Preparation method and application of fucoidan oligosaccharides with blood sugar control, liver and pancreatic repair functions

Abstract

This invention discloses a method for preparing and applying fucoidan oligosaccharides with blood sugar control, liver repair, and pancreatic islet function, belonging to the field of functional food technology. This invention provides the application of fucoidan oligosaccharides in the preparation of products with synergistic effects of blood sugar control, pancreatic repair, and liver protection. The chemical structure of the fucoidan oligosaccharide is: a linear oligosaccharide composed of β-D-mannuronic acid (M) and α-L-guluronic acid (G) linked by 1,4-glycosidic bonds, with a degree of polymerization of 2-10. This invention is the first to propose and verify the application of fucoidan oligosaccharides in the triple synergistic effects of blood sugar control, pancreatic repair, and liver protection, breaking through the limitation of the relatively singular efficacy application of fucoidan oligosaccharides in existing technologies, and providing a multi-target, synergistic comprehensive intervention program for people with diabetes and abnormal liver lipid metabolism. Through systematic in vivo pharmacodynamic experiments in animals, the effective dose range and mechanism of action of fucoidan oligosaccharides in exerting synergistic effects of blood sugar control, pancreatic repair, and liver protection were clarified, providing clear technical parameters and scientific basis for the industrial development of the product.

Description

Technical Field

[0001] This invention belongs to the field of functional food technology, specifically the preparation method and application of brown algae oligosaccharides with blood sugar control and liver and pancreatic function. Background Technology

[0002] Type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD, also known as metabolic dysfunction-associated fatty liver disease (MASLD)) are two of the most prevalent metabolic diseases in contemporary society. Not only do they have high incidence rates, but they also often form a vicious cycle of mutual causation. Epidemiological data shows that over 60% of T2DM patients also have hepatic steatosis, while NAFLD patients have a significantly higher risk of developing T2DM than the general population. Both diseases share common pathophysiological mechanisms such as insulin resistance, chronic inflammation, oxidative stress, and gut microbiota dysbiosis, making comorbid management a core clinical challenge. There is a bidirectional relationship between NAFLD and T2DM: hepatic steatosis exacerbates insulin resistance, while hyperglycemia and hyperinsulinemia further promote hepatic lipid synthesis and fat accumulation. These two factors mutually aggravate each other through pathways involving adipokines, inflammatory mediators (TNF-α, IL-6), and oxidative stress, accelerating disease progression. Furthermore, while traditional hypoglycemic drugs can control blood glucose levels, their effects on improving abnormal hepatic lipid metabolism and pancreatic β-cell function decline are limited, and long-term use of some drugs poses safety risks such as hepatotoxicity. Therefore, there is an urgent need to develop a natural and safe intervention that can effectively control blood sugar while protecting pancreatic β-cell function and improving hepatic glucose and lipid metabolism disorders.

[0003] Alginate oligosaccharides (AOS) are functional oligosaccharides obtained by degrading sodium alginate derived from brown algae. They are composed of β-D-mannuronic acid (M) and α-L-guluronic acid (G) linked by 1,4-glycosidic bonds, with a degree of polymerization typically ranging from 2 to 10. Alginate oligosaccharides are characterized by their wide availability, high safety, and diverse biological activities. They have been found to possess various biological functions, including hypoglycemic, hypolipidemic, anti-inflammatory, antioxidant, and immunomodulatory effects. In July 2025, the National Center for Food Safety Risk Assessment publicly solicited opinions on the use of alginate oligosaccharides as a new food ingredient. Japan has approved alginate oligosaccharides as a food for specific health uses, and Taiwan has also used them as a food ingredient, fully demonstrating that the safety and application value of alginate oligosaccharides have gained widespread recognition.

