A pueraria powder-based iodine complex, and a preparation method and application thereof

Abstract

The application discloses a pueraria powder-based iodine compound and a preparation method and application thereof, and comprises the following steps: mixing pueraria powder with water to form a pueraria powder water suspension; performing hydrothermal gelatinization and respiration treatment on the pueraria powder water suspension to obtain a gelatinized and respiration pueraria powder suspension; adding potassium iodide, potassium iodate and acid into the gelatinized and respiration pueraria powder suspension, adjusting the pH value of the system to be acidic, performing reaction, and obtaining the pueraria powder-based iodine compound through post-treatment. The application constructs a loading framework through gelatinization and respiration of pueraria powder, realizes stable loading of iodine by relying on in-situ reaction, and realizes the multiple effects of low stimulation, efficient inhibition of digestive tract pathogenic bacteria and precise regulation of intestinal microecology by synergistic effect of the strong bactericidal capacity of iodine which is not prone to drug resistance and the inherent intestinal flora regulation activity of pueraria powder, so that the pain points of instability and strong irritation of traditional iodine preparations are solved, and a new way for treating digestive tract infectious diseases is opened up.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical preparation technology, and particularly relates to a kudzu root powder-based iodine complex, its preparation method, and its application. Background Technology

[0002] Diarrhea caused by pathogens such as bacteria and fungi is a common gastrointestinal infection. This type of disease not only involves an increase in pathogenic bacteria in the gut but also leads to severe dysbiosis of the gut microbiota. Its strong drug resistance, high morbidity, and significant harm make it an increasingly serious public health challenge. Notably, this type of disease has significant zoonotic characteristics, particularly prominent in animal husbandry. With the global trend of "antibiotic reduction / ban," especially the implementation of "antibiotic-free feed" and "antibiotic-free farming" models in animal husbandry, the safe and effective prevention and control of this disease has become a key requirement for ensuring the healthy development of animal husbandry and food safety.

[0003] Traditional antibiotic therapy has limitations in treating gastrointestinal infections. Its irrational use has led to increasing drug resistance, which not only complicates the treatment of gastrointestinal diseases in humans and animals but also violates global policies advocating for antibiotic reduction or ban. Therefore, finding safe and effective alternatives to or supplement antibiotics is urgently needed. An ideal alternative strategy must overcome the limitations of single-therapy approaches, combining the inhibition of pathogenic bacteria growth with the regulation of gut microbiota homeostasis to achieve a synergistic "antibacterial inhibition-regulation" effect, thus effectively addressing infectious diarrhea and the resulting dysbiosis.

[0004] Intestinal flora imbalance caused by pathogenic bacteria is one of the important causes of gastrointestinal infectious diseases. Iodine is a globally recognized safe and reliable bactericide with a long history of application in the medical and health fields. Its bactericidal mechanism is mainly based on its strong oxidizing properties, which can rapidly cause irreversible damage to key biomolecules of pathogens by destroying their proteins, nucleic acids, and other key structures. It is precisely this strong oxidizing ability of iodine that makes it significantly irritating to the skin and mucous membranes, especially the digestive tract mucosa, limiting its application in vivo. Currently commonly used iodine preparations include tincture of iodine, povidone-iodine, and quaternary ammonium salt complexed iodine. Iodine is chemically unstable, easily volatilized, or its activity is reduced by factors such as light exposure. Therefore, developing suitable carriers for loading iodine is key to reducing its irritation, improving its stability, and expanding its in vivo applications.

[0005] Iodine is commonly used as an antibacterial agent for external application, but its high irritant properties and poor stability limit its in vivo use. Therefore, novel iodine preparations are needed to overcome these drawbacks. Chinese patent CN101654499A discloses a method for preparing an amphiphilic graft copolymer-nano-iodine complex. The method mainly involves adding a chitosan graft copolymer to a composite solution of iodine, iodized salt, and a surfactant, causing a complexation reaction with the iodine to obtain the amphiphilic graft copolymer-nano-iodine complex. This complex can be used as an antibacterial solution or formulated into a gel.

