Preparation method of uric acid reducing medicine based on pteridium aquilinum water extract

Abstract

The invention relates to a preparation method of a uric acid reducing medicine based on a pteridium aquilinum water extract, and belongs to the technical field of traditional Chinese medicines. The method comprises the following specific operation steps: (1) cutting fresh pteridium aquilinum into sections, adding water, and performing reflux extraction; filtering to obtain filtrate; performing vacuum concentration and spray drying to obtain brown powdery pteridium aquilinum water extract; the pteridium aquilinum polysaccharide composition contains pteridium aquilinum polysaccharide, protein, micromolecule polypeptide, linolenic acid, oxyproline, malic acid, dextro-quinic acid, choline and the like. (2) uniformly mixing the pteridium aquilinum water extract, an excipient, a disintegrating agent and a lubricant, adding water, granulating, and pressing into tablets with the mass of 0.40 g; the mass content of the pteridium aquilinum water extract in each tablet is 80-88%. The dosage of the uric acid reducing medicine is 67 mg per kilogram of body weight every day. The uric acid reducing medicine is directly prepared from the pteridium aquilinum water extract as an effective part and is a pure traditional Chinese medicine preparation; animal acute toxicity experiments prove that the uric acid reducing drug belongs to a non-toxic level and is very safe.

Description

Technical Field

[0001] The invention belongs to the technical field of traditional Chinese medicines, and particularly relates to a method for preparing a uric acid-lowering drug from a bracken water extract. Background Art

[0002] Uric acid is the end product of human purine metabolism, which is produced by hypoxanthine and xanthine under the action of xanthine oxidase (XO). Due to the lack of urate oxidase in the human body, it cannot be further broken down into soluble allantoin, making humans very prone to hyperuricemia. Any cause of increased uric acid production or decreased excretion can lead to hyperuricemia. Hyperuricemia is usually considered a sign of gout. According to statistics, about 5%-12% of hyperuricemia can eventually develop into gout. Studies have shown that hyperuricemia is not only the most important biochemical basis of gout, but also closely related to the occurrence of hypertension, hyperlipidemia, atherosclerosis, obesity, and insulin resistance. It has become a serious metabolic disease that threatens human health.

[0003] At present, the methods for relieving gout symptoms mainly start from reducing uric acid production and increasing uric acid excretion, including using purine oxidase inhibitors such as allopurinol and febuxostat to reduce uric acid production, or using probenecid, benzbromarone and other drugs to inhibit uric acid reabsorption in the renal tubules, increase uric acid excretion to relieve gout symptoms, or use colchicine to neutralize and inhibit uric acid; however, allopurinol and febuxostat are very likely to cause allergic reactions or liver and kidney damage, probenecid cannot be used for patients with renal insufficiency, and colchicine has clear cytotoxicity. In recent years, drugs such as rasburicase, pegloticase, rasburicase and peglotidase have emerged to catalyze the conversion of uric acid into allantoin, but these drugs have great toxic side effects and patients often cannot tolerate them, which limits their use to a certain extent.

[0004] Therefore, finding highly effective and low-toxic uric acid-lowering drugs remains a difficulty in the current research and development of new uric acid-lowering drugs.

[0005] The bracken used in the present invention is a plant of the genus Pteridaceae, Pteridaceae ( Pteridium aquilinum (L.) Kuhn var. a little wider (Desv.) Underw. ex Helle) has the effects of clearing away heat and resolving phlegm, diuresis and calming the nerves. The research team conducted in-depth research on the chemical composition of bracken water extracts and found that bracken contains polysaccharides, lipids, proteins, small molecule peptides, polyphenols, terpenes, organic acids, alkaloids and other compounds. Summary of the invention

[0006] Based on the research findings that bracken water extract can significantly reduce the uric acid level in hyperuricemic rats, the present invention provides a method for preparing a uric acid-lowering drug based on bracken water extract.

