Method for preparing radix pseudostellariae extract through enzymolysis

Abstract

The invention discloses a method for preparing a radix pseudostellariae extract through enzymolysis, and belongs to the technical field of plant effective component extraction. The method comprises the following steps: mixing radix pseudostellariae powder with deionized water which is 10 times of the weight of the radix pseudostellariae powder, and decocting for 2-4 hours to obtain filtrate and filter residues; mixing the filter residue, deionized water and combined enzyme to form slurry, and sequentially performing enzymolysis, inactivation and filtration on the slurry to obtain an extracting solution; mixing the extracting solution and the filtrate, hydrolyzing and catalyzing by glucoside hydrolase, and inactivating to obtain hydrolysate; and sequentially performing rotary evaporation and hot air drying on the hydrolysate to obtain the radix pseudostellariae extract. The radix pseudostellariae is subjected to enzymolysis wall breaking by adopting a combined enzyme, release of effective components is promoted, then filtrate and an extracting solution obtained through wall breaking are subjected to hydrolysis to promote generation of aglycone with higher activity, and finally, the radix pseudostellariae extract is obtained through drying treatment.

Description

Technical Field

[0001] The present invention belongs to the technical field of plant active ingredient extraction, and particularly relates to a method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis. Background Art

[0002] Plants are one of the most abundant biological resources on earth, containing a large number of active ingredients, which have important application values in the fields of medicine, food, cosmetics, etc. The extraction technology of plant active ingredients is not only the basis of modern drug research and development, but also an important means to promote the industrialization of natural products. The main extraction methods of plant active ingredients are as follows: (1) Solvent extraction method: The solvent extraction method separates the active ingredients from plant materials by utilizing the solubility differences of different solvents for the active ingredients in plants. Commonly used solvents include water, alcohols, ethers, and chloroform, etc. This method is simple to operate and has low cost, suitable for large-scale production. However, the selection of solvents needs to be optimized according to the properties of the target ingredients, and improper solvent selection may lead to the loss or degradation of active ingredients; (2) Ultrasonic extraction method: The ultrasonic extraction method utilizes the cavitation effect generated by the high-frequency vibration of ultrasonic waves to promote the penetration of solvents into plant cells, thereby improving the extraction efficiency of active ingredients. This method can significantly shorten the extraction time, increase the extraction rate, and reduce the solvent usage. But the intensity and frequency of ultrasonic waves need to be controlled, and excessive energy may cause thermal degradation or changes in components; (3) Steam distillation method: The steam distillation method is mainly used for extracting volatile components. By passing steam into plant materials, the volatile components are carried away by the steam and then condensed and collected. This method is suitable for extracting volatile components such as essential oils, and the operation is relatively simple, but it is not suitable for the extraction of a large amount of non-volatile components; (4) Microwave-assisted extraction method: The microwave-assisted extraction method uses microwave radiation to heat plant materials, causing the cell walls to rupture and promoting the release of active ingredients. This method has a fast extraction rate and high efficiency, but the equipment investment is large, and the requirement for the penetration depth of microwaves is high; (5) Supercritical fluid extraction method: The supercritical fluid extraction method uses supercritical fluids such as carbon dioxide as solvents, which have good solubility and selectivity. This method does not require the use of organic solvents, has high product purity, and is environmentally friendly, but the equipment is complex and the cost is high.

[0003] Radix Pseudostellariae was first recorded in *Bencao Congxin*. It is a commonly used traditional Chinese medicine, which is the dried tuberous root of the plant of the genus Pseudostellaria heterophylla in the Caryophyllaceae family. Radix Pseudostellariae prefers warm and humid weather and has the characteristics of germinating and taking root at low temperatures. It is generally harvested at the end of June or the beginning of July, with many roots and yellow bark. Radix Pseudostellariae can play the roles of replenishing qi and strengthening the spleen, promoting the production of body fluid and moistening the lungs, etc., and has a good effect on spleen deficiency and physical fatigue, loss of appetite, neurasthenia and physical recovery of children after illness. It is a kind of qi-tonifying medicine and belongs to the category of mild tonics. Due to its good medicinal value and nutritional value, Radix Pseudostellariae is widely used in decoctions, herbal teas, health foods and antioxidants. Radix Pseudostellariae extract is a mixture extracted from Radix Pseudostellariae and contains various active ingredients such as polysaccharides, flavonoids and saponins. In the prior art, the preparation methods of Radix Pseudostellariae extract mainly adopt water extraction method or alcohol extraction method. These methods are common means for the extraction and preparation of plant active ingredients. However, due to the structure of the plant cell wall, the active ingredients are not easily exuded, and the glycoside components do not play the main medicinal effect, but need to be metabolized by intestinal flora into aglycones before they can truly exert their efficacy, resulting in poor activity performance of the Radix Pseudostellariae extract prepared by conventional water extraction or alcohol extraction.