[0006] Chinese patent CN101073325B discloses a method for preparing a novel povidone-iodine antibacterial dressing using carboxymethyl chitosan fixation. The method mainly involves dissolving carboxymethyl chitosan grafted with polyacrylamide-copolymer-N-vinylpyrrolidone in water and then reacting it with iodine. After freeze-drying and pulverizing, the novel povidone-iodine antibacterial dressing is obtained. It has good antibacterial properties and can be used for wound antibacterial disinfection.

[0007] Chinese patent CN117626531A discloses an iodine-loaded antibacterial starch nanofiber membrane and its preparation method. The method first obtains amorphous starch through chemical modification, then prepares a starch electrospinning solution using high-temperature steam, obtains a starch nanofiber membrane through electrospinning, and finally obtains an iodine-loaded starch nanofiber membrane by "solid-phase adsorption" of the starch nanofiber membrane and iodine vapor. It is a bio-based antibacterial material with high antibacterial efficiency loaded with iodine.

[0008] The aforementioned methods for preparing iodine-containing bactericides require specific reaction conditions and equipment, resulting in complex structures, high costs, and lengthy processing times. The method based on the "solid-phase adsorption" principle requires the use of iodine vapor, which is toxic and corrosive, necessitating stringent safety measures during production. Furthermore, formulations produced using these methods often exhibit some degree of irritation, and subsequent processing into gels or other dosage forms involves complex steps, increasing the difficulty of quality control. Crucially, research on these iodine-containing bactericides has primarily focused on the epidermis, with no reports on their effects on the digestive tract. Summary of the Invention

[0009] To address the problems of the prior art, the present invention aims to provide a method for preparing a kudzu root powder-based iodine complex. This method is simple, efficient, and safe in production environment. The prepared kudzu root powder-based iodine complex can uniformly and stably load iodine, exhibiting excellent antibacterial properties and reducing iodine irritation to the digestive tract. It can be used to treat digestive tract infections.

[0010] This invention is achieved through the following technical solution:

[0011] A method for preparing a kudzu root powder-based iodine complex includes the following steps:

[0012] (1) Mix kudzu root powder with water to form a kudzu root powder aqueous suspension;

[0013] (2) The kudzu root powder water suspension was subjected to hydrothermal gelatinization-retrogradation treatment to obtain gelatinized-retrograded kudzu root powder suspension;

[0014] (3) Add potassium iodide, potassium iodate and acid to the gelatinized-reclaimed kudzu powder suspension, adjust the pH of the system to acidic, carry out the reaction, and obtain kudzu powder-based iodine complex after post-treatment.

[0015] The preparation principle of the kudzu root powder-based iodine complex of the present invention is as follows:

[0016] This invention first involves hydrothermal gelatinization of a kudzu root powder suspension to disrupt the crystalline structure of starch molecules. Then, a cold-retrogradation process induces the formation of a dense and ordered double helix structure in the amylose. Finally, iodine is generated in situ within the gelatinized-retrograded kudzu root powder system via a redox reaction (KI + KIO3 + acid). The generated iodine immediately undergoes a complexation reaction with the amylose molecules. The hydrophobic cavity within the double helix structure of amylose allows iodine molecules to be stably embedded, forming a tight complex and significantly increasing the physical loading of iodine. Furthermore, it acts as a physical barrier, encapsulating and protecting the iodine molecules, effectively preventing iodine volatilization and reducing its direct contact with light and oxygen in the environment. This significantly improves the chemical stability of iodine during storage and use, ensuring its long-lasting antibacterial activity.

[0017] Preferably, in step (1), the particle size of the kudzu root powder is 75-212 μm; for example, it can be 75-80 μm, 90-115 μm, 120-150 μm, 180-212 μm or any of the above values.

