Use of houttuynia cordata polysaccharide in preparation of drugs for preventing and treating viral-bacterial co-infection pneumonia and enteritis

Abstract

The present application relates to a kind of Houttuynia cordata polysaccharide in the use of preparation for preventing and treating virus-bacterial co-infection pneumonia and enteritis drug, HCP and uniform polysaccharide HCPM are prepared from Houttuynia cordata total polysaccharide HCP and isolated, and HCP and uniform polysaccharide HCPM of Houttuynia cordata total polysaccharide HCP are used for preparation for preventing and treating influenza virus H1N1-resistant bacteria MRSA co-infection induced lung injury and intestinal injury, and respiratory virus-bacterial co-infection drug.Compared with prior art, the present application provides a new use of Houttuynia cordata polysaccharide, and it has important value to the research and development of new drug for resisting virus-bacterial co-infection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of traditional Chinese medicine, and particularly relates to an application of a polysaccharide in a plant of Houttuynia cordata in preparation of a medicine for preventing and treating viral-bacterial co-infection pneumonia and enteritis. BACKGROUND

[0002] Bacterial co-infection is a common complication of many viral respiratory infections, leading to a significant increase in morbidity and mortality, and causing a huge health and economic burden worldwide. Although antiviral and antibacterial drugs are used in clinical treatment of patients with respiratory viral-bacterial co-infection, the clinical efficacy of these drugs is not ideal due to drug resistance, new or variant virus strains, and serious side effects. Therefore, it is of great significance to find and develop drugs against respiratory viral-bacterial co-infection. Respiratory co-infection involves complex functional interactions between viruses / bacteria and the host. Treatments targeting the host are more likely to treat co-infection and are less likely to encounter antiviral and / or antibiotic resistance.

[0003] Notably, polysaccharides are important active ingredients among all components of natural herbs due to their outstanding immunomodulatory effects. Houttuynia cordata Thunb. is a traditional Chinese medicine used for clearing heat and detoxifying, and is one of the most commonly used herbs for treating heat phlegm, cough, and lung abscess. HCP and HCPM are natural macromolecular substances isolated from Houttuynia cordata Thunb. Studies have shown that HCP can significantly reduce LPS-induced lung injury (Xu Y.Y., Zhang Y.Y., et al. Journal of Ethnopharmacology, 2015, 173:81-90), but LPS is only a component of bacterial cell wall, not live bacteria itself, and cannot completely simulate the pathological state of pneumonia caused by live bacteria infection in clinic. Patent CN201410309126.7 discloses that HCP has a significant therapeutic effect on influenza virus H3N2 / H1N1-induced acute lung injury in mice by reducing lung edema and inflammatory response. Patent CN202111606694.X discloses that HCPM has a significant therapeutic effect on influenza virus H1N1-induced acute lung injury in mice. Importantly, respiratory virus infection not only causes lung injury but also damages the intestine. Studies (Chen M.Y., Li H., et al. Chinese Journal of Natural Medicines 2019, 17(3):0187-0197) have found that HCP has a significant therapeutic effect on influenza virus H1N1-induced intestinal injury in mice. However, existing literature (Yi T., Ding W.X., et al. Microbial Pathogenesis, 2022, 166:105558) shows that influenza virus infection damages the host's defense against bacteria, and virus-bacteria co-infection causes more severe lung injury than infection with virus or bacteria alone, and co-infected animals exhibit excessive inflammatory cell infiltration, including neutrophils, accompanied by high levels of inflammatory cytokines and chemokines, increased bacterial and viral loads, and diffuse alveolar damage and even severe vascular endothelial damage. Therefore, the pathological process of virus-bacteria co-infection is much more complex than single virus or bacteria infection, and drugs that can effectively treat single infection may not necessarily treat co-infection. Although existing studies have revealed the therapeutic effects of Houttuynia cordata Thunb. polysaccharides on single virus infection or LPS-induced mice, their efficacy on virus-bacteria (especially drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus MRSA) co-infection-induced diseases remains unknown. SUMMARY

[0004] The application aims to provide a use of Houttuynia cordata polysaccharide in the preparation of a medicine for preventing and treating viral-bacterial co-infection pneumonia and enteritis.