[0004] In recent years, scholars both domestically and internationally have conducted numerous studies on the application of fucoidan oligosaccharides in diabetes and liver disease. A research team at Tianjin University of Science and Technology, using a T2DM mouse model combined with an oleic acid-induced hepatocyte steatosis in vitro model, found that AOS significantly improved glucose and lipid metabolism disorders in T2DM mice, manifested as a decrease in fasting blood glucose from 16 mmol / L to 12 mmol / L, a significant reduction in serum total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) levels, and a reduction in hepatic steatosis and fibrosis. Other studies have shown that fucoidan oligosaccharides can effectively reduce insulin resistance, pancreatic cell apoptosis, and hepatic gluconeogenesis levels in gestational diabetes model mice by alleviating oxidative stress and improving gut microbiota. Regarding liver protection, the latest research found that unsaturated fucoidan oligosaccharides (UAOS) can regulate bile acid metabolism through gut microbiota, effectively improving insulin resistance and hepatic steatosis in non-obese NAFLD mice, improving intestinal barrier integrity, and increasing the abundance of beneficial bacteria. Fucoidan oligosaccharides can also repair busulfan-induced liver damage in mice by enhancing anti-inflammatory capabilities, reducing blood levels of liver injury markers ALT and AST to levels comparable to those in the normal control group. Furthermore, fucoidan oligosaccharides also have a protective effect against D-galactose-induced liver damage in aging mouse models, and its mechanism is related to the regulation of the Nrf2 / HO-1 signaling pathway and the inhibition of hepatic oxidative stress.

[0005] However, existing technologies still have the following shortcomings: First, most current studies explore the hypoglycemic activity or hepatoprotective effects of fucoidan oligosaccharides separately, while systematic studies on the synergistic effects of fucoidan oligosaccharides in controlling blood sugar, repairing the pancreas, and protecting the liver in diabetic patients with liver damage are rarely reported; Second, there is a lack of effective dose screening and a clear definition of the optimal window of action for the integrated application of fucoidan oligosaccharides in controlling blood sugar, repairing the pancreas, and protecting the liver; Third, the efficacy applications of existing fucoidan oligosaccharide products are relatively singular, and there is no technical solution for fucoidan oligosaccharide products with multiple effects of controlling blood sugar, repairing the pancreas, and protecting the liver specifically for diabetic patients with abnormal liver lipid metabolism. Against this background, this invention, based on systematic in vivo animal experimental studies, proposes and verifies for the first time the application scheme of fucoidan oligosaccharides in the preparation of products with synergistic effects of controlling blood sugar, repairing the pancreas, and protecting the liver.

[0006] The information disclosed above in this background section is only for enhancing the understanding of the background section of this invention, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide the application of fucoidan oligosaccharides in the preparation of products with synergistic effects of blood sugar control, pancreatic repair, and liver protection, in order to solve the problems in the prior art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: the application of fucoidan oligosaccharide with blood sugar control and liver and pancreatic islet repair functions in the preparation of products with synergistic effects of blood sugar control, pancreatic repair and liver protection. The chemical structure of the fucoidan oligosaccharide is: a linear oligosaccharide composed of β-D-mannuronic acid (M) and α-L-guluronic acid (G) linked by 1,4-glycosidic bonds, with a degree of polymerization of 2 to 10.

[0009] Preferably, the degree of polymerization of the fucoidan oligosaccharide is 2 to 6, and the M / G ratio is 0.8 to 2.0.

[0010] Preferably, the brown algae oligosaccharide is prepared by using sodium alginate derived from brown algae as raw material, which is degraded by enzymatic degradation or acid degradation, and then neutralized, decolorized, purified, concentrated and dried.

[0011] Preferably, the product is any one of pharmaceuticals, health foods, foods for special medical purposes, and functional foods; the dosage form of the product is an oral dosage form, selected from tablets, capsules, granules, oral liquids, or powders.

[0012] Preferably, the effective daily dose of the alginic oligosaccharide in the product is 100 mg to 4000 mg, calculated based on the pure alginic oligosaccharide.

[0013] Preferably, the blood glucose control effect includes reducing fasting blood glucose, improving glucose tolerance, reducing glycated serum protein levels, and improving insulin resistance; the pancreatic repair effect includes repairing structural damage to pancreatic β-cells, increasing the number of pancreatic β-cells, and promoting insulin secretion; and the liver protection effect includes reducing serum transaminase levels, alleviating hepatic steatosis, improving hepatic oxidative stress, and regulating the expression of genes related to hepatic glucose and lipid metabolism.

[0014] Preferably, the fucoidan exerts a synergistic effect of blood sugar control, pancreatic repair, and liver protection through one or more of the following mechanisms: (a) reshaping the intestinal flora structure, increasing the abundance of beneficial bacteria, and promoting the production of short-chain fatty acids; (b) activating the PI3K / Akt insulin signaling pathway to promote glucose uptake and utilization; (c) activating the Nrf2 / HO-1 antioxidant pathway to reduce oxidative stress damage to the liver and pancreas; and (d) downregulating PEPCK and G6Pase expression to inhibit gluconeogenesis and downregulating HMGCR expression to inhibit cholesterol synthesis.