[0018] Preferably, in step (2), the hydrothermal gelatinization-retrogradation treatment results in an energy value of 735–5733 J / g per gram of kudzu root powder, for example, within the range of any of the above values: 735, 945, 1050, 1134, 1155, 1365, 1945, 3087, 3969, 4410, 4851, 4951, or 5733 J / g. The energy value obtained per gram of kudzu root powder in this invention is based on the total energy input during the hydrothermal treatment process, calculated using the heat transferred by water as the heat transfer medium. If the obtained energy value is lower than 735 J / g, the starch in the kudzu root powder will not gelatinize; if the obtained energy value is higher than 5733 J / g, the starch in the kudzu root powder will degrade.

[0019] Preferably, in step (2), the hydrothermal gelatinization-retrogradation treatment includes: heating at 60-90℃ for 5-15 minutes, followed by refrigeration at 0-4℃ for 2-6 hours.

[0020] This invention generates iodine in situ in a gelatinized-retrograded kudzu root powder suspension using a "KI+KIO3+acid" system. Once generated, the iodine can immediately bind with the starch in the kudzu root powder, avoiding the problems of low loading and instability caused by the easy volatilization of I2 when adding elemental iodine directly.

[0021] Preferably, in step (3), the molar ratio of potassium iodide to potassium iodate is 5:1; the acid is any one of hydrochloric acid, dilute sulfuric acid or phosphoric acid; and the pH of the system is adjusted to 1.4-3.4.

[0022] Preferably, in step (3), the post-processing includes filtration, washing, and drying. The drying is preferably spray drying or freeze drying.

[0023] This invention also provides a kudzu root powder-based iodine complex, prepared by the above-described method. The kudzu root powder-based iodine complex of this invention comprises a double-helix structure formed by starch retrogradation in kudzu root powder, with iodine molecules embedded within the double-helix cavity. This effectively reduces the concentration and reactivity of free iodine, thereby significantly mitigating the risk of direct irritation and damage to mucous membranes by iodine.

[0024] This invention also provides the application of the above-mentioned kudzu root powder-based iodine complex in the preparation of drugs for treating gastrointestinal infections.

[0025] This invention utilizes kudzu root, a plant used both as food and medicine, to construct a delivery system. Kudzu root is rich in resistant starch, which can significantly proliferate beneficial intestinal flora, inhibit the growth of potentially pathogenic bacteria, optimize the flora structure, and restore the balance of the gut microbiota. More importantly, the short-chain fatty acids produced by the proliferation of probiotics and the fermentation of resistant starch can significantly enhance the physical and immune barrier functions of the intestine. Furthermore, puerarin, an active ingredient in kudzu root, possesses both anti-inflammatory and antioxidant properties. During intestinal inflammation, puerarin can inhibit the release of inflammatory factors and reduce the damage to intestinal tissue caused by inflammation through its anti-inflammatory effects; its antioxidant capacity can scavenge free radicals in the intestine, reduce oxidative stress, and promote intestinal tissue repair. The anti-inflammatory and antioxidant effects of puerarin synergistically work with the prebiotic effect of resistant starch to jointly promote a healthy gut microenvironment and damage repair.

[0026] The core value of resistant starch from kudzu root lies not only in its prebiotic activity but also in the crystalline structure containing helical cavities formed by the amylose within it after gelatinization and retrogradation. This structural characteristic effectively loads iodine, allowing iodine molecules to embed within the helical cavities of the starch and form stable complexes through intermolecular forces. This not only helps reduce the irritation of iodine to the digestive tract mucosa but also protects iodine molecules from volatilization and degradation, improving stability. Furthermore, thanks to the inherent resistance of resistant starch to digestion in the upper digestive tract, the iodine it carries can be targeted and delivered to the lower digestive tract, achieving targeted release at the site of lesions and exerting a bactericidal effect. Simultaneously, the resistant starch itself, along with puerarin, continues to exert its prebiotic and gut microbiota regulating functions.

[0027] Preferably, the digestive tract infection includes bacterial or fungal enteritis or Helicobacter pylori infection.

[0028] The present invention also provides a pharmaceutical preparation for treating gastrointestinal infections, comprising the above-mentioned kudzu root powder-based iodine complex as an active ingredient, and pharmaceutically acceptable excipients.

