Preparation method of cavalerie mosla herb extract and application of cavalerie mosla herb extract in resisting rheumatoid arthritis

Abstract

The invention discloses a preparation method of cavalerie mosla herb extract, and relates to the field of preparation of traditional Chinese medicine active extracts.The preparation method specifically comprises the following steps that firstly, cavalerie mosla herb rhizomes are taken, smashed, sieved, soaked with water, decocted with big fire, cooled and filtered, and decoction liquid is obtained; then adding the decoction into a chromatographic column, percolating to obtain a methanol extracting solution, pouring the methanol extracting solution into a rotary evaporator, and carrying out rotary concentration to obtain a concentrated solution without methanol smell; and finally, injecting the concentrated solution into a separating funnel in batches, sequentially adding an organic solvent for extraction, carrying out rotary evaporation by using a rotary evaporator after extraction, removing the organic solvent, and carrying out vacuum concentration to obtain the cavalerie mosla herb extract. Based on a C IA rat model, the cavalerie mosla herb extract verifies that two active parts, namely dichloromethane and ethyl acetate, of a 70% methanol extract of the cavalerie mosla herb have a remarkable improvement effect on rats with rheumatoid arthritis induced by a complete Freund adjuvant, and the activity of a dose group active part in the ethyl acetate is equivalent to the effect of a positive control drug methotrexate.

Description

Technical Field

[0001] The present invention relates to the field of preparation of active extracts of traditional Chinese medicine, and particularly to a preparation method of Microsorum fortunei extract and its application in anti-rheumatoid arthritis. Background Art

[0002] Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by erosive arthritis, which can lead to joint deformity, loss of function, and even affect organs such as the lungs, heart, and blood vessels. DMARDs are disease-modifying antirheumatic drugs that can slow down or prevent joint damage and disease progression. Methotrexate is one of the most commonly used DMARDs and is usually used as a first-line drug to treat rheumatoid arthritis. However, DMARDs need to be used for a long time to maintain efficacy and require regular monitoring of side effects.

[0003] "Microsorum fortunei" is also known as "Microsorum fortunei (T. Moore) Ching", "Microsorum fortunei (T. Moore) Ching", "Macrosorium fortunei (T. Moore) Ching", "Thousands of Knives", etc. It is a fern plant of the genus Microsorum in the family Polypodiaceae, mainly distributed in the Yangtze River basin and provinces south of it in China. Among them, it is widely distributed in areas below 1920 m above sea level in Guizhou. The whole herb and rhizome of Microsorum fortunei can be used as medicine. It tastes sweet and slightly bitter, and is cool in nature. It has the effects of clearing heat and detoxifying, expelling wind and removing dampness, promoting blood circulation, and stopping bleeding. It can treat rheumatic joint pain, heat strangury, jaundice, dysentery, urinary tract infection, leukorrhea, hematemesis, hematochezia, traumatic injury, snake bite and other diseases. According to the records of herbal literatures such as "Medicinal Ferns of Guizhou" and "Flora of Medicinal Plants of Zhejiang", this medicine has an obvious therapeutic effect on rheumatic arthralgia and is a traditional folk medicine. According to the preliminary investigation of the applicant of the present invention, ethnic doctors in southeastern Guizhou, Guizhou often use the whole plant of Microsorum fortunei as a single medicine or formula to treat rheumatoid arthritis and have achieved obvious curative effects. At the same time, this medicine is used as a protocol prescription for treating rheumatoid arthritis in the rheumatology department of Miao medicine hospitals and has good clinical application effects. However, in the existing application of treating rheumatoid arthritis, the dosage of Microsorum fortunei is relatively large, which is not convenient for patients to use, and the effective active parts of Microsorum fortunei are not yet clear, which is not conducive to the popularization of Microsorum fortunei. Based on this, the present invention prepares Microsorum fortunei extract, screens out the active parts of Microsorum fortunei against rheumatoid arthritis, and verifies its effect on collagen-induced arthritis (CIA) rats, so as to provide a scientific basis for its application in anti-rheumatoid arthritis. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of Microsorum fortunei extract and its application in anti-rheumatoid arthritis to solve the above deficiencies in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: A preparation method of Microsorum fortunei extract, specifically including the following steps:

[0006] S1. Take the rhizomes of *Murdannia keisak*, crush them, sieve them, then soak them in water, decoct them several times over high heat, cool them and filter, and finally combine the filtrates obtained from multiple filtrations to obtain a decocted solution.