[0015] Preferably, the alginate oligosaccharide is prepared by the following enzymatic degradation method: (1) Sodium alginate is dissolved in water to prepare a substrate solution with a mass concentration of 2% to 8%; (2) Alginate lyase is added, with the amount of enzyme being 0.5% to 3% of the substrate mass, and enzymatic hydrolysis is performed for 4 to 12 hours at pH 6.0 to 8.0 and temperature 35 to 50°C; (3) After enzymatic hydrolysis, the enzyme is inactivated by heating, and the fraction with a molecular weight of 300 to 3000 Da is collected by decolorization with activated carbon and separation by ultrafiltration membrane; (4) After concentration under reduced pressure, the fraction is freeze-dried or spray-dried to obtain alginate oligosaccharide powder.

[0016] Preferably, the product further comprises pharmaceutically or food-grade excipients or carriers selected from one or more of fillers, disintegrants, lubricants, flow aids, flavoring agents, sweeteners, preservatives, and thickeners.

[0017] The present invention also provides a composition having synergistic effects of blood sugar control, pancreatic repair and liver protection, comprising fucoidan as the sole active ingredient, wherein the fucoidan accounts for 5% to 90% of the total mass of the composition, and the remainder is pharmaceutically or food-grade excipients.

[0018] The core mechanisms by which fucoidan oligosaccharides synergistically control blood sugar, repair the pancreas, and protect the liver include:

[0019] (1) Mechanism of gut microbiota remodeling and metabolite regulation: As a prebiotic, fucoidan can significantly remodel the gut microbiota structure, increase the relative abundance of Bacteroidetes, decrease the proportion of Firmicutes, and significantly increase the abundance of beneficial bacteria such as Prevotellaceae, Akkermansia, Bifidobacterium, and Lactobacillus. The above changes in the microbiota promote the production of short-chain fatty acids (SCFAs). SCFAs exert systemic metabolic regulation through the gut-hepatic axis and gut-pancreas axis, stimulate the secretion of glucagon-like peptide-1 (GLP-1), enhance insulin sensitivity, and regulate bile acid metabolism through the FGF15-FGFR4-CYP7A1 signaling pathway, thereby improving hepatic lipid deposition.

[0020] (2) Activation mechanism of insulin signaling pathway: Alginate can activate key signaling molecules in the insulin signaling pathway, namely phosphatidylinositol-3-kinase (PI3K) and protein kinase B (Akt), promote the phosphorylation of insulin receptor substrate-1 (IRS-1), and enhance the membrane translocation of glucose transporter (GLUT4), thereby improving the efficiency of glucose uptake and utilization in peripheral tissues (liver, skeletal muscle) and improving insulin resistance.

[0021] (3) Dual protective mechanism of anti-inflammatory and antioxidant: Fucoidan can significantly downregulate the expression level of pro-inflammatory cytokines (TNF-α, IL-6) and upregulate the expression of anti-inflammatory cytokines; at the same time, it activates the nuclear factor E2-related factor 2 / heme oxygenase-1 (Nrf2 / HO-1) signaling pathway, increases the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPX), reduces malondialdehyde (MDA) level, and alleviates oxidative stress damage to the liver and pancreas.

[0022] (4) Gene regulation mechanism of liver glucose and lipid metabolism: Alginate can downregulate the expression of key gluconeogenesis enzymes such as phosphoenolpyruvate carboxyl kinase (PEPCK) and glucose-6-phosphatase (G6Pase), thereby reducing liver glucose output; at the same time, it downregulates the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) to inhibit cholesterol synthesis and upregulates cholesterol 7α-hydroxylase (CYP7A1) to promote bile acid synthesis and cholesterol clearance, thereby achieving comprehensive regulation of liver glucose and lipid metabolism.

[0023] The molecular mechanisms at these four levels do not operate independently, but are interconnected and synergistic: gut microbiota remodeling promotes the production of SCFAs, which can both activate the insulin signaling pathway and inhibit the release of inflammatory factors. Anti-inflammatory and antioxidant protection provides a repair microenvironment for pancreatic β cells and hepatocytes, while the regulation of liver glucose and lipid metabolism genes further reduces peripheral insulin resistance, thus forming a virtuous cycle of "glucose control-pancreas repair-liver protection".