[0005] The application aims to provide a use of Houttuynia cordata polysaccharide in the preparation of a medicine for preventing and treating viral-bacterial co-infection pneumonia and enteritis.

[0006] Preferably, the Houttuynia cordata polysaccharide comprises Houttuynia cordata total polysaccharide HCP and / or Houttuynia cordata homogeneous polysaccharide HCPM.

[0007] Preferably, the Houttuynia cordata polysaccharide is obtained by ethanol extraction from Houttuynia cordata medicinal material.

[0008] Preferably, the preparation method of the Houttuynia cordata total polysaccharide HCP comprises the following steps:

[0009] The Houttuynia cordata Thunb. medicinal material is crushed, soaked with 95% ethanol overnight, dried, extracted with hot water, filtered, and the extraction liquid is combined, concentrated, centrifuged, and the supernatant is added with 4 times the volume of 90% ethanol to a concentration of 72%, and then centrifuged, and the precipitate is collected. The precipitate is redissolved, free proteins are removed with trichloroacetic acid, the supernatant is adjusted to neutral, centrifuged, concentrated, dialyzed, and the precipitate is freeze-dried to obtain the Houttuynia cordata total polysaccharide HCP.

[0010] Further preferably, the preparation method of the Houttuynia cordata homogeneous polysaccharide HCPM comprises the following steps:

[0011] The obtained Houttuynia cordata total polysaccharide HCP is dissolved in water, centrifuged, and the supernatant is filtered through ultrafiltration membranes with a molecular weight cut-off of 350.0 kDa and 3.0 kDa, respectively, and the same components are combined to obtain the Houttuynia cordata homogeneous polysaccharide HCPM (3.0 kDa≤ molecular weight≤ 350.0 kDa).

[0012] Further preferably, the Houttuynia cordata homogeneous polysaccharide HCPM has the following structural characteristics:

[0013] HCPM is composed of seven monosaccharides, the molecular weight distribution range is 3.0-350.0kDa, the relative molecular weight is 19.1kDa; the total sugar content is: 91.9%; the uronic acid content is: 38.3%; and it does not contain protein. The molar ratio of monosaccharides is mannose: rhamnose: glucuronic acid: galacturonic acid: glucose: galactose: arabinose = 6.1: 7.1: 1.8: 38.5: 22.4: 14.9: 9.2. The main linkage mode of sugar residues is: terminal connection, 1,5-connection, 1,3,5-connection of arabinose, terminal connection, 1,2-connection, 1,2,4-connection of rhamnose, terminal connection, 1,4-connection of galacturonic acid, terminal connection, 1,6-connection, 1,4,6-connection of galactose, 1,3-connection of mannose, 1,4-connection, 1,4,6-connection of glucose and 4-oxymethyl glucuronic acid, etc.

[0014] Preferably, the Houttuynia cordata polysaccharide is used for preparing a medicine for preventing and treating viral-bacterial co-infection pneumonia and small intestinal enteritis.

[0015] Preferably, the Houttuynia cordata polysaccharide is used for preparing a medicine for preventing and treating viral-bacterial co-infection pneumonia and small intestinal enteritis.

[0016] Preferably, the virus includes influenza virus strains, clinical respiratory virus strains.

[0017] Further preferably, the influenza virus strains include H1N1, H3N2, H5N1, H7N9.

[0018] Further preferably, the clinical respiratory virus strains include respiratory syncytial virus, rhinovirus.

[0019] Further preferably, the bacteria include methicillin-resistant Staphylococcus aureus (MRSA), also include non-drug-resistant Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae and other common clinical respiratory infection strains.

[0020] Preferably, the Houttuynia cordata polysaccharide is used for preparing a medicine for preventing and treating H1N1-MRSA co-infection pneumonia and enteritis.

[0021] Further preferably, the technical scheme of H1N1-MRSA co-infection is: 0.2LD 50 H1N1 virus liquid 30μL, 10 7 CFU MRSA 30μL, Day 5 end process.

[0022] Preferably, the medicine uses Houttuynia cordata polysaccharide as solute, and 0.5% carboxymethyl cellulose sodium solution as solvent.