[0007] S2. Wet the column with methanol, then add the decocted solution obtained in S1 into the chromatographic column, percolate to obtain a methanol extract, and then pour the methanol extract into a rotary evaporator for rotary concentration to obtain a concentrated solution without the smell of methanol.

[0008] S3. Inject the concentrated solution obtained in S2 into a separatory funnel in batches, then successively add organic solvents for extraction respectively to obtain organic solvent extracts, and then rotary evaporate them respectively with a rotary evaporator to remove the organic solvents, and finally concentrate them under reduced pressure to obtain extracts of each organic solvent part, namely the extract of *Murdannia keisak*.

[0009] Further, the crushing and sieving specification in S1 is 20 - 50 mesh; the number of decocting times in S1 is three times, the first decocting time is 1 h, and the second and third decocting times are both 0.5 h.

[0010] Further, the methanol concentration in S2 is 60% - 80%.

[0011] Further, the chromatographic column in S2 is any one of an alumina column, a silica gel column, and a polyamide column.

[0012] Further, the organic solvents in S3 are at least one of petroleum ether, dichloromethane, ether, ethyl acetate, acetone, and n - butanol.

[0013] The present invention also discloses an extract of *Murdannia keisak*, which is prepared by the aforementioned preparation method.

[0014] The present invention also discloses the application of the extract of *Murdannia keisak* in anti - rheumatoid arthritis.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] (1) The present invention provides a preparation method of an extract of *Murdannia keisak*, extracts the active parts of the rhizomes of *Murdannia keisak* to obtain extracts of petroleum ether part, dichloromethane part, ethyl acetate part, and n - butanol part. This preparation method is simple and repeatable, and is suitable for large - scale industrial production.

[0017] (2) Based on the CIA rat model, the present invention verifies that two active parts, dichloromethane and ethyl acetate, of the 70% methanol extract of *Murdannia keisak* have a significant improvement effect on rats with rheumatoid arthritis induced by complete Freund's adjuvant, and the activity of the active part in the medium - dose group of ethyl acetate is equivalent to the efficacy of the positive control drug methotrexate, and it can be used to develop related traditional Chinese medicines for anti - rheumatoid arthritis.

[0018] (3) The research on the mechanism of action of the extract of *Murdannia keisak* in anti-rheumatoid arthritis carried out in this invention provides more sufficient theoretical support and effective data support for the folk medicinal application of the extract of *Murdannia keisak* in the treatment of anti-rheumatoid arthritis, ensuring the safety and effectiveness of drug use and enabling it to be more widely applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is the right hind paw swelling degree diagram of each group of CIA rat models provided in the fifth embodiment of the present invention;

[0021] Figure 2 It is the pathological histological section diagram of the knee joint of each group of CIA rat models (HE staining, ×200) provided in the eighth embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the following will further introduce the present invention in detail in conjunction with the drawings.

[0023] Example 1: The preparation method of the extract of *Murdannia keisak* specifically includes the following steps:

[0024] S1. Take the rhizome of *Murdannia keisak*, crush it and sieve it, then soak it in water, boil it several times over high heat, cool it and filter it, and finally combine the filtrates obtained from multiple filtrations to obtain a decoction; the crushing and sieving specification is 20-50 meshes; the number of boiling times is three, the first boiling time is 1 h, and the second and third boiling times are both 0.5 h;

[0025] Specifically, take 300.148 g of the rhizome of *Murdannia keisak*, crush it into coarse powder with a Chinese medicine machine and sieve it through a 40-mesh sieve, then soak it in sterile distilled water for 0.5 h. For the first time, add 3600 ml of sterile distilled water, boil it over high heat and then simmer for 1 h, cool it and filter it with multiple layers of gauze. For the second and third times, add 3000 ml of sterile distilled water each time and simmer for 0.5 h in the same way, and filter it with multiple layers of gauze respectively. Finally, combine the filtrates obtained from the three filtrations to obtain a decoction;

[0026] S2. Wet the column with methanol, then add the decoction obtained in S1 into the chromatography column, percolate to obtain the methanol extract, and then pour the methanol extract into a rotary evaporator for rotary concentration to obtain a concentrated solution without the smell of methanol; the methanol concentration is 60% - 80%; the chromatography column is any one of an alumina column, a silica gel column, and a polyamide column;

