A core-removed lotus seed water extract, a preparation method thereof, and application thereof in resisting depression

Abstract

The present application belongs to the technical field of plant extracts, and relates to a water extract of core-removed lotus seeds, a preparation method and application thereof in relieving depression. The water extract of core-removed lotus seeds plays an antidepressant role by regulating the microbe-gut-brain axis in any of the following ways: 1) regulating intestinal flora; 2) repairing intestinal barrier; 3) inhibiting neural inflammation; 4) activating hippocampal BDNF-mTOR pathway; 5) up-regulating 5-HT, DA and NE neurotransmitter levels. By using a classic CUMS animal model, it is found that the water extract of core-removed lotus seeds has a significant interference effect on the depressive behavior of a CUMS rat model.

Description

Technical Field

[0001] This invention belongs to the field of plant extract technology, and relates to a water extract of lotus seeds with the core removed, its preparation method, and its application in antidepressant treatment. Background Technology

[0002] Depression is a mental disorder with a high incidence, high disability rate, and high suicide rate, affecting over 320 million people worldwide. In my country, the lifetime prevalence of depressive disorders among adults reaches 6.8%, seriously endangering human physical and mental health. Currently, clinical antidepressants (such as SSRIs and SNRIs) have drawbacks such as slow onset of action, numerous side effects, significant individual variability in efficacy, and drug resistance in some patients. Therefore, the development of safe, effective, and low-toxicity antidepressants has become a research hotspot.

[0003] The gut-microbe axis is a bidirectional communication network between the gut microbiota, gut function, and the central nervous system, regulating mood and cognitive function through neural, endocrine, immune, and metabolic pathways. Studies have confirmed that patients with depression often experience gut microbiota imbalance, intestinal barrier damage, chronic low-grade inflammation, and neurotransmitter disturbances. The gut microbiota can influence brain function by regulating tryptophan metabolism, short-chain fatty acid production, and the release of inflammatory factors, providing a novel target for the prevention and treatment of depression.

[0004] Lotus (Nelumbo nucifera Gaertn.) is a plant used for both food and medicine. Its seeds (without the core) and other parts are used in traditional Chinese medicine for their effects of nourishing the heart and calming the mind, clearing heat and relieving irritability. Modern research has found that lotus plants contain active ingredients such as flavonoids, alkaloids, and polysaccharides, possessing potential for neuroprotection, anti-inflammation, and regulation of gut microbiota. Current research mainly focuses on the basic activities of single lotus components, and its antidepressant mechanism based on the gut-microbe axis has not yet been clarified. Furthermore, there is a lack of targeted extract preparation and application strategies, limiting the in-depth development of lotus resources in the field of antidepressant therapy. Summary of the Invention

[0005] To address the aforementioned technical issues, this paper presents a water extract of lotus seeds with the core removed, its preparation method, and its application in alleviating depression.

[0006] The purpose of this invention is to provide a method for preparing a water extract of lotus seeds with the core removed, characterized by comprising the following steps: (1) Raw material pretreatment: Select lotus seeds with the core removed, and after drying, crushing and sieving, dry powder is obtained; (2) Water extraction: After the dried powder is uniformly dissolved in the solvent, the solution is refluxed multiple times. After each reflux, the liquid is filtered and combined to obtain an extract with a crude drug concentration of 1.0 g / ml. (3) Post-processing: The extract was concentrated by rotary evaporation and freeze-dried to powder to obtain the water extract of lotus seeds with core removed.

[0007] Furthermore, in step (1), the drying temperature is 40°C.

[0008] Furthermore, in step (2), the ratio of dry powder to solvent is 1:25, based on the solid-liquid ratio. The solvent is pure water; The reflux was performed twice, with a reflux temperature of 90°C and a reflux time of 120 min for each reflux.

[0009] Furthermore, in step (2), the temperature condition for rotary evaporation concentration is 60°C.

[0010] The lotus seed water extract obtained by the above method.

