Olive leaf extract, preparation method thereof and application thereof in repair cosmetics

Abstract

The present application belongs to the technical field of cosmetics, and particularly relates to an olive leaf extract and a preparation method thereof and application of the olive leaf extract in repair cosmetics. The olive leaf extract is prepared by a simple process of reflux extraction, impurity removal by precipitation in an ethanol aqueous solution and stepwise purification in a butanediol aqueous solution, and does not need complex purification equipment, and the process is simple and the production cost is low. Test results show that the olive leaf extract prepared by the present application has no cytotoxicity to human dermal fibroblasts at a concentration of 0.05%, has good safety, and can significantly promote cell scratch healing, and the 24h cell healing rate can reach more than 55%, and has excellent skin repair activity. The extract is suitable for various cosmetic dosage forms such as creams, emulsions, aqueous solutions and gels, and can be safely and efficiently applied to various skin repair cosmetics, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of cosmetic technology, and in particular relates to an olive leaf extract, its preparation method, and its application in repair cosmetics. Background Technology

[0002] The skin barrier is a crucial structure for resisting external environmental stimuli and maintaining the skin's internal moisture balance. Damage to the skin barrier is related to factors such as environmental pollution, chemical overuse, and improper skincare, and is a major cause of skin sensitivity, dryness, and decreased tolerance. When the skin barrier is damaged, transepidermal water loss increases, and external irritants can more easily penetrate, triggering a series of sensitive symptoms such as dryness, redness, stinging, itching, and inflammation, severely impacting consumers' quality of life. Currently, common repairing active ingredients in the cosmetics industry mainly include chemically synthesized anti-inflammatory agents, recombinant collagen, and peptides. Although these ingredients have certain repair effects, they generally have the following technical shortcomings: (1) Chemically synthesized ingredients may cause skin irritation or sensitization risks, which are not friendly to people with sensitive skin; (2) Some bioactive ingredients have complex preparation processes and high costs, which are not conducive to large-scale application; (3) Single active ingredients often only target a certain repair link, making it difficult to play a synergistic repair role from multiple dimensions such as anti-oxidation, anti-inflammation, barrier repair, and cell regeneration; (4) With the stricter regulation of the cosmetics industry, efficacy claims need to be supported by efficacy test data, and the compliance threshold has been significantly raised. There is still a large gap in the industry for natural repair raw materials that have both high efficacy and high safety.

[0003] Olive leaves are the leaves of the globally renowned oilseed plant, the olive (Olea europaea L.), accounting for approximately 10% of the total olive harvest. They are an inexpensive and abundant renewable resource. Existing research indicates that olive leaf extracts are rich in phenols and their derivatives, possessing various biological activities such as antioxidant, anti-inflammatory, photoprotective, and antibacterial properties.

[0004] However, existing technologies regarding the application of olive leaf extract in cosmetic repair still have the following limitations: First, existing reports mostly focus on the combination of olive leaf extract with various other plant extracts, and research on the systemic repair efficacy of olive leaf extract used alone is still insufficient; Second, there are various preparation methods for olive leaf extract in the existing technology, and there is a lack of systematic comparison on the effects of different extraction processes on the composition of active ingredients and repair efficacy, and the extraction process parameters that are conducive to exerting efficient repair efficacy have not been determined; Third, no patents or literature have clearly stated that olive leaf extract can play a repair role in promoting cell migration and proliferation, repairing the skin barrier, etc.

[0005] Therefore, how to develop a highly effective and safe cosmetic repair ingredient using olive leaf extract and its preparation method is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an olive leaf extract, its preparation method, and its application in repair cosmetics. This invention involves extracting olive leaves using a solvent, followed by precipitation with different concentrations of ethanol and butylene glycol, ultimately obtaining an olive leaf extract with repairing effects. The olive leaf extract prepared by this specific method has excellent repairing effects and can be safely and effectively used in cosmetics.

[0007] To achieve the above objectives, the technical solution adopted by the present invention includes: In a first aspect, the present invention provides an application of olive leaf extract in the preparation of repair cosmetics, wherein the preparation method of the olive leaf extract includes the following steps: (1) The olive leaves were refluxed and concentrated under reduced pressure to obtain crude extract of olive leaves; (2) Add ethanol to the crude extract of olive leaves obtained in step (1), let it stand to precipitate, filter and collect the supernatant, and concentrate it under reduced pressure to a thick paste. (3) Add butanediol to the thick paste obtained in step (2), let it stand to precipitate, and filter to collect the supernatant; (4) Add butanediol to the supernatant obtained in step (3) to obtain olive leaf extract.

