Plant polysaccharide as well as preparation method and application thereof

Abstract

The invention discloses plant polysaccharide as well as a preparation method and application thereof. Monosaccharide in jasminum grandiflorum polysaccharide consists of rhamnose, arabinose, galactose, glucose, xylose, mannose and galacturonic acid. The molar ratio of the rhamnose to the arabinose to the galactose to the glucose to the xylose to the mannose to the galacturonic acid is (14 to 22) to (100 to 120) to (160 to 185) to (200 to 240) to (16 to 25) to (18 to 27) to (400 to 450). The jasminum grandiflorum polysaccharide component has the characteristics of inhibiting inflammatory response and enhancing antioxidant activity, can effectively improve APAP-induced acute liver injury, and provides a certain theoretical basis for development and utilization of jasminum grandiflorum and research and development of liver protection products.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and specifically relates to a plant polysaccharide and a preparation method and application thereof. Background Art

[0002] Drug-induced liver injury (DILI) is a leading cause of idiosyncratic or intrinsic liver disease worldwide. Acetaminophen (APAP) is a widely used over-the-counter analgesic and antipyretic drug. Hepatotoxicity caused by APAP overdose is one of the leading causes of acute liver failure (ALF) in the United States and parts of Europe, limiting its clinical application.

[0003] When taken at recommended doses, nearly 90% of APAP is metabolized by glucuronidation or sulfation and then excreted through bile, about 2% is excreted in urine in an unmetabolized form, and less than 8% is metabolized to reactive NAPQI by CYP 450-mediated oxidases. Under normal circumstances, NAPQI can be detoxified by rapidly binding to glutathione (GSH). However, excessive APAP metabolism consumes glutathione and increases N-acetyl-p-benzoquinoneimide (NAPQI) levels, leading to oxidative stress, DNA damage, and liver cell necrosis, which in turn leads to liver damage.

[0004] N-acetyl-L-cysteine ​​(NAC) is currently the only drug approved for the treatment of APAP poisoning, but its clinical application is greatly limited due to the narrow therapeutic window of NAC in the treatment of acute liver injury and certain toxic side effects. Therefore, it is crucial to find a more effective treatment with fewer side effects. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a frangipani polysaccharide.

[0006] The invention also provides a method for preparing the frangipani polysaccharide.

[0007] The present invention also provides the application of the frangipani polysaccharide.

[0008] The invention also provides a product.

[0009] According to one aspect of the present invention, a frangipani polysaccharide is provided, wherein the monosaccharides in the frangipani polysaccharide are composed of rhamnose, arabinose, galactose, glucose, xylose, mannose and galacturonic acid; the molar ratio of the rhamnose, arabinose, galactose, glucose, xylose, mannose and galacturonic acid is (14-22): (100-120): (160-185): (200-240): (16-25): (18-27): (400-450).

[0010] In some embodiments of the present invention, the molar ratio of rhamnose, arabinose, galactose, glucose, xylose, mannose and galacturonic acid is (17-21): (105-115): (170-180): (210-230): (18-23): (19-25): (430-440).

[0011] In some embodiments of the present invention, the molar ratio of rhamnose, arabinose, galactose, glucose, xylose, mannose and galacturonic acid is 19:109:174:220:21:22:434.

[0012] In some embodiments of the present invention, the molecular weight of the frangipani polysaccharide is 69445 Da.

[0013] According to a second aspect of the present invention, a method for preparing the above-mentioned frangipani polysaccharide is provided, comprising the following steps:

[0014] The Jasmine flower sample was subjected to defatting, water extraction, alcohol precipitation, protein removal and dialysis in sequence to obtain Jasmine flower polysaccharide.

[0015] In some embodiments of the present invention, the defatting is performed using anhydrous ethanol.

[0016] In some embodiments of the present invention, in the defatting step, the solid-to-liquid ratio of the jasmine flower sample to anhydrous ethanol is 1 g: 8-12 mL.