[0011] Furthermore, based on the dry matter content of the water extract of the cored lotus seeds, the water extract of the cored lotus seeds contained ≥0.12% gallocatechin, ≥0.41% isobergamotinoin, ≥0.52% isocarboxylic acid, and ≥0.47% 4-chromone.

[0012] The above-mentioned application of the water extract of lotus seeds with the core removed in antidepressant treatment.

[0013] Furthermore, the lotus seed water extract with the core removed exerts its antidepressant effect by regulating the gut-brain axis in any of the following ways: 1) Regulates gut microbiota; 2) Repair the intestinal barrier; 3) Inhibits neuroinflammation; 4) Activate the hippocampal BDNF-mTOR pathway; 5) Upregulates the levels of 5-HT, DA, and NE neurotransmitters.

[0014] The above-mentioned application of the decored lotus seed water extract in the preparation of antidepressant drugs or functional foods.

[0015] Furthermore, the functional food includes any one of solid beverages, meal replacement powders, functional beverages, and tea products.

[0016] The beneficial effects of this invention are: (1) By utilizing the classic CUMS animal model, this invention found that the water extract of lotus seeds with the core removed has a significant interfering effect on depressive-like behavior in the CUMS rat model.

[0017] (2) The lotus seed water extract of the present invention can exert significant antidepressant and anti-anxiety-like effects through multiple pathways, such as regulating monoamine neurotransmitters, repairing intestinal barrier function, and inhibiting systemic inflammation. Its mechanism of action is consistent with the "microbe-gut-brain axis" theory. At the same time, the preparation process of this extract is simple, and it has shown good efficacy and safety in both in vivo and in vitro models, providing experimental evidence for the development of novel natural antidepressant drugs or functional foods. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0019] Figure 1 To investigate the effect of different concentrations of corticosterone at different induction times on the survival rate of PC12 cells; Figure 2 To investigate the effects of different concentrations of aqueous extracts of cored lotus seeds on corticosterone-induced survival of PC12 cells; Figure 3 To investigate the effects of different concentrations of core-free lotus seed alcohol extract on corticosterone-induced PC12 cell survival rate; Figure 4 Effects of lotus seed extract (without core) on liver, kidney, and spleen indices in CUMS mice; Figure 5 HE staining morphology of liver, kidney, and spleen tissues from mice in the blank control and high-dose groups; Figure 6 The effect of lotus seed water extract (with core removed) on body weight in CUMS mice; Figure 7 The effect of lotus seed extract (with core removed) on sucrose preference rate in CUMS mice; Figure 8 The effect of the aqueous extract of decored lotus seeds on open field behavior in CUMS mice; Figure 9 The open field test trajectory diagram of CUM mice after intervention with lotus seed water extract (with core removed); Figure 10 The effect of lotus seed water extract (with core removed) on the behavior of CUMS mice in the elevated cruciate maze; Figure 11 The trajectory of CUMS mice in the elevated cross maze after intervention with lotus seed water extract (with core removed); Figure 12 The effect of aqueous extract of core-free lotus seeds on the content of 5-HT, DA, and NE in the hippocampus of CUMS mice; Figure 13 The effect of lotus seed extract (without core) on the plasma levels of 5-HT, DA, and NE in CUMS mice; Figure 14The effect of lotus seed water extract (without core) on plasma DAO content in CUMS mice; Figure 15 The effect of the aqueous extract of lotus seeds (without the core) on the expression of ZO-1, Occludin, and MUC2 mRNA in the ileum tissue of CUMS mice; Figure 16 The effect of lotus seed extract (without core) on plasma TNF-α and IL-10 levels in CUMS mice. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this invention, it should be understood that "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] The present invention will now be further illustrated with specific examples. The following embodiments are only for explaining the present invention and do not constitute a limitation thereof. The test samples and test procedures used in the following embodiments include the following: If the specific experimental conditions are not specified in the embodiments, they are generally performed according to conventional conditions or the conditions recommended by the reagent company; unless otherwise specified, the reagents, consumables, etc. used in the following embodiments can be obtained commercially.

