Preparation method and application of composite plant extract for inhibiting adenosine deaminase activity

Abstract

The present invention discloses a preparation method and application of a composite plant extract for inhibiting the activity of adenosine deaminase, and belongs to the technical field of plant extract preparation. The present invention relates to a process of mixing clove buds and wild chrysanthemum inflorescences, and increasing the release rate of alcohol-soluble active substances (esters and ketones) in plant cells by common steam explosion, and further increasing the purity of alcohol-soluble active substances in the composite plant extract after alcohol extraction and water washing and impurity removal steps. The composite plant extract has a good inhibitory effect on the activity of adenosine deaminase, and can effectively reduce the ammonia odor of feces of pet dogs after feeding them, and can also improve the quality of dog hair.

Description

Technical Field

[0001] The invention relates to the technical field of plant extract preparation, and in particular to a method for preparing a composite plant extract capable of inhibiting adenosine deaminase activity and application of the composite plant extract in dog food. Background Art

[0002] Adenosine deaminase is widely distributed in animals and is an important enzyme in the metabolism of purine nucleosides. It catalyzes the decomposition of adenosine and converts it into creatinine and ammonia through irreversible deamination. Adenosine is a compound formed by the connection of N-9 of adenine and C-1 of D-ribose through a β-glycosidic bond. After being absorbed by the body, it will be rapidly taken up by red blood cells and vascular endothelial cells, and will be phosphorylated to produce adenylic acid, which participates in physiological processes such as energy metabolism, dilation of coronary blood vessels and increase of blood flow. It also has the effect of upregulating the expression of angiogenin, thereby promoting the growth of animal hair follicles and the proliferation of hair papilla cells. When the activity of adenosine deaminase in the intestine of animals is high, it will lead to excessive decomposition of adenosine from food, which reduces the effective utilization of adenosine in food by the body.

[0003] Clove and wild chrysanthemum, as Chinese medicinal materials, have the effects of clearing away heat and detoxifying, promoting qi and removing dampness (an ancient method of calming the nerves and preventing epidemics incense pills and their preparation method, CN202311526060.2; an antioxidant natural plant lip balm and its preparation method, CN202410733356.X). They are also used in pets. For example, Pu Jihua used the water extract of wild chrysanthemum to treat canine acute gastroenteritis (Study on the therapeutic effect of wild chrysanthemum extraction process and chicken extract on canine acute gastroenteritis model, 2012), as well as to maintain the health of pet teeth (pet dog snacks and preparation method for improving pet dog dental plaque and tartar, CN202311842812.6), promote growth and digestion (a dog food for improving growth and digestive function and its production method, CN202111204447.7), and relieve tear stains (an extruded grain for relieving dog tear stains and its preparation device, CN202311116980.7). However, there is no report on the research on preparing plant extracts with inhibitory adenosine deaminase activity using clove and wild chrysanthemum as raw materials. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a composite plant extract capable of inhibiting the activity of adenosine deaminase and the application of the composite plant extract in dog food.

[0005] The first aspect of the present invention provides a composite plant extract having the function of inhibiting the activity of adenosine deaminase, which is composed of the following raw materials in terms of mass fraction:

[0006] 30-70 portions of dried clove buds;

[0007] 30-70 portions of dried wild chrysanthemum inflorescence products.

[0008] The second aspect of the present invention provides a method for preparing a composite plant extract having the function of inhibiting the activity of adenosine deaminase, which is carried out according to the following steps:

[0009] (1) mixing 30 to 70 parts by weight of a dried clove bud product and 30 to 70 parts by weight of a dried wild chrysanthemum inflorescence product, rehydrating the mixture to adjust the moisture content to 20% to 30%, and then steam-exploding the mixture;

[0010] (2) adding the material to an ethanol solution for alcohol extraction, concentrating the filtrate after centrifugation, and freeze-drying to prepare an alcohol extract;

[0011] (3) The alcohol extract is washed with water to remove impurities and obtain a composite plant extract.

[0012] In the above step (1), the steam explosion has the following parameters: explosion pressure of 0.3-1.5 MPa and pressure holding time of 30-360 s.

[0013] In the above step (2), the alcohol extraction is carried out by adding 50-100 g / L of the material to an ethanol solution with a pH of 5.5-6.5 and an ethanol volume fraction of 40%-70%; and extracting at a temperature of 35-45° C. for 2-6 hours.