[0004] Therefore, it is of great significance to design a method that can improve the release of the active ingredients of Radix Pseudostellariae and thus improve the activity of the Radix Pseudostellariae extract prepared therefrom. Summary of the Invention

[0005] According to the deficiencies of the prior art, the present invention uses a combination enzyme to enzymatically hydrolyze and break the cell wall of Radix Pseudostellariae to promote the release of active ingredients, and then hydrolyzes the filtrate and the extract obtained by breaking the cell wall to promote the formation of aglycones with higher activity. Finally, the Radix Pseudostellariae extract is obtained through drying treatment, solving the technical problems raised in the background art. Specifically, the technical solution of the present invention includes the following contents:

[0006] One of the purposes of the present invention is to provide a method for preparing Radix Pseudostellariae extract by enzymatic hydrolysis, and the method includes the following steps:

[0007] Mix Radix Pseudostellariae powder with deionized water 10 times its own weight and decoct for 2 h to 4 h to obtain a filtrate and filter residue;

[0008] Mix the filter residue, deionized water and the combination enzyme to form a slurry, and the slurry is sequentially subjected to enzymatic hydrolysis, inactivation and filtration to obtain an extract;

[0009] The extract and the filtrate are combined and inactivated after being hydrolyzed and catalyzed by glycoside hydrolase to obtain a hydrolyzate, and the hydrolyzate is sequentially subjected to rotary evaporation and hot air drying to obtain Radix Pseudostellariae extract.

[0010] Further, the Radix Pseudostellariae powder is screened by a 200-mesh sieve.

[0011] Further, the combined enzyme is composed of cellulase, pectinase and papain mixed in a mass ratio of 1:1:1.

[0012] Further, the weight ratio of the filter residue, deionized water and the combined enzyme is 1:5:0.002 - 0.005.

[0013] Further, the conditions for enzymatic hydrolysis include a pH of 5.5 - 6.5, a temperature of 40°C - 50°C and an enzymatic hydrolysis time of 2 h - 3 h.

[0014] Further, the glycoside hydrolase is β - glucosidase.

[0015] Further, the weight ratio of the extract, the filtrate and the glycoside hydrolase is 1:1:0.005 - 0.008.

[0016] Further, the conditions for the hydrolysis catalyzed by the glycoside hydrolase include a pH of 4.6 - 5.0, a temperature of 50°C - 60°C and a hydrolysis time of 1 h - 2 h.

[0017] The second object of the present invention is to provide a Pseudostellariae Radix extract prepared by a method for preparing a Pseudostellariae Radix extract through enzymatic hydrolysis.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) In the present invention, the Pseudostellariae Radix powder is first pretreated by water extraction to release some water - soluble components, and then the obtained filter residue is subjected to enzymatic hydrolysis with a combined enzyme. The combined enzyme is composed of cellulase, pectinase and papain. In this combined enzyme system, cellulase and pectinase can synergistically decompose the α - 1,4 - glycosidic bond and β - 1,4 - glycosidic bond in the cell wall of Pseudostellariae Radix, promote the cell wall structure of Pseudostellariae Radix to be more loose and reduce the viscosity of the cell wall, thereby making various active components in Pseudostellariae Radix more easily released and flowed out. Papain mainly enzymatically cleaves the protein components flowing out after cell wall breaking, and promotes the release of active substances such as amino acids and polypeptides. After the extract obtained by enzymatic hydrolysis of the combined enzyme and the filtrate obtained by water extraction are combined, they are subjected to hydrolysis treatment with glycoside hydrolase. The glycoside hydrolase can promote the conversion of substances containing glycoside components in Pseudostellariae Radix into aglycones with higher activity. This hydrolysis treatment of converting glycosides into aglycones can improve the activity of the Pseudostellariae Radix extract and reduce the problem of low activity caused by the low efficiency of the conversion of glycoside components into aglycones due to differences in human intestinal flora.