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. This invention is the first to propose and verify the application of fucoidan oligosaccharides in the triple synergistic effects of blood sugar control, pancreatic repair, and liver protection. It breaks through the limitation of the relatively single efficacy application of fucoidan oligosaccharides in the prior art, and provides a comprehensive intervention program with multiple targets and synergistic effects for people with diabetes and abnormal liver lipid metabolism.

[0026] 2. Through systematic in vivo pharmacodynamic experiments in animals, this invention clarifies the effective dosage range and mechanism of action of fucoidan oligosaccharides in exerting synergistic effects of blood sugar control, pancreatic repair, and liver protection, providing clear technical parameters and scientific basis for the industrial development of the product.

[0027] 3. This invention uses a bio-enzymatic degradation method to prepare brown algae oligosaccharides. The process conditions are mild and controllable, the molecular weight and activity of the product are stable, no toxic or harmful organic solvents are used in the preparation process, the product has high safety, and it is suitable for large-scale production.

[0028] 4. Fucoidan oligosaccharides are derived from natural marine brown algae, a abundant and renewable raw material. The preparation process is green and environmentally friendly, aligning with the concept of sustainable development. As a new food ingredient, fucoidan oligosaccharides have entered the national approval process, possessing clear safety evaluation criteria and regulatory support, and have broad market application prospects.

[0029] 5. The product of this invention has been experimentally proven to have the following comprehensive effects: significantly reducing fasting blood glucose and glycated serum protein levels; effectively improving pancreatic islet structural damage and protecting pancreatic β-cell function; significantly reducing serum transaminase levels and alleviating hepatic steatosis and oxidative stress damage; and through multi-pathway synergistic effects, comprehensively improving hepatic metabolic disorders complicated by diabetes. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0031] Figure 1 This is a schematic diagram of the method for preparing brown algae oligosaccharides according to the present invention. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] Example 1: Preparation of fucoidan oligosaccharides

[0034] Using food-grade sodium alginate as raw material, fucoidan was prepared according to the following steps:

[0035] (1) Weigh 100 g of sodium alginate, dissolve it in 2000 mL of deionized water, stir until fully dissolved, prepare a 5% (w / v) substrate solution, and adjust the pH to 7.0.

[0036] (2) Add 2.0 g of alginate lyase with an enzyme activity ≥20000 U / g. The amount of enzyme used is 2% of the substrate mass. The enzymatic hydrolysis reaction is carried out at 40℃ and pH 7.0 for 8 hours with a stirring speed of 150 rpm.

[0037] (3) After the enzymatic hydrolysis is completed, the temperature is raised to 90℃ and held for 15 min to inactivate the enzyme. After cooling, activated carbon is added at a volume of 1.5% of the reaction liquid volume. The mixture is stirred at 60℃ for 40 min to decolorize. The activated carbon is removed by filtration and the filtrate is collected. The filtrate is then passed through ultrafiltration membranes with molecular weight cutoffs of 3000 Da and 300 Da in sequence for fractionation and separation. The components with molecular weights between 300 and 3000 Da are collected.

[0038] (4) The collected target components were concentrated under reduced pressure at 50°C to a solid content of about 20%, and then freeze-dried at a cold trap temperature of -50°C, a vacuum degree of <20 Pa, and a drying time of 48 h to obtain about 65 g of brown algae oligosaccharide powder with a yield of about 65%.

[0039] The obtained alginate oligosaccharides were analyzed by high performance liquid chromatography (HPLC) and found to have a purity of 93.2% (calculated as uronic acid), a degree of polymerization of 2–6, and an M / G ratio of 1.2–1.8.

[0040] Example 2: Pharmacodynamic experiment on the synergistic effects of fucoidan on blood sugar control, pancreas repair, and liver protection in diabetic mice.

[0041] 2.1 Experimental Materials

[0042] (1) Test substance: brown algae oligosaccharide powder prepared in Example 1.

[0043] (2) Positive control drug: metformin hydrochloride, purity ≥99%.

[0044] (3) Experimental animals: SPF-grade male C57BL / 6J mice, 6-8 weeks old, weighing 18-22 g, purchased from qualified experimental animal centers.

[0045] (4) Feed: High-fat feed, purchased from qualified feed suppliers.

[0046] (5) Modeling reagent: streptozotocin (STZ), purity ≥98%.

