Pomegranate peel polysaccharide, its preparation method and its application in lipid-lowering

Abstract

The application discloses a pomegranate peel polysaccharide, a preparation method thereof and application of the pomegranate peel polysaccharide in lipid reduction, wherein the pomegranate peel polysaccharide PPP-1 is a polysaccharide component obtained through water extraction, alcohol precipitation and chromatography from dried pomegranate peel, and has a molecular weight of 1.5*10 4 Da, a total sugar content of 96.65%, and is composed of mannose, glucose, galactose and arabinose with a molar ratio of 3.33:75.24:1:1.18. The pomegranate peel polysaccharide component PPP-1 obtained in the application has no obvious toxic and side effects, and in-vivo and in-vitro experiments prove that the pomegranate peel polysaccharide component PPP-1 has good lipid-lowering effect and can be used for preparing lipid-lowering food or medicine, and has a good application prospect in preventing and treating hyperlipidemia and related chronic diseases.

Description

Technical Field

[0001] This invention relates to a pomegranate peel polysaccharide, its preparation method, and its application in lowering lipids, belonging to the field of biomedicine. Background Technology

[0002] With the improvement of people's living standards, changes in dietary structure, faster pace of life, and increased stress, the "three highs" (high blood pressure, high blood sugar, and high cholesterol) have gradually become more serious. Over the past 50 years, the prevalence of hyperlipidemia has increased dramatically worldwide. Hyperlipidemia, as a common metabolic disorder, is also a risk factor for cardiovascular disease. This poses a significant threat to the health of residents; therefore, the necessity of lowering blood lipids cannot be ignored. Currently, commonly used drugs for treating hyperlipidemia include statins and fibrates, but these are expensive and have certain side effects. Therefore, discovering natural active ingredients with lipid-lowering functions has become a common focus of scientific research and industry.

[0003] Pomegranate (Punica granatum), a plant belonging to the genus Punica in the family Punicaceae, is one of my country's signature fruits, with its planting area and yield ranking among the world's leading sources. Pomegranates are not only delicious and juicy but also rich in nutrients, containing various vitamins and trace elements beneficial to the human body, as well as bioactive components with potential health benefits such as antioxidant, anti-inflammatory, and anti-tumor properties. The edible portion of a pomegranate accounts for only 15%-40% of its total weight. During processing, a large amount of pomegranate byproducts are generated, especially the peel, which is often not fully utilized, leading to serious resource waste and environmental pollution. The level of full-value utilization of pomegranate resources needs improvement; in fact, from an industrial perspective, a breakthrough has not yet been achieved. Furthermore, the isolation of homogeneous polysaccharides with lipid-lowering effects from pomegranate peel is currently rare. Summary of the Invention

[0004] This invention provides a pomegranate peel polysaccharide, its preparation method, and its application in lowering blood lipids. The pomegranate peel polysaccharide PPP-1 of this invention has good lipid-lowering effects, no toxic side effects, and can be widely used in the preparation of lipid-lowering foods, pharmaceuticals, and other fields.

[0005] The pomegranate peel polysaccharide of this invention, abbreviated as PPP-1, is obtained by extraction and separation from pomegranate peel. Its total sugar content is 96.65%, and its molecular weight is 1.5 × 10⁻⁶. 4 Da is composed of four monosaccharides: glucose, mannose, arabinose, and galactose, with a molar ratio of Man:Glc:Gal:Ara = 3.33:75.24:1:1.18.

[0006] The preparation method of pomegranate peel polysaccharide PPP-1 of the present invention includes the following steps:

[0007] Step 1: Take dried pomegranate peel, pulverize it into ultrafine powder, and pass it through an 80-mesh sieve to obtain pomegranate peel powder;

[0008] Step 2: Mix the pomegranate peel powder obtained in Step 1 with 95% ethanol at a ratio of 1g:10mL, reflux in an 80℃ water bath for 2.5h, collect the precipitate by centrifugation, and dry it to obtain pretreated pomegranate peel powder.