[0027] Specifically, wet the column with 900 ml of 70% methanol, then add the decoction into the silica gel column, percolate to obtain 4 L of methanol extract, and then pour the methanol extract into a rotary evaporator for rotary concentration to obtain 2100 ml of a concentrated solution without the smell of methanol;

[0028] S3. Inject the concentrated solution without the smell of methanol obtained in S2 into a separatory funnel in batches, then add organic solvents in turn for extraction to obtain each organic solvent extract, and then use a rotary evaporator to evaporate each extract to remove the organic solvents, and finally concentrate under reduced pressure to obtain the extracts of each organic solvent part, namely the extract of Herba seu Radix Orthospathae Cochinchinensis; the organic solvent is at least one of petroleum ether, dichloromethane, ether, ethyl acetate, acetone, and n-butanol;

[0029] Specifically, inject 2100 ml of the concentrated solution into a 5000 ml separatory funnel in batches, and then add petroleum ether, dichloromethane, ethyl acetate, and n-butanol for extraction in turn according to the polarity of the extraction solvent. Repeat several times until the color of the extract gradually becomes colorless to obtain the petroleum ether, dichloromethane, ethyl acetate, and n-butanol extracts respectively. Then use a rotary evaporator to evaporate each extract to remove petroleum ether, dichloromethane, ethyl acetate, and n-butanol respectively, and finally concentrate under reduced pressure to obtain the extracts of the petroleum ether part, dichloromethane part, ethyl acetate part, and n-butanol part of Herba seu Radix Orthospathae Cochinchinensis. Finally, 0.431 g of the extract of the petroleum ether extraction part is obtained, and the extract yield is 0.2%; 0.312 g of the extract of the dichloromethane extraction part is obtained, and the extract yield is 0.1%; 8.790 g of the extract of the ethyl acetate extraction part is obtained, and the extract yield is 4.1%; 17.924 g of the extract of the n-butanol part is obtained, and the extract yield is 8.4%. The liquid remaining after n-butanol extraction is evaporated to dryness with a rotary evaporator to obtain 26.432 g of the water-soluble part extract, and the extract yield is 12.3%; 24.18 g of the extract of the 70% methanol extract of Herba seu Radix Orthospathae Cochinchinensis, and the extract yield is 28.2%.

[0030] Preparation of drug administration for rats in each extraction part: The basis for the design of the drug administration dose is the clinical human dose of Microsorum fortunei (T. Moore) Ching, which is 15 - 30 g. The equivalent dose for humans and mice or rats is calculated according to a coefficient of 12 or 6. Assuming the human body weight is 60 kg, the equivalent dose for mice is 30 g / 60 kg × 12 = 6 g crude drug / kg, and the equivalent dose for rats is 30 g / 60 kg × 6 = 3 g / kg. Therefore, the drug preparation for rats is: equivalent dose (mg / kg) = 6 × (30 g / 60 kg) × the extract yield of each extraction part. The equivalent dose is used as the low dose, 2 times the equivalent dose as the medium dose, and 4 times the equivalent dose as the high dose. The drug administration dose of the positive control drug methotrexate is calculated in the same way. Before drug administration, the extracts of each part are formulated into corresponding doses with 0.5% sodium carboxymethylcellulose for administration.

[0031] Example 2: Establishment and grouping of a rat model of rheumatoid arthritis induced by complete Freund's adjuvant

[0032] Rats were induced with arthritis using complete Freund's adjuvant. They were fasted overnight before immunization. Except for the normal group (injected with 0.9% NaCl solution in the same way), the other groups were injected with 0.1 mL of complete Freund's adjuvant into the middle of the right hind paw plantar surface to induce arthritis. On the 3rd day after immunization, the swelling changes of the part below the right hind ankle joint of the rats were observed to evaluate whether the model was successful. After the successful establishment of the CIA rat model, the rats were grouped. Ninety clean-grade SD rats, half male and half female, with a body weight range of 200 ± 20 g, were randomly divided into 9 groups, with 10 rats in each group, namely the blank group, the model group, the methotrexate group (1.05 mg / kg), the low, medium, and high-dose groups of the dichloromethane extraction part (0.79, 1.58, 3.15 mg / kg), the low, medium, and high-dose groups of the ethyl acetate extraction part (32.29, 64.58, 129.15 mg / kg), and the methotrexate group was the positive control group. The grouped rats were given intragastric administration, while the normal group and the model group rats were given intragastric administration of an equal volume of distilled water, with a gavage volume of 10 mL / kg, once a day, and the methotrexate control group was given intragastric administration once every 3 days for 28 consecutive days.