[0029] The pharmaceutically acceptable excipients described in this invention refer to conventional drug carriers in the pharmaceutical field, including conventional diluents, fillers (such as starch), binders (such as cellulose derivatives, gelatin, etc.), humectants (such as glycerin, etc.), disintegrants (such as agar, calcium carbonate, etc.), absorption promoters (such as quaternary ammonium compounds, etc.), lubricants (such as talc, etc.), etc., and their dosages are conventional dosages in the field.

[0030] The drug of the present invention can be prepared in any pharmaceutically acceptable dosage form according to conventional methods in the art. Preferably, the dosage form of the drug preparation is an oral suspension, an enteric-coated capsule, or a gastric mucosa adhesive tablet.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] This invention constructs a loading framework through the gelatinization and retrogradation of kudzu root powder, achieving stable iodine loading through in-situ reaction. By leveraging the powerful bactericidal ability of iodine, which is less likely to induce drug resistance, and the inherent intestinal flora regulating activity of kudzu root powder, the synergistic effect achieves multiple benefits, including low irritation, high efficiency in inhibiting pathogenic bacteria in the digestive tract, and precise regulation of the intestinal microecology. This solves the problems of instability and high irritation of traditional iodine preparations, opening up new avenues for the treatment of infectious diseases of the digestive tract.

[0033] This invention achieves two core synthesis steps directly within kudzu root powder: starch gelatinization-retrogradation modification and iodine redox reaction. This eliminates the need for pre-extraction of starch, avoids complex purification processes, significantly shortens the process flow, and reduces time and energy costs. Furthermore, this invention avoids the highly toxic and corrosive iodine vapor fumigation method and the use of organic solvents to dissolve iodine or chemically modify the carrier in traditional iodine-loaded processes, fundamentally eliminating the risk of toxic reagent residues and making the production environment safer and more environmentally friendly. Attached Figure Description

[0034] Figure 1 Scanning electron microscope images of Example 3 and Comparative Examples 1-2;

[0035] Figure 2 The particle size distribution diagrams are for Examples 1-3;

[0036] Figure 3 The release rate of iodine in simulated gastric and intestinal fluid environments in Example 3 and Comparative Examples 1-2;

[0037] Figure 4 The inhibition rates of Escherichia coli and Staphylococcus aureus in Example 3 and Comparative Examples 1-2 are shown.

[0038] Figure 5 HE staining results of the duodenum in Examples 3 and Comparative Examples 1-2 for the treatment of bacterial enteritis in mice. Detailed Implementation

[0039] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Unless otherwise specified, the methods used in the embodiments of this invention are conventional methods, and the reagents used are all commercially available.

[0041] Example 1:

[0042] A method for preparing a kudzu root powder-based iodine complex includes the following steps:

[0043] (1) Mix 0.5g of kudzu root powder with a particle size of 75μm with 10mL of water to form a 5% kudzu root powder aqueous suspension;

[0044] (2) The kudzu root powder suspension was heated by hydrothermal method, the temperature was maintained at 60℃, the heating time was 5min, the energy value obtained per gram of kudzu root powder was controlled to be 3087J / g, and the gelatinized-retrograded kudzu root powder suspension was obtained by standing and refrigerating.

[0045] (3) Potassium iodide and potassium iodate (molar ratio 5:1) were added sequentially to the gelatinized-retrograded kudzu root powder suspension. The pH of the system was adjusted to 2.1 with hydrochloric acid, and the reaction was carried out to obtain an iodine-loaded kudzu root powder suspension. The suspension was first filtered, and the precipitate was washed and then freeze-dried to finally obtain the kudzu root powder-based iodine complex (HT). 3087 PL 75 @I2).

[0046] Example 2:

[0047] A method for preparing a kudzu root powder-based iodine complex includes the following steps:

[0048] (1) Mix 2g of kudzu root powder with a particle size of 115μm with 10mL of water to form a 20% kudzu root powder aqueous suspension;

[0049] (2) The kudzu root powder suspension was heated by hydrothermal method, the temperature was maintained at 70℃, the heating time was 10min, the energy value obtained per gram of kudzu root powder was controlled to be 1134J / g, and the gelatinized-retrograded kudzu root powder suspension was obtained by standing and refrigerating.