[0017] In some embodiments of the present invention, the solid-liquid ratio is 1 g:10 mL.

[0018] In some embodiments of the present invention, degreasing is performed by heating under reflux.

[0019] In some embodiments of the present invention, the heating reflux is carried out at a temperature of 70 to 90° C. for a time of 1 to 2 hours, and the heating reflux step is repeated 2 to 3 times.

[0020] In some embodiments of the present invention, in the water extraction step, the solid-liquid ratio of the defatted jasmine flower sample to water is 1 g: 10-20 mL.

[0021] In some embodiments of the present invention, the solid-liquid ratio is 1 g:15 mL.

[0022] In some embodiments of the present invention, water extraction is performed by combining ultrasonic extraction and water bath extraction.

[0023] In some embodiments of the present invention, the ultrasonic extraction is performed under the condition of ultrasonic power of 90-110w for 15-25min.

[0024] In some embodiments of the present invention, the water bath extraction is performed at 95-105° C. for 2-3 h.

[0025] In some embodiments of the present invention, the water extraction further includes a step of solid-liquid separation and collecting the separated liquid phase.

[0026] In some embodiments of the present invention, the alcohol precipitation uses ethanol with a mass fraction of 95% or more.

[0027] In some embodiments of the present invention, in the alcohol precipitation step, the volume ratio of the water extract to ethanol is 1:(3-5).

[0028] In some embodiments of the present invention, the alcohol precipitation temperature is 0-4°C, and the alcohol precipitation time is 8-12 hours.

[0029] In some embodiments of the present invention, the step of washing the precipitate obtained by alcohol precipitation with anhydrous ethanol, ether and acetone in sequence is also included.

[0030] In some embodiments of the present invention, the protein removal is performed using Sevag reagent.

[0031] In some embodiments of the present invention, the Sevag reagent is a mixed solution of chloroform and n-butanol in a volume ratio of 4:1.

[0032] In some embodiments of the present invention, the volume ratio of the Sevag reagent to the polysaccharide solution obtained by dissolving the precipitate obtained by washing with anhydrous ethanol, ether and acetone in water is 1:4-6.

[0033] In some embodiments of the present invention, the dialysis is performed using a dialysis bag with a molecular weight cut-off of >8000Da.

[0034] In some embodiments of the present invention, the dialysis time is 1 to 3 days.

[0035] According to the third aspect of the present invention, an application of the above-mentioned Jasmine flower polysaccharide is proposed, and the application is an application in the preparation of a product for treating acute liver injury.

[0036] In some embodiments of the present invention, the acute liver injury comprises acute liver injury induced by APAP.

[0037] In some embodiments of the present invention, the application is application in the preparation of a product for inhibiting the expression level of inflammatory factors.

[0038] In some embodiments of the present invention, the inflammatory factors include IL-1β, IL-6, and TNF-α.

[0039] In some embodiments of the present invention, the use is for preparing a product for reducing serum alanine aminotransferase (ALT) and / or aspartate aminotransferase (AST) levels.

[0040] In some embodiments of the present invention, the application is application in the preparation of a product with enhanced antioxidant activity.

[0041] In some embodiments of the present invention, the enhanced antioxidant activity includes increasing the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH).

[0042] In some embodiments of the present invention, the enhancing antioxidant activity comprises reducing the content of malondialdehyde (MDA) and reactive oxygen species (ROS).

[0043] In some embodiments of the present invention, the product is at least one of a medicine, a health product and a functional food.

[0044] According to a fourth aspect of the present invention, a product is provided, comprising the above-mentioned frangipani polysaccharide.

[0045] In some embodiments of the invention, the product is used to treat acute liver injury.

[0046] In some embodiments of the present invention, the acute liver injury comprises acute liver injury induced by APAP.

[0047] In some embodiments of the present invention, the product is at least one of a medicine, a health product and a functional food.

[0048] In some embodiments of the present invention, the product is a medicine, and the medicine further includes a pharmaceutically acceptable excipient.