[0033] Example 3: Effects of the extract of Herba seu Radix Oenanthes javanicae (Bl.) DC. on the appearance and body weight of rats

[0034] After drug administration, the glossiness of the rats' fur and their mental state were observed to evaluate the appearance of the rats, and the body weight of the rats was measured on the 1st, 7th, 14th, 21st, and 28th days to observe the changes in the body weight of the rats and make records.

[0035] Appearance evaluation results of rats: After modeling, the rats in the model group were listless, with dull hair, red and swollen right hind feet, restricted movement. After 24 hours, the paw swelling was obvious. After 14 days, secondary lesions occurred in the contralateral paws of the rats in the model group. After 21 days, the paws of the rats in the model group were generally red and swollen. The rats in the drug administration group had better spirits, normal food intake, shiny hair color, similar to the blank group. There was only slight redness and swelling in the primary and secondary feet. Among them, the rats in the medium-dose group of the ethyl acetate fraction of the extract of *Spatholirion longifolium* had the mildest paw symptoms, closest to the positive control methotrexate group.

[0036] Results of changes in rat body weight: After modeling, the increase in body weight of the rats in the model group decreased significantly, showing a significant difference compared with the blank group (P<0.01). After 21 days of drug administration, there were significant differences in the increase in body weight of the rats in the positive control group of methotrexate, the low-dose dichloromethane group, the high-dose ethyl acetate group, the medium-dose ethyl acetate group, and the low-dose ethyl acetate group compared with the rats in the model group. After 28 days of drug administration, there were significant differences in the increase in body weight of the rats in the positive control group of methotrexate, the medium-dose dichloromethane group, the low-dose dichloromethane group, the high-dose ethyl acetate group, the medium-dose ethyl acetate group, and the low-dose ethyl acetate group compared with the model group. Although the petroleum ether fraction and the n-butanol fraction had the effect of inhibiting the decrease in body weight of the drug-administered rats, there was no statistical significance (P>0.05). The specific results are shown in Table 1.

[0037] Table 1 Effects of dichloromethane and ethyl acetate fractions of *Spatholirion longifolium* on the body weight of CIA rats (N = 10, x±s)

[0038]

[0039] Note: Compared with the normal control group, #P<0.05, ##P<0.01; compared with the CIA model control group, *P<0.05, **P<0.01

[0040] Example 4: Effects of *Spatholirion longifolium* extract on the arthritis index of rats

[0041] From after inflammation induction, the hind paw joints and the degree of secondary lesions of the rats in each group were observed and recorded every 3 days, once every 3 days. The arthritis index scoring standard for each paw was as follows: If the paw was normal or without redness and swelling, the arthritis index score was recorded as 0 points; if there was mild redness and swelling in the small toe joint, the arthritis index score was recorded as 1 point; if there was redness and swelling in the small toe joint and the toes, the arthritis index score was recorded as 2 points; if all the toes below the ankle joint were red and swollen, the arthritis index score was recorded as 3 points; if the ankle joint was completely red, purple, and even deformed, the arthritis index score was recorded as 4 points.

[0042] Inflammatory index evaluation results: After modeling the rats, the inflammatory index of the rats in the model group increased significantly with the prolongation of the disease course, and was significantly higher than that of the blank group on the 4th day (P<0.01); the inflammatory index growth in the positive control methotrexate group, high-dose dichloromethane group, medium-dose ethyl acetate group, and low-dose ethyl acetate group was relatively slow, and there were significant differences compared with the model group, thus proving that the extract of *Spatholirion longifolium* has an inhibitory effect on rat arthritis. Among them, the inflammatory index of the rats in the medium-dose ethyl acetate part was the lowest and was closest to that of the positive control methotrexate group. Although the petroleum ether part and the n-butanol part had an inhibitory effect on the growth of the rat arthritis index, there was no statistical significance (P>0.05). The specific results are shown in Table 2.

[0043] Table 2 Effects of dichloromethane and ethyl acetate parts of *Spatholirion longifolium* on arthritis index in CIA rats (N = 10, x±s)

[0044]

[0045]

[0046] Note: Compared with the blank group, ##P<0.01; compared with the model group, *P<0.05*; *P<0.01

[0047] Example 5: Effects of *Spatholirion longifolium* extract on rat foot swelling degree

[0048] The swelling degree of the right hind foot of each rat was measured with a vernier caliper, and the swelling degree of the right hind foot was measured 28 days after inflammation induction to calculate the paw swelling degree.