[0008] This invention uses olive leaf extract as an active ingredient in repair cosmetics. A specific preparation process, involving reflux extraction, ethanol precipitation for impurity removal, and stepwise butylene glycol purification, refines the olive leaves. First, reflux fully dissolves oleuropein, hydroxytyrosol, and other repair-active substances from the leaves. Then, ethanol precipitation removes polysaccharides and large molecular impurities to increase the stability of the raw material. Subsequent butylene glycol treatment precisely enriches small-molecule antioxidant and repair-active components, thereby significantly improving the extract's efficacy, purity, and skin compatibility in soothing the skin barrier and providing antioxidant repair. This invention addresses the industry pain points of conventional olive leaf extracts, such as high impurity levels, poor stability, low activity content, poor skin feel, and weak repair effects. It broadens the application value of natural active ingredients from olive leaves in barrier repair and soothing / stabilizing cosmetics, providing a high-quality, easily compounded, and highly stable core active ingredient for gentle and effective plant-based repair cosmetics.

[0009] Preferably, in step (1), the reflux extraction method is selected from one or more of the following: reflux extraction, boiling extraction, ultrasonic extraction, and more preferably reflux extraction.

[0010] Preferably, in step (1), the specific method of reflux extraction is as follows: add solvent to olive leaves and reflux extract at 40~90℃ for 0.5~5h, wherein the mass-volume ratio of olive leaves to solvent is 1:(1~25).

[0011] More preferably, the olive leaves are refluxed at 80°C for 3 hours, and the mass-to-volume ratio of the olive leaves to the solvent is 1:5.

[0012] Preferably, the solvent includes ethanol, and the volume concentration of the ethanol is 50-90% (v / v).

[0013] More preferably, the volume concentration of the ethanol is 80% (v / v).

[0014] This invention preferably uses reflux extraction parameters with a material-to-liquid ratio of 1:(1~25), reflux at 40~90℃ for 0.5~5h, and 50~90% ethanol as the extraction solvent. This approach balances the dissolution efficiency of repairing active ingredients such as oleuropein and hydroxytyrosol from olive leaves with the control of impurity dissolution. The ethanol solvent polarity is well-suited to the target active ingredient. The optimized temperature and extraction time range avoids both high-temperature, long-term degradation of antioxidant components and insufficient precipitation of active substances caused by low-temperature, short-time extraction. A reasonable material-to-liquid ratio ensures sufficient extraction while reducing solvent waste and subsequent concentration energy consumption. This effectively increases the active ingredient content of the crude extract, reduces the simultaneous dissolution of large molecular impurities, lightens the burden on subsequent stepwise purification processes with ethanol and butanediol, and steadily improves the repairing efficacy of the final extract.

[0015] Preferably, in step (1), the temperature of the vacuum concentration is 40~80℃, the vacuum degree is -0.02~-0.09MPa, and the vacuum concentration is carried out until the mass of the crude extract is 0.5~1.5 times the mass of the olive leaves.

[0016] More preferably, the vacuum concentration temperature is 60°C, the vacuum degree is -0.06MPa, and the vacuum concentration is carried out until the mass of the crude extract is 1.2 times the mass of the olive leaves.

[0017] Experimental studies have revealed that precise control of the concentration endpoint significantly impacts the efficacy of the final extract. Too low a concentration increases the amount of solvent used for subsequent ethanol precipitation, raising purification costs; too high a concentration can cause active substances to encapsulate impurities, forming clumps and hindering efficient stratification and impurity removal. Therefore, the aforementioned optimized parameter range ensures effective separation of impurities from the crude extract, providing a suitable material system for subsequent stepwise precipitation and purification processes.

[0018] Preferably, in step (1), the olive leaves are crushed before reflux extraction, and the crushed olive leaves have a particle size of less than 200 mesh, preferably less than 100 mesh, and more preferably less than 80 mesh.