[0049] In some embodiments of the present invention, the pharmaceutically acceptable excipients include at least one of a diluent, an excipient, a filler, a binder, a disintegrant, an absorption enhancer, a surfactant, an adsorption carrier, a lubricant, a sweetener and a flavoring agent.

[0050] In some embodiments of the invention, the excipient comprises water.

[0051] In some embodiments of the present invention, the filler comprises at least one of starch and sucrose.

[0052] In some embodiments of the present invention, the binder includes at least one of a cellulose derivative, alginate, gelatin and polyvinyl pyrrolidone.

[0053] In some embodiments of the invention, the humectant comprises glycerin.

[0054] In some embodiments of the present invention, the disintegrant comprises at least one of agar, calcium carbonate and sodium bicarbonate.

[0055] In some embodiments of the invention, the absorption enhancer comprises a quaternary ammonium compound.

[0056] In some embodiments of the invention, the surfactant comprises cetyl alcohol.

[0057] In some embodiments of the present invention, the adsorption carrier includes at least one of kaolin and bentonite.

[0058] In some embodiments of the present invention, the lubricant includes at least one of talc, calcium stearate, magnesium stearate and polyethylene glycol.

[0059] In some embodiments of the present invention, the dosage form of the drug is in the form of solid, semi-solid or liquid, and can be an aqueous solution, non-aqueous solution or suspension.

[0060] In some embodiments of the present invention, the dosage form of the drug is tablets, capsules, soft capsules, granules, pills, oral liquids, dry suspensions, pellets, dry extracts, injections or infusions, transdermal agents, and transdermal microneedles.

[0061] In some embodiments of the present invention, the drug may be administered by conventional methods in the art, including but not limited to injection or oral administration.

[0062] In some embodiments of the present invention, the injection administration can be intravenous injection, intramuscular injection, intraperitoneal injection, intradermal injection or subcutaneous injection.

[0063] In some embodiments of the present invention, the mass fraction of the frangipani polysaccharide in the product is 0.01% to 100%.

[0064] According to some preferred embodiments of the present invention, the mass fraction of the frangipani polysaccharide in the product is 0.05% to 95%.

[0065] According to some preferred embodiments of the present invention, the mass fraction of the frangipani polysaccharide in the product is 0.05% to 50%.

[0066] According to some embodiments of the present invention, at least the following beneficial effects are achieved: the present invention extracts and separates jasmine flower polysaccharide components from jasmine flowers. The jasmine flower polysaccharide components of the present invention have the characteristics of inhibiting inflammatory response and enhancing antioxidant activity, and can also effectively improve APAP-induced acute liver injury, providing a certain theoretical basis for the development and utilization of jasmine flowers and the research and development of liver protection products. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0068] Figure 1 The glucose standard curve diagram in Example 1 of the present invention;

[0069] Figure 2 It is the ultraviolet spectrum analysis diagram in Example 1 of the present invention;

[0070] Figure 3 This is an infrared spectrum analysis diagram in Example 1 of the present invention;

[0071] Figure 4 This is a high performance gel permeation chromatography analysis chart in Example 1 of the present invention;

[0072] Figure 5 This is a graph showing the monosaccharide composition of the frangipani polysaccharide in Example 1 of the present invention;

[0073] Figure 6 The test results of the weight of mice and the liver and spleen indexes in Example 2 of the present invention are shown in Figure 2, wherein A is the test result of the weight of mice, B is the test result of the spleen index, and C is the test result of the liver index. ##p<0.01, ####p<0.0001 compared with the blank group; *p<0.05 compared with the model group, (n=7);

[0074] Figure 7 The liver phenotype and liver tissue pathology analysis test results in Example 2 of the present invention are shown in Figure 2, wherein A is a liver morphology diagram, and B is a HE pathology section staining result diagram; ####p<0.0001 compared with the blank group; **p<0.01, ***p<0.001, ****p<0.0001 compared with the model group, (n=7);