[0047] 2.2 Establishment and Grouping of Diabetic Mouse Model

[0048] After one week of acclimatization, all mice were randomly divided into a normal control group (NC group, n=10) and a model group (n=60). The normal control group was fed a standard maintenance diet, while the model group was fed a high-fat diet for 4 weeks. After 4 weeks, the mice in the model group were fasted for 12 hours and then injected intraperitoneally with STZ solution (35 mg / kg, prepared with 0.1 mol / L citrate buffer, pH 4.5) for 3 consecutive days. On day 7 after the last injection, fasting blood glucose was measured, and a fasting blood glucose level ≥11.1 mmol / L was considered a successful model of type 2 diabetes.

[0049] The successfully modeled diabetic mice were randomly divided into the following groups according to their fasting blood glucose levels (n=10 per group):

[0050] Model control group: administered an equal volume of physiological saline by gavage.

[0051] Metformin group (Met): Metformin 200 mg / kg / day administered orally.

[0052] Low-dose AOS group (AOS-L): 50 mg / kg / day of fucoidan administered orally.

[0053] AOS medium-dose group (AOS-M): 100 mg / kg / day of fucoidan administered by gavage.

[0054] High-dose AOS group (AOS-H): 200 mg / kg / day of fucoidan administered by gavage.

[0055] Mice in each group were administered the drug once daily by gavage for 8 consecutive weeks. During the experiment, the normal control group was given a standard maintenance diet, while the other groups were given a high-fat diet.

[0056] 2.3 Detection Indicators and Methods

[0057] (1) Fasting blood glucose (FBG): Measured every 2 weeks. Mice were fasted for 6 hours, blood was collected from the tail vein, and the fasting blood glucose concentration was measured by a blood glucose meter.

[0058] (2) Oral glucose tolerance test (OGTT): After the last administration, the mice were fasted for 12 h and then administered glucose solution (2 g / kg) by gavage. Blood glucose values ​​were measured at 0, 30, 60, 90 and 120 min, and the area under the blood glucose curve (AUC) was calculated.

[0059] (3) Glycated serum protein (GSP) and fasting insulin (FINS): At the end of the experiment, mice were fasted for 12 h, blood was collected from the orbital rim, serum was separated, and GSP and FINS levels were measured using commercial kits.

[0060] (4) Insulin resistance index (HOMA-IR): calculated according to the formula HOMA-IR = FBG (mmol / L) × FINS (mIU / L) / 22.5.

[0061] (5) Liver function indicators: Serum was collected and the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using a fully automated biochemical analyzer.

[0062] (6) Liver oxidative stress indicators: liver tissue homogenate was taken and superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were determined using commercial kits.

[0063] (7) Histopathological examination: Pancreatic and liver tissues were taken, fixed in 4% paraformaldehyde, embedded in paraffin, sectioned, stained with hematoxylin and eosin (HE), and observed under an optical microscope to observe the changes in tissue morphology.

[0064] 2.4 Data Processing

[0065] Experimental data are expressed as mean ± standard error (mean ± SEM). One-way ANOVA was performed using SPSS software, and pairwise comparisons between groups were performed using the LSD method. P < 0.05 indicated statistical significance, and P < 0.01 indicated extremely significant difference.

[0066] 2.5 Experimental Results

[0067] 2.5.1 Effects of fucoidan oligosaccharides on fasting blood glucose

[0068] At the start of the experiment, before drug administration, the fasting blood glucose levels of mice in the model control group and each drug administration group were significantly higher than those in the normal control group (P<0.01), with no statistically significant differences among the groups. The results after 8 weeks of drug administration are shown in Table 1.

[0069] Table 1. Effects of fucoidan oligosaccharides on fasting blood glucose in diabetic mice (mean ± SEM, n=10)

[0070]

[0071] Note: Compared with the NC group, **P<0.01; compared with the Model group, #P<0.05, ##P<0.01.

[0072] The results showed that, compared with the model control group, fasting blood glucose was significantly reduced in both the medium and high dose groups of fucoidan (P<0.01). The blood glucose reduction in the high dose group was similar to that in the metformin group, with a blood glucose reduction rate of 34.2%, demonstrating a significant dose-dependent hypoglycemic effect.

[0073] 2.5.2 Effects of brown algae oligosaccharides on glycated serum proteins and oral glucose tolerance

[0074] Eight weeks after administration, the levels of glycated serum protein in each group were measured, and the results are shown in Table 2.

[0075] Table 2. Effects of fucoidan oligosaccharides on GSP and OGTT-AUC in diabetic mice (mean ± SEM, n=10)

[0076]

[0077] Note: Compared with the NC group, **P<0.01; compared with the Model group, #P<0.05, ##P<0.01.