[0023] The application provides use of total Houttuynia cordata polysaccharide HCP and uniform polysaccharide HCPM in preparation of a treatment drug for preventing and treating lung injury induced by virus-bacteria co-infection.

[0024] The application provides use of total Houttuynia cordata polysaccharide HCP and uniform polysaccharide HCPM in preparation of a treatment drug for preventing and treating intestinal injury induced by virus-bacteria co-infection.

[0025] The application provides use of Houttuynia cordata polysaccharide in preparation of a drug for preventing and treating lung injury and intestinal injury induced by influenza virus H1N1-resistant bacteria MRSA co-infection and respiratory virus-bacteria co-infection.

[0026] Throughout the research at home and abroad, no drug efficacy report of Houttuynia cordata polysaccharide for treating virus-bacteria co-infection is found.

[0027] Compared with the prior art, the application has the following beneficial effects:

[0028] 1. The application provides a new use of Houttuynia cordata polysaccharide for preparing a drug for preventing and treating respiratory virus-bacteria co-infection.

[0029] 2. The application provides use of total Houttuynia cordata polysaccharide and uniform polysaccharide in preparation of a drug for preventing and treating lung injury and intestinal injury induced by influenza virus H1N1-resistant bacteria MRSA co-infection and respiratory virus-bacteria co-infection.

[0030] 3. The application has important value for research and development of a new drug for resisting virus-bacteria co-infection.

[0031] 4. The application separates and extracts total polysaccharide HCP and uniform polysaccharide HCPM from traditional Chinese medicine Houttuynia cordata. The total polysaccharide HCP and the uniform polysaccharide HCPM are verified by whole animal experiments to have significant treatment effects on lung injury and intestinal injury induced by respiratory virus-bacteria co-infection, and the treatment effects specifically include: reducing pulmonary edema, inhibiting infiltration of inflammatory cells in the lung, reducing secretion of inflammatory cytokines, thereby reducing acute lung injury; inhibiting secretion of inflammatory cytokines in the small intestine, promoting secretion of mucin by small intestinal goblet cells, thereby reducing small intestinal injury, protecting intestinal mucosa, thereby relieving weight loss, and improving survival rate of co-infected mice, and the total polysaccharide HCP and the uniform polysaccharide HCPM can be further used for preparing a drug for preventing and treating respiratory virus-bacteria co-infection. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 Fig. 1 is a survival protection effect of total Houttuynia cordata polysaccharide HCP and uniform polysaccharide HCPM on H1N1-MRSA co-infected mice according to the application.

[0033] Figure 2 Fig. 2 is an effect of total Houttuynia cordata polysaccharide HCP and uniform polysaccharide HCPM on weight of H1N1-MRSA co-infected mice according to the application.

[0034] Figure 3 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on lung index of H1N1-MRSA co-infected mice.

[0035] Figure 4 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on lung lesions of H1N1-MRSA co-infected mice.

[0036] Figure 5 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on IL-6 in lung homogenate of H1N1-MRSA co-infected mice.

[0037] Figure 6 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on IFN-γ in lung homogenate of H1N1-MRSA co-infected mice.

[0038] Figure 7 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on MPO in lung homogenate of H1N1-MRSA co-infected mice.

[0039] Figure 8 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on small intestine injury of H1N1-MRSA co-infected mice.

[0040] Figure 9 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on mucin secretion of small intestine of H1N1-MRSA co-infected mice.

[0041] Figure 10 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on IL-6 in small intestine homogenate of H1N1-MRSA co-infected mice.

[0042] Figure 11 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on IFN-γ in small intestine homogenate of H1N1-MRSA co-infected mice.

[0043] Figure 12 Effects of Houttuynia cordata polysaccharides HCP and homogeneous polysaccharides HCPM on MPO in small intestine homogenate of H1N1-MRSA co-infected mice. DETAILED DESCRIPTION

[0044] The present application will be described in detail below with reference to the drawings and specific embodiments. The embodiments are implemented on the premise of the technical solutions of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following embodiments.