[0075] Figure 8 It is a test result diagram of mouse serum biochemical indicators in Example 2 of the present invention, wherein A is a test result diagram of AST, B is a test result diagram of ALT, C is a test result diagram of IL-6, D is a test result diagram of IL-1β, and E is a test result diagram of TNF-α. #p<0.05, ##p<0.01, ###p<0.001, ####p<0.0001 are compared with the blank group; *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001 are compared with the model group, (n=7);

[0076] Fig. 9It is a graph showing the test results of mouse liver biochemical indicators in Example 2 of the present invention, wherein A is a graph showing the test results of SOD, B is a graph showing the test results of MDA, C is a graph showing the test results of GSH, D is a graph showing the test results of CAT, and E is a graph showing the test results of ROS content, ##p<0.01, ###p<0.001, ####p<0.0001 compared with the blank group; *p<0.05, **p<0.01 compared with the model group, (n=7). DETAILED DESCRIPTION

[0077] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0078] Example 1 Preparation of Jasmine Flower Polysaccharide

[0079] This example prepares a frangipani polysaccharide, and the specific preparation and verification methods are as follows:

[0080] 1. Extraction of Jasmine Flower Polysaccharide

[0081] (1) crushing: crushing the fully dried jasmine flowers, sieving, and drying to obtain jasmine flower pollen;

[0082] (2) Degreasing: Jasmine pollen is degreased with 10 times the amount of anhydrous ethanol (i.e., the ratio of Jasmine pollen to anhydrous ethanol is 1 g: 10 mL) at 85°C and refluxed for 90 min. The reflux is repeated once, filtered, and the anhydrous ethanol is evaporated to obtain the residue, which is then dried.

[0083] (3) Ultrasonic-assisted extraction: The defatted dry powder was mixed with distilled water at a solid-liquid ratio of 1 g:15 mL, with an ultrasonic power of 100 W for 20 min, and then placed in a 100 °C water bath for extraction for 2.5 h. After centrifugation, the aqueous extract was filtered;

[0084] (4) Alcohol precipitation: The filtrate is concentrated to 20% of the original volume using a rotary evaporator, and then 4 times the amount of anhydrous ethanol is added to the concentrate, which is placed in a refrigerator overnight, and the precipitate is collected by filtration. The ethanol on the surface is evaporated in a fume hood to obtain a precipitate;

[0085] (5) Washing: The precipitate is washed twice with anhydrous ethanol, ether, and acetone in sequence, and dried to obtain a crude polysaccharide extract I;

[0086] (6) Protein removal: Take the above-mentioned crude polysaccharide extract I and dissolve it in an appropriate amount of water, add Sevag reagent according to the ratio of crude polysaccharide to Sevag reagent 5:1, shake thoroughly for 30 minutes, and then centrifuge at 6000r / min for 15 minutes; carefully aspirate the upper polysaccharide solution, remove the organic phase and precipitate, and then add Sevag solvent equivalent to 1 / 5 of its volume, repeat several times until no obvious precipitation is produced, and store at 4°C to prevent deterioration for subsequent impurity removal;

[0087] (7) Impurity removal: Use a ready-to-use dialysis bag of >8000D to remove impurities. First, cut the dialysis bag into a suitable length, soak the preservation solution with deionized water, place the deproteinized frangipani polysaccharide solution in the bag, seal it with a dialysis bag clip, and place a weight at the bottom to make it vertical to the bottom; then immerse the dialysis bag in a beaker filled with deionized water and a magnet, and then place the entire beaker on a magnetic stirrer to speed up the dialysis rate, thereby assembling a complete dialysis device. Dialysis is performed for 48 hours, and the liquid in the dialysis bag is taken out and centrifuged to obtain a precipitate. After freeze-drying the precipitate, a crude frangipani polysaccharide extract II (i.e., purified frangipani polysaccharide) is obtained.