[0007] The preparation steps of a uric acid-lowering drug based on bracken water extract are as follows: (1) Preparation of bracken water extract 200 kg of fresh bracken was cut into 0.5-1.5 cm pieces, 400-600 kg of water was added, and reflux extraction was performed at 50-100° C. for 2-5 hours; the filtrate was filtered; the filtrate was concentrated under reduced pressure, and spray-dried to obtain 8.0-9.1 kg of brown powdered bracken water extract; The bracken water extract contains: 15.1-40.5% by mass of bracken polysaccharides, 5.1-11.6% by mass of proteins and small molecule polypeptides; and a certain amount of linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, a-linolenic acid and other small molecule substances.

[0008] The fresh bracken is a plant of the genus Pteridaceae, Pteridaceae ( Pteridium aquilinum (L.) Kuhn var. a little wider (Desv.) Underw. ex Heller) young leaves.

[0009] (2) Preparation of uric acid-lowering drugs 80-88% by weight of the extract, 10-15% by weight of the excipient, 1.5-3% by weight of the disintegrant and 0.5-2% by weight of the lubricant are uniformly mixed, an appropriate amount of water is added for granulation, and granules are obtained by a granulator; The granules are pressed into tablets by a tablet press; the mass of each tablet is 0.40 g, and the mass content of the bracken water extract in each tablet is 80-88%; The uric acid lowering drug has a daily dosage of 67 mg of bracken water extract per kilogram of body weight, achieving a significant uric acid lowering effect.

[0010] The technical solution is further defined as follows: In step (1), the fresh bracken is freshly picked bracken or fresh bracken frozen and stored at -20°C to -10°C.

[0011] In step (2), the excipient is microcrystalline cellulose.

[0012] In step (2), the disintegrant is two of cross-linked sodium carboxymethyl starch, sodium starch glycolate, and cross-linked sodium carboxymethyl cellulose.

[0013] In step (2), the lubricant is one or two of talc and stearic acid or talc or polyethylene glycol.

[0014] In step (2), the extract, excipient, disintegrant and lubricant are mixed uniformly according to the formula to prepare granules or capsules.

[0015] The beneficial technical effects of the present invention are embodied in the following aspects: 1. The present invention uses bracken water extract as an effective part to directly prepare a uric acid-lowering drug, without further separation and purification, and does not require any other special separation or purification treatment, and is a pure Chinese medicine preparation. The uric acid-lowering drug was prepared according to Example 1 and used in animal experiments on uric acid-lowering effects, and the results showed that it had a significant uric acid-lowering effect.

[0016] The specific animal experiments are as follows: (1) Materials and methods (1.1) Animals Rats: Clean grade adult male Kunming rats were purchased from the Medical Experimental Animal Center of Nanjing Medical University.

[0017] (1.2) Instruments and reagents: high-speed refrigerated centrifuge (Beckman, USA), ultra-low temperature refrigerator (Thermo, USA), electric constant temperature water box (Shanghai Boxun Industrial Co., Ltd.), UV2100 ultraviolet visible spectrophotometer (Beijing Rayleigh Analytical Instrument Co., Ltd.), uric acid test kit (Nanjing Jiancheng Bioengineering Institute), high yeast feed, adenine (SIGMA), allopurinol tablets (produced by Shanghai Xinyi Wanxiang Pharmaceutical Co., Ltd.); water was double distilled water, homemade. Uric acid-lowering drugs were crushed and dissolved in water for oral administration to rats.

[0018] (1.3) Experimental method: Rats were randomly divided into 6 groups, namely, blank control group, hyperuricemia group (model group), allopurinol group (positive drug group), high-, medium-, and low-dose groups of uric acid-lowering drugs. The model group was fed with 10% high yeast feed and given intragastric administration of adenine solution to prepare a hyperuricemia model; the control group was fed with ordinary rat pellet feed and given intragastric administration of the same volume of distilled water. The treatment group was given high-purine feed and adenine by intragastric administration and was given high, medium, and low doses of uric acid-lowering drugs by intragastric administration. The dosage was the amount of fresh bracken water extract in the uric acid-lowering drug, and the high, medium, and low doses were 0.8 g·kg -1 , 0.4g·kg -1 , 0.2g·kg -1 The experimental time was 30 days. Blood samples were collected from rats in each group 1 hour after administration of the corresponding drugs on the 10th, 20th and 30th days, and the blood samples were centrifuged (3000 r·min -1 , 10 min), take the supernatant and determine the uric acid content according to the instructions of the kit.