[0009] Step 3: Add the pomegranate peel powder obtained in Step 2 to deionized water at a material-to-liquid ratio of 1g:20mL, incubate in a 90℃ water bath for 1.5h, separate the supernatant, and repeat three times; combine the three supernatants, concentrate to 1 / 6 to 1 / 8 of the original volume, add thermostable α-amylase (5000U / mL, 95℃, pH 6.5, 1h) and saccharifying enzyme (1000U / mL, 60℃, pH 4.5, 30min) to remove starch, centrifuge to collect the supernatant after the reaction, mix it with anhydrous ethanol at a volume ratio of 1:4, let it stand at 4℃ for 12h, and centrifuge to collect the precipitate;

[0010] Step 4: Dissolve the precipitate obtained in Step 3 with deionized water, remove protein using macroporous resin method, collect the eluent, dialyze in a 3500 Da dialysis bag, dialyze with running water for 48 h, dialyze with deionized water for 48 h, and freeze-dry to obtain pomegranate peel crude polysaccharide.

[0011] Step 5: Dissolve the crude polysaccharide fraction of pomegranate peel obtained in Step 4 in deionized water, elute with deionized water by DEAE-FF column chromatography, collect the elution peak, concentrate and freeze dry to obtain the homogeneous fraction of pomegranate peel PPP-1.

[0012] The present invention relates to the application of pomegranate peel polysaccharide PPP-1 in the preparation of food or pharmaceutical formulations with lipid-lowering effects.

[0013] The lipid-lowering effect is manifested in its ability to effectively alleviate lipid accumulation in oleic acid-induced HepG2 cells in a dose-dependent manner. Furthermore, the pomegranate peel polysaccharide PPP-1 effectively improves blood lipid levels and epididymal fat accumulation in obese mice induced by a high-fat diet, demonstrating a good regulatory effect on lipid metabolism.

[0014] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0015] 1. This invention is the first to extract, separate, and purify a homogeneous polysaccharide PPP-1 from pomegranate peel, with a simple procedure and high yield. The application of this method will significantly promote the development and high-value utilization of pomegranate peel polysaccharides and other active ingredients from natural products.

[0016] 2. The pomegranate peel polysaccharide PPP-1 provided by this invention has a good effect on alleviating lipid accumulation in oleic acid-induced HepG2 cells and obese mice induced by a high-fat diet, showing a significant lipid-lowering effect. It can provide a theoretical basis and technical support for the research and development of pomegranate peel polysaccharide as a functional lipid-lowering food. Attached Figure Description

[0017] Figure 1 The image shows the high-performance liquid chromatogram of PPP-1, indicating that pomegranate peel polysaccharide PPP-1 is a homogeneous component. Based on the molecular weight standard curve, the molecular weight is calculated to be 1.5 × 10⁻⁶. 4 Da.

[0018] Figure 2 It is composed of monosaccharides from PPP-1. Figure 2 It can be seen that PPP-1 is a neutral polysaccharide composed of four monosaccharides: glucose, mannose, arabinose and galactose, with a molar ratio of Man:Glc:Gal:Ara = 3.33:75.24:1:1.18.

[0019] Figure 3 It is the inhibitory effect of the polysaccharide PPP-1 and orlistat on pancreatic lipase. From Figure 3 It can be seen that when PPP-1 reaches 800 μg / mL, the inhibition rate is close to that of the positive control drug orlistat, proving that PPP-1 has a good inhibitory activity against pancreatic lipase.

[0020] Figure 4 This study describes the cytotoxicity of the polysaccharide PPP-1 against HepG2 cells. (The text appears to be incomplete and requires further context.) Figure 4 It can be seen that, compared with the blank control group, polysaccharide PPP-1 has no toxic side effects on HepG2 cells treated with oleic acid.

[0021] Figure 5 This is an image of HepG2 cells stained with Oil Red O. Figure 5 The results showed that, compared with the model group, different concentrations of pomegranate peel polysaccharide PPP-1 intervention improved intracellular lipid accumulation to varying degrees, and the red area gradually faded. The 200 μg / mL and 600 μg / mL groups showed significant improvement, especially the 600 μg / mL group, which had the lowest intracellular lipid droplet content, indicating that PPP-1 has a good lipid-lowering effect.

[0022] Figure 6 The effect of polysaccharide PPP-1 on oleic acid-induced total cholesterol (TC) and triglycerides (TG) in HepG2 cells. Figure 6The results showed that after administration of different concentrations of pomegranate peel polysaccharide PPP-1, the contents of TC and TG gradually decreased with increasing dose. Specifically, compared with the model group of HepG2 cells, the high-dose (600 μg / mL) PPP-1 group showed a 76.2% decrease in intracellular TC and a 70.4% decrease in TG, comparable to the simvastatin group, demonstrating that pomegranate peel polysaccharide PPP-1 has a lipid-lowering effect on HepG2 cells.

