Centella asiatica filtrate, preparation method and application thereof

Abstract

The present invention belongs to the field of plant extraction, particularly to the field of C07J63 / 00, and more specifically to a Centella asiatica filtrate, its preparation method, and application. The preparation method of the Centella asiatica filtrate comprises the steps of pulverization, pure water spraying, cyclic extraction, constant temperature ripening cyclic extraction, filtration, and the like. The preparation method provided by the present invention is simple and low in cost. The resulting Centella asiatica filtrate has a high mineral content and a low residual heavy metal ion content, is highly safe, and can be well applied in the cosmetics field. It has the effects of reducing the expression of inflammatory factors, repairing cell damage, alleviating transepidermal water loss and increased erythema caused by external stimuli, and repairing the skin barrier.

Description

Technical Field

[0001] The present invention belongs to the field of plant extraction, in particular to the field of C07J63 / 00, and more specifically to a Centella asiatica filtrate and a preparation method and application thereof. Background Art

[0002] Bioretention / BioPorosity is the artificial use of sustainable organic matter such as fallen leaves and branches. This is shallowly buried underground to form a micro-fermented, mature fertilizer, which is then reused by plants. This promotes the expansion and growth of plant roots, significantly enhances rainwater absorption, and slows soil erosion. However, there are no studies on the extraction and maturation of bioporosity exudates from natural plants, nor on the application of active ingredients in cosmetics.

[0003] Centella asiatica (L.) Urban, a species of Centella asiatica in the genus Centella of the family Apiaceae, is the dried whole herb. Because its leaves resemble horseshoes or half a copper coin, it is also known as horseshoe grass, coin-shaped grass, and is also known locally as mint and liverwort. Centella asiatica is widely distributed in the area south of the Yangtze River in my country. It is cold in nature, bitter, and pungent in flavor, and has the effects of clearing heat and dampness, detoxifying, and reducing swelling. It is used to treat damp-heat jaundice, heatstroke-induced diarrhea, carbuncles, sores, and traumatic injuries. Modern research indicates that the main active ingredients of Centella asiatica are triterpenoid saponins (asiaticoside, madecassoside), triterpenoid acids (such as asiatic acid and madecassic acid), polyacetylenes, volatile oils, flavonoids, alkaloids, and amino acids. It is also rich in essential trace elements such as Mn, Fe, Cu, Zn, Sr, Co, and Cr. At present, the extraction and application of Centella asiatica in China are mostly focused on Centella asiatica saponins. The preparation method is to extract with high-concentration ethanol, and then enrich and purify it with organic solvents such as macroporous resin or n-butanol. There are problems such as the medicinal materials cannot be fully extracted, the extraction method is costly or easy to pollute the environment. Traditional Chinese medicine contains many types of active ingredients, which often correspond to different targets. The synergistic combination of various ingredients plays an indispensable role in the overall efficacy. However, the effect of a single active ingredient in traditional Chinese medicine is relatively weak. In addition, the purpose of the extraction process of traditional Chinese medicine is to obtain a single medicinal ingredient. There are effective medicinal ingredients that have not been completely extracted in the residue after the extraction of the medicinal ingredients, which is bound to cause a waste of medicinal resources.

[0004] Prior art is that patent CN106380504B discloses a method for extracting madecassoside from Centella asiatica. The extraction method mainly includes the steps of alcohol extraction, rare earth salt mixing, chromatography, and drying. The obtained madecassoside has a high yield and purity. Prior art is that patent CN107903296B discloses a method for extracting madecassoside. The main extraction steps include water reflux extraction, acid elution, macroporous resin alcohol washing, thin layer chromatography, etc., which also has the characteristics of high purity and yield. However, the above extraction method does not effectively remove heavy metal substances accumulated in Centella asiatica and some pesticide residues on the surface. At the same time, the alcohol extraction method may bring out some by-products containing fat-soluble components, which is not conducive to the subsequent application of Centella asiatica extract in the cosmetics field. Therefore, it is necessary to provide a new Centella asiatica filtrate and its preparation method and application. Summary of the Invention

[0005] In order to solve the above problems, the first aspect of the present invention provides a method for preparing Centella asiatica filtrate, comprising at least the following steps:

[0006] S1. After drying, the Centella asiatica is crushed, and then filtered through filters of different mesh sizes to obtain Centella asiatica powder of different mesh sizes;

