A way to alleviate PM 2.5 Platycodon grandiflorum polysaccharides that cause respiratory diseases and their applications

Abstract

The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of relieving PM 2.5 The present application relates to a kind of alleviating PM 2.5 The present application relates to a kind of alleviating PM 2.5 The present application relates to a kind of alleviating PM The present application relates to a kind of alleviating PM

Description

Technical Field

[0001] This invention relates to the field of biomedicine, specifically to Platycodon grandiflorus polysaccharide and its applications, particularly the role of Platycodon grandiflorus polysaccharide in alleviating PM2.5. 2.5 Applications include treating organ damage, anti-inflammatory effects, antioxidant effects, and regulating lung flora. Background Technology

[0002] Haze mainly consists of sulfur dioxide, nitrogen oxides, and inhalable particulate matter (PM2.5). 2.5 Of these three components, the first two are gaseous pollutants, while the last one, particulate matter, is the main cause of severe smog pollution. Haze with a diameter ≤2.5μm (equivalent to one-thirtieth the diameter of a human hair) is called PM2.5. 2.5 PM2.5, also known as fine particulate matter, is very harmful to the human body because it can penetrate deep into the lungs and even the bloodstream. 2.5 As particulate matter enters the upper respiratory tract during respiration, about half of the particles, due to their small size, can enter the lower respiratory tract and deposit on the mucous membrane of the lower respiratory tract wall, causing tissue damage and secondary pathogenic microbial infections. This can induce tracheitis, bronchial asthma, bronchiolitis, pneumonia, and pneumoconiosis. A meta-analysis of the correlation between atmospheric particulate matter and the number of hospitalizations for childhood asthma showed that atmospheric PM2.5... 2.5 For every 10 μg / m 3 The number of children hospitalized for asthma has increased by an average of 3.45% in the short term. Those with pre-existing chronic respiratory diseases such as chronic bronchitis, bronchial asthma, emphysema, or pulmonary heart disease will experience further exacerbation of their condition. This is due to PM2.5. 2.5 It adsorbs carcinogenic substances such as polycyclic aromatic hydrocarbons and heavy metals, thus potentially inducing lung cancer. Alveoli are the sites of oxygen and carbon dioxide exchange in the human body, constituting the main structure of the lungs. The alveolar walls are very thin, and adjacent alveoli are separated by thin alveolar septa containing dense capillaries. PM2.5 entering the alveoli... 2.5 This damages the alveolar walls, creating a pathway for minute foreign objects to enter the lungs. 2.5 After some fine particles (less than 1 μm in diameter) are dissolved, they can easily enter the alveolar septum through this channel, and then enter the bloodstream through the thin walls of capillaries via osmosis. They are then carried throughout the body by the blood flow, forming PM. 2.5 Toxemia. It has been reported that if PM2.5 levels in the air... 2.5 Concentration consistently above 10 μg / m 3 This will increase the risk of death. PM 2.5 For every 10 μg / m³ increase in concentration 3 The risk of overall death increases by 4%, the risk of death from cardiovascular disease increases by 6%, and the risk of death from lung cancer increases by 8%. Therefore, it is crucial to investigate and explore ways to prevent and control PM2.5. 2.5 The methods used to treat respiratory diseases are of great practical significance.

[0003] Various factors in smoggy environments increase the pathogenicity and transmissibility of pathogens, making the prevention and treatment of lung diseases more difficult. Currently, traditional Chinese medicine theories of "turbidity and toxins" are used to address lung diseases in smoggy environments; measures include controlling pollution at its source; improving energy efficiency; and taking personal protective measures. However, these methods have drawbacks such as limited therapeutic effects, difficulty in implementation, and suitability for everyone. Therefore, the search for a safe, non-toxic, and effective method to alleviate PM2.5 pollution is crucial. 2.5 Preparations that cause respiratory diseases are of great significance.