[0088] 2. Determination of Jasmine Flower Polysaccharide Content

[0089] (1) Glucose standard curve drawing and polysaccharide determination method

[0090] Standard curve drawing: The purified frangipani polysaccharide was determined by the phenol-sulfuric acid method. Accurately weigh 100 mg of glucose standard into a 100 mL volumetric flask, dilute to 100 mL with distilled water, and prepare a 0.1 mg / mL glucose standard solution; pipette the prepared glucose standard solution and dilute to 5 mL with distilled water, and prepare 0.02 mg / mL, 0.04 mg / mL, 0.06 mg / mL, 0.08 mg / mL, 0.10 mg / mL, 0.12 mg / mL, and 0.14 mg / mL respectively. Take 200 μL of each dilution and place them in 2 mL test tubes. Add 100 μL of 6% phenol and 500 μL of concentrated sulfuric acid to each test tube, let it stand for 10 min, shake it well, and leave it at room temperature for 20 min. Punch 200 μL into each well of a 96-well plate, and punch 3 wells into each test tube. Use an enzyme reader to measure the absorbance at a wavelength of 490 nm, and use distilled water as a blank control to obtain a standard curve (such as Figure 1 shown).

[0091] Determination of polysaccharide content: Take the total polysaccharide of Jasmine flower and prepare it into a 1mg / mL solution with distilled water, dilute it 10 times with distilled water, take 200μL with a pipette, put it into a 96-well plate, make 3 holes, add phenol and sulfuric acid in proportion, let it stand for 10 minutes, shake it well, put it at room temperature for 20 minutes, and measure the absorbance at a wavelength of 490nm with an enzyme marker. Calculate according to the following formula: Polysaccharide content (%) = (C×V2×D) / (W×V1×10)×100% (Formula 2); where C—sugar content calculated by the standard curve (mg); V2—total volume of the extract (mL); V1—volume taken for determination (mL); D—dilution factor; W—sample weight (g).

[0092] The standard curve of glucose measured by phenol-sulfuric acid method is as follows: Figure 1 As shown, the regression equation is y = 6.8588x-0.0177; the fit of the equation is R 2 =0.999. In the range of 0-0.14 mg / mL, there is a good linear relationship between glucose concentration and absorbance value.

[0093] The absorbance of total polysaccharide was measured, substituted into the regression equation to obtain the concentration of polysaccharide, and then substituted into (Formula 2) to obtain the total polysaccharide content of 66.03%. There are many factors that affect the concentration and purity of polysaccharides, and the main factors include the following: higher extraction temperature will cause polysaccharide decomposition, and more times of deproteinization by Sevage method will also cause polysaccharide loss.

[0094] 3. Ultraviolet spectrum analysis of frangipani polysaccharide

[0095] The purified Jasmine flower polysaccharide was dissolved in ultrapure water to prepare a polysaccharide solution with a concentration of 1 mg / mL, and the ultraviolet absorption spectrum of the polysaccharide solution was scanned (200-600 nm) using an ultraviolet visible spectrophotometer.

[0096] The results are as follows Figure 2 As shown in the figure, it can be seen that aromatic amino acids in proteins (such as tryptophan, tyrosine, and phenylalanine) have characteristic absorption peaks near 280nm, and frangipani polysaccharide has a small absorption peak near 280nm, indicating that it contains a small amount of protein; chlorophyll, carotenoids, etc. usually have characteristic absorption peaks near 380nm, and frangipani polysaccharide has no absorption peak at 380nm, indicating that it does not contain these pigments or the pigment content is extremely low.

[0097] 4. Infrared spectroscopy analysis of frangipani polysaccharides

[0098] Take a certain amount of the purified dried frangipani polysaccharide sample, mix it with dry KBr powder and press it into tablets. -1 Infrared spectrum scanning is carried out within the range and infrared spectrum graph is recorded.