[0049] Results of rat foot swelling degree: After modeling, the rat foot swelling degree increased significantly. The results are shown in Figure 1 , and it was found in the measurement of rat foot swelling degree on the 28th day that there were significant differences in the foot swelling degree between the rats in the model group and the rats in the drug administration groups compared with the blank group (P<0.01); the drug administration groups all had a tendency to callback the rat foot swelling degree, proving that the extract of *Spatholirion longifolium* can inhibit the inflammatory response of rats with rheumatoid arthritis. The inhibitory effects of each drug administration group were as follows: medium-dose ethyl acetate group > low-dose ethyl acetate group > high-dose ethyl acetate group, high-dose dichloromethane group, medium-dose dichloromethane group > low-dose dichloromethane group. Among them, the inhibitory effect of the medium-dose ethyl acetate part of the *Spatholirion longifolium* extract on the rat foot swelling degree was the best (P<0.05) and was closest to the effect of the positive control methotrexate group. Although the petroleum ether part and the n-butanol part had an inhibitory effect on the rat foot swelling degree, there was no statistical significance (P>0.05). The specific results are shown in Table 3.

[0050] Table 3 Effects of dichloromethane and ethyl acetate parts of *Spatholirion longifolium* on rat foot swelling degree in CIA rats (N = 10, x±s)

[0051]

[0052] Example 6: Effects of the extract of *Spatholobi Caulis* on the thymus and spleen indices of rats

[0053] As important immune organs of the body, the indices of the thymus and spleen can reflect the strength of the body's immune function to a certain extent. After 28 days of administration, the rats were sacrificed, the spleen and thymus were removed, fat and fascia were removed, the surface liquid was blotted dry with filter paper and precisely weighed, and the proportion of each in body weight (mg / g) was calculated respectively.

[0054] Evaluation results of immune organ indices: After modeling, the thymus index and spleen index of the rats in the model group increased significantly, showing significant differences compared with the blank group (P < 0.001); while after treatment, the thymus index and spleen index of the positive control methotrexate group, the dichloromethane medium-dose group, dichloromethane low-dose group, ethyl acetate medium-dose group, and ethyl acetate low-dose group of the extract of *Spatholobi Caulis* were significantly down-regulated; the high-dose dichloromethane group had no obvious down-regulation of the thymus index and spleen index; the high-dose ethyl acetate group only down-regulated the thymus index (P < 0.05), and had no obvious down-regulation of the spleen index. Although the petroleum ether fraction and n-butanol fraction had the effect of down-regulating the immune organ indices of rats, there was no statistical significance (P > 0.05). The specific results are shown in Table 4.

[0055] Table 4 Effects of dichloromethane and ethyl acetate fractions of *Spatholobi Caulis* on immune organs of CIA rats (N = 10, x±s)

[0056]

[0057] Note: Compared with the blank group: P < 0.001; compared with the model group: *P < 0.05, **P < 0.01, ***P < 0.001;

[0058] Example 7: Effects of the extract of *Spatholobi Caulis* on the levels of TNF-α, IL-1, and IL-6 in the serum of rats with rheumatoid arthritis

[0059] After 28 days, the plasma of rats in each group was allowed to stand for 2 h, and then centrifuged at 3500 r / min for 5 min to separate the serum. The contents of the above-mentioned indicators in the serum of rats in each group were detected according to the methods of TNF-α, IL-1, and IL-6 kits respectively.

[0060] Inflammatory factor detection results: The levels of IL-1, IL-6, and TNF-α in the serum of rats are shown in Table 5. TNF-α, IL-1, and IL-6 in the model group were significantly increased, showing differences compared with the blank group (P<0.001). After administration, except for the high-dose dichloromethane group and the high-dose ethyl acetate group showing no significant difference in TNF-α, the levels of IL-1, IL-6, and TNF-α that had increased in the model group were all decreased in other groups of the extract of Herba Sphaeranthi, and all showed significant differences. Among them, the low-dose ethyl acetate group and the low-dose dichloromethane group had the best effects, being closest to the positive control methotrexate group. Although the petroleum ether fraction and the n-butanol fraction had the effect of decreasing the levels of TNF-α, IL-1, and IL-6 in the serum of rats, there was no statistical significance (P>0.05).