[0019] Preferably, in step (1), the reflux extraction is performed 1 to 5 times, more preferably 1 to 4 times, and even more preferably 1 to 3 times.

[0020] Preferably, in step (2), ethanol is added until the final volume concentration of ethanol in the crude olive leaf extract is 40-75% (v / v).

[0021] More preferably, the final volume concentration of ethanol added to the crude olive leaf extract is 60-65% (v / v).

[0022] This preferred solution limits the final ethanol concentration to 40-75%, allowing for precise control of system polarity to achieve selective impurity removal. This concentration range ensures sufficient precipitation of large-molecule polysaccharides, proteins, and other impurities in the crude extract that lack repairing effects and can easily cause skin stickiness and sensitization, while maximizing the retention of small-molecule repairing active ingredients such as oleuropein and hydroxytyrosol. If the final ethanol concentration is below 40%, the system polarity is too high, resulting in incomplete precipitation of large-molecule impurities and leaving a large amount of residue, thus reducing the extract's efficacy and increasing the irritation of cosmetics. If the final concentration is above 75%, the polarity is too low, easily causing simultaneous precipitation and loss of the target active ingredients, significantly reducing the yield and repairing effect of the raw materials. The preferred parameter range of this invention balances the impurity removal effect with the activity retention rate, simplifies filtration and separation operations, and ensures the purity and efficacy stability of the final extract.

[0023] Preferably, in step (2), the volume concentration of the added ethanol is 70-100% (v / v); the mesh size of the filter is 80-500 mesh, preferably 100-400 mesh, and more preferably 200-400 mesh; the standing temperature is 0-20℃, preferably 4-15℃, and more preferably 10-15℃; the standing time is 4-24 hours, preferably 10-18 hours, and more preferably 10-15 hours.

[0024] Preferably, in step (3), the mass concentration of butanediol is 10~60% (w / w), and the mass ratio of butanediol to olive leaves is (0.5~3):1.

[0025] Experimental studies have shown that limiting the butylene glycol concentration to 10-60% and the butylene glycol to olive leaf raw material mass ratio to 0.5-3:1 allows for precise adjustment of the system polarity, achieving efficient dissolution of the target repair active ingredients in the precipitate and continuous retention of ineffective macromolecular impurities. However, if the butylene glycol concentration is below 10%, the dissolving capacity is insufficient, resulting in a large amount of oleuropein and hydroxytyrosol failing to fully dissolve in the supernatant, significantly reducing the effective yield of the raw material. If the concentration is above 60%, the system viscosity is too high, making it difficult for impurities to settle and separate, increasing filtration difficulty. Furthermore, using less than 0.5 times the raw material mass of butylene glycol results in insufficient dissolution medium for the active ingredients and incomplete extraction, while using more than 3 times will excessively dilute the active components, thereby increasing the cost of subsequent raw material preparation. The above-mentioned optimized parameter range can balance the dissolution rate of active substances and the separation effect of impurities, optimize material flowability and filtration performance, and thus steadily increase the content of repair active ingredients in the supernatant.

[0026] More preferably, the butanediol has a mass concentration of 30% (w / w) and the mass ratio of butanediol to olive leaves is 1.2:1.

[0027] Preferably, in step (3), the mesh size of the filter is 80~500 mesh, more preferably 100~400 mesh, and more preferably 200~400 mesh; the settling temperature is 0~20℃, more preferably 4~15℃, and more preferably 10~15℃; the settling time is 4~24 hours, more preferably 10~18 hours, and more preferably 10~15 hours.

[0028] Preferably, in step (4), the mass concentration of butanediol is 10-60% (w / w), and the addition of butanediol makes the mass of the obtained olive leaf extract 0.5-3 times that of the olive leaves.

[0029] This invention limits step (4) to adding 10-60% butylene glycol, and controls the total mass of the final extract to 0.5-3 times that of the olive leaf raw material. Butylene glycol not only serves as a stable carrier for the active ingredients but also helps enhance the moisturizing and soothing abilities of the extract. The 10-60% concentration range avoids the oxidation and inactivation of active ingredients due to excessively low concentrations, and the viscous consistency of the system due to excessively high concentrations, making it difficult to incorporate into cosmetics. Furthermore, the final product mass range is strictly controlled. If the total mass is less than 0.5 times that of the raw material, the extract concentration is too high, and active substances are prone to precipitation and deterioration during storage. If it is more than 3 times that of the raw material, the effective ingredients are excessively diluted, thus weakening the repair and skincare effects. The above-mentioned optimal parameter combination effectively balances the active concentration of the extract, system stability, and compatibility with cosmetic formulations. No additional preservatives or solubilizers are needed, effectively simplifying the development of cosmetic formulations and ensuring consistent efficacy, texture, and storage stability of the extract during mass production.