[0045] Unless otherwise indicated, the reagents, methods, instruments and apparatus employed in the present application are those conventional in the art. Unless otherwise indicated, the reagents and materials used in the following examples are commercially available.

[0046] Example 1

[0047] Preparation of total polysaccharide HCP from Houttuynia cordata

[0048] Houttuynia cordata 20 kg was crushed, and then soaked with 95% ethanol overnight. The soaked material was dried, and then added with deionized water in a weight ratio of 1:20. The mixture was boiled at 90°C for 2 hours for 3 times. The boiled liquid was collected. The boiled liquid was concentrated at 50°C to 0.12 g of crude drug per ml. Then, 4 times of 90% ethanol was added, and the mixture was left at room temperature for 24 hours. The supernatant was removed by centrifugation, and the precipitate was redissolved in water until the solution was clear. Then, 10% trichloroacetic acid was added to the solution, and the mixture was left at 4°C for 2 hours. The pH of the solution was adjusted to 7.0 with 10% NaOH solution. The solution was centrifuged, and the supernatant was collected. The supernatant was concentrated and dialyzed under running water for 72 hours. The dialyzed solution was freeze-dried to obtain crude polysaccharide HCP from Houttuynia cordata.

[0049] Example 2

[0050] Preparation of homogeneous polysaccharide HCPM from Houttuynia cordata

[0051] 4 g of total polysaccharide HCP from Houttuynia cordata was dissolved in 0.5 L of distilled water, and then centrifuged. The supernatant was added to a material tank, and then ultrafiltered through an ultrafiltration membrane with a molecular weight cut-off of 350.0 kDa to obtain a permeate with a molecular weight of less than 350.0 kDa. Then, the permeate was ultrafiltered through an ultrafiltration membrane with a molecular weight cut-off of 3.0 kDa to obtain a cut-off component HCPM (3.0 kDa≤ molecular weight≤ 350.0 kDa). The pressure during the ultrafiltration process was less than 0.7 MPa. The same components were combined by HPGPC detection, concentrated, and freeze-dried to obtain homogeneous polysaccharide HCPM (average yield: 36.4%).

[0052] Example 3

[0053] Effect of total polysaccharide HCP and homogeneous polysaccharide HCPM from Houttuynia cordata on the survival rate of H1N1-MRSA co-infected mice

[0054] C57BL / 6 female mice 99, body weight 14-16g. Regular feed, free water. Mice were randomly divided into 9 groups: control group, co-infection model group (H1N1+MRSA group), HCPM-20mg / kg group, HCPM-40mg / kg group, HCPM-80mg / kg group, HCP-80mg / kg group, oseltamivir group (oseltamivir group, 22.75mg / kg), linezolid group (linezolid group, 200mg / kg) group, oseltamivir+linezolid combination group (oseltamivir+linezolid group), 11 in each group. All drugs were dissolved in 0.5% sodium carboxymethyl cellulose solution. Except for the control group, other groups of animals were anesthetized with isoflurane, and 0.2LD 50 H1N1 virus liquid 30μL, 10 7 CFU MRSA 30μL, respectively, 2 hours after infection with H1N1 and MRSA, gavage administration; at the same time, the control group was given 0.5% sodium carboxymethyl cellulose solution as a control. One day of administration, continuous administration for seven days, drug withdrawal observation to 14 days, the number of animals was recorded every day, and the life protection rate of drugs on co-infected mice was calculated. As Figure 1 As shown in the table, all mice in the co-infection group died within 9 days after modeling, and the survival rates of HCP-80mg / kg and HCPM-80mg / kg groups were increased by about 10%, 36%, respectively. In the positive drug administration group, the oseltamivir group, the linezolid group, and the oseltamivir+linezolid combination group increased the survival rate by about 27%, 10%, and 82%, respectively. The results showed that HCPM-80mg / kg could improve the survival rate of co-infected mice to a certain extent, and its effect was better than that of HCP-80mg / kg group.