[0061] Table 5 Effects of dichloromethane and ethyl acetate fractions of Herba Sphaeranthi on IL-1, IL-6, and TNF-α in CIA rats (N = 10, x±s)

[0062]

[0063]

[0064] Note: Compared with the blank group, P<0.001; compared with the model group, *P<0.05, **P<0.01, ***P<0.001

[0065] Example 8: Effects of the extract of Herba Sphaeranthi on the knee joint tissues of rats

[0066] The right knee joints of rats in each group were fixed, decalcified, embedded, and sectioned, and then stained with HE. The knee joint parts of rats in each group were observed under an optical microscope, and the degree of knee joint lesions was evaluated based on inflammatory cell infiltration, synovial hyperplasia, cartilage destruction, and bone erosion.

[0067] Observation results of knee joint pathological histology: The HE staining results were observed under an electron microscope as shown in Figure 2。Blank control group: The HE staining of the knee joint was uniform, and the overall tissue structure was basically normal. Cartilage, muscle fibers and capillaries were visible, and no obvious inflammatory cell infiltration was found in the tissue. Model group: The overall tissue structure of the knee joint was slightly abnormal, and inflammatory cell infiltration was visible in the connective tissue. Methotrexate group: The overall tissue structure was basically normal, cartilage and connective tissue were visible, and a small amount of inflammatory cell infiltration was visible in the tissue. High-dose group of dichloromethane fraction: The overall tissue structure was basically normal, cartilage and connective tissue were visible, the connective tissue showed mild hyperplasia, and a small amount of inflammatory cell infiltration was visible in the tissue. Medium-dose group of dichloromethane fraction: The overall tissue structure was slightly abnormal, cartilage and connective tissue were visible, capillary hyperplasia was observed, and a small amount of inflammatory cell infiltration was visible in the tissue. Low-dose group of dichloromethane fraction: The overall tissue structure was basically normal, the connective tissue showed mild hyperplasia, and a small amount of inflammatory cell infiltration was visible in the tissue. High-dose group, medium-dose group and low-dose group of ethyl acetate fraction: The overall tissue structure was basically normal, the connective tissue showed mild hyperplasia, and no obvious inflammatory cell infiltration was found in the tissue. The HE staining results showed that the extracts of *Orthosiphon aristatus* in each group could significantly inhibit the pathological changes of rat joint tissues and reduce the joint damage in rats with rheumatoid arthritis.

[0068] Only some exemplary embodiments of the present invention have been described above by way of illustration. Without doubt, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. Preparation method of Sphaeranthus indicus extract, characterized in that, Specifically, it includes the following steps: S1. Take the rhizome of *Spatholobus suberectus*, crush it, sieve it, then soak it in water, decoct it with strong fire for multiple times, cool it and filter it, and finally combine the filtrates obtained from multiple filtrations to obtain a decocted liquid; S2. Moisten the column with methanol, then add the decocted liquid obtained in S1 into the chromatographic column, percolate to obtain a methanol extract, and then pour the methanol extract into a rotary evaporator for rotary concentration to obtain a concentrated liquid without the smell of methanol; S3. Inject the concentrated liquid obtained in S2 into a separating funnel in batches, then add organic solvents in turn for extraction respectively to obtain organic solvent extracts, then rotary evaporate them respectively with a rotary evaporator to remove the organic solvents, and finally concentrate them under reduced pressure to obtain extracts of each organic solvent part, namely *Spatholobus suberectus* extract.

2. The preparation method of the extract of Qixing Sword according to claim 1, characterized in that The crushing and sieving specification in S1 is 20 - 50 meshes; the number of decocting times in S1 is three times, the decocting time for the first time is 1 h, and the decocting times for the second and third times are both 0.5 h.

3. The preparation method of the extract of Qixingjian according to claim 1, characterized in that, The methanol concentration in S2 is 60% - 80%.

4. The preparation method of the extract of Qixingjian according to claim 1, wherein, The chromatographic column in S2 is any one of an alumina column, a silica gel column, and a polyamide column.

5. The preparation method of the extract of Qixingjian as claimed in claim 1, wherein, The organic solvent in S3 is at least one of petroleum ether, dichloromethane, ether, ethyl acetate, acetone, and n-butanol.

6. A Sphaeranthus africanus extract, characterized in that, It is applicable to the preparation method of the *Spatholobus suberectus* extract according to any one of claims 1 - 5.

7. Use of the *Spatholobus suberectus* extract according to claim 6 in the treatment of rheumatoid arthritis.

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