[0030] More preferably, the butanediol has a mass concentration of 50% (w / w), and the addition of butanediol makes the mass of the resulting olive leaf extract 1.2 times that of the olive leaves.

[0031] Preferably, the olive leaves are dried leaves of the olive tree (Olea europae L.), a plant belonging to the Oleaceae family and the Oleaceae genus.

[0032] Preferably, the dosage form of the cosmetic is selected from one or more of the following: cream, lotion, aqueous solution, gel, oil, powder, mud, aerosol, patch, film.

[0033] Secondly, the present invention provides a method for preparing olive leaf extract, comprising the following steps: (1) The olive leaves were refluxed and concentrated under reduced pressure to obtain crude extract of olive leaves; (2) Add ethanol to the crude extract of olive leaves obtained in step (1), let it stand to precipitate, filter and collect the supernatant, and concentrate it under reduced pressure to a thick paste. (3) Add butanediol to the thick paste obtained in step (2), let it stand to precipitate, and filter to collect the supernatant; (4) Add butanediol to the supernatant obtained in step (3) to obtain olive leaf extract.

[0034] Thirdly, the present invention provides an olive leaf extract prepared by the aforementioned preparation method.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The preparation process is simple and low-cost. After extraction and concentration, this invention only uses aqueous solutions of ethanol and butanediol of different concentrations for fractional precipitation purification, eliminating the need for complex and expensive equipment such as macroporous resin chromatography and supercritical extraction. The operation is simple, easy to scale up for industrial production, and significantly reduces production costs.

[0036] 2. It exhibits good cell safety. The olive leaf extract prepared in this invention showed no cytotoxic effect on human dermal fibroblasts at a concentration of 0.05% (v / v), and the cell survival rate was good, indicating that the extract is safe and mild at this test concentration.

[0037] 3. Significantly promotes cell scratch healing and exhibits excellent skin repair efficacy. The cell scratch assay is a recognized in vitro model for evaluating the skin's repair capacity after injury. The experimental results of this invention show that after treatment with 0.05% concentration of the olive leaf extract of this invention, the 24-hour scratch healing rate of HaCaT cells reached 56.21%~58.32%, which was significantly different from the blank control group (46.44%) (P<0.05). This indicates that the extract of this invention can effectively promote skin cell migration and proliferation, accelerating the repair process of the epidermal barrier.

[0038] 4. The raw material comes from olive leaves, a byproduct of olive oil processing. It is a renewable resource, environmentally friendly, and combines high efficacy with high safety, filling the current technological gap in the cosmetics industry for efficient and safe natural repair ingredients.

[0039] 5. Compared with the complex compound formulations of multiple plants in the prior art, the single olive leaf extract provided by the present invention can promote the migration and proliferation of keratinocytes, repair the skin barrier, and has a wide range of applications. Attached Figure Description

[0040] Figure 1 The figures show the cell activity results of different olive leaf extracts obtained in the examples and comparative examples. Detailed Implementation

[0041] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0042] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available general-purpose materials.

[0043] Example 1 This embodiment provides a method for preparing olive leaf extract, including the following steps: (1) Select 0.5 kg of fresh olive leaves and grind them into powder using a 60-mesh granulator; (2) Add 2.5L of 80% (v / v) ethanol to olive leaves, extract at 80℃ for 3 hours, repeat the reflux extraction once, and collect the extract; (3) The extract from step (2) was concentrated at 60°C and -0.06 MPa to obtain 0.6 kg of concentrate.