[0023] The first aspect of this invention is to protect a method for preparing a water extract of de-cored lotus seeds, comprising the following steps: (1) Raw material pretreatment: Select lotus seeds with the core removed, dry them at 40℃, pulverize them, and sieve them to obtain dry powder; (2) Water extraction: Add pure water at a solid-liquid ratio of 1:25, reflux at 90℃ twice for 120 min each time, and filter the liquid after each reflux and combine the extracts with a crude drug concentration of 1.0 g / ml. (3) Concentration and drying: The extract was concentrated by rotary evaporation at 60℃, freeze-dried to powder, and stored in a sealed container at -80℃.

[0024] In this invention, the cored lotus seeds used are space lotus from Honghu Lake in Hubei Province.

[0025] The second objective of this invention is to protect the aqueous extract of lotus seeds obtained by the above method, the main active ingredients of which are: gallocatechin, isobergamotin, isoharonin, and 4-chromone, and the percentages of gallocatechin ≥ 0.12%, isobergamotin ≥ 0.41%, isoharonin ≥ 0.52%, and 4-chromone ≥ 0.47%.

[0026] The third objective of this invention is to protect the application of the above-mentioned decored lotus seed aqueous extract in the preparation of antidepressant drugs or functional foods. The functional foods include any one of solid beverages, meal replacement powders, functional beverages, and tea products.

[0027] <Example 1> A method for preparing water extract of lotus seeds with core removed (1) Raw material pretreatment: Select lotus seeds with the core removed, dry them at 40℃, pulverize them, and sieve them to obtain dry powder; (2) Water extraction: Add pure water at a solid-liquid ratio of 1:25, reflux at 90℃ twice for 120 min each time, and combine the extracts after each reflux by filtration to obtain 1.0 g / ml extracts; (3) Concentration and drying: The extract was concentrated by rotary evaporation at 60℃ and freeze-dried to powder to obtain the water extract of lotus seeds with core removed.

[0028] <Comparative Example 1> (1) Raw material pretreatment: Select lotus seeds with the core removed, dry them at 40℃, pulverize them, and sieve them to obtain dry powder; (2) Alcohol extraction: Add 80% ethanol at a solid-liquid ratio of 1:25, and extract with ultrasonication at 70W for 45 min to obtain an extract of 1.0 g / ml; (3) Concentration and drying: The extract was concentrated by rotary evaporation at 60℃ and freeze-dried to powder to obtain the core-free lotus seed alcohol extract.

[0029] The antagonistic effects of the aqueous and ethanolic extracts of lotus seeds (without the core) on corticosterone-induced damage to the viability of PC12 cells were analyzed. It should be noted that the corticosterone used in the following experimental examples was purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0030] PC12 cells were cultured routinely at 37°C and 5% CO2, with the first medium change performed 24 hours later. When cell confluence reached 80%-90% (approximately 48 hours of culture), the cells were washed twice with PBS, digested with 0.25% trypsin until detached, and immediately 2 ml of culture medium was added to terminate the reaction. The suspension was collected, centrifuged at 1000 rpm for 5 minutes, resuspended in fresh culture medium, aliquoted into new culture flasks at a 1:2 ratio, and brought to a final volume of 5 ml. The cells were then dispersed using a cross-linking method and cultured at an insulated temperature.

[0031] Accurately weigh 10 mg of corticosterone standard and dissolve it in 2.8863 ml of dimethyl sulfoxide (DMSO) to prepare a stock solution with a concentration of 10 mmol / L. After counting cells in the logarithmic growth phase, prepare cells at a density of 5 × 10⁻⁶. 4Cell suspensions of 100 μl / well were seeded into 96-well plates at a concentration of 1 / ml, with the outer wells buffered with PBS. After 24 hours of adherent culture, the culture medium was changed. The control group used complete culture medium (RPMI-1640 basal medium supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin (P / S), ready for cell culture). The experimental group used complete culture medium containing different concentrations of corticosterone (DMSO solvent, pH 7.4). Seven concentration gradients (25, 50, 100, 200, 400, 600, 1000 µmol / L) were set up, with five replicates for each concentration. The culture plates were placed in a constant temperature incubator (37℃, 5% CO2) for continuous culture. Cell viability was measured and calculated at three time points (8h, 12h, 24h), and the results are shown below. Figure 1-2 As shown.