[0023] Figure 7 The effect of polysaccharide PPP-1 on oleic acid-induced high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) in HepG2 cells. Figure 7 The results showed that after oleic acid induction, the HDL-C and LDL-C contents of HepG2 cells changed significantly. Compared with the model group, the HDL-C content increased by 2.1 times and the LDL-C content decreased by 2.0 times after high-dose PPP-1 treatment, proving that pomegranate peel polysaccharide PPP-1 effectively improved the lipoprotein levels of HepG2 cells.

[0024] Figure 8 The effect of polysaccharide PPP-1 on oleic acid-induced extracellular aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in HepG2 cells. Figure 8 As shown, PPP-1 significantly reduced oleic acid-induced AST and ALT levels in HepG2 cells in a concentration-dependent manner, demonstrating that pomegranate peel polysaccharide PPP-1 has the function of repairing HepG2 cell damage.

[0025] Figure 9 The effect of polysaccharide PPP-1 on epididymal fat in obese mice induced by a high-fat diet. Figure 9 It can be seen that under the induction of a high-fat diet, the weight of epididymal fat in mice increased significantly; while PPP-1 effectively improved the increase in epididymal fat weight in mice, proving that pomegranate peel polysaccharide PPP-1 has the effect of reducing fat accumulation in mice.

[0026] Figure 10 This involves the measurement of serum indicators. Comparing the HFD and ND groups, we found that excessive energy intake led to lipid metabolism dysfunction. We discovered that HFD significantly increased serum lipid levels in mice, manifested as elevated serum TC, TG, and LDL-C, and decreased HDL-C, which was reversed after PPP-1 treatment. Compared to the HFD group, oral administration of PPP-1 to mice primarily reduced TG and increased HDL-C levels. Furthermore, compared to the ND group, PPP-1 intake had no toxic side effects on mice and reduced blood lipid levels.

[0027] Figure 11This is an observation of Oil Red O staining of mouse livers. Large areas of red appeared in liver sections of mice in the HFD group, indicating excessive lipid accumulation, while PPP-1 supplementation significantly improved this phenomenon.

[0028] Figure 12 This study observed liver hepatitis and liver endothelial growth factor (H&E) in mice. The H&E results also showed that a high-fat diet caused significant liver damage in mice, with a large number of fat vacuoles appearing in the livers of mice in the HFD group; supplementation with PPP-1 significantly reduced the number of fat vacuoles and promoted the integrity of hepatocyte morphology.

[0029] Figure 13 This study observed H&E in the epididymal adipose tissue of mice. Supplementation with polysaccharide PPP-1 significantly inhibited the HFD-induced increase in adipocyte size and decrease in adipocyte number in the epididymal adipose tissue. This result is consistent with... Figure 9 Correspondingly. Detailed Implementation

[0030] The technical solution of the present invention will be further analyzed and explained through specific embodiments below.

[0031] Example 1: Preparation of pomegranate peel polysaccharide PPP-1

[0032] Step 1: Take dried pomegranate peel, pulverize it into ultrafine powder, and pass it through an 80-mesh sieve to obtain pomegranate peel powder.

[0033] Step 2: Mix the pomegranate peel powder obtained in Step 1 with 95% ethanol at a ratio of 1g:10mL, reflux in an 80℃ water bath for 2.5h, collect the precipitate by centrifugation, and dry it to obtain pretreated pomegranate peel powder.

[0034] Step 3: Add the pomegranate peel powder obtained in Step 2 to deionized water at a material-to-liquid ratio of 1g:20mL, incubate in a 90℃ water bath for 1.5h, separate the supernatant, and repeat three times; collect the supernatant three times, concentrate it to 1 / 6 to 1 / 8 of the original volume, add α-amylase (5000U / mL, 95℃, pH 6.5, 1h) and saccharifying enzyme (1000U / mL, 60℃, pH 4.5, 30min), centrifuge to collect the supernatant after the reaction, mix it with anhydrous ethanol at a ratio of 1:4, let it stand at 4℃ for 12h, and centrifuge to collect the precipitate.

[0035] Step 4: Dissolve the precipitate obtained in Step 3 with deionized water, remove proteins using macroporous resin, collect the eluent, dialyze it in a 3500 Da dialysis bag, dialyze with running water for 48 h, dialyze with deionized water for 48 h, and freeze-dry to obtain pomegranate peel crude polysaccharide PPP.