[0044] (4) Add 95% ethanol to the concentrate obtained in step (3) to adjust the final concentration of ethanol to 60%, let it stand at 10°C for 12 hours to precipitate, then filter it through 200 mesh to remove the precipitate, and concentrate it under reduced pressure to a thick paste. (5) Add 0.6 kg of 30% (w / w) butanediol aqueous solution to the thick paste obtained in step (4), let it stand at 10°C for 15 hours to precipitate, and then filter through 200 mesh to collect the supernatant; (6) Add 50% (w / w) butanediol aqueous solution to 0.6 kg of the supernatant obtained in step (5) to obtain the olive leaf extract.

[0045] Example 2 This embodiment provides a method for preparing olive leaf extract, including the following steps: (1) Select 1.0 kg of olive leaves and grind them into powder using a 40-mesh sieve; (2) Add 10L of 70% (v / v) ethanol to olive leaves and extract at 65℃ for 2 hours. Repeat the extraction twice and collect the extract. (3) The extract from step (2) was concentrated at 65°C and -0.05 MPa to obtain 0.8 kg of concentrate; (4) Add 70% (v / v) ethanol to the concentrate obtained in step (3) to adjust the final ethanol concentration to 50%, let it stand at 10°C for 12 hours to precipitate, then filter at 400°C to remove the precipitate, and concentrate under reduced pressure to a thick paste. (5) Add 0.6 kg of 30% (w / w) butanediol aqueous solution to the thick paste obtained in step (4), let it stand at 10°C for 15 hours to precipitate, and then filter through 200 mesh to collect the supernatant; (6) Add 30% (w / w) butanediol aqueous solution to 0.6 kg of the supernatant obtained in step (5) to obtain the olive leaf extract.

[0046] Example 3 This embodiment provides a method for preparing olive leaf extract, including the following steps: (1) Select 2.0 kg of olive leaves and grind them into powder using an 80-mesh sieve; (2) Add 40L of 60% (v / v) ethanol to olive leaves and extract at 50℃ for 3 hours. Repeat the extraction 3 times and collect the extract. (3) The extract in step (2) was concentrated at 60℃ and -0.06MPa to obtain 3kg of concentrate; (4) Add 95% (v / v) ethanol to the concentrate obtained in step (3) to adjust the final ethanol concentration to 65%, let it stand at 10°C for 10 hours to precipitate, then filter at 300°C to remove the precipitate, and concentrate under reduced pressure to a thick paste. (5) Add 2 kg of 50% (w / w) butanediol aqueous solution to the thick paste obtained in step (4), let it stand at 10°C for 10 hours to precipitate, and then filter through 300 mesh to collect the supernatant; (6) Add 20% (w / w) butanediol aqueous solution to 3 kg of the supernatant obtained in step (5) to obtain the olive leaf extract.

[0047] Example 4 This embodiment provides a method for preparing olive leaf extract, including the following steps: (1) Select 1 kg of fresh olive leaves and grind them into powder using an 80-mesh granule; (2) Add 1L of 50% (v / v) ethanol to olive leaves and extract at 90℃ for 0.5 hours. Repeat the reflux extraction 5 times and collect the extract. (3) The extract from step (2) was concentrated at 40°C and -0.09 MPa to obtain 0.5 kg of concentrate.

[0048] (4) Add 70% (v / v) ethanol to the concentrate obtained in step (3) to adjust the final ethanol concentration to 60%, let it stand at 10°C for 12 hours to precipitate, then filter it through 200 mesh to remove the precipitate, and concentrate it under reduced pressure to a thick paste. (5) Add 0.5 kg of 10% (w / w) butanediol aqueous solution to the thick paste obtained in step (4), let it stand at 10°C for 15 hours to precipitate, and then filter through 200 mesh to collect the supernatant; (6) Add 10% (w / w) butanediol aqueous solution to 0.5 kg of the supernatant obtained in step (5) to obtain the olive leaf extract.

[0049] Example 5 This embodiment provides a method for preparing olive leaf extract, including the following steps: (1) Select 1 kg of fresh olive leaves and grind them into powder using an 80-mesh granule; (2) Add 25L of 90% (v / v) ethanol to olive leaves and extract at 40℃ for 5 hours. Repeat the reflux extraction once and collect the extract. (3) The extract from step (2) was concentrated at 80°C and -0.02 MPa to obtain 1.5 kg of concentrate.