[0032] like Figure 1 As shown, after 24 h of induction, the survival rates of PC12 cells at corticosterone concentrations of 50, 100, 200, 400, 600, and 1000 μmol / L were 78.00±4.47%, 67.91±11.34%, 49.16±5.87%, 15.12±2.38%, 10.91±1.86%, and 2.32±1.58%, respectively. The results indicate that the survival rate of PC12 cells gradually decreases with increasing corticosterone concentration in a dose-dependent manner. Furthermore, the cell survival rate is closest to 50% when the corticosterone concentration is 200 μmol / L and the induction time is 24 h, which is more suitable for subsequent experiments.

[0033] like Figure 2 As shown, the results of the water extract indicate that the water extract of lotus seeds (without the core) significantly increased the cell survival rate of the PC12 cell injury model at certain drug concentrations, and this increase was dose-dependent. In some concentrations, the cell survival rate even reached or exceeded that of the control group. Furthermore, it can be basically determined that the water extract of lotus seed coat has no significant cell-protective effect. Figure 3 As shown, the results of the ethanol extract indicated that certain concentrations of the core-removed lotus seed ethanol extract (400, 600, and 800 mg / L) had a certain effect on promoting PC12 cell survival, but there was no significant difference compared with the model group. To ensure the rigor of the experiment and the smooth progress of subsequent experiments, the aqueous extract with better effects was further replicated three times, and a certain concentration of core-removed lotus seed aqueous extract was screened to show good and stable protective effect against corticosterone-induced PC12 cell damage model.

[0034] The following experiments used 50 male SPF-grade C57BL / 6 mice, aged 6-8 weeks, purchased from the Hubei Provincial Center for Disease Control and Prevention. Husbandry conditions: Indoor temperature maintained at 20-25℃; indoor humidity maintained at 40-70%; except for the needs of experimental modeling, the experimental animals had free access to food and drinking water.

[0035] Fifty SPF-grade C57BL / 6 mice were randomly divided into five groups: a control group (CON), a model group (Model), a positive control group (Y), a high-dose group (H), and a low-dose group (L), with ten mice in each group. The positive control group received fluoxetine hydrochloride at a dose of 10 mg / kg; the high-dose group received lotus seed extract (without core) at a dose of 1560 mg / kg; and the low-dose group received lotus seed extract (without core) at a dose of 780 mg / kg.

[0036] Model establishment and drug administration: Except for the control group, mice in the other four groups were subjected to stress treatment to establish the model. The model establishment period was 4 weeks. The stressors used included: fasting for 24 hours, water deprivation for 24 hours, damp bedding for 24 hours, a 45-degree inclined cage for 24 hours, swimming in 6℃ cold water for 5 minutes, foot electric shock (0.5mA, frequency 0.5s), restraint for 2 hours, and reversed day and night lighting. One type of stimulus was randomly selected each day, and the specific arrangement is shown in Table 1.

[0037] Table 1

[0038] Design behavioral evaluation criteria, including the following: (1) Open field experiment A cubic behavioral observation box (60×60×50cm inner diameter) made of polyvinyl chloride (PVC) was used. The box surface had a matte finish, and the bottom was equipped with a 16-grid coordinate system. The outer 12 grids were defined as the edge area (a buffer zone 7.5cm from the box wall), and the central 4 grids constituted the core area (30×30cm). The observation area division was automatically calibrated by Shanghai Xinruan. After acclimatization training, the experimental animals were gently placed in the geometric center area of ​​the observation box. The infrared camera system was activated to perform continuous digital behavioral tracking for 5 minutes, simultaneously recording the three-dimensional movement trajectory. After each animal completed the test, the observation box was immediately thoroughly disinfected with 75% ethanol solution and left to stand for 15 minutes to remove volatile substances.

