invention and are not intended to be limiting.

Example 1

Preparation of crude selenium polysaccharide

15g of selenium-enriched oyster mushroom powder (supplied by Hunan Wanzhen biotechnology Co., ltd.) is taken in a round-bottomed flask, 80% ethanol-water solution 120mL is added, stirring reflux is carried out for 3h at 65 ℃, suction filtration is carried out, a filter cake is obtained, and drying is carried out.

Water extraction: 10g of filter cake was taken in a flask, 300mL of ultrapure water was added thereto, stirred at 85℃for 3 hours, centrifuged, and the supernatant was collected and concentrated to obtain a viscous liquid.

Alcohol precipitation: dripping 4 times of absolute ethyl alcohol into the viscous liquid, standing at 4 ℃ for 24 hours, and centrifuging to obtain a precipitate.

Deproteinization: dissolving the precipitate in 100mL of water, adding sevage reagent with quarter volume, centrifuging to obtain supernatant, repeating for 6 times, dialyzing with dialysis bag, and lyophilizing to obtain crude polysaccharide (also called as crude Pleurotus ostreatus polysaccharide or crude selenium polysaccharide).

(II) refining selenium polysaccharide

(2.1) ion exchange column purification procedure: purifying polysaccharide by DEAE-52 cellulose ion exchange column, dissolving 300mg sample (crude polysaccharide of oyster mushroom) in 10mL water, and loading by wet method. Then sequentially eluting with distilled water, 0.1,0.3 and 0.5mol/L sodium chloride solution in a gradient way. The polysaccharide content was checked by phenol-sulfuric acid method at 490nm in a tube-separating manner, and the elution profile was drawn and the main component was collected. Three components were separated in total, and the present invention was derived from a component eluted from a 0.3mol/L aqueous sodium chloride solution, namely, component 3.

(2.2) dialysis: the sample-water solution (step (2.1) component 3) was concentrated to 10-15mL with a rotary evaporator, then pH was adjusted to 7 with hydrochloric acid solution, dialyzed against deionized water for 36h, and then concentrated to 5mL.

(2.3) dextran column purification procedure: g-100 glucan is selected to purify component 3 (step (2.2)) and 5mL of sample is applied by a wet method, then is eluted by deionized water, is detected by a phenol-sulfuric acid method in a separation tube, is concentrated and is freeze-dried, and refined oyster mushroom polysaccharide selenoside-III (also called polysaccharide selenoside-III in the invention) is obtained.

Hydrolysis of oyster mushroom polysaccharide selenoside-III and analysis of monosaccharide components: the sample was precisely weighed into a 5mL ampoule, 2.0mL (2 mol/L) trifluoroacetic acid was added to the 5.0mL ampoule, the tube was sealed, and acidolysis was performed at 110℃for 8 hours. Taking out and volatilizing trifluoroacetic acid, adding 2.0ml of water for redissolving, and completing the hydrolysis. After that, 250. Mu.L of the hydrolyzed solution was precisely aspirated into a 5mL EP tube, 250. Mu.L (0.6 mol/L) of sodium hydroxide and 500. Mu.L (0.4 mol/L) of a methanol solution of 1-phenyl-3-methyl-5-pyrazolone were added, and reacted at 70℃for 1 hour. Cooling in cold water for 10min; add 500 μl (0.3 mol/L) hydrochloric acid to neutralize, add 1mL chloroform to vortex for 1min, centrifuge for 10min at 3000r/min, carefully take the supernatant, extract 3 times. Taking supernatant fluid and completing derivatization. The reference sample was a sugar mixture solution containing 50. Mu.g/mL of each of the reference sugars, and derivatization was performed under the same conditions. Finally, the sample and the reference are eluted by an Xtime C18 high performance liquid phase device, an elution curve is recorded, and a monosaccharide component can be calculated through the peak area ratio of the sample and the reference (the eluent is 0.05M pH=6.7 potassium dihydrogen phosphate solution-acetonitrile=83-17). The monosaccharide composition analysis results are shown in Table 1 and FIG. 5.

TABLE 1 content of polysaccharide selenoside-III constituent monosaccharides of oyster mushroom

The following anticancer and normal cytotoxicity studies were performed using the oyster mushroom polysaccharide selenoside-III obtained in example 1, specifically:

example 2

Experiments on the efficacy of polysaccharide selenoside-III (obtained in example 1) on human prostate cancer cells

When the PC-3 cell density reached 80-90%, the cells were allowed to round by pancreatin, after which the digestion was stopped by adding cell culture medium. The cell suspension was diluted appropriately and counted in a blood cell counting plate, and the 96-well plate was placed in a cell incubator for incubation for 24 hours at a density of 8000 cells per well (96-well plate).

The culture medium in the 96-well plate was then replaced with serum-free cell culture medium and incubated in a cell incubator for 24h.