[0055] Example 4

[0056] Effect of total polysaccharide HCP and homogeneous polysaccharide HCPM from Houttuynia cordata on lung injury and intestinal injury caused by H1N1-MRSA co-infection:

[0057] C57BL / 6 female mice (14-16g) were randomly divided into 9 groups, 6 in each group. Experimental grouping and infection dose were the same as in Example 3. One day of administration, continuous administration for five days. On Day 5, the body weight was weighed, and the eyeball was taken for blood. The whole lung and small intestine were carefully cut off, the lung weight was weighed and recorded. The left upper lobe of the lung tissue and the small intestine about 5cm were cut off and fixed with 4% paraformaldehyde solution, and HE staining was performed for pathological observation; Alcian blue- nuclear fast red staining was performed to detect the secretion of mucin by small intestinal goblet cells; the rest of the lung and small intestine were used for detection of inflammatory mediators IL-6, IFN-γ, and MPO content.

[0058] (1) Effects of total polysaccharide HCP and homogeneous polysaccharide HCPM on lung injury in mice co-infected with H1N1-MRSA.

[0059] We evaluated the therapeutic effect of polysaccharides on lung injury induced by co-infection by measuring changes in mouse body weight and detecting differences in lung index, lung hematoxylin and eosinophil (HE) and inflammatory regulatory factors. Figure 2 As shown, the body weight of mice in the control group increased normally every day. Compared with the control group, the body weight of mice in the co-infected group began to decrease on Day 3 and reached its lowest point on Day 5. Both the HCP-80mg / kg and HCPM-80mg / kg groups effectively alleviated the weight loss caused by co-infection, with the HCPM-80mg / kg group being slightly better than the HCP-80mg / kg group. The lung index of mice in the co-infected group was significantly higher than that in the control group. Treatment with HCP-80mg / kg and HCPM-80mg / kg reduced the lung index of co-infected mice (e.g., ...). Figure 3 (As shown). Consistent with the lung index results, co-infection caused significant lung histopathological changes, manifested as severe destruction of normal lung structure, narrowing of airway lumen, significantly increased inflammatory cell infiltration, and thickening of alveolar walls. Treatment with HCP-80mg / kg and HCPM-80mg / kg effectively alleviated the above pathological changes (e.g. Figure 4 (As shown). Furthermore, lung tissue analysis on Day 5 revealed that IL-6 (as shown in the image) was present in the lung tissue homogenate of the co-infected mice. Figure 5 (as shown) and IFN-γ (as shown) Figure 6 Content and MPO activity (as shown) Figure 7 The levels of IL-6 and IFN-γ and MPO activity in the HCP-80mg / kg and HCPM-80mg / kg groups were significantly higher than those in the co-infection group (*P<0.05,**P<0.01,***P<0.001).

[0060] (2) Effects of total polysaccharide HCP and homogeneous polysaccharide HCPM on intestinal damage in mice co-infected with H1N1-MRSA.

[0061] We evaluated the therapeutic effect of polysaccharides on small intestinal injury caused by co-infection by analyzing small intestinal HE staining, Alcian blue-nuclear solid red staining, and changes in the levels of inflammatory regulatory factors. Figure 8As shown, no obvious histopathological changes were observed in the small intestine of the control mice. However, the co-infected mice developed more obvious enteritis of the small intestine, the most significant manifestations of which were disordered and shortened villi of the small intestine, severely damaged crypts, and inflammatory cell infiltration. HCP-80mg / kg and HCPM-80mg / kg can significantly improve the pathological changes of the intestine. According to the staining experiment of the Alcian Blue- Nuclear Fast Red Staining Kit, the results show that the mucin in the small intestine of the control group is blue, and the expression amount is high; the small intestine structure of the co-infected group is damaged, and the expression amount of mucin is small, and the secretion amount of mucin is significantly reduced compared with the control group; the small intestine structure of the HCP-80mg / kg and HCPM-80mg / kg administration groups is protected, and the secretion amount of mucin is close to that of the normal group, and is significantly increased compared with the co-infected group (as shown in Figure 9 The small intestine homogenate supernatant was determined according to the IL-6, IFN-γ and MPO kit instructions, and the results show that, compared with the control group, the co-infection significantly increases the contents of IL-6, IFN-γ and MPO in the small intestine, and HCP-80mg / kg and HCPM-80mg / kg can effectively reduce the increase of the IL-6 (as shown in Figure 10 , IFN-γ (as shown in Figure 11 ) and MPO levels (as shown in Figure 12 ) in the intestine of mice (*P<0.05, **P<0.01, ***P<0.001).