[0019] (1.4) Statistical methods The data of each group were expressed as x±s, and the differences between the means of each group were analyzed by variance analysis using statistical software.

[0020] (2) Experimental results The results of the blood samples on the 10th and 20th days showed that the uric acid-lowering effect of the uric acid-lowering drug was not significant. The results of the blood sample analysis on the 30th day are shown in Table 1.

[0021]

[0022] As can be seen from Table 1, the high-dose group and the medium-dose group administered for 30 days had an excellent inhibitory effect on hyperuricemia in rats, and uric acid dropped to the level of uric acid in the blank control group ( P >0.05), the low-dose group had no significant effect on reducing uric acid in rats with hyperuricemia. Overall, there was a dose-effect relationship.

[0023] Similarly, the uric acid-lowering drugs prepared in Examples 2 to 8 were used in animal experiments on anti-hyperuricemia in rats. The results showed that the uric acid-lowering drugs prepared in Examples 2 to 8 all had similar uric acid-lowering activity as the uric acid-lowering drug prepared in Example 1.

[0024] 2. The present invention uses bracken water extract as the effective part and directly prepares a uric acid-lowering drug according to Example 1 for clinical experiments as follows: 27 patients with hyperuricemia were treated clinically; 22 males with an average age of 49 years old took 4-7 tablets three times a day according to body weight for 30 consecutive days, and their uric acid levels were normal or basically normal. 5 females with an average age of 52 years old took 4-7 tablets three times a day for 30 consecutive days, and their uric acid levels were normal or basically normal.

[0025] The water extract of bracken has a strong effect in lowering uric acid, is safe and non-toxic, and is easy to take, and has excellent development prospects.

[0026] Application of bracken as a uric acid-lowering drug: Taking 67 mg of fresh bracken water extract per kilogram of body weight per day can achieve a significant uric acid-lowering effect.

[0027] The application of the bracken water extract provided by the present invention in uric acid lowering drugs can prepare the bracken water extract of the present invention into a variety of clinical drug dosage forms as uric acid lowering drugs, which have wide market applications and significant economic and social benefits.

[0028] 3. The animal acute toxicity experiment proves that the uric acid-lowering drug prepared by the present invention is non-toxic and very safe. The acute toxicity test of fresh bracken water extract is as follows: (1) Materials and methods (1.1) Animals Kunming mice, weighing (20±2) g, half male and half female, were purchased from the Medical Experimental Animal Center of Nanjing Medical University and were kept in the laboratory for one week for adaptation.

[0029] (1.2) Preparation of fresh bracken water extract A concentrated solution is prepared according to the above method for preparing the fresh bracken water extract, and the concentrated solution is spray-dried to obtain an extract.

[0030] (1.3) Animal experiment: Forty mice weighing (20±2)g, half male and half female, were randomly divided into four groups according to Horn's method, namely, the extract 2.15, 4.64, 10.00 and 21.50g / kg groups; the mice were fasted but not watered for 16h before oral gavage, and different concentrations of extract 40ml / kg were given by oral gavage according to the groups; after oral gavage, the activity, diet, hair, defecation and urine and death of the mice were observed for 7 consecutive days. For the dead mice, the tissue changes of their main organs such as heart, liver, spleen, lung and kidney were observed by dissection; the mice that did not die were killed on the 8th day of the experiment, and the tissue changes of their main organs such as heart, liver, spleen, lung and kidney were observed by dissection.

[0031] (1.4) Statistical methods The data of each group were expressed as x±s, and the differences between the means of each group were analyzed by variance analysis using statistical software.