[0099] The results are as follows Figure 3 As shown in the figure, it can be seen that the frangipani polysaccharide is at 3414.351cm -1 It is caused by the stretching vibration of OH, a strong absorption peak, which is a characteristic peak of sugars; it proves that the substance is sugar. -1 The absorption peak at wave number 1748.156 cm is the characteristic peak of CH stretching vibration; -1 It is the characteristic absorption peak of carboxyl group, indicating that frangipani polysaccharide contains carboxyl group. -1 The observed absorption peaks are related to the stretching of COC and COH, indicating the possible presence of a pyranose ring.

[0100] 5. Determination of relative molecular weight of frangipani polysaccharide

[0101] The molecular weight of the purified frangipani polysaccharide was determined by high performance gel permeation chromatography (HPGPC). The chromatographic conditions were as follows: mobile phase: 0.05 M NaCl solution; chromatographic column: BRT105-103-101 series gel column (8×300 mm); flow rate: 0.7 mL / min; column temperature: 40°C; injection volume: 25 μL; detector: differential detector RID-20A; analysis time: 70 min.

[0102] The molecular weight spectrum of Jasmine polysaccharide is as follows Figure 4 As shown in the figure, it can be seen that the frangipani polysaccharide peaks at 34.879 min, its relative peak area is 100%, and its molecular weight is 69445 Da.

[0103] 6. Determination of monosaccharide composition of Jasmine polysaccharide

[0104] Use ion chromatography to determine the monosaccharide composition. Accurately weigh 5 mg of the purified frangipani polysaccharide sample and place it in an ampoule, add 2 mL of 3MTFA, and hydrolyze at 120°C for 3 h. Accurately transfer the acid hydrolysis solution to a tube and blow it dry with nitrogen, add 5 mL of water and vortex to mix. Pipette 100 μL and add 900 μL of deionized water, centrifuge at 12000 rpm for 5 min. Take the supernatant for IC analysis.

[0105] The results are shown in Table 1 and Figure 5As shown, it can be seen that the main monosaccharide composition and molar percentage of Jasmine polysaccharide are rhamnose (Rha): arabinose (Ara): galactose (Gal): glucose (Glc): xylose (Xyl): mannose (Man): galacturonic acid (GalA) = 0.019: 0.109: 0.174: 0.220: 0.021: 0.022: 0.434; among which the monosaccharides with the highest content are galacturonic acid (GalA), glucose (Glc), galactose (Gal) and arabinose (Ara).

[0106] Table 1

[0107]

[0108]

[0109] Example 2 Application of Jasmine Flower Polysaccharide in the Development of Drugs for the Treatment of APAP-Induced Acute Liver Injury

[0110] This example verifies the effect of Jasmine flower polysaccharide on APAP-induced liver injury in BALB / c mice. The specific verification method is as follows:

[0111] 1. Animals and groups

[0112] Animal model: 35 commercially purchased SPF-grade BALB / c male mice, aged 6-8 weeks, weighing 20-24 g; after one week of adaptive feeding, the 35 mice were randomly divided into 5 groups, with 7 mice in each group, and the average weight of each group was 24 g.

[0113] Grouping: (1) blank control group (CON); (2) model group (APAP, i.e., MOD group); (3) positive control group (200 mg / kg·BW, NAC), (4) low-dose jasmine polysaccharide group (60 mg / kg·BW, SP-L); (5) high-dose jasmine polysaccharide group (120 mg / kg·BW, SP-H).