[0036] Step 5: Dissolve the crude polysaccharide fraction of pomegranate peel obtained in Step 4 in deionized water, elute with deionized water by DEAE-FF column chromatography, collect the elution peak, concentrate and freeze dry to obtain the homogeneous fraction of pomegranate peel PPP-1.

[0037] The physicochemical properties of pomegranate peel crude sugar (PPP) and pomegranate peel polysaccharide (PPP-1) are compared in the table below. As can be seen from the table, PPP has a lower sugar content and contains a large amount of protein and phenols. PPP-1, purified using the steps of this invention, has high purity and contains no protein or phenols.

[0038]

[0039] Example 2: Structural characteristics of pomegranate peel polysaccharide PPP-1

[0040] Molecular weight determination: Molecular weight (Mw) was determined by high-performance liquid chromatography (HPLC) with evaporative light detection (ELSD). The chromatographic column was a TSK-G6000 (300×7.0 mm, 13 μm), and the instrument was an Agilent 1260 series. Experimental conditions: N2 was used as the carrier gas at a flow rate of 2.5 L / min, the column temperature was 30℃, the drift tube temperature was 100℃, the mobile phase was ultrapure water at a flow rate of 0.6 mL / min, and the injection volume was 20 μL. PPP-1 solution (3 mg / mL) was filtered through a 0.22 μm filter membrane and injected into the HPLC system. The relative molecular mass of PPP-1 was calculated to be 1.5 × 10⁻⁶ m³ / s based on the molecular weight standard curve. 4 Da.

[0041] Monosaccharide composition analysis: Samples were treated using an acid hydrolysis-pre-column PMP derivatization method, and analyzed by high-performance liquid chromatography (HPLC). Standard curves were prepared using arabinose, rhamnose, glucose, galactose, mannose, glucuronic acid, and galacturonic acid as standard samples. 10 mg of PPP-1 was dissolved in 5 mL of TFA (2.5 mol / L) and completely hydrolyzed at 110 °C for 6 hours. After the reaction, the solution was evaporated under reduced pressure at 60 °C until dry. Methanol was added repeatedly until the hydrolysis product reached neutrality, and then deionized water was added and rotary evaporated to remove methanol. 2 mg of different standard monosaccharide samples were weighed and dissolved in deionized water to prepare 2 mg / mL solutions of different standard monosaccharides. The hydrolyzed samples and mixed monosaccharide standard samples were mixed with NaOH (0.3 mol / L) and PMP (0.5 mol / L), respectively, at 70 °C for 1 hour. Subsequently, the solutions were neutralized with hydrochloric acid (0.3 M) to pH 7. Finally, the derivatives were extracted three times with equal volumes of chloroform and filtered through a 0.22 μm microporous membrane. The resulting products were detected by high-performance liquid chromatography (HPLC) with a 245 nm DAD detector. The separation process was performed at Waters XBridge. TM C18 column The reaction was performed at 30℃. By comparing the retention time with that of the standard sample, the monosaccharide composition was analyzed. The analysis revealed that PPP-1 is composed of four monosaccharides: glucose, mannose, arabinose, and galactose, with a molar ratio of Man:Glc:Gal:Ara = 3.33:75.24:1:1.18.

[0042] Example 3: Inhibition of pancreatic lipase by pomegranate peel polysaccharide PPP-1

[0043] Prepare the substrate working solution (0.08 g of 4-nitrobenzene laurate dissolved in 5 mM sodium acetate solution containing 1% Tritium X-100), 0.1 M Tris buffer, and solutions of orlistat and PPP-1 at different concentrations (50, 100, 200, 400, 600, 800 μg / mL). Add the sample, pancreatic lipase, and buffer solution sequentially to the tubes, react at 37°C for 10 min, then add the substrate working solution, react at 37°C for 2 h, centrifuge for 10 min, and measure the absorbance at 405 nm. The experimental control group used buffer instead of pancreatic lipase, the blank group used buffer instead of the sample, and the blank control group used buffer instead of both the sample and pancreatic lipase. Calculate the inhibition rate of PPP-1 against pancreatic lipase using the following formula. The results are shown below. Figure 3 As shown.

[0044] Pancreatic lipase inhibition capacity (%) = [1 - (A2 - A3) / (A0 - A1)] × 100

[0045] Where A0 represents the blank group, A1 represents the blank control group, A2 represents the experimental group, and A3 represents the experimental control group.