[0004] Platycodon grandiflorus, also known as bellflower, is a perennial herb with dark blue or dark purplish-white flowers, used as an ornamental plant. Its root is used medicinally; it is bitter and pungent in taste, neutral in nature, and enters the lung meridian. It has antitussive, expectorant, lung-clearing, and pus-draining effects, and is a commonly used herb in Traditional Chinese Medicine. Platycodon grandiflorus has expectorant and antitussive effects, lowers blood sugar, has anti-inflammatory properties, enhances immunity, inhibits gastric juice secretion, and has anti-ulcer effects. Polysaccharides are high-molecular-weight compounds, widely distributed in nature, and are very important, with no toxic side effects. However, different preparation processes and extraction sites can affect the activity and uses of polysaccharides. This invention, based on the theory of "medicine and food sharing the same origin," provides a method for preparing and purifying Platycodon grandiflorus polysaccharides. The polysaccharides extracted by this method can alleviate respiratory diseases caused by smog.

[0005] No patent publications related to this invention patent application were found through a search. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies and provide a method for alleviating PM2.5 pollution. 2.5 Platycodon polysaccharides that cause respiratory diseases and their applications.

[0007] To achieve the above objectives, we have implemented the following technical solutions:

[0008] Moreover, the polysaccharide from the platycodon root is mainly a neutral polysaccharide;

[0009] Alternatively, the Platycodon grandiflorus polysaccharide is obtained by water extraction and alcohol precipitation with a material-to-water ratio of 1:20 and 70% ethanol precipitation to obtain crude polysaccharide. The crude polysaccharide is then purified by Q-Sephadex anion exchange column and dextran gel G-100 column to obtain a single component.

[0010] Alternatively, the said platycodon polysaccharide is mainly composed of arabinose (30.7%) and galactose (22.4%); its molecular weight is approximately 244 kDa.

[0011] Alternatively, the Platycodon grandiflorus polysaccharide at a concentration of 25–200 μg / mL is non-toxic to human lung epithelial cells; and it can improve PM2.5 levels.2.5 The resulting cell damage;

[0012] Or the aforementioned Platycodon polysaccharide can alter PM 2.5 Organ indices in mice after injury can improve liver and kidney atrophy in mice;

[0013] Alternatively, the aforementioned Platycodon grandiflorus polysaccharide may have anti-inflammatory effects and be able to reduce PM2.5 levels. 2.5 Release of inflammatory factors TNF-α and IL-1β in bronchoalveolar lavage fluid of mice after injury.

[0014] Alternatively, the aforementioned Platycodon grandiflorus polysaccharide can regulate lung flora and optimize PM2.5 levels. 2.5 Composition of lung flora in mice after injury.

[0015] The aforementioned Platycodon grandiflorus polysaccharide is one of the important bioactive substances in the traditional Chinese medicine Platycodon grandiflorus.

[0016] As mentioned above, Platycodon grandiflorum polysaccharide, which can promote cell proliferation, alleviate organ damage, and reduce inflammatory factor levels, can be used in the preparation of products for the prevention and / or treatment of PM. 2.5 Its use in drugs that cause acute lung injury and pneumonia.

[0017] As described above, the polysaccharide from Platycodon grandiflorus was confirmed to significantly improve PM through organ index determination, pathological morphological observation, and superoxide dismutase (SOD) assay. 2.5 Induced multi-organ injury has broad application prospects, especially in PM. 2.5 Treatment or prevention of induced acute lung injury. Using PM 2.5 A mouse model of induced acute lung injury was established. Pathological morphological observation, including the expression of inflammatory factors in bronchoalveolar lavage fluid and the levels of SOD and MDA in lung tissue, demonstrated that the Platycodon grandiflorus polysaccharide of this invention significantly improves PM2.5. 2.5 Induced acute lung injury.

[0018] The advantages and positive effects of this invention are as follows:

[0019] 1. The Platycodon grandiflorus polysaccharide of this invention is non-toxic to cells and can protect PM. 2.5 This leads to cell damage.