[0062] The total polysaccharide HCP and the uniform polysaccharide HCPM are prepared from Houttuynia cordata. The representative virus-bacteria co-infection mouse model is established by using the combined infection of influenza virus H1N1 and methicillin-resistant Staphylococcus aureus MRSA, and the fishgrass polysaccharide is proved to be able to improve the survival rate of H1N1-MRSA co-infected mice and improve the body weight of the mice through the animal survival rate experiment, and has a certain protective effect on the co-infected model mice, thereby providing a basis for preventing and treating co-infection.

[0063] The in vivo animal experiment is performed, and the results show that the total polysaccharide HCP and the uniform polysaccharide HCPM of Houttuynia cordata have a significant therapeutic effect on the acute lung injury of mice induced by H1N1-MRSA co-infection. The lung injury of mice is relieved by reducing the lung index and inhibiting the inflammatory response in the lung of the co-infected mice, and the total polysaccharide HCP and the uniform polysaccharide HCPM of Houttuynia cordata can be used for preparing a virus-bacteria co-infection pneumonia prevention and treatment drug.

[0064] The fishwort total polysaccharide HCP and the uniform polysaccharide HCPM have significant therapeutic effects on small intestinal injury caused by H1N1-MRSA co-infection, and can be used for preparing drugs for preventing and treating intestinal inflammation caused by virus-bacteria co-infection.

[0065] The above description of the embodiments is for facilitating the ordinary skilled person in the art to understand and use the application. The person skilled in the art can easily make various modifications to the embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the application is not limited to the above embodiments, and the improvements and modifications made by the person skilled in the art according to the disclosure of the application without departing from the scope of the application should be within the protection scope of the application.

Claims

1. The use of Houttuynia cordata polysaccharide in the preparation of drugs for preventing and treating viral-bacterial co-infection pneumonia and enteritis, characterized in that, Houttuynia cordata polysaccharides were used to prepare drugs for the prevention and treatment of viral-bacterial co-infection pneumonia and enteritis. The Houttuynia cordata polysaccharide is a homogeneous Houttuynia cordata polysaccharide HCPM; The preparation method of the Houttuynia cordata homogeneous polysaccharide HCPM includes the following steps: The herb Houttuynia cordata was pulverized, percolated with 95% ethanol overnight, dried, extracted with hot water, filtered, the extracts were combined, concentrated, centrifuged, and the supernatant was added with 4 times the volume of 90% ethanol to a concentration of 72%. After standing, centrifuged, the precipitate was collected, the precipitate was redissolved, free proteins were removed with trichloroacetic acid, the supernatant was adjusted to neutral, centrifuged, concentrated, dialyzed, and the precipitate was freeze-dried to obtain total polysaccharide HCP from Houttuynia cordata. The obtained total polysaccharide HCP from Houttuynia cordata was dissolved in water, centrifuged, and the supernatant was filtered through ultrafiltration membranes with molecular weight cutoffs of 350.0 kDa and 3.0 kDa respectively. The same components were combined to prepare a homogeneous polysaccharide HCPM from Houttuynia cordata. Houttuynia cordata polysaccharide was used to prepare a drug for the prevention and treatment of H1N1-MRSA co-infection pneumonia and enteritis.

2. The use of the Houttuynia cordata polysaccharide according to claim 1 in the preparation of drugs for preventing and treating viral-bacterial co-infection pneumonia and enteritis, characterized in that, The Houttuynia cordata polysaccharide was used to prepare drugs for the prevention and treatment of viral-bacterial co-infection pneumonia and enteroenteritis.

3. The use of the Houttuynia cordata polysaccharide according to claim 1 in the preparation of drugs for preventing and treating viral-bacterial co-infection pneumonia and enteritis, characterized in that, The drug uses houttuynia cordata polysaccharide as the solute and 0.5% sodium carboxymethyl cellulose solution as the solvent.

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