[0046] Example 4: Determination of the in vitro lipid-lowering activity of pomegranate peel polysaccharide PPP-1

[0047] The lipid-lowering activity of pomegranate peel polysaccharide PPP-1 fraction was evaluated using oleic acid-induced HepG2 cells as a model.

[0048] 1. Detection of HepG2 cytotoxicity

[0049] HepG2 cells in logarithmic growth phase were seeded into 96-well plates and cultured in a 5% CO2 incubator for 24 hours for adaptation. After oleic acid induction, the culture medium was removed. Fresh culture medium was added to the blank control group, and PPP-1 solution was added to the sample groups sequentially at concentrations of 50 μg / mL, 100 μg / mL, 200 μg / mL, 400 μg / mL, and 600 μg / mL, respectively, and cultured for another 24 hours. The culture medium was then removed, and cell viability was detected using the MTT assay. The results are shown below. Figure 4 As shown.

[0050] 2. Detection of lipid-lowering activity

[0051] (1) Detection of total lipids: HepG2 cells in logarithmic growth phase were seeded into 6-well plates and cultured in a 5% CO2 incubator for 24 h. After culture, the medium was removed, and the cells were starved for 24 h. Fresh medium was added to the blank control group, 0.25 mM oleic acid solution was added to the model group, and 0.25 mM oleic acid and 50 μg / mL, 200 μg / mL, and 400 μg / mL polysaccharide PPP-1 solution were added to the experimental groups, respectively. The cells were cultured for another 24 h, stained with Oil Red O, and observed and photographed under a microscope. After photography, 200 μL of isopropanol was added to each well, and the total lipid content was measured. The results are as follows: Figure 5 As shown.

[0052] (2) Detection of total cholesterol (TC) and triglycerides (TG): HepG2 cells in logarithmic growth phase were seeded into 6-well plates and cultured in a 5% CO2 incubator for 24 h. After culture, the medium was removed, and the cells were starved for 24 h. Fresh medium was added to the blank control group, 0.25 mM oleic acid solution was added to the model group, and 0.25 mM oleic acid and 50 μg / mL, 200 μg / mL, and 600 μg / mL polysaccharide PPP-1 solution were added to the experimental groups, respectively. After culturing for another 24 h, the cells were collected, lysed, and the intracellular total cholesterol and triglyceride content were measured. The results are as follows: Figure 6 As shown.

[0053] (3) Detection of high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C): HepG2 cells in logarithmic growth phase were seeded in 6-well plates and cultured in a 5% CO2 incubator for 24 hours. After culture, the medium was removed, and the cells were starved for 24 hours. Fresh medium was added to the blank control group, 0.25 mM oleic acid solution was added to the model group, and 0.25 mM oleic acid and polysaccharide PPP-1 solutions (50 μg / mL, 200 μg / mL, and 600 μg / mL, respectively) were added to the experimental groups. After culturing for another 24 hours, the cells were collected, lysed, centrifuged, and the supernatant was used to determine the levels of HDL-C and LDL-C. The results are as follows: Figure 7 As shown.

[0054] (4) Determination of Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT): HepG2 cells in logarithmic growth phase were seeded into 6-well plates and cultured in a 5% CO2 incubator for 24 h. After culture, the medium was removed, and the cells were starved for 24 h. Fresh medium was added to the blank control group, 0.25 mM oleic acid solution was added to the model group, and 0.25 mM oleic acid and polysaccharide PPP-1 solution (50 μg / mL, 200 μg / mL, and 600 μg / mL, respectively) were added to the experimental groups. After culturing for another 24 h, the cells were collected, and the extracellular AST and ALT levels were measured using homogenate. The results are as follows: Figure 8 As shown.

[0055] Example 5: Determination of the lipid-lowering activity of pomegranate peel polysaccharide PPP-1 in vivo

[0056] Forty 6-week-old male C57BL / 6J mice were randomly divided into four groups (n=10 each) after a one-week acclimatization period: normal diet (ND), high-fat diet (HFD), normal diet + polysaccharide PPP-1 (ND+PPP-1), and high-fat diet + polysaccharide PPP-1 (HFD+PPP-1). The ND and ND+PPP-1 groups were fed a normal diet, while the HFD and HFD+PPP-1 groups were fed a high-fat diet. The ND and HFD groups received an equal volume of 0.9% saline via oral gavage daily, while the ND+PPP-1 and HFD+PPP-1 groups received 200 mg / kg bw of pomegranate peel polysaccharide PPP-1 via oral gavage daily. The experiment lasted for nine weeks. After nine weeks, mice were sacrificed under ether anesthesia via orbital blood sampling, and serum and organs were collected for further investigation.