[0020] 2. The Platycodon grandiflorus polysaccharide of this invention has the effect of improving PM 2.5 The effect of the organ index on mice after injury showed a significant repair effect.

[0021] 3. The Platycodon grandiflorus polysaccharide of this invention has the effect of reducing PM2.5. 2.5 Functional analysis of the levels of inflammatory factors TNF-α and IL-1β in bronchoalveolar lavage fluid of mice after injury.

[0022] 4. The Platycodon grandiflorus polysaccharide of the present invention has antioxidant function, which can increase SOD activity and reduce MDA content in lung tissue.

[0023] 5. The Platycodon grandiflorus polysaccharide of this invention can regulate lung flora and optimize the composition of lung flora in mice caused by injury.

[0024] 6. The Platycodon grandiflorus polysaccharide of this invention can be used in traditional Chinese medicine preparations for the prevention and treatment of respiratory diseases such as lung injury and pneumonia caused by smog. It provides theoretical support for the development of traditional Chinese medicine preparations for the prevention and treatment of acute or subacute lung injury and has a very broad application prospect. Attached Figure Description

[0025] Figure 1 The effect of Platycodon grandiflorum polysaccharide on the proliferation of human lung epithelial cells in this invention shows that the polysaccharide is non-toxic to cells;

[0026] Figure 2 The effect of Platycodon grandiflorum polysaccharide on cell proliferation after injury was investigated in this invention. The results showed that the polysaccharide can protect against cell damage.

[0027] Figure 3 The polysaccharide of Platycodon grandiflorus in this invention improves PM 2.5 Liver coefficient in mice after injury;

[0028] Figure 4 The polysaccharide of Platycodon grandiflorus in this invention improves PM 2.5 Kidney coefficient in mice after injury;

[0029] Figure 5 To reduce PM in the Platycodon grandiflorum polysaccharide of this invention 2.5 Expression of the inflammatory factor TNF-α in bronchoalveolar lavage fluid of mice after injury;

[0030] Figure 6 To reduce PM in the Platycodon grandiflorum polysaccharide of this invention 2.5 Expression of the inflammatory factor IL-1β in bronchoalveolar lavage fluid of mice after injury;

[0031] Figure 7 The polysaccharide of Platycodon grandiflorus in this invention improves PM 2.5 Pathological structure of mouse lung tissue after injury. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0033] Unless otherwise specified, the raw materials used in this invention are all conventional commercially available products; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0034] A way to alleviate PM2.5 Platycodon polysaccharides that cause respiratory diseases and their applications.

[0035] Preferably, the polysaccharide is extracted from dried Platycodon grandiflorus roots. The dried Platycodon grandiflorus slices are ground into powder and passed through a 40-mesh sieve. The crude polysaccharide is obtained by water extraction and alcohol precipitation with a material-to-water ratio of 1:20 and 70% ethanol.

[0036] Alternatively, the crude polysaccharide can be purified by Q-Sephadex anion exchange column and dextran gel G-100 column to obtain a single component of Platycodon grandiflorum polysaccharide.

[0037] Alternatively, the Platycodon grandiflorus polysaccharide is mainly composed of arabinose (30.7%), galactose (22.4%), glucose (14.3%), rhamnose (13.5%), mannose (9.7%), and xylose (9.4%); its molecular weight is approximately 244 kDa.

[0038] Preferably, the Platycodon grandiflorum polysaccharide at a concentration of 25–200 μg / mL is non-toxic to human lung epithelial cells; and it can improve PM2.5 levels. 2.5 The resulting cell damage;

[0039] Alternatively, the aforementioned Platycodon grandiflorus polysaccharide can improve PM 2.5 Organ indices in mice after injury can improve liver and kidney atrophy in mice;

[0040] Alternatively, the aforementioned Platycodon grandiflorus polysaccharide may have anti-inflammatory effects and be able to reduce PM2.5 levels. 2.5 Release of inflammatory factors TNF-α and IL-1β in bronchoalveolar lavage fluid of mice after injury;

[0041] Or the aforementioned Platycodon grandiflorum polysaccharide has antioxidant properties, PM 2.5 After injury, the SOD activity in mouse lung tissue decreased from 29.91±1.82 U / mg prot to 24.51±1.36 U / mg prot, while the malondialdehyde (MDA) content increased from 7.61±2.60 nmol / mg prot to 11.72±2.47 nmol / mg prot. After injury, the SOD activity in mouse tissue protected by Platycodon grandiflorus polysaccharide increased to 29.14±2.34 U / mg prot, while the MDA content decreased to 7.53±1.74 nmol / mg prot.