[0032] (2) Results (2.1) Effects on general physical signs of mice: Four groups of mice were gavaged with the extract at 2.15, 4.64, 10.00 and 21.50 g / kg, respectively. Within 10 minutes after gavage, the mice showed poor mental state and reduced activity. Ten minutes later, the mice were active again, which was considered to be due to the effects of gavage. After 7 consecutive days of observation, all the test mice had smooth fur, normal diet, activity and defecation, and no abnormal secretions from the nose, eyes and mouth, and no adverse conditions occurred.

[0033] (2.2) Effects on the body weight of mice before and after administration As shown in Table 2, the extract groups had no effect on the body weight of mice ( P >0.05).

[0034]

[0035] (2.3) Death of mice Seven days after oral administration, the mice in each group appeared normal and no death was observed.

[0036] (2.4) Effects on the heart, liver, spleen, lungs, kidneys and other organs All mice were killed and dissected. No abnormal changes were found in the heart, liver, spleen, lungs, kidneys and stomach of the mice in each extract group.

[0037] From the above, it can be seen that there was no abnormality in mice after oral administration of 2.15, 4.64, 10.00 and 21.5 g / kg of the extract, indicating that the LD50 of the extract on mice 50 >21.50 g / kg, therefore, the bracken water extract is non-toxic.

[0038] 4. The present invention uses fresh bracken and does not require drying, thereby reducing energy consumption; does not require ether defatting, thereby reducing costs and increasing production safety; does not require ethanol extraction, but uses water for extraction, does not require solvent recovery, and thereby has low costs and high production safety. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with embodiments.

[0040] The fresh bracken used in the following examples is a plant of the genus Pteridaceae, Pteridaceae ( Pteridium aquilinum (L.) Kuhnvar. a little wider (Desv.) Underw. ex Heller) young leaves. Example 1

[0041] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract 200 kg of fresh bracken was directly cut into 0.5 cm pieces; 400 kg of water was added, and reflux extraction was performed at 50°C for 5 hours; the filtrate was filtered; the filtrate was concentrated under reduced pressure; and 8.8 kg of bracken water extract was obtained by spray drying.

[0042] The water extract of bracken contains: 15.1% bracken polysaccharides by mass, 11.6% protein and small molecule peptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0043] (2) Preparation of uric acid-lowering drugs Take 850g of bracken water extract, 110g of microcrystalline cellulose, 10g of cross-linked sodium carboxymethyl starch, 10g of sodium starch glycolate and 20g of talc, mix well; add appropriate amount of water to granulate; granulate with a granulator; and obtain granules.

[0044] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 85%, and the tablets are packaged to prepare finished products. Example 2

[0045] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract 200 kg of fresh bracken was directly cut into 1.5 cm pieces; 600 kg of water was added, and reflux extraction was performed at 100°C for 2 hours; the filtrate was filtered; the filtrate was concentrated under reduced pressure; and 8.0 kg of bracken water extract was obtained by spray drying.

[0046] The water extract of bracken contains: 19.9% ​​bracken polysaccharides by mass, 7.3% protein and small molecule peptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0047] (2) Preparation of uric acid-lowering drugs Take 800g of bracken water extract, 150g of microcrystalline cellulose, 20g of sodium starch glycolate, 10g of cross-linked sodium carboxymethyl cellulose and 20g of polyethylene glycol, mix them evenly; add appropriate amount of water to granulate; granulate with a granulator; and obtain granules.

[0048] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 80%, and the tablets are packaged to prepare finished products. Example 3

[0049] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract Take 200 kg of fresh bracken frozen at -20°C to -10°C, cut it into 1.5 cm pieces directly; add 400 kg of water, reflux extract at 100°C for 2 hours; filter to obtain the filtrate; concentrate under reduced pressure; spray dry to obtain 8.4 kg of bracken water extract.