[0014] In the above step (3), the water washing and impurity removal is carried out by adding distilled water at a rate of 100 g / L to the alcohol extract, stirring the mixture at 30-50° C. for 1-2 hours, centrifuging the mixture, collecting the precipitate, drying the mixture in an oven at 40-60° C., and then crushing the mixture to obtain the composite plant extract.

[0015] The third aspect of the present invention provides the use of the composite plant extract prepared by the above method in dog food.

[0016] Furthermore, the above-mentioned composite plant extract can also be applied to other pets such as cats, foxes, hamsters, etc.

[0017] Furthermore, the application method is to feed the composite plant extract prepared by the above method to dogs by directly feeding or mixing it into dog food (or snacks).

[0018] The beneficial effects of the present invention are as follows:

[0019] In the present invention, the clove buds and wild chrysanthemum inflorescences are subjected to rehydration and steam explosion operations, which are helpful to destroy the plant cell walls with dense structures and produce micropores, so that active substances can be fully released from the cells, which is conducive to the efficient dissolution of alcohol-soluble active substances (esters and ketones) rich in the clove buds and wild chrysanthemum inflorescences during alcohol extraction, and the materials are not crushed to facilitate rapid filtration. In addition, the alcohol extract is washed and impurities are removed, and some impurities (such as some amides and tannins) that are both alcohol-soluble and water-soluble can be cleaned and removed, thereby further enriching effective alcohol-soluble active substances. The composite plant extract prepared by the co-extraction and processing of the clove buds and wild chrysanthemum inflorescences shows better activity inhibition on adenosine deaminase than the mixture prepared by extracting and mixing the two plants separately, and the co-processing helps the active substances between the two plants to play a synergistic role.

[0020] According to the method of the present invention, the flavonoid content of the composite plant extract prepared by steam explosion and extraction of clove buds and wild chrysanthemum inflorescences reaches 2.46-2.63 mg / g, which is 5.23-6.26 times that of the mixture prepared by direct crushing without extraction (reference examples 2-4), and 2.18-2.68 times that of the mixture of extracts obtained by extracting the two plants separately (reference examples 5-7); it has a good inhibitory effect on adenosine deaminase, IC 50 It is 8.14-8.72 g / L, which is 73.28%-77.08% lower than the mixture prepared by direct crushing without extraction (Control Examples 2-4), and is 49.27%-62.28% lower than the mixture of extracts obtained by extracting two plants separately (Control Examples 5-7).

[0021] The results of the dog feeding test show that the composite plant extract prepared by the method of the present invention has the effect of reducing the activity of adenosine deaminase in dog feces. The activity of adenosine deaminase in dog feces fed with the extract is 9.72-10.24 U / mL, which is 62.14%-64.07% lower than that of the dog without the extract (control example 1), 57.65%-62.12% lower than that of the dog without the extract (control examples 2-4), and 43.83%-55.12% lower than that of the dog with the extract obtained by directly crushing without extraction (control examples 5-7).

[0022] The composite plant extract prepared by the method of the present invention has a good effect of alleviating the ammonia odor of dog feces. The feces odor score of dogs fed with the extract is 2.2-2.4 points, the volatile basic nitrogen content is 52.7-61.3 mg / 100g, and the ammonia content is 0.36-0.44 ppm / g. These three indicators are reduced by 46.67%-60.87% compared with the case where the extract is not fed (control example 1), reduced by 41.95%-59.09% compared with the case where the mixture prepared by directly crushing without extraction is fed (control examples 2-4), and reduced by 27.27%-52.63% compared with the case where the mixture of extracts obtained by extracting two plants separately is fed (control examples 5-7).

[0023] The composite plant extract prepared by the method of the present invention has the effect of improving the hair quality of dogs. The hair beauty score of dogs fed with the extract is 9.62-10.13 points, which is 83.24%-92.95% higher than that of dogs not fed with the extract (control example 1), 26.41%-38.20% higher than that of dogs fed with the mixture prepared by directly crushing without extraction (control examples 2-4), and 12.12%-25.68% higher than that of dogs fed with the mixture of extracts obtained by extracting two plants separately (control examples 5-7). DETAILED DESCRIPTION

[0024] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art. The present invention will be further described in detail below in conjunction with specific embodiments and with reference to data. It should be understood that these embodiments are only further explanations of the present invention and cannot be construed as limiting the scope of protection of the present invention. Technical engineers in this field may make some non-essential improvements and adjustments to the present invention based on the content of the above invention.