[0039] (2) Elevated cross maze experiment The four-armed maze apparatus consists of two opposing closed arms (75cm × 7.5cm × 10cm, with three light-blocking plates) and open arms (only the base plate of the same size is retained), with a central connecting area of ​​a 7.5 × 7.5cm² square platform. The entire apparatus is erected at a height of 60cm above the ground, with an infrared motion capture grid installed in the open arm area. The experimental environment maintains uniform lighting and constant temperature conditions. After dark adaptation, the experimental animals are gently placed in the central platform area (head facing the axis of the open arms). Continuous behavioral recording is performed for 5 minutes using Shanghai XinXin software, simultaneously acquiring three-dimensional motion trajectory data. During the interval between tests for each animal, the maze surface is disinfected with a 75% ethanol solution and left to stand for 15 minutes to remove volatile substances.

[0040] The effects of lotus seed extract (without core) on visceral toxicity, neurotransmitters, intestinal permeability, and inflammatory factors in CUMS mice were tested on days 0, 7, 14, 21, and 28 after administration to rats in each group. It should be noted that the test methods for the following test indicators in this invention are all existing technologies.

[0041] The effects of the core-removed lotus seed water extract on the visceral toxicity of CUMS mice were analyzed, and the results are as follows: Figure 4 As shown in the figure. The results showed no significant differences in organ indices among the groups, indicating that CUMS modeling does not cause significant organ damage in mice, and that the aqueous extract of lotus seeds (without the core) has no significant visceral toxicity in mice. Figure 5 As shown, HE staining was performed on the liver, kidney, and spleen tissues of mice in the blank group and the high-dose group. Pathological tissue analysis showed that there was basically no significant difference between the tissues of the high-dose group and the blank group, further demonstrating the safety of the lotus seed water extract without core.

[0042] The weight of mice in each group was monitored weekly, such as Figure 6 The results showed that two weeks after CUMS modeling, the body weight of mice in the model group was significantly lower than that in the control group, and the difference in body weight gradually increased in the third and fourth weeks. Compared with the model group, the body weight of the positive drug group and the group treated with lotus seed extract was significantly higher, indicating that lotus seed extract can alleviate the slow weight gain of CUMS mice and its effect is close to that of the positive drug.

[0043] Analysis of the effects of lotus seed extract (without core) on sucrose preference in mice, such as... Figure 7 The results showed that compared with the blank group (80.88±1.336%), the sugar water preference rate of mice in the model group (68.39±2.579%) was significantly reduced; compared with the model group, the sugar water preference rate of mice in the positive drug group (82.93±3.993%), the high-dose drug group (81.79±6.599%), and the low-dose drug group (91.24±1.807%) was significantly increased, indicating that administration of lotus seed water extract can significantly improve the preference of CUMS mice for sweet substances.

[0044] Analyze the effect of the aqueous extract of lotus seeds (without the core) on the results of the mouse open field test, such as... Figure 8-9 The results showed that compared with the blank group (5174±786.1mm, 3.743±1.344s, 52.80±6.834), the model group (3643±391.7mm, 0.7433±0.8500s, 36.00±4.528) mice had significantly reduced total movement distance, time spent in the middle area, and total number of squares crossed; compared with the model group, the positive drug group (5977±372.3mm, 4.023±0.8307s, 5... The total distance traveled, time spent in the intermediate area, and total number of squares crossed by mice were significantly increased in the high-dose group (5632±1164 mm, 3.294±1.033 s, 58.17±12.35). Although there was no significant difference in these three indicators in the low-dose group (4996±905.2 mm, 2.885±0.8278 s, 50.14±9.856), they were also increased.