[0007] S2. Place the Centella asiatica powder of different mesh sizes prepared in step S1 into a funnel-shaped filter, and fill the outside of the filter with ore;

[0008] S3. Spraying the top layer of Centella asiatica powder with pure water, and then letting water flow through the Centella asiatica powder layers of different mesh sizes in sequence under the action of gravity to obtain a Centella asiatica extract;

[0009] S4, spraying the obtained Centella asiatica extract onto the Centella asiatica powder again, performing cyclic extraction, and obtaining a Centella asiatica cyclic extraction extract;

[0010] S5, mixing the Centella asiatica cyclic extraction extract and the Centella asiatica powder after cyclic extraction, then heating, performing a constant temperature ripening cyclic extraction operation, and collecting to obtain a Centella asiatica filtrate semi-finished product;

[0011] S6. Filter the semi-finished Centella asiatica filtrate using a membrane, and then mix it with alcohol to obtain the Centella asiatica filtrate.

[0012] Preferably, the mesh size of the Centella asiatica powder in step S1 is 20-400; as an practicable case, the mesh size of the Centella asiatica powder may include at least two of 20, 40, 80, 100, 120, 150, 200, 250, 300 or 400.

[0013] Further preferably, the mesh size of the Centella asiatica powder in step S1 includes at least 20, 80, 100 and 200.

[0014] Preferably, the mass ratio of the Centella asiatica powder of 20 mesh, 80 mesh, 100 mesh and 200 mesh in step S2 is (1-5): (1-5): (1-3): (1-3); as an implementable case, the mass ratio of the Centella asiatica powder of 20 mesh, 80 mesh, 100 mesh and 200 mesh can include one of 1:1:1:1, 2:2:1:1, 3:3:1:1, 5:5:1:1 or 5:5:3:3.

[0015] Further preferably, the mass ratio of the 20-mesh, 80-mesh, 100-mesh and 200-mesh Centella asiatica powders is 2:2:1:1.

[0016] Preferably, in the step S2, the stacking order of the Centella asiatica powders of different mesh sizes is from top to bottom in space and from low to high mesh sizes.

[0017] Preferably, the ore includes one of diatomite, expanded perlite, expanded vermiculite, medical stone, zeolite, bentonite, attapulgite, sepiolite and rectorite.

[0018] Further preferably, the ore at least includes medical stone.

[0019] Preferably, the mass ratio of pure water and Centella asiatica powder in the S3 step is (80-200):1; as an implementable case, the mass ratio of pure water and Centella asiatica powder in the S3 step includes one of 80:1, 100:1, 120:1, 150:1 or 200:1.

[0020] Further preferably, the mass ratio of the pure water to the Centella asiatica powder is 100:1.

[0021] Preferably, the spraying rate of pure water in the S3 step is 20-50 mL / s; as an implementable case, the spraying rate of pure water includes one of 20 mL / s, 30 mL / s, 40 mL / s or 50 mL / s.

[0022] Further preferably, the spraying speed of the pure water is 30 mL / s.

[0023] Preferably, the cyclic extraction time in step S4 is 2-5 hours; as an implementable case, the cyclic extraction time may include one of 2 hours, 3 hours, 4 hours or 5 hours.

[0024] Further preferably, the cyclic extraction time is 3 hours.

[0025] Preferably, the heating temperature in the S5 step is 40-60°C; as an implementable case, the heating temperature includes one of 40°C, 45°C, 50°C, 55°C or 60°C.

[0026] More preferably, the heating temperature in step S5 is 50°C.

[0027] Preferably, the constant temperature aging cycle extraction operation time in the S5 step is 4-12 hours; as a feasible case, the constant temperature aging cycle extraction operation time can include 4 hours, 6 hours, 8 hours, 10 hours or 12 hours.

[0028] Further preferably, the constant temperature aging cycle extraction operation time is 6 hours.

[0029] Preferably, the mass concentration of the alcohol is 1-5%. As an implementable case, the mass concentration of the alcohol may include one of 1%, 2%, 3%, 4% or 5%.

[0030] More preferably, the mass concentration of the alcohol is 2%.

[0031] Preferably, the alcohol in step S6 includes one of ethanol, ethylene glycol, 1,2-propylene glycol, isopropyl alcohol, diethylene glycol, glycerol, 1,3-butanediol, and 1,2-hexanediol.

[0032] More preferably, the alcohol includes 1,2-hexanediol.