[0025] In the following examples, various processes and methods not described in detail are conventional methods known in the art. The sources, trade names and components of the reagents used are indicated when they first appear, and the same reagents used thereafter are the same as those indicated for the first time unless otherwise specified.

[0026] The dried clove buds and wild chrysanthemum inflorescences in the present embodiment and the comparative example are both commercially available.

[0027] The method for determining the flavonoid content of the extract or mixture in the present embodiment and the reference example is as follows:

[0028] The extract was extracted with anhydrous ethanol, diluted to a reasonable multiple, and the total flavonoid content was determined by spectrophotometry. The specific operation was carried out according to the steps of SN / T 4592-2016.

[0029] The half inhibitory concentration (IC 50) Determination method:

[0030] Prepare adenosine deaminase enzyme solution, and centrifuge the aqueous solution of the extract to retain the supernatant. Mix the supernatant and adenosine deaminase enzyme solution in equal volumes and let stand at 37°C for 15 minutes. Determine the adenosine deaminase enzyme activity of the mixed solution according to the instructions of the kit. Replace the supernatant with distilled water and follow the same steps to determine the enzyme activity as the control group. Enzyme activity inhibition rate (%) = [(enzyme activity of the control group - enzyme activity of the sample group) / enzyme activity of the control group] × 100%. Use the extract concentration as the horizontal axis and the enzyme activity inhibition rate as the vertical axis to draw a curve and calculate its IC 50 .

[0031] Method for determining the activity of adenosine deaminase in canine feces in this embodiment and control example:

[0032] Fresh dog feces samples were collected, mixed with physiological saline at a mass ratio of 1:1, and the supernatant was collected after tissue disruption and centrifugation (10000r / min, 10min). The adenosine deaminase activity of the sample solution was determined according to the kit instructions.

[0033] The manual evaluation method of feces odor degree in this embodiment and reference example is as follows:

[0034] 30g of fresh dog feces was placed in a 50mL stoppered test tube, and the tester conducted a sensory evaluation of the odor of the dog feces at a distance of 10cm from the tube mouth. The higher the odor, the higher the score, with a faint odor of 1 point, a perceptible odor of 2 points, a tolerable odor of 3 points, a strong odor that is difficult to tolerate of 4 points, and an extremely strong odor that is unbearable of 5 points.

[0035] The method for determining the volatile basic nitrogen content of dog feces in the present embodiment and the reference example is as follows:

[0036] Weigh 5g of fresh dog feces sample into a conical flask, add 10mL trichloroacetic acid solution (150g / L) and 40mL distilled water, and stir and extract for 30min. Take 30mL of the extract and centrifuge (3500r / min, 10min), then take 10mL of the supernatant into the digestive tube, add 10mL of sodium hydroxide solution (40g / L) and immediately distill it on the machine. Refer to "GB / T 32141-2015 Determination of Volatile Basic Nitrogen in Feed" to determine the volatile basic nitrogen content of the supernatant.

[0037] Method for determining ammonia content in dog feces in this embodiment and reference examples:

[0038] Weigh 10 g of fresh dog feces sample and put it into a ziplock bag. Insert the portable gas detector probe into the bag and ensure that the insertion length and angle are consistent. Record the reading after it stabilizes.

[0039] Each extract and mixture prepared in the control example and the embodiment was directly mixed into the dog's daily diet at 1% for supplementary feeding. In the control example 1, no supplementary feeding was performed, and the feces of the fed pet dogs had a serious ammonia odor (the odor score exceeded 4 points). 30 Teddy, Beagle, Corgi and Bichon Frise dogs were randomly divided into 10 groups, each group containing 3 dogs of each of the above 4 types. After 3 days of supplementary feeding, the feces were taken for fecal adenosine deaminase enzyme activity determination, odor degree evaluation, volatile basic nitrogen content, and ammonia content determination.