[0042] Alternatively, the aforementioned Platycodon grandiflorus polysaccharide can increase the relative abundance of beneficial bacteria Rhodococcus and Raoultella, and decrease the relative abundance of harmful bacteria Desulfovibrionaceae and Xanthomonadaceae, thereby optimizing PM2.5 levels. 2.5 Composition of lung flora in mice after injury.

[0043] Or, more specifically, the relevant preparation and detection steps are as follows:

[0044] Example 1: Extraction, separation, and purification of polysaccharides

[0045] Dried Platycodon grandiflorum slices were pulverized into powder using a pulverizer and passed through a 40-mesh sieve. The sample (g):water (mL) was mixed in a conical flask at a ratio of 1:20, and incubated at 80℃ for 6-7 hours. The mixture was then filtered through three layers of gauze, and the filtrate was centrifuged at 6000 rpm for 10 minutes to obtain an aqueous extract of Platycodon grandiflorum. The extract was concentrated using a rotary evaporator, and then anhydrous ethanol (70% final concentration) was slowly added to the concentrate. After overnight sedimentation, the precipitate was collected by centrifugation at 8000 rpm for 10 minutes, which was the crude polysaccharide of Platycodon grandiflorum. The crude polysaccharide was allowed to stand to evaporate residual alcohol, and after freeze-drying, the sample was purified using a Q-Sephadex anion exchange column and a dextran gel G-100 column to obtain a single component, namely Platycodon grandiflorum polysaccharide.

[0046] Example 2: Physicochemical properties of polysaccharides

[0047] (1) Relative molecular mass of Platycodon grandiflorum polysaccharide: The relative molecular mass of the polysaccharide was determined by high performance liquid chromatography (HPLC) combined with a refractive index detector. The polysaccharide sample was centrifuged at 12000 r / min for 10 min and placed in the inner liner tube of the HPLC bottle. The molecular weight was obtained by observing the retention time and peak surface area of ​​the peak and normalizing the product. The molecular weight of the Platycodon grandiflorum polysaccharide was 244 kDa.

[0048] (2) Monosaccharide composition of Platycodon grandiflorum polysaccharide: Weigh 2 mg of sample into an ampoule, add 5 mL of trifluoroacetic acid, seal with an alcohol lamp, and hydrolyze in an oil bath at 120 °C for 3 h (complete hydrolysis). Remove excess trifluoroacetic acid by nitrogen blowing, and finally dissolve the product in ultrapure water, mix well, and store at 4 °C. Before loading, the sample was filtered through a 0.22 μm aqueous filter membrane and a solid-phase extraction column, respectively. The Platycodon grandiflorum polysaccharide is mainly composed of arabinose (30.7%), galactose (22.4%), glucose (14.3%), rhamnose (13.5%), mannose (9.7%), and xylose (9.4%).

[0049] Example 3: Effects of Platycodon grandiflorus polysaccharide on PM 2.5 Effects of A549 cell proliferation induction

[0050] (1) Cell Culture: Human lung epithelial cells were cultured in F12K medium containing 10% fetal bovine serum for 2 days. Cell status and density were observed under a microscope. If the cells were in the logarithmic growth phase and the density reached 80%, they could be used for subsequent experiments. The cell density was adjusted to 1×10⁶ cells / year. 5100 μL of cell suspension was seeded into each well of a 96-well plate and cultured overnight until the cells adhered. After 12 hours of cell adhesion, the culture medium was aspirated.