[0033] The present invention adopts a multi-level nested nesting doll-like extraction process, that is, Centella asiatica is first crushed and then sieved through filter screens of different mesh sizes to obtain Centella asiatica powders of different mesh sizes. The different degrees of crushing of Centella asiatica powder can have a significant impact on the subsequent extraction rate and component types of active ingredients. The inventors have found that when the Centella asiatica powder is sieved using filter screens of 20, 80, 100, and 200 meshes, not only can madecassoside, the main component of Centella asiatica, be extracted to the greatest extent in the subsequent extraction, but impurities such as quercetin and kaempferol can also be removed, ensuring that the Centella asiatica filtrate has a high effective purity. Centella asiatica powders of different mesh sizes are stacked sequentially from top to bottom in descending particle size, followed by cyclic extraction. This not only allows madecassoside to be dissolved in a gradient concentration manner under the action of gravity, but also ensures that the entire stacked layer has a certain structural stability, ensuring that the solvent in the cyclic extraction process can more saturately dissolve the effective components of Centella asiatica. Although water extraction has a certain impact on the purity and yield of madecassoside compared to alcohol extraction, the intermolecular forces between water and madecassoside can still achieve a high purity and extraction rate. In addition, water extraction can avoid the dissolution of some fat-soluble impurities in Centella asiatica. In the conventional extraction process of Centella asiatica extract, some heavy metal ions and trace pesticides on the surface of Centella asiatica are often extracted, which may produce certain toxicity in subsequent use, seriously affecting the use effect. The inventors use a specific mineral medical stone for filling outside the filter. Minerals are important factors influencing enzyme activity in skin metabolism. Minerals and trace elements added to cosmetics combine with proteins and other organic groups to form biomacromolecules such as enzymes, hormones, and vitamins, effectively acting as catalysts to aid skin repair. Medical stone, a natural silicate medicinal mineral, can absorb harmful components such as heavy metal ions and pesticide residues accumulated during the cultivation and growth of traditional Chinese medicines. It can also absorb harmful bacteria during the processing and transportation of traditional Chinese medicines and provide a wide range of trace elements. Applicants have discovered that filtering medical stone during the extraction and maturation of Centella asiatica can mitigate the cytotoxicity of the extract and enhance the soothing effect of the Centella asiatica filtrate in cosmetics. In order to further improve the extraction effect of hydroxymadecassoside, the inventors carried out a constant-temperature ripening circular extraction operation after the cyclic extraction of Centella asiatica powder. The constant-temperature ripening circular extraction operation refers to the macromolecular substances such as carbohydrates, fats, proteins carried by Centella asiatica itself, under the action of microorganisms carried on the surface of Centella asiatica or in the air and the enzymes after the plant itself is broken, so that the tough plant cell walls and cell membranes are broken, releasing the active ingredients inside the cells, which is more conducive to the conversion and fermentation of the active substance hydroxymadecassoside. On this basis, the constant-temperature ripening extract collected by gravity is sprayed onto the Centella asiatica powder again for cyclic extraction. The obtained Centella asiatica filtrate can be used in cosmetics in the later stage to better exert the product efficacy.

[0034] A second aspect of this embodiment provides a Centella asiatica filtrate.

[0035] A third aspect of this embodiment provides an application of Centella asiatica filtrate, wherein the Centella asiatica filtrate is applied in the field of cosmetics.

[0036] Beneficial effects

[0037] (1) In the present invention, water is selected as the extraction solvent for the Centella asiatica filtrate instead of an organic alcohol solvent, so that various types of components such as polysaccharides, alkaloids, and amino acids can be obtained while extracting Centella asiatica saponins from Centella asiatica, while reducing the fat-soluble component by-products extracted by alcohol organic solvents. In addition, instead of using high-concentration alcohol, water with a wide source, non-toxicity, and low cost is used for extraction, which has the advantages of saving raw materials, reducing costs, and having no environmental pollution, and is conducive to the quantitative production of Centella asiatica filtrate.

[0038] (2) The present invention uses Centella asiatica powder of different particle sizes for extraction. In addition, the multi-level nested cyclic extraction process is also conducive to the continuous precipitation of active substances, maximizing the extraction rate of active ingredients and extracting different types of components.

[0039] (3) The medical stone used in the present invention as a filter material can absorb heavy metal ions and harmful microorganisms that may be brought into the snow grassland material, and at the same time upgrade the product into an active water product rich in mineral components, which has better safety and can be used in cosmetics to better help skin repair.