[0078] The results showed that the GSP levels in the medium and high dose groups of fucoidan were significantly lower than those in the model control group (P<0.01), indicating that fucoidan has a long-term and stable glycemic regulatory effect. OGTT results showed that all dose groups of fucoidan reduced the area under the blood glucose curve and improved glucose tolerance in a dose-dependent manner.

[0079] 2.5.3 Effects of fucoidan on serum insulin and insulin resistance

[0080] Table 3. Effects of fucoidan oligosaccharides on insulin resistance in diabetic mice (mean ± SEM, n=10)

[0081]

[0082] Note: Compared with the NC group, **P<0.01; compared with the Model group, #P<0.05, ##P<0.01.

[0083] The results showed that medium and high doses of fucoidan significantly reduced fasting insulin levels, and the HOMA-IR index was significantly lower than that of the model control group (P<0.01), demonstrating that fucoidan can effectively improve insulin resistance in diabetic mice and restore the body's sensitivity to insulin.

[0084] 2.5.4 Effects of fucoidan oligosaccharides on pancreatic islet histopathology

[0085] HE staining revealed that in the normal control group, the pancreatic islets of Langerhans exhibited regular, round or oval clusters with abundant, tightly packed β-cells, full cytoplasm, and round, centrally located nuclei. In the model control group, the pancreatic islet structure was severely damaged, with significantly reduced islet area, irregular shape, a marked decrease in the number of β-cells, loose cell arrangement, cytoplasmic vacuolar degeneration, and inflammatory cell infiltration in some areas. The medium- and high-dose groups of fucoidan and metformin significantly improved islet structure, increasing islet area, resembling regular shape, increasing the number of β-cells, and ensuring tighter arrangement, while reducing cytoplasmic vacuolar degeneration. The high-dose group showed the most significant repair effect, with islet morphology approaching that of the normal control group.

[0086] The results of pancreatic β-cell counting showed that the number of pancreatic β-cells in the normal control group was (245.6 ± 18.3) cells / islet, the number in the model control group was (98.2 ± 12.5) cells / islet, and the number in the high-dose fucoidan group recovered to (198.4 ± 16.7) cells / islet, with statistically significant differences (P<0.01). These results fully demonstrate that fucoidan has a significant repair and protective effect on damaged pancreatic β-cells.

[0087] 2.5.5 Effects of fucoidan oligosaccharides on liver function indicators

[0088] Table 4. Effects of fucoidan oligosaccharides on serum transaminase levels in diabetic mice (mean ± SEM, n=10)

[0089]

[0090] Note: Compared with the NC group, **P<0.01; compared with the Model group, #P<0.05, ##P<0.01.

[0091] The results showed that serum ALT and AST levels in the model control group were significantly higher than those in the normal control group (P<0.01), indicating significant liver damage in diabetic mice. ALT and AST levels in the medium- and high-dose fucoidan groups were significantly lower than those in the model control group (P<0.01), with the high-dose group showing reductions of 47.0% and 44.6% in ALT and AST levels, respectively, indicating that fucoidan can significantly alleviate liver damage associated with diabetes.

[0092] 2.5.6 Effects of fucoidan oligosaccharides on liver histopathology

[0093] HE staining of the liver showed that in the normal control group, the liver lobule structure was clear and intact, and the hepatocytes were arranged neatly and orderly, radiating around the central vein, with no fatty degeneration of the hepatocytes. In the model control group, the liver lobule structure was disordered, and the hepatocytes showed diffuse macrovesicular and microvesicular fatty degeneration. Lipid droplets of varying sizes were visible in a large number of hepatocytes, and some areas were accompanied by inflammatory cell infiltration and focal necrosis. The liver pathology of the low-dose group of fucoidan oligosaccharide was slightly improved, but fatty degeneration of varying degrees was still visible. The area of ​​fatty degeneration in the liver of the medium-dose group was significantly reduced, and the number of lipid droplets decreased. The liver lobule structure of the high-dose group was relatively intact, the hepatocytes were arranged more neatly, the fatty degeneration was significantly reduced, and only a few scattered micro lipid droplets were seen. The hepatocyte damage was significantly repaired, and the morphology was close to that of the normal control group.

[0094] 2.5.7 Effects of fucoidan oligosaccharides on liver oxidative stress indicators

[0095] Table 5. Effects of fucoidan oligosaccharides on liver oxidative stress indices in diabetic mice (mean ± SEM, n=10)

[0096]

[0097] Note: Compared with the NC group, **P<0.01; compared with the Model group, #P<0.05, ##P<0.01.