[0114] 2. Experimental methods

[0115] 1) Construction of APAP-induced acute liver injury model in BALB / c mice

[0116] The drug was continuously gavaged at 0.1 mL / 10 g for 14 days. The blank control group and the model group were gavaged with pure water, and the other groups were gavaged according to the above dosage. Two hours after gavage on the 14th day, APAP was injected intraperitoneally to the other mice except the normal group to cause an acute liver injury model at a dose of 300 mg / kg. The mice in the normal group were injected with pure water. In order to stabilize the model and eliminate the influence of diet on modeling, fasting for 15 hours before APAP injection was required. The body weight before death was recorded 18 hours after injection, the eyeball was removed and blood was placed in a 1.5 mL ordinary centrifuge tube at room temperature for more than 2 hours, centrifuged at 3000 rpm and 4°C for 10 minutes, and the supernatant was placed in another new centrifuge tube as serum, which was stored at -80°C for standby use. After blood was drawn, the mice were killed, the liver and spleen were removed, washed in physiological saline and the excess blood was blotted out, the liver morphology was photographed, and the liver and spleen were weighed for calculation of organ coefficients: a portion of the liver tissue was fixed in 4% paraformaldehyde solution, and the rest was placed in a cryovial and rapidly frozen in liquid nitrogen and stored at -80°C. This was used to calculate the liver and spleen organ coefficients.

[0117] 2) Detection of mouse body weight and liver and spleen indexes

[0118] Body weight was recorded every two days and before death, and the removed liver and spleen were weighed. The organ coefficient was calculated according to the following formula: organ coefficient = liver or spleen mass (mg) / mouse body weight (mg) × 100%.

[0119] The results of mouse body weight and liver and spleen indices are shown in Figure 6 As shown, from Figure 6 As can be seen from the weight graph in Figure A, there was no significant change in the weight of mice in each group during the 14 days of drug administration, indicating that Jasmine polysaccharide had no toxic effect on mice. However, after the injection of APAP, the weight of mice decreased significantly in a short period of time, indicating that the mouse model was successfully established.

[0120] from Figure 6 It can be seen from the BC figure and body weight figure that the liver and spleen indexes of the model group were significantly increased. After treatment with Jasmine flower polysaccharide, their liver index and spleen index decreased to varying degrees.

[0121] 3) Liver phenotype and liver histopathological analysis

[0122] Experimental method: The liver tissue was removed from 4% paraformaldehyde, dehydrated, paraffin-embedded, sliced, dewaxed, rehydrated, and HE-stained, and then stained with hematoxylin-eosin. Finally, the slices were sealed with neutral gum, dried in a fume hood overnight, and observed and photographed under an upright bright-field microscope.

[0123] Liver phenotype and liver histopathological analysis results Figure 7 As shown, from Figure 7 As can be seen from the liver morphology in Figure A, in the APAP-induced liver injury model group, the liver was obviously congested and swollen, and had a clear granular texture. After pretreatment with frangipani polysaccharide, the dark red congestion on the liver surface was effectively alleviated, and the surface granular texture was significantly weakened.

[0124] from Figure 7 The results of HE pathological section staining in Figure B show that APAP poisoning can cause severe hepatocyte necrosis, nuclear condensation, and a large number of inflammatory cell infiltration. However, no obvious abnormalities were found in the livers of mice in the CON group. The mice pretreated with NAC, SP-L, and SP-H could alleviate APAP-induced liver injury, with a significant reduction in necrosis area and inflammatory cell infiltration.

[0125] 4) Detection of mouse serum biochemical indicators

[0126] Experimental method: Mouse serum was taken out and directly tested after being diluted a certain multiple with normal saline; AST and ALT were determined according to the operating instructions of Nanjing Jiancheng kit, and inflammatory factors (IL-6, IL-1β, TNF-α) in serum were detected using Xinbosheng QuantiCyto○RELISA kit.

[0127] Serum biochemical index test results such as Figure 8 As shown, from Figure 8 As can be seen from the AB graph, compared with the normal group, the ALT and AST levels of the MOD group were significantly increased (P<0.0001), but the ALT and AST levels were significantly decreased after intervention with frangipani polysaccharide (the results are shown), indicating that frangipani polysaccharide can improve APAP-induced acute liver injury in mice.

[0128] from Figure 8 The results of measuring inflammatory factors in serum shown in CE show that compared with the CON group, the levels of serum TNF-α, IL-1β, and IL-6 in the MOD group were significantly increased (p<0.01). However, pretreatment with SP-L and SP-H reversed the increase in inflammatory factors. This suggests that Jasmine polysaccharide may have a protective effect on APAP-induced liver injury by inhibiting inflammatory response.