[0040] (4) The present invention realizes the self-microbial fermentation of Centella asiatica through the constant temperature ripening cycle extraction operation, which can increase the conversion of active ingredients in Centella asiatica, improve the extraction rate of active ingredients, and improve the soothing effect of the product when applied in cosmetics.

[0041] (5) The Centella asiatica filtrate prepared by the present invention has the effect of reducing the expression of inflammatory factors, repairing cell damage, alleviating transepidermal water loss and increased erythema caused by external stimuli, and repairing the skin barrier. It can be used as a soothing raw material in cosmetics. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the result of the cell scratch healing rate in the HaCaT cell migration test.

[0043] Figure 2 This is a trend chart of ΔTEWL changes in the irritating clinical repair test.

[0044] Figure 3 This is a graph showing the changing trend of ΔErythema in the irritation clinical repair test. DETAILED DESCRIPTION

[0045] Example 1

[0046] A first aspect of this embodiment provides a method for preparing Centella asiatica filtrate, which specifically comprises the following steps:

[0047] S1. After drying, the Centella asiatica is crushed, and then passed through 20-mesh, 80-mesh, 100-mesh, and 200-mesh sieves to obtain Centella asiatica powder of different mesh sizes;

[0048] S2. Place the Centella asiatica powder obtained in step S1 in a funnel-shaped filter with a mass ratio of 20 mesh, 80 mesh, 100 mesh, and 200 mesh from top to bottom in the order of 20 mesh, 80 mesh, 100 mesh, and 200 mesh, and fill the outside of the filter with ore;

[0049] S3, using pure water with a mass ratio of 100:1 to Centella asiatica powder, spraying the top layer of Centella asiatica powder at a spraying rate of 30 mL / s, and then letting the water flow through the Centella asiatica powder layers of different mesh sizes in sequence under the action of gravity to obtain the Centella asiatica extract;

[0050] S4, spraying the obtained Centella asiatica extract onto the Centella asiatica powder again, and performing cyclic extraction for 3 hours to obtain a Centella asiatica cyclic extraction extract;

[0051] S5, mixing the Centella asiatica cyclic extraction extract and the Centella asiatica powder after cyclic extraction, then heating to 50° C., performing a constant temperature aging cyclic extraction operation for 6 hours, and collecting to obtain a Centella asiatica filtrate semi-finished product;

[0052] S6. Filter the Centella asiatica filtrate using a semi-finished membrane, and then compound it with 1,2-hexanediol having a mass concentration of 2% to obtain the Centella asiatica filtrate.

[0053] In a second aspect, this embodiment provides a Centella asiatica filtrate.

[0054] A third aspect of this embodiment provides an application of Centella asiatica filtrate in the field of cosmetics.

[0055] Comparative Example 1

[0056] The implementation method of this comparative example is that 20 mesh, 80 mesh, 100 mesh, and 200 mesh Centella asiatica powder are in a mass ratio of 2:2:1:1, and the mass ratio of water to Centella asiatica powder is 100:1. The overhead stirrer is 550 rpm, and after extraction at room temperature for 3 hours, the temperature is raised to 50°C, 550 rpm, and extraction is carried out for 6 hours. After collection and filtration, the mixture is compounded with 2% 1,2-hexanediol.

[0057] Comparative Example 2

[0058] The specific implementation of this comparative example is the same as that of Example 1, except that: in the step S1, only an 80-mesh filter is used for filtration and screening, and the filling amount of Centella asiatica powder in the step S2 is the same as that in Example 1.

[0059] Comparative Example 3

[0060] The specific implementation of this comparative example is the same as that of Example 1, except that medical stone is not included outside the filter screen in the S2 step.

[0061] Comparative Example 4

[0062] The specific implementation of this comparative example is the same as that of Example 1, except that the S5 step does not include a constant temperature aging cycle extraction operation.

[0063] Performance evaluation

[0064] 1. Physical performance test

[0065] 1. Dry weight determination

[0066] The dry weight content of the Centella asiatica filtrates obtained in Example 1 and Comparative Examples 1-4 was measured using a moisture meter (Ohaus, MB120). The meter's lid was opened, an empty sample pan was placed on the sample pan handle, the lid was closed, and the meter was tared. The lid was opened again, and 1.0 g of sample from Example or Comparative Examples 1-4 was added. The lid was closed, and the moisture meter began automatic drying and measurement. After the test, the dry weight content (%MC) was recorded.