[0098] The results showed that the SOD activity in the medium and high dose groups of fucoidan was significantly increased (P<0.01) and the MDA content was significantly decreased (P<0.01) compared with the model control group, suggesting that fucoidan can effectively improve the liver's antioxidant defense capacity and reduce the damage to the liver caused by oxidative stress. This result is consistent with the mechanism reported in the literature that fucoidan can inhibit hepatic oxidative stress by regulating the Nrf2 / HO-1 signaling pathway.

[0099] 2.5.8 Comprehensive Effect Analysis

[0100] Based on the comprehensive analysis of the above experimental results, fucoidan oligosaccharides exhibited triple effects of blood glucose control, pancreatic repair, and liver protection in a streptozotocin-induced diabetic mouse model. In terms of blood glucose reduction, the fasting blood glucose reduction rate in the medium- and high-dose groups reached 29.6%–34.2%. Regarding pancreatic islet repair, the number of pancreatic β cells in the high-dose group recovered to 80.8% of the normal control group. In terms of liver protection, serum ALT and AST decreased by 47.0% and 44.6%, respectively, and hepatic steatosis was significantly improved in the high-dose group. All indicators in the medium-dose group (100 mg / kg / d) and the high-dose group (200 mg / kg / d) showed statistically significant differences compared to the model control group (P<0.05 or P<0.01), and the effects exhibited a clear dose-response relationship.

[0101] The above results indicate that fucoidan oligosaccharides do not exert their hypoglycemic, pancreatic islet repair, and liver protection effects independently, but rather improve hepatic metabolic disorders in diabetes mellitus at an overall level through synergistic effects of multiple pathways. Mechanisms such as gut microbiota remodeling, insulin signaling pathway activation, anti-inflammatory and antioxidant protection, and regulation of glucose and lipid metabolism genes work synergistically to form a positive cycle that improves insulin resistance, protects pancreatic β-cells, inhibits hepatic glucose output, reduces hepatic lipid deposition, and alleviates systemic inflammation and oxidative stress, achieving a synergistic effect of blood sugar control, pancreatic repair, and liver protection.

[0102] Example 3: Preparation of brown algae oligosaccharide tablets

[0103] Brown algae oligosaccharide tablets were prepared according to the following formula and process:

[0104] The following were prepared in Example 1: 400 g of fucoidan with a purity of 93.2%, equivalent to approximately 373 g of pure product; 120 g of microcrystalline cellulose; 25 g of sodium carboxymethyl starch; 5 g of magnesium stearate; and 5 g of silicon dioxide.

[0105] Preparation process: Fucoidan oligosaccharides and microcrystalline cellulose are mixed evenly, sodium carboxymethyl starch is added, and a soft mass is prepared using a suitable amount of 75% ethanol as a wetting agent. Granulation is performed through an 18-mesh sieve, dried at 60℃ until the moisture content is ≤3%, and then sized through a 16-mesh sieve. Magnesium stearate and silica are added and mixed evenly, then compressed into tablets, with a tablet weight of approximately 0.55 g / tablet. Each tablet contains approximately 400 mg of fucoidan oligosaccharides (equivalent to approximately 373 mg of pure product). The recommended dosage is 1-2 tablets once daily.

[0106] Example 4: Preparation of brown algae oligosaccharide granules

[0107] Example 1 prepared the following: 300 g of brown algae oligosaccharide with a purity of 93.2%; 250 g of erythritol; 8 g of citric acid; 2 g of steviol glycosides; and 1000 g of soluble starch.

[0108] Preparation process: Each component is passed through an 80-mesh sieve separately, mixed evenly using an equal-incremental mixing method, and granulated using an appropriate amount of 80% ethanol as a wetting agent. The granules are then granulated through a 16-mesh sieve, dried at 55℃, sized through a 14-mesh sieve, and packaged into 5.0 g packets. Each packet contains approximately 1.5 g of fucoidan, equivalent to approximately 1.4 g of pure product. The recommended dosage is 1-2 times daily, one packet each time, dissolved in warm water.

[0109] Example 5: Preparation of Brown Alginate Oligosaccharide Oral Solution

[0110] Example 1 prepared the following: 20 g of alginate oligosaccharide with a purity of 93.2%; 80 g of xylitol; 2 g of sodium citrate; 1 g of potassium sorbate; 0.5 g of xanthan gum; and purified water to a final volume of 1000 mL.