The previous serum-free medium was replaced with cell culture media (0. Mu.g/mL, 50. Mu.g/mL, 100. Mu.g/mL, 200. Mu.g/mL, 400. Mu.g/mL, 600. Mu.g/mL) containing different concentrations of the polysaccharide selenoside-III, and incubated for 24h. And the cell-free and simple cell culture solution is used as a negative control group.

mu.L of cck-8 reagent was added to each well, and after 2 hours of co-incubation, the absorbance OD was measured at 450nm with a microplate reader to calculate the cell viability.

Cell viability= (OD _{Experimental group} -OD _{Negative control group} )/(OD _{Blank group} -OD _{Negative control group} )。

Plates (96 well plates) were plated at 5000 cells per well, and the 96 well plates were placed in a cell incubator for 24h incubation. The culture medium in the 96-well plate was then replaced with serum-free cell culture medium and incubated in a cell incubator for 24h. Cell culture media (0. Mu.g/mL, 300. Mu.g/mL, 600. Mu.g/mL) containing different concentrations of the polysaccharide selenoside-III were used instead of the previous serum-free medium and incubated for 24h. Wash with PBS and add 90 μl of PBS,5 μl of OA solution and 5 μl of EB solution, stain for 5min, then wash with PBS, observe under high content (AO excitation 488nm, emission 515nm, EB excitation 518nm, emission 605 nm).

Afterwards, apoptosis was quantified by flow cytometry at 5×10 per well ⁵ Is incubated for 24h. The medium was refreshed with cell culture media (0. Mu.g/mL, 300. Mu.g/mL, 600. Mu.g/mL) containing different concentrations of the polysaccharide selenoside-III drug and incubated for 24h. Cells were then collected by digestion with annexin V-FITC/PI apoptosis assay kit and detected on a flow cytometer.

Scratch experiments were used to verify the effect of drugs on cell migration capacity at 1x10 per well ⁶ Cells were inoculated for 24h for adherence, then streaked with 200. Mu.L of gun tips, then cultured in a drug-containing serum-free medium for 0, 12h,24h,48h, and then observed under a fluorescent inverted microscope.

After 24h incubation of PC-3 cells with the polysaccharide selenoside-III, the cell survival rate is less than 62% when the administration concentration is 600 mug/mL, namely, the tumor inhibition rate can reach more than 38% (shown in figure 7). This may suggest from the front that the polysaccharide selenoside-III may be effective in inhibiting prostate cancer cells. As shown in fig. 8, from the AO/EB staining results, PC-3 cells incubated without the drug did not see a significant apoptosis signal, and with increasing administration concentration, EB channel fluorescence was significantly enhanced, and apoptotic cells were significantly increased, which more intuitively showed that polysaccharide selenoside-iii can effectively induce apoptosis of prostate cancer cells. As shown in FIG. 9, the proportion of apoptotic cells was 37.34% at a drug administration concentration of 600. Mu.g/mL. As shown in fig. 10, as the administration concentration increases, the ability of scratch recovery gradually decreases, and as a result, it was demonstrated that the polysaccharide selenoside-iii can inhibit the migration ability of tumor cells to some extent.

Comparative example 1:

experimental results on the efficacy of crude oyster Mushroom polysaccharide (crude polysaccharide product of step (one) of example 1) on human prostate cancer cells without column purification

The previous serum-free medium was replaced with cell culture media (0. Mu.g/mL, 50. Mu.g/mL, 100. Mu.g/mL, 200. Mu.g/mL, 400. Mu.g/mL, 600. Mu.g/mL) containing crude oyster mushroom polysaccharide at different concentrations, and incubated for 24h. And the cell-free and simple cell culture solution is used as a negative control group.

As shown in fig. 11, after the PC-3 cells were incubated with the crude oyster mushroom polysaccharide for 24 hours, the cell viability did not change significantly with increasing concentration of the drug administered, which proves that the crude oyster mushroom polysaccharide had no significant inhibitory effect on prostate cancer cells to some extent.

Example 3

Drug efficacy experiment of polysaccharide selenoside-III (example 1) on Normal cells

When the normal liver cell density of the human reaches 80-90%, the human liver is digested by pancreatin until the cells become round, and then the digestion is stopped by adding cell culture solution. The cell suspension was diluted appropriately and counted in a blood cell counting plate, and the 96-well plate was placed in a cell incubator for incubation for 24 hours at a density of 8000 cells per well (96-well plate).

Afterwards, apoptosis was quantified by flow cytometry at 5×10 per well ⁵ Is incubated for 24h. The medium was refreshed with cell culture media (0. Mu.g/mL, 300. Mu.g/mL, 600. Mu.g/mL) containing different concentrations of the polysaccharide selenoside-III drug and incubated for 24h. Then staining with annexin V-FITC/PI apoptosis detection kit, digesting and collecting cells, and performing flow cytometryAnd (5) detecting.