[0020] (2) In addition, the present invention also found that the particle size of Pseudostellaria heterophylla powder has an important influence on the efficiency of enzymatic hydrolysis by the combined enzymes. If Pseudostellaria heterophylla powder with larger particles is used, the hydrolysis efficiency may be reduced due to the lower effective contact area between the enzymes and the powder, thereby resulting in a lower release of active substances in Pseudostellaria heterophylla and affecting the activity of the prepared Pseudostellaria heterophylla extract. Therefore, the enzymatic hydrolysis system constructed in the present invention has strict requirements for the particle size of Pseudostellaria heterophylla powder. Detailed implementation mode

[0021] The technical solutions of the present invention will be clearly and completely described below through the examples of the present invention. Obviously, the described examples are only a part of the examples of the present invention, rather than all the examples. All other examples obtained by those skilled in the art based on the examples of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] Unless otherwise specified, the raw materials and reagents used in the present invention below are all commercially available products or can be prepared by known methods.

[0023] Cellulase, pectinase, papain and β-glucosidase were purchased from Shanghai Yuanye Bio-Technology Co., Ltd.

[0024] Example 1:

[0025] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis specifically includes the following process:

[0026] Wash Pseudostellaria heterophylla and dry it to constant weight, then cut Pseudostellaria heterophylla into small pieces with a slicing machine and put them into a pulverizer for grinding. Subsequently, sieve with a 200-mesh sieve to obtain Pseudostellaria heterophylla powder. Mix 1 part by weight of Pseudostellaria heterophylla powder with 10 parts by weight of deionized water, stir and disperse evenly, and then heat up to 100 °C and decoct for 2 h. After the decoction is completed, filter with a filter screen to obtain a filtrate and filter residue. According to the ratio of solid-liquid ratio of 1:5, mix 1 part by weight of the filter residue and 5 parts by weight of deionized water, stir and disperse evenly, and then use a pipette to absorb 0.002 part by weight of a combined enzyme (use a pipette to absorb and mix cellulase, pectinase and papain in the same mass ratio, and gently blow back and forth with a pipette to mix evenly to obtain the combined enzyme) and add it to the mixture of filter residue and water, and mix and stir at a speed of 50 r / min for 30 min to form a slurry. Adjust the pH value of the slurry to 5.5 with dilute hydrochloric acid, and then place it in a temperature environment of 40 °C for 2 h of enzymatic hydrolysis treatment. After the enzymatic hydrolysis treatment is completed, heat up to 80 °C to inactivate for 10 min and then cool to room temperature. Subsequently, filter with a filter membrane to remove impurities to obtain an extract. Combine the above-obtained extract and filtrate according to equal amounts, and then use a pipette to absorb β-glucosidase with a weight of 0.005 times the weight of the extract and add it to the mixture of the extract and filtrate, and mix and stir at a speed of 50 r / min for 30 min to obtain a reaction solution. Subsequently, adjust the pH value of the reaction solution to 4.6 with dilute hydrochloric acid, and then place it in a temperature environment of 50 °C for 1 h of hydrolysis treatment. After the hydrolysis treatment is completed, further heat up to 80 °C for inactivation treatment for 15 min, and then cool to room temperature to obtain a hydrolysate. Put the hydrolysate on a rotary evaporator to evaporate water until the water content reaches 18-20% to obtain a concentrated solution, and the concentrated solution is further dried with hot air at 70 °C to form a powder to obtain the Pseudostellaria heterophylla extract.

[0027] Example 2:

[0028] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis, specifically including the following process:

[0029] Wash Pseudostellaria heterophylla and dry it to constant weight, then cut Pseudostellaria heterophylla into small pieces with a slicing machine and put them into a pulverizer for powdering. Subsequently, sieve with a 200-mesh sieve to obtain Pseudostellaria heterophylla powder. Mix 1 part by weight of Pseudostellaria heterophylla powder with 10 parts by weight of deionized water, stir and disperse evenly, and then heat up to 100 °C and decoct for 2.5 h. After the decoction, filter with a filter screen to obtain a filtrate and filter residue. According to the ratio of solid-liquid ratio of 1:5, mix 1 part by weight of the filter residue and 5 parts by weight of deionized water, stir and disperse evenly, and then use a pipette to suck 0.003 part by weight of a combined enzyme (use a pipette to suck and mix cellulase, pectinase and papain in the same mass ratio, and gently blow back and forth with a pipette to mix evenly to obtain the combined enzyme) and add it to the mixture of the filter residue and water, and mix and stir at a speed of 50 r / min for 30 min to form a slurry. Adjust the pH value of the slurry to 6.0 with dilute hydrochloric acid, and then place it in a temperature environment of 45 °C for 2.5 h of enzymatic hydrolysis treatment. After the enzymatic hydrolysis treatment, heat up to 80 °C to inactivate for 10 min and then cool to room temperature, and then filter with a filter membrane to remove impurities to obtain an extract. Combine the above-obtained extract and filtrate and mix them equally, and then use a pipette to suck β-glucosidase with a weight 0.006 times that of the extract and add it to the mixture of the extract and filtrate, and mix and stir at a speed of 50 r / min for 30 min to obtain a reaction solution. Subsequently, adjust the pH value of the reaction solution to 4.8 with dilute hydrochloric acid, and then place it in a temperature environment of 55 °C for 1.5 h of hydrolysis treatment. After the hydrolysis treatment, further heat up to 80 °C for inactivation treatment for 15 min, and then cool to room temperature to obtain a hydrolyzate. Put the hydrolyzate on a rotary evaporator to rotary evaporate and remove water until the water content reaches the range of 18-20% to obtain a concentrated solution, and the concentrated solution is further dried by hot air at 70 °C to form a powder to obtain Pseudostellaria heterophylla extract.

[0030] Example 3:

[0031] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis, specifically including the following process:

[0032] The Pseudostellaria heterophylla is washed and dried to a constant weight, then cut into small pieces by a slicing machine and ground into powder in a pulverizer. Subsequently, the Pseudostellaria heterophylla powder is screened through a 200-mesh sieve to obtain the Pseudostellaria heterophylla powder. 1 part by weight of the Pseudostellaria heterophylla powder is mixed with 10 parts by weight of deionized water and stirred until evenly dispersed, and then heated to 100 °C and decocted for 3 h. After the decoction is completed, it is filtered through a filter screen to obtain a filtrate and residues. According to the ratio of solid to liquid of 1:5, 1 part by weight of the residues and 5 parts by weight of deionized water are mixed and stirred until evenly dispersed. Subsequently, 0.004 part by weight of a combined enzyme (the cellulase, pectinase and papain are sucked and mixed in the same mass ratio with a pipette, and gently pipetted back and forth with a pipette to mix evenly to obtain the combined enzyme) is added to the mixture of residues and water, and the mixture is stirred at a speed of 50 r / min for 30 min to form a slurry. The pH value of the slurry is adjusted to 6.0 with dilute hydrochloric acid, and then placed in a temperature environment of 45 °C for an enzymatic hydrolysis treatment for 2.5 h. After the enzymatic hydrolysis treatment is completed, it is heated to 80 °C for inactivation for 10 min and then cooled to room temperature. Subsequently, it is filtered through a filter membrane to remove impurities to obtain an extract. The above-obtained extract and filtrate are combined and mixed in equal amounts, and then 0.007 times the weight of the extract of β-glucosidase is sucked with a pipette and added to the mixture of the extract and the filtrate, and the mixture is stirred at a speed of 50 r / min for 30 min to obtain a reaction solution. Subsequently, the pH value of the reaction solution is adjusted to 4.8 with dilute hydrochloric acid, and then placed in a temperature environment of 55 °C for a hydrolysis treatment for 1.5 h. After the hydrolysis treatment is completed, it is further heated to 80 °C for inactivation treatment for 15 min, and then cooled to room temperature to obtain a hydrolysate. The hydrolysate is placed on a rotary evaporator to evaporate water until the water content reaches the range of 18-20% to obtain a concentrated solution, and the concentrated solution is further dried by hot air at 70 °C to form a powder to obtain the Pseudostellaria heterophylla extract.

[0033] Example 4:

[0034] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis specifically includes the following process:

[0035] Wash Pseudostellaria heterophylla, dry it to a constant weight, then cut Pseudostellaria heterophylla into small pieces with a slicer and put them into a pulverizer for grinding. Subsequently, sieve with a 200-mesh sieve to obtain Pseudostellaria heterophylla powder. Mix 1 part by weight of Pseudostellaria heterophylla powder with 10 parts by weight of deionized water, stir and disperse evenly, and then heat to 100 °C and decoct for 4 h. After the decoction, filter with a filter screen to obtain a filtrate and residues. According to the ratio of solid-liquid ratio of 1:5, mix 1 part by weight of residues and 5 parts by weight of deionized water, stir and disperse evenly. Subsequently, pipette 0.005 part by weight of a combined enzyme (pipette cellulase, pectinase and papain according to the same mass ratio and gently pipette back and forth to mix evenly to obtain the combined enzyme) into the mixture of residues and water, and mix and stir at a speed of 50 r / min for 30 min to form a slurry. Adjust the pH value of the slurry to 6.5 with dilute hydrochloric acid, and then place it in a temperature environment of 50 °C for 3 h of enzymatic hydrolysis treatment. After the enzymatic hydrolysis treatment, heat to 80 °C to inactivate for 10 min and then cool to room temperature. Subsequently, filter with a filter membrane to remove impurities to obtain an extract. Combine the above-obtained extract and filtrate according to equal amounts and mix. Then, pipette 0.008 times the weight of the extract of β-glucosidase into the mixture of the extract and the filtrate, and mix and stir at a speed of 50 r / min for 30 min to obtain a reaction solution. Subsequently, adjust the pH value of the reaction solution to 5.0 with dilute hydrochloric acid, and then place it in a temperature environment of 60 °C for 2 h of hydrolysis treatment. After the hydrolysis treatment, further heat to 80 °C for inactivation treatment for 15 min, and then cool to room temperature to obtain a hydrolyzate. Place the hydrolyzate on a rotary evaporator to evaporate water until the water content reaches the range of 18-20% to obtain a concentrated solution. The concentrated solution is further dried by hot air at 70 °C to form a powder to obtain Pseudostellaria heterophylla extract.

[0036] Comparative Example 1:

[0037] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis, specifically including the following process:

[0038] Replace the combined enzyme in Example 4 with a single cellulase, and keep the other conditions the same as in Example 4.

[0039] Comparative Example 2:

[0040] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis, specifically including the following process:

[0041] Replace the combined enzyme in Example 4 with a single pectinase, and keep the other conditions the same as in Example 4.

[0042] Comparative Example 3:

[0043] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis, specifically including the following process:

[0044] Replace the combined enzyme in Example 4 with a single papain, and keep the other conditions the same as in Example 4.

[0045] Comparative Example 4:

[0046] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis specifically includes the following process:

[0047] Replace the cellulase and pectinase in the combined enzyme of Example 4 with hemicellulase and ligninase, and keep the other conditions the same as in Example 4.

[0048] Comparative Example 5:

[0049] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis specifically includes the following process:

[0050] Mix the filtrate and the extract obtained in Example 4 according to a mass ratio of 1:1, and directly place it on a rotary evaporator to perform rotary evaporation to remove water until the water content reaches the range of 18 - 20% to obtain a concentrated solution. The concentrated solution is then dried by hot air at 70°C to form a powder to obtain the Pseudostellaria heterophylla extract.

[0051] Comparative Example 6:

[0052] A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis specifically includes the following process:

[0053] Replace the Pseudostellaria heterophylla powder in Example 4 with Pseudostellaria heterophylla slices with a length of 2 cm processed by a slicing machine, and keep the other conditions the same as in Example 4.

[0054] Detection of antioxidant activity:

[0055] (1) Determination of DPPH scavenging effect:

[0056] First, weigh a certain amount of DPPH (1,1-diphenyl-2-picrylhydrazyl), and prepare a DPPH solution with a molar concentration of 0.08 mmol / L using absolute ethanol. Take the Radix Pseudostellariae extracts powders prepared in Examples 1-4 and Comparative Examples 1-6 and uniformly prepare a Radix Pseudostellariae extract solution with a concentration of 2 mg / mL. Use the solution without the Radix Pseudostellariae extracts powder as a blank control. Then, mix the 0.08 mmol / L DPPH solution and the 2 mg / mL Radix Pseudostellariae extract solution in equal amounts and react in the dark at room temperature for 10 min. Measure the absorbance at a wavelength of 517 nm in a microplate reader. Subsequently, calculate the scavenging rate of the Radix Pseudostellariae extract against DPPH according to the calculation formula of DPPH free radical scavenging rate = [A1 - (A2 - A3)] ÷ A1 × 100% (where A1: the absorbance of the blank control, A2: the absorbance after the equal amount mixing reaction of the 0.08 mmol / L DPPH solution and the 2 mg / mL Radix Pseudostellariae extract solution, A3: the absorbance of the 2 mg / mL Radix Pseudostellariae extract solution). The results are shown in Table 1 below.