[0050] (3) Potassium iodide and potassium iodate (molar ratio 5:1) were added sequentially to the gelatinized-reclaimed kudzu root powder suspension. The pH of the system was adjusted to 2.5 with dilute sulfuric acid, and the reaction was carried out to obtain an iodine-loaded kudzu root powder suspension. The suspension was first filtered, and the precipitate was washed and then freeze-dried to finally obtain the kudzu root powder-based iodine complex (HT). 1134 PL 115 @I2).

[0051] Example 3:

[0052] A method for preparing a kudzu root powder-based iodine complex includes the following steps:

[0053] (1) Mix 5g of kudzu root powder with a particle size of 200μm with 20mL of water to form a 25% kudzu root powder aqueous suspension;

[0054] (2) The kudzu root powder suspension was heated by hydrothermal method, the temperature was maintained at 75℃, the heating time was 15min, the energy value obtained per gram of kudzu root powder was controlled to be 1050J / g, and the gelatinized-retrograded kudzu root powder suspension was obtained by standing and refrigerating.

[0055] (3) Potassium iodide and potassium iodate (molar ratio 5:1) were added sequentially to the gelatinized-reclaimed kudzu root powder suspension. The pH of the system was adjusted to 1.6 with phosphoric acid, and the reaction was carried out to obtain an iodine-loaded kudzu root powder suspension. The suspension was first filtered, and the precipitate was washed and then freeze-dried to finally obtain the kudzu root powder-based iodine complex (HT). 1050PL 200 @I2).

[0056] Example 4:

[0057] A method for preparing a kudzu root powder-based iodine complex includes the following steps:

[0058] (1) Mix 0.5g of kudzu root powder with a particle size of 150μm with 10mL of water to form a 5% kudzu root powder aqueous suspension;

[0059] (2) The kudzu root powder suspension was heated by hydrothermal method, the temperature was maintained at 80℃, the heating time was 5min, the energy value obtained per gram of kudzu root powder was controlled to be 4851J / g, and the gelatinized-retrograded kudzu root powder suspension was obtained by standing and refrigerating.

[0060] (3) Potassium iodide and potassium iodate (molar ratio 5:1) were added sequentially to the gelatinized-retrograded kudzu root powder suspension. The pH of the system was adjusted to 2.9 with hydrochloric acid, and the reaction was carried out to obtain an iodine-loaded kudzu root powder suspension. The suspension was first filtered, and the precipitate was washed and then freeze-dried to finally obtain the kudzu root powder-based iodine complex (HT). 4851 PL 150 @I2).

[0061] Example 5:

[0062] A method for preparing a kudzu root powder-based iodine complex includes the following steps:

[0063] (1) Mix 0.5g of kudzu root powder with a particle size of 180μm with 10mL of water to form a 5% kudzu root powder aqueous suspension;

[0064] (2) The kudzu root powder suspension was heated by hydrothermal method, the temperature was maintained at 90℃, the heating time was 5min, the energy value obtained per gram of kudzu root powder was controlled to be 5733J / g, and the gelatinized-retrograded kudzu root powder suspension was obtained by standing and refrigerating.

[0065] (3) Potassium iodide and potassium iodate (molar ratio 5:1) were added sequentially to the gelatinized-reclaimed kudzu root powder suspension, and the pH of the system was adjusted to 3.2 with hydrochloric acid. The reaction was carried out to obtain an iodine-loaded kudzu root powder suspension. The suspension was first filtered, and the precipitate was washed and then freeze-dried to finally obtain the kudzu root powder-based iodine complex (HT). 5733 PL 180 @I2).

[0066] Comparative Example 1:

[0067] The difference from Example 3 is that kudzu root powder was replaced with corn starch, while the rest was the same as in Example 3, resulting in a corn starch-iodine complex.