As shown in FIG. 12, when L02 normal cells were incubated with the polysaccharide selenoside-III, the cell viability could reach 150% at a concentration of 400. Mu.g/mL, and the cell proliferation rate was greatly increased relative to normal cells not dosed. As shown in FIG. 13, no apparent apoptotic or dead cells were seen at the increased dosing concentrations following AO/EB staining. As shown in FIG. 14, the flow cytometry results show that the proportion of apoptotic cells is less than 4% when the drug adding concentration is 600 mug/mL, so that the polysaccharide selenoside-III has no obvious toxic or side effect on normal cells. As shown in FIG. 15, the migration ability of normal cells incubated with the polysaccharide selenoside-III was not significantly changed, so that the migration ability of normal cells was not significantly affected by the composition. The data show that the polysaccharide selenoside-III has no obvious injury effect on normal liver cells.

Comparative example 1:

drug efficacy experiment of crude oyster Mushroom polysaccharide (crude polysaccharide prepared in step (I) of example 1) on Normal cells without column purification

When the normal cell density of human source reaches 80-90%, the cells are digested by pancreatin until the cells become round, and then the cell culture solution is added to stop the digestion. The cell suspension was diluted appropriately and counted in a blood cell counting plate, and the 96-well plate was placed in a cell incubator for incubation for 24 hours at a density of 8000 cells per well (96-well plate).

As shown in fig. 16, after incubating the L02 normal cells with the crude oyster mushroom polysaccharide for 24 hours, the cell viability did not significantly change after the co-incubation of the drug administration, which proves that the crude oyster mushroom polysaccharide had neither inhibitory effect nor proliferation-promoting effect on the normal cells to some extent.

Claims

1. An application of oyster mushroom polysaccharide selenoside-III anticancer active ingredient in preparing an anti-prostate cancer medicament for specifically apoptosis of PC-3 cells, which is characterized in that: the oyster mushroom polysaccharide selenoside-III anticancer active ingredient is a heteropolysaccharide compound modified with organic selenium; the heteropolysaccharide compound is obtained by connecting monosaccharides including glucose, galactose, mannose, glucuronic acid, galacturonic acid, xylose, glucosamine, fucose, arabinose, ribose and rhamnose through glycosidic bonds;

the mass percentage of each monosaccharide in the hydrolyzed heteropolysaccharide compound is as follows: the glucose content is 83.74%, the galactose content is 4.04%, the mannose content is 2.80%, and the glucuronic acid content is 1.55%; galacturonic acid 0.54%, xylose 0.37%, glucosamine 0.28%, fucose 0.2%, arabinose 0.11%, ribose 0.03% and rhamnose 0.01%;

the preparation process of the oyster mushroom polysaccharide selenoside-III anticancer active ingredient comprises the following steps:

preparation of crude selenium polysaccharide

Adding 80% ethanol-water solution 120mL into selenium-rich oyster mushroom powder 15g, stirring and refluxing for 3h at 65 ℃, filtering to obtain a filter cake, and drying;

water extraction: putting filter cake 10g into a flask, adding 300mL ultrapure water, stirring at 85 ℃ for 3h, centrifuging, and concentrating supernatant to obtain viscous liquid;

alcohol precipitation: dripping 4 times of absolute ethyl alcohol into the viscous liquid, placing the viscous liquid at the temperature of 4 ℃ for 24h, and centrifuging to obtain a precipitate;

deproteinization: dissolving the precipitate in 100mL water, adding one-fourth volume of sevage reagent, centrifuging to obtain supernatant, repeating for 6 times, dialyzing with dialysis bag, and lyophilizing to obtain crude polysaccharide;

(II) refining selenium polysaccharide

(2.1) ion exchange column purification procedure: purifying polysaccharide by using DEAE-52 cellulose ion exchange column, dissolving the crude polysaccharide in step (one) of 300mg in 10mL water, and loading by wet method; sequentially carrying out gradient elution by using distilled water, 0.1,0.3 and 0.5mol/L sodium chloride solution; detecting polysaccharide content by phenol-sulfuric acid method at 490 and nm by pipe separation, drawing elution graph, and collecting main component; separating three components from the component eluted from 0.3mol/L sodium chloride water solution, namely component 3;

(2.2) dialysis: concentrating component 3 in step (2.1) to 10-15mL by a rotary evaporator, adjusting the pH to 7 by hydrochloric acid solution, dialyzing 36h by deionized water, and concentrating to 5 mL;

(2.3) dextran column purification procedure: and (3) selecting a dialysis component in the G-100 glucan purification step (2.2), loading a sample of 5mL by a wet method, eluting with deionized water, detecting by a phenol-sulfuric acid method in a separation tube, concentrating, and freeze-drying to obtain the refined oyster mushroom polysaccharide selenoside-III.

2. The use of an anticancer active ingredient of oyster mushroom polysaccharide selenoside-iii according to claim 1, characterized in that: the preparation method is used for preparing the anti-prostate cancer drug which can specifically apoptosis PC-3 cells, has no damage to normal cells and even has metabolism promotion and proliferation promotion on the normal cells.

3. The use of an anticancer active ingredient of oyster mushroom polysaccharide selenoside-iii according to claim 2, characterized in that: the normal cells are normal liver cells L02.