[0051] (2) Platycodon grandiflorum polysaccharide is non-toxic to cells: Except for the blank group, 100 μL of different concentrations of Platycodon grandiflorum polysaccharide solution was added to each group, with 6 replicates per group. Three identical 96-well plates were seeded and cultured for 24 h, 48 h, and 72 h, respectively. After 24 h of culture, 10 μL of LTT solution was added to each well in the dark, and incubation continued for 4 h. After 4 h, the cells were removed from the incubator, the supernatant was carefully aspirated, 100 μL of LDMSO was added to each well, and the plates were shaken for 10 minutes to fully dissolve the crystals. The absorbance of each group at 490 nm was measured using a microplate reader. Calculate the survival rate for each group and plot a bar chart, such as Figure 1 .

[0052] (3) PM 2.5 Treatment to inhibit cell proliferation: Except for the control group, each of the other groups was treated with 100 μL of PM at different concentrations. 2.5 For the solution, each group has 6 replicates. The remaining experimental procedures are the same as above.

[0053] (4) Platycodon grandiflorum polysaccharide protects PM 2.5 Damaged cells: After seeding and adhesion of cells, different concentrations of polysaccharides were added to the polysaccharide pretreatment group, while the control and model groups were added with an equal volume of culture medium. Two hours after pretreatment, the model and polysaccharide groups were added with 50 μg / mL PM2.5. 2.5 For the suspension, add an equal volume of culture medium to the control group. The remaining experimental procedures are the same as above. Calculate the survival rate of each group and plot a bar chart, as shown below. Figure 2 .

[0054] Example 4: Effects of Platycodon grandiflorus polysaccharide on PM 2.5 Improvement of induced lung injury

[0055] Thirty C57 mice were randomly divided into three groups: a control group (saline), a model group (saline + PM), and a control group (saline + PM). 2.5 ), polysaccharide group (Platycodon grandiflorum polysaccharide + PM) 2.5 Mice were acclimatized for 7 days with unlimited food and water, and then modeling began. They were administered polysaccharides and saline via gavage daily for 14 days before being exposed to PM2.5. 2.5 Mice were anesthetized with ether, their noses were pinched to force them to breathe through their trachea, and PM2.5 was then introduced. 2.5Inject the drug into the trachea of ​​mice and observe their condition. Expose the mice to the drug once daily for three consecutive days, euthanizing them 24 hours after the last exposure. At the end of the experiment, blood was collected from the eyeballs, and the mice were euthanized by dislocation. Mouse weight, liver weight, and kidney weight were recorded, and organ coefficients (organ weight / body weight, g / 100g) were calculated. Bronchoalveolar lavage fluid (BALF), lung tissue, and lung tissue sections were collected.

[0056] Example 5: Platycodon grandiflorus polysaccharides improve PM 2.5 The liver and kidneys of mice atrophied after injury.

[0057] Accurately weigh the fresh weight of the mouse liver and kidneys, and calculate the organ coefficient. The organ coefficient, also known as the organ-to-body ratio, is the ratio of the weight of a specific organ to the body weight of an experimental animal. Normally, the ratio of each organ to body weight is relatively constant. After an animal is exposed to a toxin, the weight of the damaged organs can change, thus altering the organ coefficient. An increased organ coefficient indicates organ congestion, edema, or hyperplasia and hypertrophy; a decreased organ coefficient indicates organ atrophy and other degenerative changes. 2.5 Following injury, the liver and kidneys of mice atrophied. Pretreatment with Platycodon grandiflorus polysaccharide significantly improved this atrophy. Figure 3 and Figure 4 .

[0058] Example 6: Platycodon grandiflorus polysaccharides reduce PM 2.5 TNF-α and IL-1β expression in BALF of mice after injury

[0059] Collection of bronchoalveolar lavage fluid (BALF): After euthanizing mice, their trachea was exposed, an incision was made, and BALF was lavaged using an 8-gastrium syringe. This was repeated three times, with 700 μL each time, and the recovery rate was approximately 80%. The collected BALF was centrifuged at 4000 rpm for 10 min at 4 °C, and the supernatant was collected, aliquoted, and stored at -80 °C for later use.