[0111] Preparation process: Xanthan gum is pre-swelled in a small amount of purified water. Fucoidan, xylitol, sodium citrate, and potassium sorbate are dissolved in purified water and stirred until homogeneous. The xanthan gum solution is then added, and purified water is added to the final volume. The mixture is stirred until homogeneous, filtered through a 0.22 μm microporous membrane, and filled into brown glass bottles (30 mL per bottle). Each bottle is sealed and pasteurized (80℃, 30 min). Each bottle contains approximately 600 mg of fucoidan (equivalent to approximately 559 mg of pure product). The recommended dosage is 1-2 times daily, one bottle each time.

[0112] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. The application of fucoidan oligosaccharides with blood sugar control and liver / pancreatic islet repair functions in the preparation of products with synergistic effects of blood sugar control, pancreatic repair, and liver protection, characterized by: The brown algae oligosaccharide is a linear oligosaccharide composed of β-D-mannuronic acid and α-L-guluronic acid linked by 1,4-glycosidic bonds, with a degree of polymerization of 2 to 10.

2. The application according to claim 1, characterized in that: The degree of polymerization of the fucoidan oligosaccharide is 2-6, and the M / G ratio is 0.8-2.

0.

3. The application according to claim 1, characterized in that: The brown algae oligosaccharide is prepared by using sodium alginate derived from brown algae as raw material, which is degraded by enzymatic degradation or acid degradation, and then neutralized, decolorized, purified, concentrated and dried.

4. The application according to claim 1, characterized in that: The product is any one of pharmaceuticals, health foods, foods for special medical purposes, and functional foods; the dosage form of the product is an oral dosage form, selected from tablets, capsules, granules, oral liquids, or powders.

5. The application according to claim 1, characterized in that: The effective daily dose of the alginic oligosaccharide in the product is 100 mg to 4000 mg, calculated based on the pure alginic oligosaccharide.

6. The application according to claim 1, characterized in that: The blood glucose control effects include lowering fasting blood glucose, improving glucose tolerance, reducing glycated serum protein levels, and improving insulin resistance; the pancreatic repair effects include repairing structural damage to pancreatic β-cells, increasing the number of pancreatic β-cells, and promoting insulin secretion; the liver protection effects include lowering serum transaminase levels, reducing hepatic steatosis, improving hepatic oxidative stress, and regulating the expression of genes related to hepatic glucose and lipid metabolism.

7. The application according to claim 1, characterized in that: The aforementioned fucoidan exerts a synergistic effect of blood sugar control, pancreatic repair, and liver protection through one or more of the following mechanisms: (a) reshaping the intestinal flora structure, increasing the abundance of beneficial bacteria, and promoting the production of short-chain fatty acids; (b) activating the PI3K / Akt insulin signaling pathway, promoting glucose uptake and utilization; (c) activating the Nrf2 / HO-1 antioxidant pathway, reducing oxidative stress damage to the liver and pancreas; and (d) downregulating PEPCK and G6Pase expression to inhibit gluconeogenesis and downregulating HMGCR expression to inhibit cholesterol synthesis.

8. The application according to claim 1, characterized in that: The alginic oligosaccharide was prepared by the following enzymatic degradation method: (1) Sodium alginate was dissolved in water to prepare a substrate solution of 2% to 8%; (2) Alginate lyase was added, with the amount of enzyme being 0.5% to 3% of the substrate mass, and enzymatic hydrolysis was performed for 4 to 12 hours at pH 6.0 to 8.0 and temperature 35 to 50°C; (3) After enzymatic hydrolysis, the enzyme was inactivated by heating, and the fraction with a molecular weight of 300 to 3000 Da was collected by decolorization with activated carbon and separation by ultrafiltration membrane; (4) After concentration under reduced pressure, the fraction was freeze-dried or spray-dried to obtain alginic oligosaccharide powder.

9. The application according to claim 1, characterized in that: The product also contains pharmaceutically or food-grade excipients or carriers selected from one or more of fillers, disintegrants, lubricants, flow aids, flavoring agents, sweeteners, preservatives, and thickeners.

10. A composition having synergistic effects of blood sugar control, pancreatic repair, and liver protection, characterized in that: The composition contains a brown algae oligosaccharide as the sole active ingredient, wherein the brown algae oligosaccharide accounts for 5% to 90% of the total mass of the composition, and the remainder is pharmaceutically or food-grade excipients.

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