[0050] (4) Add 70% (v / v) ethanol to the concentrate obtained in step (3) to adjust the final ethanol concentration to 65%, let it stand at 10°C for 12 hours to precipitate, then filter it through 200 mesh to remove the precipitate, and concentrate it under reduced pressure to a thick paste. (5) Add 3 kg of 60% (w / w) butanediol aqueous solution to the thick paste obtained in step (4), let it stand at 10°C for 15 hours to precipitate, and then filter through 200 mesh to collect the supernatant; (6) Add 60% (w / w) butanediol aqueous solution to 3 kg of the supernatant obtained in step (5) to obtain the olive leaf extract.

[0051] Comparative Example 1 This comparative example provides a method for preparing olive leaf extract, using conventional ethanol extraction followed by preparation with butylene glycol aqueous solution to finally obtain the olive leaf extract. Specifically, it includes the following steps: (1) Select 0.2 kg of olive leaves and grind them into powder using an 80-mesh sieve; (2) Add 200 mL of 50% (v / v) ethanol to olive leaves and extract at 50°C for 2 hours. Repeat the extraction twice and collect the extract. (3) The extract in step (2) was concentrated at 60°C and -0.06 MPa to obtain 0.2 kg of concentrate; (4) The concentrate obtained in step (3) is dried to obtain olive leaf extract powder; (5) Add 200g of 50% (w / w) butylene glycol aqueous solution to the olive leaf extract powder obtained in step (4), stir evenly, and let it stand at 10℃ for 24 hours to precipitate; (6) Filter the solution obtained in step (5) through a 300-mesh filter and collect the supernatant to obtain the olive leaf extract.

[0052] Comparative Example 2 This comparative example provides a method for preparing olive leaf extract, which differs from Example 1 only in that: in step (2), the concentration of added ethanol is 40% (v / v); in step (4), the final concentration of ethanol in the concentrate is adjusted to 80% (v / v).

[0053] Comparative Example 3 This comparative example provides a method for preparing olive leaf extract, which differs from Example 1 only in that: in step (2), olive leaves are extracted at 35°C for 6 hours and the extract is collected; in step (4), the final concentration of ethanol in the concentrate is adjusted to 35% (v / v).

[0054] Comparative Example 4 This comparative example provides a method for preparing olive leaf extract, which differs from Example 1 only in that: in step (2), olive leaves are extracted at 95°C for 20 minutes and the extract is collected; in step (5), the concentration of the added butanediol aqueous solution is 5% (w / w).

[0055] Test Example 1 This test example uses olive leaf extracts prepared in Examples 1-5 and Comparative Examples 1-4 as test samples to conduct cell scratch healing tests to evaluate the repair efficacy of olive leaf extracts prepared in this invention.

[0056] (1) Required drugs: human dermal fibroblasts (HDF); DMEM high glucose medium; fetal bovine serum; penicillin-streptomycin mixed solution (100*double antibiotic); thiazolyl blue (MTT).

[0057] (2) Main instruments and equipment: Yamato / HQIP610 carbon dioxide incubator; BSC-1300IIA2 biosafety cabinet; HQ / HQICX inverted fluorescence microscope; DL-6000B low-speed refrigerated centrifuge; SYNERGY-H1 full-wavelength multi-functional microplate reader.

[0058] (2) Cell viability detection: HDF cells were seeded in 96-well plates. After 24 hours, the culture medium was removed and basal culture medium containing different concentrations of the test samples was added. After 24 hours, the effect of the test samples on the viability of HaCaT cells was calculated and analyzed.

[0059] (3) Cell scratch test: HDF cells were seeded into 6-well plates and cultured for 24 hours. A line was drawn in the middle of the 6-well plate with a sterile pipette tip to create a scratch. The culture medium was then discarded. Culture medium for the blank control group and the corresponding sample group was added. The cell healing was observed and photographed at two time points: 0 h and 24 h.

[0060] (4) Blank control: basal culture medium (cell viability test); 2% serum culture medium (scratch test); Positive control: basal culture medium (10% fetal bovine serum); Sample: Filter the sample through a 0.22μm filter and then dilute it to a concentration of 0.05%.