[0050] The water extract of bracken contains: 24.1% bracken polysaccharides by mass, 8.3% protein and small molecule polypeptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0051] (2) Preparation of uric acid-lowering drugs Take 880g of bracken water extract, 100g of microcrystalline cellulose, 5g of cross-linked sodium carboxymethyl starch, 10g of cross-linked sodium carboxymethyl cellulose, 2g of talc and 3g of stearic acid, mix them evenly; add appropriate amount of water to granulate; granulate with a granulator to obtain granules.

[0052] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 88%, and the tablets are packaged to prepare finished products. Example 4

[0053] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract Take 200 kg of fresh bracken frozen at -20°C to -10°C, cut it into 0.5 cm pieces directly; add 600 kg of water, reflux extract at 50°C for 5 hours; filter to obtain the filtrate; concentrate under reduced pressure; spray dry to obtain 9.1 kg of bracken water extract.

[0054] The water extract of bracken contains: 29.7% bracken polysaccharides by mass, 8.6% protein and small molecule peptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0055] (2) Preparation of uric acid-lowering drugs Take 880g of bracken water extract, 100g of microcrystalline cellulose, 5g of cross-linked sodium carboxymethyl starch, 10g of cross-linked sodium carboxymethyl cellulose, 2g of talc and 3g of stearic acid, mix them evenly; add appropriate amount of water to granulate; granulate with a granulator to obtain granules.

[0056] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 88%, and the tablets are packaged to prepare finished products. Example 5

[0057] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract Take 200 kg of fresh bracken frozen at -20°C to -10°C, cut it into 0.5 cm pieces directly; add 600 kg of water, reflux extract at 50°C for 5 hours; filter to obtain the filtrate; concentrate under reduced pressure; spray dry to obtain 8.7 kg of bracken water extract.

[0058] The water extract of bracken contains: 33.6% bracken polysaccharides by mass, 10.7% protein and small molecule peptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0059] (2) Preparation of uric acid-lowering drugs Take 800g of bracken water extract, 150g of microcrystalline cellulose, 20g of sodium starch glycolate, 10g of cross-linked sodium carboxymethyl cellulose and 20g of polyethylene glycol, mix them evenly; add appropriate amount of water to granulate; granulate with a granulator; and obtain granules.

[0060] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 80%, and the tablets are packaged to prepare finished products. Example 6

[0061] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract Take 200 kg of fresh bracken frozen at -20°C to -10°C, cut it into 1.5 cm pieces directly; add 400 kg of water, reflux extract at 100°C for 2 hours; filter to obtain the filtrate; concentrate under reduced pressure; spray dry to obtain 8.2 kg of bracken water extract.

[0062] The water extract of bracken contains: 35.8% bracken polysaccharides by mass, 9.6% protein and small molecule peptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0063] (2) Preparation of uric acid-lowering drugs Take 850g of bracken water extract, 110g of microcrystalline cellulose, 10g of sodium starch glycolate, 10g of cross-linked sodium carboxymethyl starch and 20g of talc, mix well; add appropriate amount of water to granulate; granulate with a granulator; and obtain granules.

[0064] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 85%, and the tablets are packaged to prepare finished products. Example 7

[0065] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract 200 kg of fresh bracken was directly cut into 0.5 cm pieces; 400 kg of water was added, and reflux extraction was performed at 50°C for 5 hours; the filtrate was filtered; the filtrate was concentrated under reduced pressure; and 8.9 kg of bracken water extract was obtained by spray drying.

[0066] The water extract of bracken contains: 38.5% bracken polysaccharides by mass, 6.9% protein and small molecule peptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0067] (2) Preparation of uric acid-lowering drugs Take 880g of bracken water extract, 100g of microcrystalline cellulose, 5g of cross-linked sodium carboxymethyl starch, 10g of cross-linked sodium carboxymethyl starch, 2g of talc and 3g of stearic acid, mix them evenly; add appropriate amount of water to granulate; granulate with a granulator to obtain granules.