[0045] Analyze the effect of the aqueous extract of lotus seeds (without the core) on the results of the elevated cruciate maze test in mice, such as... Figure 10-11 The results showed that, compared with the blank group (13.19±1.878%, 17.91±6.147%), the proportion of time spent in the open arm and the proportion of the number of times mice entered the open arm to the sum of the number of times they entered the open arm and the closed arm were significantly reduced in the model group (7.233±1.417%, 3.016±5.160%) (p<0.05, p<0.001). Compared with the model group, the positive drug group (12.63±3.026%, 15.88±1.374%), the high-dose drug group (13.24±3.082%, 16.19±3.297%), and the low-dose drug group (19.55±4.355%, 17.53±5.642%) mice showed significantly increased values ​​for both indicators.

[0046] Analysis of the effects of lotus seed water extract (without core) on neurotransmitters in mice, such as Figure 12The results showed that, in the hippocampus, compared with the blank control group (337.7±8.820 ng / mL, 1378±48.28 ng / mL, 1090±18.08 ng / mL), the levels of 5-HT, DA, and NE in mice in the model group (251.0±19.76 ng / mL, 1078±16.61 ng / mL, 929.8±17.29 ng / mL) were significantly lower; compared with the model group, the levels in the positive control group (342.8±35.45 ng / mL, 1322±149.5 ng / mL) were significantly lower. The levels of 5-HT, DA, and NE in mice were significantly increased in the high-dose group (1116±64.28 ng / mL, 343.4±23.56 ng / mL, 1230±98.94 ng / mL, 1207±49.28 ng / mL, 357.3±24.45 ng / mL, 1262±45.40 ng / mL, 1084±104.8 ng / mL, 1116±64.28 ng / mL, 1230±98.94 ng / mL, 1207±49.28 ng / mL, 1207±49.28 ng / mL, 1262±45.40 ng / mL, 1084±104.8 ng / mL, 1230±98.94 ng / mL, 1207±49.2 ...

[0047] like Figure 13 As shown, in plasma, compared with the blank group (692.5±58.28 ng / mL, 1283±115.6 ng / mL, 942.8±38.78 ng / mL), the levels of 5-HT, DA, and NE in mice in the model group (592.9±21.53 ng / mL, 1134±52.51 ng / mL, 875.7±25.01 ng / mL) were significantly reduced. Compared with the model group, the levels of 5-HT, DA, and NE in mice in the positive control group (722.4±38.68 ng / mL, 1307±86.68 ng / mL, 929.3±82.41 ng / mL) and the high-dose administration group (660.2±42.16 ng / mL, 1272±85.91 ng / mL, 1008±44.28 ng / mL) were significantly reduced. The levels of 5-HT, DA, and NE in mice were significantly increased in the low-dose groups (1367±90.69 ng / mL and 977.4±42.01 ng / mL), with significantly increased levels of DA and NE. This indicates that CUMS modeling significantly reduces the levels of neurotransmitters in the hippocampus and plasma of mice, and administration of the lotus seed extract (without the core) can significantly reverse this phenomenon.

[0048] Analysis of the effects of lotus seed extract (without core) on diamine oxidase (DAO) levels in mouse plasma and ileum tissue. ZO-1, Occludin and MUC2 The effect on gene expression was investigated, and the influence of the core-removed lotus seed water extract on intestinal permeability in mice was further evaluated. Figure 14As shown, compared with the blank group (4.386±0.5780ng / mL), the DAO content in the plasma of mice in the model group (6.072±0.1279ng / mL) was significantly increased; compared with the model group, the DAO content in the plasma of mice in the positive drug group (4.903±0.2108ng / mL) and the low-dose drug group (4.975±0.5914ng / mL) was significantly decreased, indicating that CUMS modeling damages the integrity of the intestinal mechanical barrier in mice, and that administration of lotus seed water extract can alleviate this phenomenon.

[0049] like Figure 15 As shown, compared with the blank group, the ileum tissue of the model group mice... ZO-1, Occludin and MUC2 Gene expression was significantly downregulated in both the positive control group and the high-dose administration group; compared with the model group, the expression of ileum tissue in mice was significantly downregulated. ZO-1 , Occludin and MUC2 Gene expression was significantly upregulated in the ileum tissue of mice in the low-dose administration group. ZO-1 and Occludin Gene expression was significantly upregulated, indicating that CUMS modeling damages the integrity of the intestinal mucosal barrier in mice, and administration of lotus seed water extract after core removal can alleviate this phenomenon.