[0061] (5) Calculation of cell viability: Cell viability (%) = A 样品 / A 阴性 *100% (6) Formula for calculating scratch healing rate: 24-hour scratch healing rate (%) = (Scratch area at 1-24 hours / Scratch area at 0 hours) * 100% (7) Test results: The cell activity of olive leaf extracts obtained in different embodiments and comparative examples is as follows: Figure 1 As shown in the figure; the cell scratch results are shown in Table 1.

[0062] Table 1. Results of cell scratch assays for different olive leaf extracts. Figure 1 The results showed that the olive leaf extract prepared by the process of this invention exhibited excellent overall cell activity at a concentration of 0.05%, with cell activity values ​​in all groups exceeding those of the blank control group, indicating that the olive leaf extract of this invention is non-cytotoxic at this concentration. In contrast, the olive leaf extract prepared using conventional extraction processes in Comparative Example 1 showed a certain degree of decrease in cell activity after treatment compared to the blank control group.

[0063] Table 1 shows that the olive leaf extracts prepared using the specific preparation process of this invention in Examples 1-5 all exhibited HDF cell healing rates exceeding 56% after 24 hours, significantly different from the blank control. This confirms that the samples prepared according to the present invention can significantly promote HDF cell migration and healing, possessing excellent skin repair activity. Among them, the extract of Example 1 showed the best repair effect. In contrast, the extract of Comparative Example 1, prepared using a conventional extraction process, showed lower cell scratch healing ability than the examples, with a significantly weakened repair efficacy. Similarly, after adjusting the extraction process parameters of Comparative Examples 2-4 and deviating from the scope defined by this invention, the cell healing-promoting effect of the resulting extracts also decreased significantly. These results collectively demonstrate that the entire set of defined preparation processes and corresponding parameter ranges of this invention are necessary conditions for obtaining olive leaf extracts with high repair activity. Conventional extraction processes or deviations from the process parameters of this invention will significantly weaken the repair efficacy of the extracts.

[0064] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. The application of an olive leaf extract in the preparation of repair cosmetics, characterized in that, The preparation method of the olive leaf extract includes the following steps: (1) The olive leaves were refluxed and concentrated under reduced pressure to obtain crude extract of olive leaves; (2) Add ethanol to the crude extract of olive leaves obtained in step (1), let it stand to precipitate, filter and collect the supernatant, and concentrate it under reduced pressure to a thick paste. (3) Add butanediol to the thick paste obtained in step (2), let it stand to precipitate, and filter to collect the supernatant; (4) Add butanediol to the supernatant obtained in step (3) to obtain olive leaf extract.

2. The application as described in claim 1, characterized in that, In step (1), the reflux extraction method is as follows: add solvent to olive leaves and reflux extract at 40~90℃ for 0.5~5h, wherein the mass-volume ratio of olive leaves to solvent is 1:(1~25).

3. The application as described in claim 2, characterized in that, The solvent includes ethanol, and the volume concentration of the ethanol is 50-90%.

4. The application as described in claim 1, characterized in that, In step (1), the temperature of the vacuum concentration is 40~80℃, the vacuum degree is -0.02~-0.09MPa, and the vacuum concentration is carried out until the mass of the crude extract is 0.5~1.5 times the mass of the olive leaves.

5. The application as described in claim 1, characterized in that, In step (2), ethanol is added until the final volume concentration of ethanol in the crude olive leaf extract is 40-75%.

6. The application as described in claim 1, characterized in that, In step (3), the mass concentration of butanediol is 10-60%, and the mass ratio of butanediol to olive leaves is (0.5-3):

1.

7. The application as described in claim 1, characterized in that, In step (4), the mass concentration of butanediol is 10-60%, and the addition of butanediol makes the mass of the obtained olive leaf extract 0.5-3 times that of the olive leaves.

8. A method for preparing olive leaf extract, characterized in that, Includes the following steps: (1) The olive leaves were refluxed and concentrated under reduced pressure to obtain crude extract of olive leaves; (2) Add ethanol to the crude extract of olive leaves obtained in step (1), let it stand to precipitate, filter and collect the supernatant, and concentrate it under reduced pressure to a thick paste. (3) Add butanediol to the thick paste obtained in step (2), let it stand to precipitate, and filter to collect the supernatant; (4) Add butanediol to the supernatant obtained in step (3) to obtain olive leaf extract.

9. An olive leaf extract prepared by the method described in claim 8.

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