[0129] 5) Detection of biochemical indicators in mouse liver

[0130] Experimental method: 20-50 mg of liver tissue was cut and placed in a 1.5 ml centrifuge tube. Normal saline was added as a homogenization medium at a ratio of 1:9 between tissue and normal saline. A 10% liver homogenate was prepared using a manual tissue homogenizer. The homogenate was diluted a certain multiple with normal saline to obtain the optimal detection concentration and then used for the detection of biochemical indicators. The contents of SOD, MDA, GSH, CAT, and ROS were determined in sequence according to the operating instructions of the kit.

[0131] The results are as follows Fig. 9 As shown in the figure, compared with the CON group, the levels of SOD, CAT and GSH in the liver of the MOD group were significantly reduced (P<0.01), and the levels of MDA and ROS were significantly increased (P<0.01). Pretreatment with frangipani polysaccharide significantly increased the enzyme activities of SOD, GSH and CAT, and reduced the contents of MDA and ROS. These results indicate that frangipani polysaccharide can enhance antioxidant activity and protect the liver from damage.

[0132] Jasmine is a winding, vine-like evergreen ornamental shrub of the genus Jasmine (Oleaceae). Jasmine tastes bitter, is mild and non-toxic, and belongs to the liver meridian; it has the traditional efficacy of "soothing the liver and relieving depression, promoting qi and relieving pain". Modern medicinal chemistry research has found that Jasmine contains iridoids, triterpenes, flavonoids, lignans and other ingredients. Among them, there are monomer compounds such as oleuropein, hydroxytyrosol, hydroquinone, kaempferol, ethyl gallate, salidroside and quercetin. It is a medicinal and edible resource plant rich in active ingredients. The research team previously found that Jasmine extract has significant anti-inflammatory and antioxidant activities. The present invention is the first to discover that Jasmine polysaccharides can improve APAP-induced acute liver injury.

[0133] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A frangipani polysaccharide, characterized in that: The monosaccharides in the frangipani polysaccharide are composed of rhamnose, arabinose, galactose, glucose, xylose, mannose and galacturonic acid; the molar ratio of rhamnose, arabinose, galactose, glucose, xylose, mannose and galacturonic acid is (14-22): (100-120): (160-185): (200-240): (16-25): (18-27): (400-450).

2. The frangipani polysaccharide according to claim 1, characterized in that The molecular weight of the frangipani polysaccharide is 69445 Da.

3. A method for preparing frangipani polysaccharide as claimed in claim 1 or 2, comprising the following steps: The Jasmine flower sample was subjected to defatting, water extraction, alcohol precipitation, protein removal and dialysis in sequence to obtain Jasmine flower polysaccharide.

4. The preparation method according to claim 3, characterized in that: The dialysis is performed using a dialysis bag with a molecular weight cut-off of >8000Da; And / or, the dialysis time is 1-3 days.

5. Use of the Jasmine flower polysaccharide according to claim 1 or 2 in the preparation of a product for treating acute liver injury.

6. The use according to claim 5, characterized in that: The acute liver injury includes acute liver injury caused by APAP.

7. Use of the frangipani polysaccharide according to claim 1 or 2 in preparing a product for inhibiting the expression of inflammatory factors; Preferably, the inflammatory factors include IL-1β, IL-6, and TNF-α.

8. Use of the Jasmine flower polysaccharide according to claim 1 or 2 in the preparation of a product for reducing serum ALT and AST levels.

9. Use of the frangipani polysaccharide according to claim 1 or 2 in preparing a product having enhanced antioxidant activity; Preferably, the enhancing antioxidant activity comprises increasing catalase, superoxide dismutase and / or glutathione activity; Preferably, said enhancing antioxidant activity comprises reducing the content of malondialdehyde and / or active oxygen.

10. A product, characterized in that The product comprises the frangipani polysaccharide according to claim 1 or 2.

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