[0050] The effects of the aqueous extract of lotus seeds (without the core) on inflammatory factors such as tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in mouse plasma were analyzed. Figure 16 As shown, compared with the blank group (524.2±51.45 pg / mL), the plasma TNF-α level in the model group (678.5±36.62 pg / mL) was significantly increased; compared with the model group, the plasma TNF-α level in the positive control group (513.1±20.09 pg / mL), high-dose group (522.5±40.14 pg / mL), and low-dose group (553.2±34.23 pg / mL) was significantly decreased. Compared with the blank group (28.03±4.177 pg / mL), the plasma IL-10 level in the model group (23.90±1.448 pg / mL) was significantly decreased; compared with the model group, the plasma IL-10 level in the positive control group (27.03±1.276 pg / mL) and high-dose group (27.84±1.753 pg / mL) was significantly increased. The results indicate that CUMS modeling significantly increases the level of pro-inflammatory factor TNF-α and significantly decreases the level of anti-inflammatory factor IL-10 in mouse plasma, and administration of lotus seed water extract (without core) can significantly reverse this phenomenon.

[0051] In summary, the aqueous extract of lotus seeds with the core removed has an antidepressant mechanism based on the gut-brain axis, and its antidepressant effect is significant.

[0052] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments and equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. A method for preparing a water extract of lotus seeds with the core removed, characterized in that, Includes the following steps: (1) Raw material pretreatment: Select lotus seeds with the core removed, and after drying, crushing and sieving, dry powder is obtained; (2) Water extraction: After the dried powder is uniformly dissolved in the solvent, the solution is refluxed multiple times. After each reflux, the liquid is filtered and combined to obtain an extract with a crude drug concentration of 1.0 g / ml. (3) Post-processing: The extract was concentrated by rotary evaporation and freeze-dried to powder to obtain the water extract of lotus seeds with core removed.

2. The method for preparing the water extract of de-cored lotus seeds as described in claim 1, characterized in that, In step (1), the drying temperature is 40°C.

3. The method for preparing the water extract of de-cored lotus seeds as described in claim 1, characterized in that, In step (2), the ratio of dry powder to solvent is 1:25, based on the solid-liquid ratio. The solvent is pure water; The reflux was performed twice, with a reflux temperature of 90°C and a reflux time of 120 min for each reflux.

4. The method for preparing the water extract of de-cored lotus seeds as described in claim 1, characterized in that, In step (3), the temperature condition for rotary evaporation concentration is 60°C.

5. The decored lotus seed water extract prepared by the method according to any one of claims 1-4.

6. The lotus seed water extract with core removed as described in claim 5, characterized in that, Based on the dry matter content of the water extract of lotus seeds without cores, the water extract of lotus seeds without cores contains ≥0.12% gallocatechin, ≥0.41% isobergamotinoin, ≥0.52% isocarboxylic acid, and ≥0.47% 4-chromone.

7. The application of the lotus seed water extract with core removed as described in claim 5 or 6 in antidepressant effects.

8. The application as described in claim 7, characterized in that, The de-cored lotus seed water extract exerts its antidepressant effect by modulating the gut-brain axis in any of the following ways: 1) Regulates gut microbiota; 2) Repair the intestinal barrier; 3) Inhibits neuroinflammation; 4) Activate the hippocampal BDNF-mTOR pathway; 5) Upregulates the levels of 5-HT, DA, and NE neurotransmitters.

9. The use of the lotus seed water extract with core removed as described in claim 5 or 6 in the preparation of antidepressant drugs or functional foods.

10. The application as described in claim 9, characterized in that, The functional foods include any one of solid beverages, meal replacement powders, functional beverages, and tea products.

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