[0057] Table 1 DPPH Scavenging Rate

[0058]

[0059]

[0060] The following conclusions can be drawn from the results of the above antioxidant activity tests:

[0061] (1) It can be found from Examples 1-4 that by subjecting the Radix Pseudostellariae powder with a certain particle size to pre-water decoction treatment and then enzymatically hydrolyzing and breaking the cell wall of the Radix Pseudostellariae filter residue obtained after water decoction with a combined enzyme, the further release of the active ingredients of Radix Pseudostellariae can be promoted. Then, hydrolyzing the filtrate and the extract obtained by breaking the cell wall with β-glucosidase can promote the generation of aglycones with higher activity, making the finally prepared Radix Pseudostellariae extract have good performance in terms of antioxidant.

[0062] (2) It can be seen from Comparative Examples 1-3 that the effect of single enzyme catalyzing the cell wall breaking of Radix Pseudostellariae is poor, resulting in poor antioxidant performance of the finally prepared Radix Pseudostellariae extract. Especially when only papain is used, the effect is even worse. This may be because papain mainly catalyzes the decomposition of proteases into peptides or amino acids and hardly decomposes the cell wall, so the antioxidant activity is extremely poor.

[0063] (3) It can be seen from Comparative Example 4 that although both hemicellulase and ligninase have the function of catalyzing cell wall decomposition, their catalytic efficiency in this system is poor, thus resulting in poor antioxidant activity performance of the prepared Radix Pseudostellariae extract.

[0064] (4) It can be found from Comparative Example 5 that without the hydrolysis treatment by β-glucosidase, the antioxidant activity of the Pseudostellariae Radix extract is relatively low. Thus, it can be seen that in this system, the use of glycoside hydrolase plays an important role in improving the activity of the Pseudostellariae Radix extract.

[0065] (5) It can be found from Comparative Example 6 that in this system, when using enzymatic catalysis, the contact area between the block-shaped Pseudostellariae Radix and the combined enzyme is smaller compared with that of the powdered Pseudostellariae Radix, which may lead to incomplete enzymatic hydrolysis, and further may result in less release of the active ingredients of Pseudostellariae Radix, making the antioxidant activity of the finally prepared Pseudostellariae Radix extract relatively poor.

[0066] The above-described embodiments have detailed the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis, characterized in that, The method comprises the following steps: Mix the Pseudostellaria heterophylla powder with deionized water 10 times its own weight and decoct for 2 h to 4 h to obtain a filtrate and residues; Mix the residues, deionized water and composite enzyme to form a slurry, and the slurry is sequentially subjected to enzymatic hydrolysis, inactivation and filtration to obtain an extract; After the extract and the filtrate are combined, they are hydrolyzed and catalyzed by glycoside hydrolase and then inactivated to obtain a hydrolysate, and the hydrolysate is sequentially subjected to rotary evaporation and hot air drying to obtain the Pseudostellaria heterophylla extract.

2. The method for preparing Pseudostellariae Radix extract by enzymatic hydrolysis according to claim 1, wherein The Pseudostellaria heterophylla powder is obtained by screening through a 200-mesh sieve.

3. The method for preparing Pseudostellariae Radix extract by enzymatic hydrolysis according to claim 1, wherein The composite enzyme is composed of cellulase, pectinase and papain mixed in a mass ratio of 1:1:

1.

4. The method for preparing Radix Pseudostellariae extract by enzymatic hydrolysis according to claim 1, wherein The weight ratio of the residues, deionized water and composite enzyme is 1:5:0.002 to 0.

005.

5. The method for preparing Radix Pseudostellariae extract by enzymatic hydrolysis according to claim 1, wherein, The conditions for the enzymatic hydrolysis include a pH of 5.5 to 6.5, a temperature of 40°C to 50°C and an enzymatic hydrolysis time of 2 h to 3 h.

6. The method for preparing Pseudostellaria heterophylla extract by enzymatic hydrolysis according to claim 1, wherein The glycoside hydrolase is β-glucosidase.

7. The method for preparing Pseudostellariae Radix extract by enzymatic hydrolysis according to claim 1, characterized in that, The weight ratio of the extract: filtrate: glycoside hydrolase is 1:1:0.005 to 0.

008.

8. The method for preparing Pseudostellariae Radix extract by enzymatic hydrolysis according to claim 1, wherein The conditions for the hydrolysis and catalysis by the glycoside hydrolase include a pH of 4.6 to 5.0, a temperature of 50°C to 60°C and a hydrolysis time of 1 h to 2 h.

9. A Pseudostellaria heterophylla extract prepared by the method for preparing a Pseudostellaria heterophylla extract by enzymatic hydrolysis according to any one of claims 1 to 8.

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