[0068] Comparative Example 2:

[0069] The difference from Example 3 is that the kudzu root powder suspension in step (1) does not undergo gelatinization-retrogradation treatment, while the rest is the same as in Example 3, resulting in a physical mixture of kudzu root powder and iodine.

[0070] The samples in the above examples and comparative examples were examined using scanning electron microscopy (SEM) to determine the particle size, iodine loading, and stability in the gastrointestinal tract. Their antibacterial properties were also investigated, as well as their effects on mice with bacterial enteritis. The methods are as follows:

[0071] 1. Scanning was performed using a Hitachi SU-8100 scanning electron microscope (SEM) from Japan. SEM detection conditions: 2kV accelerating voltage, 500x magnification.

[0072] like Figure 1 As shown, the scanning electron microscope (SEM) image of the corn starch-iodine complex prepared in Comparative Example 1 of this invention shows an irregular shape with some wrinkles and pores on the surface. The SEM image of the kudzu root powder-iodine physical mixture prepared in Comparative Example 2 shows a relatively smooth, regular spherical structure with small particle size and relatively uniform distribution. In contrast, the SEM image of the kudzu root powder-iodine complex prepared in Example 3 shows a rough, porous, irregular sheet-like or flocculent structure, indicating that a dense layer has formed on the surface of the kudzu root powder, which is beneficial for protecting iodine and improving its stability.

[0073] 2. Particle size determination method: The particle size of each sample was analyzed using a dry laser particle size analyzer. Specific steps: Each sample was weighed and poured into a feed funnel. Measurement parameters: refractive index 1.53, optical mode Mie, feed rate 16, air pressure 0.35 MPa. Each sample was tested in triplicate, and the average value was taken.

[0074] like Figure 2 As shown, the kudzu root powder-based iodine complex (HT) prepared in Example 1 3087 PL 75 The particle size distribution curve of @I2) shows a peak value around 75 μm, indicating a uniform distribution. Example 2 prepared a kudzu root powder-based iodine mixture (HT). 1134 PL 115 The particle size distribution curve of @I2) shows a peak value around 105 μm, indicating a uniform distribution. Example 3 prepared a kudzu root powder-based iodine complex (HT). 1050 PL 200 The particle size distribution curve of @I2) shifted to the right, with the peak value around 200 μm, indicating that the starch in kudzu is gelatinized more fully as the energy value increases.

[0075] 3. Determination of iodine content:

[0076] First, weigh a certain amount of the samples prepared in Examples 1-3 and Comparative Examples 1-2 into an iodine flask and disperse them in 10 mL of 0.1 M Na₂S₂O₃ solution until the deep blue solution turns milky white. After centrifugation, collect the supernatant in the iodine flask. Then, add 2-3 drops of starch solution as an indicator. Titrate the remaining sodium thiosulfate with 0.5 M iodine solution until the color changes from colorless to blue, then stop the titration. Perform three parallel titrations for each group (titering error ≤ 0.05 mL), record the data, and apply the formula mI₂ = 254°C. Na2S2O3· V Na2S2O3 Iodine content was calculated using / 2VI2. The results are shown in Table 1:

[0077] Table 1

[0078]

[0079] As shown in Table 1, Examples 1-3 show that the iodine content in the kudzu root powder-based iodine complex increases with the increase of energy value. Example 3 and the comparison with Comparative Examples 1-2 show that the iodine loading of kudzu root powder after gelatinization-retrogradation treatment is higher than that of kudzu root powder without gelatinization-retrogradation treatment and corn starch after gelatinization-retrogradation treatment.

[0080] 4. Determination of gastrointestinal stability:

[0081] The samples prepared in Example 3 and Comparative Examples 1-2 were incubated in artificial gastric juice for 2 hours and then incubated in artificial intestinal juice for 2, 4, 6, 8, 10 and 24 hours. The iodine content in each group of samples was then determined.