[0067] Test results:

[0068] Table 1 Dry weight content test results

[0069] name Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Dry weight content 0.37％ 0.12％ 0.18％ 0.39％ 0.23％

[0070] 2. Determination of Madecassoside Content

[0071] The content of madecassoside in the Centella asiatica filtrate was quantitatively determined by high performance liquid chromatography (Agilent 1260 Infinity II).

[0072] (1) Chromatographic conditions

[0073] Mobile phase: Mobile phase A, water; Mobile phase B, acetonitrile;

[0074] Chromatographic column: Agilent Zorbax SB C18 column (4.6 mm × 150 mm, 3.5 μm);

[0075] Column temperature: 30°C;

[0076] Detection wavelength: 205nm;

[0077] Flow rate: 1.0 mL / min;

[0078] Injection volume: 10 μL;

[0079] Gradient elution program:

[0080] Time (min) 0 5 16 Mobile phase A (%) 80 70 70 Mobile phase B (%) 20 30 30

[0081] (2) Drawing of standard curve

[0082] Accurately weigh 5.0 mg of madecassoside sample and dilute to 10 mL with acetonitrile to prepare a standard sample solution. Accurately pipette aliquots from this standard sample solution and prepare a series of standard working solutions with acetonitrile, each containing 0.05 mg / mL, 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, and 0.5 mg / mL of madecassoside. Pass the solution through a 0.45 μm filter membrane and measure the absorption peak area using the above-described chromatographic conditions. Plot a regression curve between madecassoside concentration and absorption peak area.

[0083] (3) Sample processing

[0084] The filtrate of Centella asiatica was filtered through a 0.45 μm filter membrane, and 10 μL was injected. The content of madecassoside was calculated according to the standard curve.

[0085] Test results:

[0086] Table 2 Madecassoside content test results

[0087] name Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Madecassoside content (μg / mL) 325.8 101.6 193.4 342.1 228.3

[0088] 2. Efficacy Test

[0089] 3. Cytotoxicity test

[0090] RAW264.7 cells were cultured in DMEM medium (containing 10% FBS, 1% double antibody) at 37°C and 5% CO2. Cells in the logarithmic growth phase were taken to prepare a cell suspension at 1.5×10 4 The cells were seeded at a density of 100 μL per well in a 96-well plate. After 24 hours of cell culture, 100 μL of culture medium containing the corresponding concentration of sample was added to each well of the sample group, and 100 μL of cell culture medium was added to the blank control group (CK). After administration, the 96-well plate was placed in an incubator (37°C, 5% CO2) for culture. After 24 hours of incubation, 20 μL of 5 mg / mL MTT solution was added and incubated in an incubator (37°C, 5% CO2) in the dark for 2 hours. The supernatant was discarded, 100 μL of isopropanol was added to each well, and the cells were shaken on a horizontal shaker in the dark for 30 minutes, and the absorbance (OD570) was read at 570 nm.

[0091] Test result processing and analysis: Cell viability = OD570 样品组 / OD570 CK组 ×100%

[0092] Test results:

[0093] Table 3 Cell viability test results

[0094]

[0095] *The concentration mentioned is volume concentration, the same below

[0096] Combining the results in Tables 1-3, it can be seen that, compared with Comparative Example 3, after the Centella asiatica filtrate is treated with medical stone, the dry weight content and madecassoside content of the Centella asiatica filtrate are slightly decreased, but the cytotoxicity is significantly reduced.

[0097] 4. Detection of NO secretion in RAW264.7 cell supernatant

[0098] RAW264.7 cells were cultured in DMEM medium (containing 10% FBS, 1% double antibody) at 37°C and 5% CO2. Cells in the logarithmic growth phase were taken to prepare a cell suspension at 1.5×10 5 Cells were seeded at a density of 100 cells / well in a 24-well plate. After 24 hours of cell culture, the positive drug (dexamethasone, Dex), 30%-90% of Example 1 / Comparative Examples 1-4, and LPS (lipopolysaccharide) were added and treated for 24 hours. The supernatant was collected and centrifuged at 4°C and 12,000 rpm for 3 minutes. NO secretion in the supernatant was determined according to the Griess method kit instructions.

[0099] Test results:

[0100] Table 4 NO generation test results (% of Control)

[0101]

[0102] *Not within the safe concentration range, NO generation test not conducted.