[0040] The test method for dog hair beauty scoring in this embodiment and the control example is as follows:

[0041] Each extract and mixture prepared in the control example and the embodiment was directly mixed into the dog's daily diet at 0.03% for supplementary feeding. In the control example 1, no supplementary feeding was performed, and the hair luster, hair smoothness and skin elasticity of the fed pet dogs were poor (the hair beauty score was less than or equal to 6 points). 30 Teddy, Beagle, Corgi and Bichon Frise dogs were randomly divided into 10 groups, each group containing 3 dogs of each of the above 4 types. After feeding for 21 days, the hair beauty scores of the dogs in each group were performed.

[0042] When the test dog is in a relaxed state, use a fine-tooth comb to slowly comb the dog's hair on the back until the skin is exposed, and evaluate the hair gloss, hair smoothness and skin elasticity through vision and touch. The hair beauty score = hair gloss score + hair smoothness score + skin elasticity score. The scoring criteria are as follows:

[0043] Hair gloss score: 1 point, dull hair; 2 points, darker hair; 3 points, average hair gloss; 4 points, glossy and bright hair; 5 points, glossy and shiny hair.

[0044] Hair smoothness score: 1 point, hair is tangled and dry; 2 points, hair is slightly tangled; 3 points, hair is rough and split; 4 points, hair is not tangled or split, and the smoothness is average; 5 points, hair is not tangled or split, and the smoothness is good.

[0045] Skin elasticity score: 1 point, no rebound after pressing; 2 points, slow rebound after pressing, more than 5 seconds; 3 points, average rebound after pressing, taking 3 to 5 seconds; 4 points, fast rebound after pressing, taking 1 to 3 seconds; 5 points, immediate rebound after pressing.

[0046] Comparative Example 1

[0047] Dogs with severe fecal ammonia odor were fed a normal diet without adding extracts. After the feeding test, the fecal adenosine deaminase activity was 27.05U / mL, the odor score was 4.5 points, the volatile basic nitrogen content was 116.4mg / 100g, and the ammonia content was 0.92ppm / g. The hair beauty score test result was 5.25 points.

[0048] Comparative Example 2

[0049] Take the dried clove buds, grind them and pass them through a 60-mesh sieve to obtain clove bud powder.

[0050] The results of physical and chemical tests showed that the flavonoid content of the clove bud powder was 0.42 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs was 25.66U / mL, the odor score was 4.2 points, the volatile basic nitrogen content was 107.1mg / 100g, and the ammonia content was 0.88ppm / g. The hair beauty score test result was 7.33 points.

[0051] Comparative Example 3

[0052] The dried wild chrysanthemum inflorescence was taken, crushed and passed through a 60-mesh sieve to obtain wild chrysanthemum inflorescence powder.

[0053] The results of physical and chemical tests showed that the flavonoid content of the wild chrysanthemum inflorescence powder was 0.47 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs was 24.18U / mL, the odor score was 4.4 points, the volatile basic nitrogen content was 105.6mg / 100g, and the ammonia content was 0.85ppm / g. The hair beauty score test result was 7.61 points.

[0054] Comparative Example 4

[0055] The dried clove bud product and the dried wild chrysanthemum inflorescence product were taken, crushed separately and passed through a 60-mesh sieve, and the two powders were mixed in a mass ratio of 7:3 to obtain a mixture of clove bud powder and wild chrysanthemum inflorescence powder.

[0056] The results of physical and chemical tests showed that the flavonoid content of the mixture of clove bud powder and wild chrysanthemum inflorescence powder was 0.44 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs was 24.95U / mL, the odor score was 4.2 points, the volatile basic nitrogen content was 106.9mg / 100g, and the ammonia content was 0.84ppm / g. The hair beauty score test result was 7.44 points.

[0057] Comparative Example 5

[0058] Take the dried clove bud product, rehydrate to adjust the water content to 30%, and steam explode under the conditions of blasting pressure of 1.5MPa and pressure holding time of 30s. Collect the material after steam explosion, take the material and add ethanol solution (pH 6.5, ethanol volume fraction 40%) at 50g / L, extract for 6h at 35℃, and keep stirring during the extraction process. After centrifugation, retain the filtrate, and obtain the alcohol extract after reduced pressure concentration, freeze drying and crushing. Take the alcohol extract and add distilled water at 100g / L, stir at 50℃ for 1h, retain the precipitate after centrifugation, dry it in an oven at 40℃, and crush it to obtain the clove bud extract.