[0082] like Figure 3 In Comparative Example 1, the corn starch-iodine complex exhibited an iodine release rate of 5% after 2 hours in a simulated gastric fluid environment and 80% after 12 hours in a simulated intestinal fluid environment. In Comparative Example 2, the iodine in the kudzu root powder-iodine physical mixture showed an iodine release rate of 25% after 2 hours in a simulated gastric fluid environment and 100% after 4 hours in a simulated intestinal fluid environment. In Example 3, the iodine in the kudzu root powder-iodine-based complex showed an iodine release rate of 10% after 2 hours in a simulated gastric fluid environment and 50% after 12 hours in a simulated intestinal fluid environment. In the acidic environment of simulated gastric fluid, the kudzu root powder-iodine-based complex (HT...) of Example 3... 1050 PL 200 The iodine release rate in Example 3 (@I2) was significantly lower than that in the iodine release rate in the physical mixture of kudzu root powder and iodine in Comparative Example 2, indicating that the gelatinization-retrogradation treatment of kudzu root powder effectively protected the iodine complex. In a simulated intestinal fluid environment, Example 3 released only 50% of its iodine within 12 hours, while Comparative Example 2 released it rapidly within 4 hours. This suggests that the iodine in Example 3 can be slowly and continuously released in the intestine, avoiding a sudden release of iodine.

[0083] 5. Determination of antibacterial properties:

[0084] Plate count method for detecting bacterial colonies: Diluted Escherichia coli and Staphylococcus aureus bacterial suspensions (concentration 1×10⁻⁶) 6 The bacterial suspension (CFU / mL) was mixed with the substances from Comparative Example 1, Comparative Example 2, and Example 3, with iodine-free bacterial culture medium serving as a control. The mixture was incubated on a shaker for 6 hours. After 6 hours, the bacterial suspension from the control group was diluted again with culture medium to 1×10⁻⁶. 3 CFU / mL, and the bacterial suspensions of other experimental groups were diluted in the same way as the control group. 100 μL of each group's mixture was plated separately; the plates were inverted and incubated in a 37℃ bacterial incubator. The bacterial colonies of each group were observed and photographed.

[0085] Figure 4 Comparative Example 1: Corn starch-iodine complex; Comparative Example 2: Kudzu root powder-iodine physical mixture; and Example 3: Kudzu root powder-iodine complex (HT). 1050 PL 200 @I2) showed a 100% inhibition rate against both Escherichia coli and Staphylococcus aureus. The inhibition rate was calculated as (number of colonies in the control group - number of colonies in the experimental group) * 100% / number of colonies in the control group. This indicates that the antibacterial effect of iodine was not reduced after kudzu root powder was loaded with iodine.

[0086] 6. The therapeutic effect of kudzu root powder-based iodine complex on intestinal inflammation caused by Staphylococcus aureus:

[0087] Thirty 4-week-old male Kunming mice, weighing 18–22 g, were used in this study. After one week of acclimatization, all mice were randomly divided into a normal control group (n=6) and a model group (n=24). Mice in the model group were administered approximately 10 mg of [unspecified substance] via gavage for 7 consecutive days. 7 The model was established using CFU / mL Staphylococcus aureus bacterial suspension. Seven days after modeling, the model group was further randomly divided into the following four subgroups (6 animals per subgroup): model group, corn starch-iodine complex group (comparative example 1), kudzu root powder-iodine physical mixture group (comparative example 2), and kudzu root powder-iodine complex (HT). 1050 PL 200 @I2) group (Example 3). Except for the model group which was administered 0.9% sterile saline by gavage, the other treatment groups were treated with an equivalent dose of iodine at a concentration of 0.012 g / mL.