[0060] Detection of inflammatory factors: Based on the "double antibody sandwich" principle, the levels of TNF-α and IL-1β in BALF were detected using an ELISA inflammatory factor detection kit. For example... Figure 5 and Figure 6 As shown, compared with the control group, PM 2.5 The levels of TNF-α and IL-1β in the group were significantly increased; compared with PM 2.5 Compared with the control group, the polysaccharide treatment group showed a significant decrease in TNF-α and IL-1β levels.

[0061] Example 7: Platycodon grandiflorus polysaccharides improve PM 2.5 Pathological structure of mouse lung tissue after injury

[0062] The right lower lobe of a mouse lung was taken, fixed in 4% paraformaldehyde, routinely embedded in paraffin, sectioned, and stained with hematoxylin and eosin (HE). Edema, hemorrhage, and inflammatory cell infiltration were observed. Figure 7As shown, compared with the control group, PM 2.5 The alveolar septa of the group were significantly widened, showing inflammation with obvious infiltration of lymphocytes and plasma cells; compared with PM 2.5 Compared with the control group, the polysaccharide-treated group showed a significant narrowing of the lung septa and a significant reduction in the infiltration of lymphocytes and plasma cells within them.

[0063] Example 8: Platycodon grandiflorum polysaccharides increase PM 2.5 Antioxidant capacity of mice after injury

[0064] Exposure to environmental stressors, such as air pollution, can lead to lipid oxidation, which has many adverse effects on human health. Superoxide dismutase (SOD) is an important component of the antioxidant enzyme system in biological systems, playing a crucial role in the body's oxidation-antioxidant balance and is closely related to the occurrence and development of many diseases. Inhalation of high concentrations of environmental PM is associated with elevated levels of hepatic lipid peroxidation, evidenced by elevated levels of malondialdehyde (MDA) in the liver, a marker of lipid peroxidation.

[0065] Accurately weigh 0.1g of lung tissue, add 900μL of physiological saline, and homogenize on ice; centrifuge at 8000g at 4℃ for 10min, collect the supernatant, and place on ice for testing. Antioxidant indicators in lung tissue were detected using both an SOD activity assay kit and an MDA content assay kit.

[0066] Compared with the control group, PM 2.5 Following injury, SOD activity in mouse lung tissue decreased from 29.91±1.82 U / mg prot to 24.51±1.36 U / mg prot, while malondialdehyde (MDA) content increased from 7.61±2.60 nmol / mg prot to 11.72±2.47 nmol / mg prot. After protection against injury, Platycodon grandiflorus polysaccharide increased SOD activity in mouse tissue to 29.14±2.34 U / mg prot, while decreasing MDA content to 7.53±1.74 nmol / mg prot. These results indicate that the Platycodon grandiflorus polysaccharide of this invention can enhance the antioxidant capacity of mice and improve oxidative damage in mice.

[0067] Example 9: Lung microbiota in mice after Platycodon grandiflorum polysaccharide remodeling injury

[0068] Microbial DNA was extracted from cells in BALF precipitate, and the V3-V4 hypervariable region of the bacterial 16S rRNA gene was amplified and then sequenced. Rhodococcus is a widely distributed genus involved in the detoxification of environmental pollutants; it can improve the degradation efficiency of highly toxic chloroxylenol in wastewater. Raoultella plays an important role in the degradation of phthalates in soil or food. Desulfobacterota is a harmful intestinal bacterium that poisons intestinal epithelial cells, causing intestinal sensitivity, leaky gut, or abdominal pain. Xanthomonadaceae causes black rot in cruciferous plants. Therefore, Platycodon grandiflorus polysaccharide can reshape PM2.5 levels by increasing the relative abundance of beneficial bacteria Rhodococcus and Raoultella and decreasing the relative abundance of harmful bacteria Desulfovibrionaceae and Xanthomonadaceae. 2.5 Damage leads to an imbalance in the lung flora.