[0059] The results of physical and chemical tests showed that the flavonoid content of the clove bud extract was 0.98 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs was 21.66U / mL, the odor score was 3.8 points, the volatile basic nitrogen content was 94.3mg / 100g, and the ammonia content was 0.72ppm / g. The hair beauty score test result was 8.06 points.

[0060] Comparative Example 6

[0061] Take the dried product of wild chrysanthemum inflorescence, adjust the water content to 30% by rehydration, and steam explode under the conditions of blasting pressure of 1.5MPa and pressure holding time of 30s. Collect the materials after steam explosion, take the materials and add ethanol solution (pH 6.5, ethanol volume fraction 40%) at 50g / L, extract for 6h at 35℃, and keep stirring during the extraction process. After centrifugation, retain the filtrate, and obtain the alcohol extract after reduced pressure concentration, freeze drying and crushing. Take the alcohol extract and add distilled water at 100g / L, stir at 50℃ for 1h, retain the precipitate after centrifugation, dry it in an oven at 40℃, and crush it to obtain the wild chrysanthemum inflorescence extract.

[0062] The results of physical and chemical tests showed that the flavonoid content of the wild chrysanthemum inflorescence extract was 1.13 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs was 18.23U / mL, the odor score was 3.5 points, the volatile basic nitrogen content was 91.5mg / 100g, and the ammonia content was 0.75ppm / g. The hair beauty score test result was 8.58 points.

[0063] Comparative Example 7

[0064] Take the dried clove buds and wild chrysanthemum inflorescences, rehydrate them to adjust the water content to 30%, and steam explode them under the conditions of blasting pressure of 1.5MPa and holding time of 30s. Collect the materials after steam explosion, add ethanol solution (pH 6.5, ethanol volume fraction 40%) at 50g / L, extract for 6h at 35℃, and keep stirring during the extraction process. After centrifugation, retain the filtrate, concentrate under reduced pressure, freeze-dry and crush to obtain the alcohol extract. Take the alcohol extract and add distilled water at 100g / L, stir at 50℃ for 1h, centrifuge and retain the precipitate, dry it in an oven at 40℃, crush it separately, and mix the two powders at a mass ratio of 7:3 to obtain a mixture of clove bud extract and wild chrysanthemum inflorescence extract.

[0065] The results of physical and chemical tests showed that the flavonoid content of the clove bud extract-wild chrysanthemum inflorescence extract mixture was 1.08 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs was 19.19U / mL, the odor score was 3.3 points, the volatile basic nitrogen content was 88.6mg / 100g, and the ammonia content was 0.76ppm / g. The hair beauty score test result was 8.29 points.

[0066] Example 1

[0067] Take 700g of dried clove buds and 300g of dried wild chrysanthemum inflorescence by weight, rehydrate them together to adjust the water content to 30%, and steam explode them under the conditions of blasting pressure 1.5MPa and pressure holding time 30s. Collect the materials after steam explosion, take the materials and add ethanol solution (pH 6.5, ethanol volume fraction 40%) at 50g / L, extract for 6h at 35°C, and keep stirring during the extraction process. After centrifugation, retain the filtrate, and obtain an alcohol extract after reduced pressure concentration, freeze drying and crushing. Take the alcohol extract and add distilled water at 100g / L, stir and treat for 1h at 50°C, retain the precipitate after centrifugation, place it in an oven at 40°C for drying, and crush it to obtain a composite plant extract.

[0068] The results of physical and chemical tests showed that the flavonoid content of this composite plant extract reached 2.46 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs dropped to 9.72U / mL, the odor score dropped to 2.4 points, the volatile basic nitrogen content dropped to 52.7mg / 100g, and the ammonia content dropped to 0.42ppm / g. The hair beauty score test result was 9.84 points.