[0088] After 7 days of treatment, all mice were euthanized by cervical dislocation following orbital blood sampling. Duodenal tissue was collected and fixed in paraformaldehyde for subsequent hematoxylin-eosin (HE) staining. Results are as follows: Figure 5In the normal group, the duodenal villi of the mice were intact, arranged in a finger-like or leaf-like pattern; the crypt structure was clear, with no signs of hyperplasia or atrophy; and the muscle layer was neatly arranged. Compared with the normal group, the duodenum of the model group mice showed severe damage: the intestinal villi were significantly shorter, the villi tips were severely damaged, the interstitial spaces were enlarged, the muscle layer was thinned, and the intestinal gland structure was blurred. The duodenum of the corn starch-iodine complex group (Comparative Example 1) showed no significant improvement: the intestinal villi were still relatively short, and the villi tips were severely damaged. The villi height in the kudzu root powder-iodine physical mixture group (Comparative Example 2) was somewhat restored, the interstitial spaces were reduced, but the muscle layer was still relatively thin. Kudzu root powder-iodine complex (HT... 1050 PL 200 The intestinal villi structure of mice in group @I2 (Example 3) was clear and the length was restored to the normal level; the crypt structure was intact, which also shows that the iodine in this complex did not damage the structure of the intestinal tissue, indicating that iodine did not irritate the intestine.

[0089] The collected blood was centrifuged at 3000 r / min for 10 min to separate serum. The levels of IL-6 and TNF-α in the serum of different treatment groups were determined according to the ELISA kit instructions.

[0090] The results are shown in Table 2:

[0091] Table 2 shows the levels of inflammatory factors IL-6 and TNF-α in mouse serum.

[0092] Note: Different letters in the same column of the table indicate significant differences (p<0.05).

[0093] As shown in Table 2, no inflammation occurred in the normal group, while the inflammation in the model group was severe. The anti-inflammatory effect of Comparative Example 1 was poor because ordinary starch does not contain puerarin, an anti-inflammatory component, but the iodine in it has a bactericidal effect, thus reducing the inflammatory response. In Comparative Example 2, the kudzu root powder that had not undergone gelatinization-retrogradation treatment had almost no anti-inflammatory effect because the release rate of puerarin in the untreated kudzu root powder increased in the stomach, while the content entering the intestine decreased, thus losing its anti-inflammatory activity. In Example 3, the iodine-based complex of the kudzu root powder that underwent gelatinization-retrogradation treatment had the best anti-inflammatory effect because the release of puerarin in the stomach decreased while the release in the intestine increased, thus increasing the anti-inflammatory activity.

Claims

1. The application of kudzu root powder-based iodine complex in the preparation of drugs for treating gastrointestinal infections, including bacterial enteritis, fungal enteritis, or Helicobacter pylori infection; the kudzu root powder-based iodine complex comprises a double helix structure formed by starch retrogradation in kudzu root powder, with iodine molecules embedded within the double helix cavity; the preparation method of the kudzu root powder-based iodine complex includes the following steps: (1) Mix kudzu root powder with water to form a kudzu root powder aqueous suspension; (2) The kudzu root powder aqueous suspension is subjected to hydrothermal gelatinization-retrogradation treatment to obtain a gelatinized-retrograded kudzu root powder suspension; the hydrothermal gelatinization-retrogradation treatment includes: Heat at 60-90 ℃ for 5-10 min, then refrigerate at 0-4 ℃ for 2-6 h; The hydrothermal gelatinization-retrogradation treatment results in an energy value of 735~5733 J / g per gram of kudzu root powder. (3) Add potassium iodide, potassium iodate and acid to the gelatinized-reclaimed kudzu powder suspension, adjust the pH of the system to acidic, carry out the reaction, and obtain kudzu powder-based iodine complex after post-treatment; the molar ratio of potassium iodide and potassium iodate is 5:

1.

2. The application according to claim 1, characterized in that: In step (1), the particle size of the kudzu root powder is 75-212 μm.

3. The application according to claim 1, characterized in that: In step (3), the acid is any one of hydrochloric acid, dilute sulfuric acid or phosphoric acid; the pH of the system is adjusted to 1.4-3.

4.

4. The application according to claim 1, characterized in that, The drug contains kudzu root powder-based iodine complex as the active ingredient, as well as pharmaceutically acceptable excipients.

5. The application according to claim 1, characterized in that, The dosage form of the drug is an oral suspension, enteric-coated capsule, or gastric mucosa adhesion tablet.

Images