[0103] As shown in Table 4, compared to the blank control group, the NO content in the negative control group (LPS group) increased significantly, demonstrating the effectiveness of the experimental stimulation conditions. Compared to the LPS group, the NO content in the positive control group decreased significantly, demonstrating the effectiveness of the positive control assay. The 30%-90% reduction in NO production in the Centella asiatica filtrate from the Examples demonstrated a more pronounced NO suppression effect than the unripened Centella asiatica filtrate (Comparative Example 4).

[0104] The test results showed that the filtrate of Centella asiatica obtained from Example 1 effectively inhibited the increase in NO production induced by LPS, and the overall effect was better than that of the control example.

[0105] 5. HaCaT cell migration test

[0106] HaCaT cells were cultured in DMEM high glucose medium containing 10% fetal bovine serum and 1% double antibody at 37°C in a constant temperature incubator with 5% CO2. A straight line was drawn on the back of a 24-well plate with a marker pen in advance, crossing the wells. Cells in the logarithmic growth phase were taken and cell suspension was prepared at 2×10 5 Cells were seeded at a density of 100 cells / well in a 24-well plate and incubated in a CO2 incubator for 24 hours. After 24 hours of incubation, the central area of ​​cell growth was streaked with a pipette tip. The supernatant was discarded and the cells were washed twice with serum-free medium to remove floating cells. A blank control group, a positive drug group (100 ng / mL EGF), and a sample group (test sample at different concentrations) were administered. At 0, 24, 48, and 72 hours after administration, the cells were photographed and recorded. The scratch area was measured and the wound healing rate was calculated using Image J.

[0107] Scratch healing rate (%) = (scratch area 0h -Scratch area t ) / scratch area 0h ×100%.

[0108] The test results are as follows Figure 1 As shown:

[0109] Compared with the blank control, the wound healing rate was significantly improved after 48h and 72h treatment with 100ng / mL EGF, and the relative migration rate of cells with positive drug (EGF) increased significantly.

[0110] The ability of 30% Example 1 to promote HaCaT cell scratch healing was equivalent to that of the blank group; the scratch healing rates of 60% Example 1 were 11.68% and 15.45% higher than those of the blank group after 48h and 72h of action, respectively; the scratch healing rates of 90% Example 1 were 22.27% and 27.51% higher than those of the blank group after 48h and 72h of action, respectively, indicating that the Centella asiatica filtrate of the example has the effect of accelerating the repair of keratinocyte damage and promoting barrier recovery.

[0111] Under the test conditions, the relative cell migration rates of 30%, 60%, and 90% in Comparative Example 4 were not as good as those in Example 1.

[0112] 6. Skin patch safety test

[0113] According to the skin occlusive patch test method in the "Technical Specifications for Safety of Cosmetics" (2015 edition), 32 subjects aged 20-55 years old were selected to meet the conditions. Example 1 and Comparative Example 3 were prepared with distilled water to prepare sample solutions with mass fractions of 30%, 60%, and 90%, respectively. 2 , a spot test device with a depth of approximately 1mm. 20μL of sample solution was added to each chamber of the spot tester. The blank control group was treated with an equal dose of distilled water. The spot tester containing the test substance was applied to the subject's flexed forearm using hypoallergenic tape. Gently press the test substance evenly onto the skin using the palm of your hand for 24 hours. After removing the test substance spot tester, observe the skin for reactions according to the criteria in Table 1 at 30 minutes (after the indentation disappears), 24 hours, and 48 hours, and record the results.

[0114] Table 5 Skin reaction grading standards for skin occlusive patch test

[0115]

[0116]

[0117] Test results:

[0118] 30%-90% Example 1: All 32 subjects tested negative for the patch test, without any adverse reactions;

[0119] 30% Comparative Example 3: All 32 subjects had negative patch results and no adverse reactions;

[0120] 60% Comparative Example 3: 29 of the 32 subjects had negative patch results; 0.5h and 24h after removing the patch, 2 subjects had suspicious patch results and 1 had a weak positive result; 48h after removing the patch, 1 subject had a suspicious patch result.

[0121] 90% Comparative Example 3: 29 of the 32 subjects had negative patch results; 0.5h, 24h, and 48h after removing the patch, 2 subjects had suspicious patch results and 1 had a weak positive result.