[0069] Example 2

[0070] Take 300g of dried clove buds and 700g of dried wild chrysanthemum inflorescence by weight, adjust the water content to 20% by rehydration, and steam explosion is performed under the conditions of blasting pressure 0.3MPa and pressure holding time 360s. Collect the materials after steam explosion, take the materials and add ethanol solution (pH 5.5, ethanol volume fraction 70%) at 100g / L, extract for 2h at 45°C, and keep stirring during the extraction process. After centrifugation, retain the filtrate, and obtain an alcohol extract after reduced pressure concentration, freeze drying and crushing. Take the alcohol extract and add distilled water at 100g / L, stir and treat for 2h at 30°C, retain the precipitate after centrifugation, place it in an oven at 60°C for drying, and crush it to obtain a composite plant extract.

[0071] The results of physical and chemical tests showed that the flavonoid content of this composite plant extract reached 2.63 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs dropped to 10.24U / mL, the odor score dropped to 2.2 points, the volatile basic nitrogen content dropped to 61.3mg / 100g, and the ammonia content dropped to 0.44ppm / g. The hair beauty score test result was 9.62 points.

[0072] Example 3

[0073] Take 500g of dried clove buds and 500g of dried wild chrysanthemum inflorescence by weight, adjust the water content to 25% by rehydration, and steam explode under the conditions of blasting pressure 0.9MPa and pressure holding time 195s. Collect the materials after steam explosion, add ethanol solution (pH 6.0, ethanol volume fraction 55%) at 75g / L, extract for 4h at 40°C, and keep stirring during the extraction process. After centrifugation, retain the filtrate, and obtain an alcohol extract after reduced pressure concentration, freeze drying and crushing. Take the alcohol extract and add distilled water at 100g / L, stir and treat at 40°C for 1.5h, retain the precipitate after centrifugation, place it in an oven at 50°C for drying, and crush it to obtain a composite plant extract.

[0074] The results of physical and chemical tests showed that the flavonoid content of this composite plant extract reached 2.57 mg / g, and the IC 50 The animal test results show that after the feeding test, the fecal adenosine deaminase activity of dogs dropped to 9.89U / mL, the odor score dropped to 2.3 points, the volatile basic nitrogen content dropped to 56.5mg / 100g, and the ammonia content dropped to 0.36ppm / g. The hair beauty score test result was 10.13 points.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite plant extract for inhibiting the enzymatic activity of adenosine deaminase, characterized in that: It is composed of the following raw materials by mass fraction: 30-70 portions of dried clove buds; 30-70 portions of dried wild chrysanthemum inflorescence products.

2. The method for preparing a composite plant extract having the function of inhibiting adenosine deaminase activity according to claim 1, characterized in that Follow these steps: (1) mixing 30 to 70 parts by weight of a dried clove bud product and 30 to 70 parts by weight of a dried wild chrysanthemum inflorescence product, rehydrating the mixture to adjust the moisture content to 20% to 30%, and then steam-exploding the mixture; (2) adding the material to an ethanol solution for alcohol extraction, concentrating the filtrate after centrifugation, and freeze-drying to prepare an alcohol extract; (3) The alcohol extract is washed with water to remove impurities and obtain a composite plant extract.

3. The method for preparing a composite plant extract having the function of inhibiting the activity of adenosine deaminase according to claim 1, characterized in that In the above step (1), the steam explosion has the following parameters: explosion pressure of 0.3-1.5 MPa and pressure holding time of 30-360 s.

4. The method for preparing a composite plant extract having the function of inhibiting the activity of adenosine deaminase according to claim 1, characterized in that In the above step (2), the alcohol extraction is carried out by adding 50-100 g / L of the material to an ethanol solution with a pH of 5.5-6.5 and an ethanol volume fraction of 40%-70%; and extracting at a temperature of 35-45° C. for 2-6 hours.

5. The method for preparing a composite plant extract having the function of inhibiting the activity of adenosine deaminase according to claim 1, characterized in that In the above step (3), the water washing and impurity removal is carried out by adding distilled water at a rate of 100 g / L to the alcohol extract, stirring the mixture at 30-50° C. for 1-2 hours, centrifuging the mixture, collecting the precipitate, drying the mixture in an oven at 40-60° C., and then crushing the mixture to obtain the composite plant extract.

6. Use of the composite plant extract having the function of inhibiting the activity of adenosine deaminase according to claim 1 in dog food.

7. The composite plant extract having the function of inhibiting the activity of adenosine deaminase according to claim 1 is used in cats, foxes, hamsters and other pets.