[0057] 1. Weighing of epididymal fat in mice

[0058] Epididymal fat was collected from four groups of mice, weighed, and recorded. The results are as follows: Figure 9 As shown.

[0059] 2. Serum marker measurement

[0060] The extracted mouse blood was centrifuged at low speed for 20 min, and the serum was then separated and stored at -20℃ for later use. Following the kit instructions, the levels of total triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL-C), and low-density lipoprotein (LDL-C) in the serum were measured. The results are as follows: Figure 10 As shown.

[0061] 3. Histopathological sections

[0062] Liver and epididymal adipose tissue fixed in 4% paraformaldehyde solution were observed by H&E staining; to observe lipid accumulation in the liver, the liver was subjected to ice cutting and Oil Red O staining. All prepared sections were observed under a microscope, and the results are as follows. Figure 11-13 As shown ( Figure 11 Oil Red O staining for liver Figure 12 For liver H&E, Figure 13 (H&E of epididymal fat).

Claims

1. A pomegranate peel polysaccharide, characterized in that: The pomegranate peel polysaccharide, abbreviated as PPP-1, is a homogeneous fraction obtained by DEAE-FF column chromatography and elution with deionized water from crude pomegranate peel polysaccharide; the total sugar content of PPP-1 is 96.65%, and the molecular weight is 1.5 × 10⁻⁶. 4 Da is composed of four monosaccharides: glucose, mannose, arabinose, and galactose, with a molar ratio of Man: Glc: Gal: Ara = 3.33: 75.24: 1:1.

18. The pomegranate peel polysaccharide PPP-1 was prepared by a method comprising the following steps: Step 1: Take dried pomegranate peel, pulverize it into ultrafine powder, and pass it through an 80-mesh sieve to obtain pomegranate peel powder; Step 2: Mix the pomegranate peel powder obtained in Step 1 with 95% ethanol at a ratio of 1g:10mL, reflux in an 80℃ water bath for 2.5h, collect the precipitate by centrifugation, and dry it to obtain pretreated pomegranate peel powder. Step 3: Add the pomegranate peel powder obtained in Step 2 to deionized water at a material-to-liquid ratio of 1g:20mL, incubate in a 90℃ water bath for 1.5h, separate the supernatant, repeat three times, combine the supernatants, and concentrate to 1 / 6 to 1 / 8 of the original volume; treat with thermostable α-amylase at 5000 U / mL, 95℃, pH 6.5 for 1h, and treat with saccharifying enzyme at 1000 U / mL, 60℃, pH 4.5 for 30min to remove starch; after the reaction, centrifuge, collect the supernatant and mix it with anhydrous ethanol at a ratio of 1:4, let stand at 4℃ for 12h, and centrifuge to collect the precipitate; Step 4: Dissolve the precipitate obtained in Step 3 with deionized water, remove protein using macroporous resin method, collect the eluent, dialyze in a 3500 Da dialysis bag, dialyze with running water for 48 h, dialyze with deionized water for 48 h, and freeze-dry to obtain pomegranate peel crude polysaccharide. Step 5: Dissolve the crude polysaccharide fraction of pomegranate peel obtained in Step 4 in deionized water, elute with deionized water by DEAE-FF column chromatography, collect the deionized water eluted fraction, concentrate and freeze dry to obtain the homogeneous fraction of pomegranate peel PPP-1.

2. The application of pomegranate peel polysaccharide PPP-1 according to claim 1 in the preparation of food or pharmaceutical preparations with lipid-lowering effects, characterized in that: The pomegranate peel polysaccharide PPP-1 can inhibit pancreatic lipase activity, thus alleviating lipid accumulation in a dose-dependent manner.

3. The application according to claim 2, characterized in that: The pomegranate peel polysaccharide PPP-1 can regulate and improve the levels of high-density lipoprotein and low-density lipoprotein in oleic acid-induced HepG2 cells, and can significantly reduce the levels of AST and ALT in oleic acid-induced HepG2 cells in a concentration-dependent manner.

4. The application according to claim 2, characterized in that: The pomegranate peel polysaccharide PPP-1 can effectively improve blood lipid indicators and epididymal fat accumulation in obese mice induced by a high-fat diet, and has a good regulatory effect on lipid metabolism.

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