Claims

1. A method to alleviate PM 2.5 Platycodon polysaccharide that causes respiratory diseases is characterized by: This polysaccharide was extracted from dried Platycodon grandiflorus roots at a material-to-water ratio of 1:20, and precipitated with 70% ethanol; after purification, it is a neutral polysaccharide. Extraction, separation, and purification of polysaccharides: Dried Platycodon grandiflorum slices were pulverized into powder using a pulverizer and passed through a 40-mesh sieve. The sample and water were mixed in an Erlenmeyer flask at a ratio of 1:20 (sample g: water mL), and incubated in a water bath at 80 ℃ for 6-7 h. The mixture was then filtered through three layers of gauze, and the filtrate was centrifuged at 6000 r / min for 10 min to obtain an aqueous extract of Platycodon grandiflorum. The extract was concentrated using a rotary evaporator, and then anhydrous ethanol was slowly added to the concentrate until the final ethanol concentration was 70%. After overnight sedimentation, the precipitate was collected by centrifugation at 8000 r / min for 10 min, which was the crude polysaccharide of Platycodon grandiflorum. The crude polysaccharide was allowed to stand to evaporate residual alcohol, and after freeze-drying, the sample was purified using a Q-Sephadex anion exchange column and a dextran gel G-100 column to obtain a single component, namely Platycodon grandiflorum polysaccharide. Physicochemical properties of polysaccharides: (1) Relative molecular mass of Platycodon grandiflorum polysaccharide: The relative molecular mass of polysaccharide was determined by high performance liquid chromatography (HPLC) combined with a refractive index detector. The polysaccharide sample was centrifuged at 12000 r / min for 10 min and placed in the inner liner tube of the HPLC bottle. The molecular weight was obtained by observing the retention time and peak surface of the peak and normalizing the product. The molecular weight of the Platycodon grandiflorus polysaccharide is 244 kDa; (2) Platycodon grandiflorum polysaccharide monosaccharide Composition: Weigh 2 mg of sample into an ampoule, add 5 mL of trifluoroacetic acid, seal with an alcohol lamp, and hydrolyze in an oil bath at 120℃ for 3 h until complete hydrolysis. Remove excess trifluoroacetic acid by nitrogen blowing, and finally dissolve the product in ultrapure water, mix well, and store at 4℃. Before loading, the sample is filtered through a 0.22 μm aqueous filter membrane and a solid-phase extraction column, respectively. The Platycodon grandiflorus polysaccharide is composed of 30.7% arabinose, 22.4% galactose, 14.3% glucose, 13.5% rhamnose, 9.7% mannose, and 9.4% xylose.

2. The Platycodon grandiflorum polysaccharide according to claim 1, characterized in that: The Platycodon grandiflorus polysaccharide exhibits no cytotoxicity in the concentration range of 25-200 μg / mL and can improve PM2.5 levels. 2.5 This leads to cell damage.

3. The Platycodon grandiflorum polysaccharide according to claim 1, characterized in that: The polysaccharide from Platycodon grandiflorus can improve organ atrophy and repair pathological damage.

4. The Platycodon grandiflorus polysaccharide according to claim 1, characterized in that: The polysaccharide from Platycodon grandiflorus can enhance the antioxidant capacity of mice after injury and alleviate PM2.

5. 2.5 The resulting lung damage reduces the release of inflammatory factors caused by the damage.

5. The Platycodon grandiflorum polysaccharide according to claim 1, characterized in that: The polysaccharide from Platycodon grandiflorus can regulate the lung flora and optimize PM2.5 levels. 2.5 Composition of lung flora in mice after injury.

6. The use of Platycodon grandiflorum polysaccharide as described in any one of claims 1 to 5 in the preparation of traditional Chinese medicine preparations for the prevention and treatment of acute or subacute lung injury.

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