[0068] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 88%, and the tablets are packaged to prepare finished products. Example 8

[0069] The preparation of the uric acid-lowering drug based on the bracken water extract is as follows: (1) Preparation of bracken water extract 200 kg of fresh bracken was directly cut into 1.5 cm pieces; 600 kg of water was added, and reflux extraction was performed at 100°C for 2 hours; the filtrate was filtered; the filtrate was concentrated under reduced pressure; and 8.2 kg of bracken water extract was obtained by spray drying.

[0070] The water extract of bracken contains: 40.5% bracken polysaccharides by mass, 5.1% protein and small molecule peptides by mass, as well as a certain amount of small molecule substances such as linolenic acid, 4-oxyproline, L-malic acid, dextrorotatory quinic acid, choline, gluconic acid, 4-guanidinobutyric acid, and a-linolenic acid.

[0071] (2) Preparation of uric acid-lowering drugs Take 800g of bracken water extract, 150g of microcrystalline cellulose, 20g of sodium starch glycolate, 10g of cross-linked sodium carboxymethyl cellulose and 20g of polyethylene glycol, mix them evenly; add appropriate amount of water to granulate; granulate with a granulator; and obtain granules.

[0072] The granules are compressed by a tablet press to prepare fresh bracken water extract tablets; the mass of each tablet is 0.40 g, the mass content of bracken water extract in each tablet is 80%, and the tablets are packaged to prepare finished products.

[0073] It will be easily understood by those skilled in the art that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a uric acid-lowering drug based on a bracken water extract, characterized in that: The steps are as follows: (1) Preparation of bracken water extract 200 kg of fresh bracken was cut into 0.5-1.5 cm pieces, 400-600 kg of water was added, and reflux extraction was performed at 50-100° C. for 2-5 hours; the filtrate was filtered; the filtrate was concentrated under reduced pressure, and spray-dried to obtain 8.0-9.1 kg of brown powdered bracken water extract; The bracken water extract contains: bracken polysaccharides with a mass content of 15.1-40.5%, and proteins and small molecule polypeptides with a mass content of 5.1-11.6%. The fresh bracken is a plant of the genus Pteridaceae, Pteridaceae ( Pteridium aquilinum (L.) Kuhn var. latiusculum (Desv.) Underw. ex Heller) young leaves; (2) Preparation of uric acid-lowering drugs 80-88% by weight of the extract, 10-15% by weight of the excipient, 1.5-3% by weight of the disintegrant and 0.5-2% by weight of the lubricant are uniformly mixed, an appropriate amount of water is added for granulation, and granules are obtained by a granulator; The granules are pressed into tablets by a tablet press; the mass of each tablet is 0.40 g, and the mass content of the bracken water extract in each tablet is 80-88%; The uric acid lowering drug, with a daily dosage of 67 mg of bracken water extract per kilogram of body weight, achieves a significant uric acid lowering effect.

2. A method for preparing a uric acid-lowering drug based on steam-exploded dried bracken according to claim 1, characterized in that: In step (1), the fresh bracken is young leaves of a fern in the tender leaf curling period picked in April or May each year, specifically, young leaves of a fern with petioles that grow 15 to 25 cm above the ground.

3. A method for preparing a uric acid-lowering drug based on bracken water extract according to claim 1, characterized in that: In step (1), the fresh bracken is freshly picked bracken or fresh bracken frozen and stored at -20°C to -10°C.

4. A method for preparing a uric acid-lowering drug based on bracken water extract according to claim 1, characterized in that: In step (2), the excipient is microcrystalline cellulose.

5. The method for preparing a uric acid-lowering drug based on bracken water extract according to claim 1, characterized in that: In step (2), the disintegrant is two of cross-linked sodium carboxymethyl starch, sodium starch glycolate, and cross-linked sodium carboxymethyl cellulose.

6. A method for preparing a uric acid-lowering drug based on bracken water extract according to claim 1, characterized in that: In step (2), the lubricant is one or two of talc and stearic acid or talc or polyethylene glycol.

7. A method for preparing a uric acid-lowering drug based on bracken water extract according to claim 1, characterized in that: In step (2), the extract, excipient, disintegrant and lubricant are mixed uniformly according to the formula to prepare granules or capsules.

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