[0122] In summary, the safety of the Centella asiatica filtrate (Example 1) treated with medical stone was effectively improved (compared with the untreated group, Comparative Example 3).

[0123] Table 6 Human body closed patch test results

[0124]

[0125]

[0126] 7. Stimulant clinical repair test

[0127] Twenty-five healthy volunteers aged 25-60 were selected. A fixed area of ​​skin on the flexor side of the forearm was selected. The test area was treated with a control group (blank), a model group (0.075% capsaicin, CAP), and a sample group (30%-90% Example 1 / Comparative Example 4 + 0.075% capsaicin) for 30 minutes. Transepidermal water loss (TEWL) and erythema were measured to evaluate the repair status. The test results are shown in the figure below. Figure 2 shown.

[0128] Depend on Figure 2 It can be seen that the Centella asiatica filtrate of Example 1 can effectively alleviate the increase in transepidermal water loss (TEWL) caused by capsaicin stimulation, with repair rates of 40.94%, 55.03%, and 63.05% at concentrations of 30%, 60%, and 90%, respectively. However, the TEWL-alleviating effect of Comparative Example 4 was limited, with repair rates of 20.78%, 32.64%, and 37.86% at the above concentrations, respectively. Overall, the Example performed better than the Comparative Example.

[0129] Depend on Figure 3 It can be seen that the Centella asiatica filtrate of Example 1 can effectively alleviate the increase in erythema caused by capsaicin stimulation, with repair rates of 12.47%, 30.66%, and 37.65% at concentrations of 30%, 60%, and 90%, respectively. However, the effect of Comparative Example 4 on erythema is limited, with repair rates of 3.75%, 10.89%, and 22.56% at the above concentrations, respectively. The overall effect of the Example is superior to that of the Comparative Example.

Claims

1. A method for preparing Centella asiatica filtrate, characterized by: At least the following steps are included: S1. After drying, the Centella asiatica is crushed, and then filtered through filters of different mesh sizes to obtain Centella asiatica powder of different mesh sizes; S2. Place the Centella asiatica powder of different mesh sizes prepared in step S1 into a funnel-shaped filter, and fill the outside of the filter with ore; S3. Spraying the top layer of Centella asiatica powder with pure water, and then letting water flow through the Centella asiatica powder layers of different mesh sizes in sequence under the action of gravity to obtain a Centella asiatica extract; S4, spraying the obtained Centella asiatica extract onto the Centella asiatica powder again, performing cyclic extraction, and obtaining a Centella asiatica cyclic extraction extract; S5, mixing the Centella asiatica cyclic extraction extract and the Centella asiatica powder after cyclic extraction again, then heating, performing a constant temperature ripening cyclic extraction operation, and collecting to obtain a Centella asiatica filtrate semi-finished product; S6. Filtering the semi-finished Centella asiatica filtrate using a membrane, and then compounding with alcohol to obtain the Centella asiatica filtrate; In the step S2, the stacking order of the Centella asiatica powder of different mesh sizes is from top to bottom in space and from low to high mesh sizes.

2. The method for preparing the Centella asiatica filtrate according to claim 1, wherein: The mesh size of the Centella asiatica powder in step S1 is 20-400.

3. The method for preparing the Centella asiatica filtrate according to claim 2, wherein: The mesh size of the Centella asiatica powder in step S1 includes at least 20, 80, 100 and 200.

4. The method for preparing the Centella asiatica filtrate according to claim 1, wherein: The ore comprises one of diatomite, expanded perlite, expanded vermiculite, medical stone, zeolite, bentonite, attapulgite, sepiolite and rectorite.

5. The method for preparing the Centella asiatica filtrate according to claim 4, wherein: The ore at least includes medical stone.

6. The method for preparing the Centella asiatica filtrate according to claim 1, wherein: The mass ratio of pure water to Centella asiatica powder in the S3 step is (80-200):

1.

7. The method for preparing the Centella asiatica filtrate according to claim 1, wherein: The alcohol in step S6 includes one of ethanol, ethylene glycol, 1,2-propylene glycol, isopropyl alcohol, diethylene glycol, glycerol, 1,3-butanediol, and 1,2-hexanediol.

8. A Centella asiatica filtrate prepared according to the method for preparing the Centella asiatica filtrate according to any one of claims 1 to 7.

9. A use of the Centella asiatica filtrate according to claim 8, characterized in that: Centella asiatica filtrate is used in the cosmetics field.

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