Brightening and whitening plant essence composition as well as preparation method and application thereof

Abstract

The invention discloses a plant essence composition for brightening and whitening as well as a preparation method and application thereof. The composition is prepared from the following components in percentage by weight: 3 to 6 percent of a polygonatum odoratum root extract, 1 to 3 percent of a pomegranate extract, 1 to 3 percent of a mulberry root bark extract, 3 to 6 percent of a polygonum cuspidatum root extract, 30 to 40 percent of polysorbate-20, 30 to 40 percent of butanediol and 20 to 30 percent of water. The preparation method comprises the following key steps: performing cryogenic embrittlement and low-temperature airflow superfine grinding on four plant raw materials, and performing low-temperature directional extraction by adopting compound enzyme; carrying out two-stage centrifugation and deep filtration on the extracting solution, specifically collecting a target precipitate under the ethanol concentration of 65% by virtue of a multi-stage gradient alcohol precipitation process, and washing and purifying by virtue of a 80% ethanol solution; and performing high-pressure homogenization on the purified active matter to construct a layered liquid crystal structure, performing membrane filtration and low-temperature instantaneous sterilization in sequence to perform terminal refining, and finally performing sterile filling to obtain the product.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, specifically to a plant extract composition with effects of brightening skin tone, whitening and brightening, anti-glycation and anti-oxidation, as well as its preparation method and application in cosmetics. Background Technology

[0002] Skin pigmentation, dullness, and uneven skin tone are among the core demands that plague consumers and drive cosmetic research and development. These problems are typically closely related to various physiological and pathological mechanisms, including excessive melanin synthesis and deposition, non-enzymatic glycation of proteins (i.e., skin glycation), oxidative stress, and micro-inflammatory states. In recent years, with consumers' increasing demands for "safe ingredients," "natural and green" products, and "proven efficacy," plant-derived whitening active ingredients have received widespread attention and favor due to their excellent skin compatibility and rich diversity of efficacy.

[0003] Plants, as an important source of natural active ingredients, have a long history of application in beauty and skincare. Their efficacy relies on the various secondary metabolites they contain, primarily including flavonoids, polyphenols, terpenes, and alkaloids. These components typically possess broad biological activities, such as antioxidant, anti-inflammatory, tyrosinase inhibition, anti-glycation, and antibacterial effects, precisely targeting multiple key pathways contributing to skin tone problems. Compared to traditional chemically synthesized ingredients, plant extracts often have advantages such as gentler effects, fewer side effects, and higher consumer acceptance. However, plant raw materials also present inherent challenges: the content of active ingredients is significantly affected by the origin and harvesting season; the extraction process is prone to degradation and inactivation; the synergistic or antagonistic effects of components in complex matrices are difficult to control; and the color, odor, and stability of extracts pose challenges to formulation systems.

[0004] Currently, the development status and existing technical bottlenecks in this field are mainly reflected in the following aspects: 1. Insufficient extraction efficiency and stability of plant active ingredients. Existing extraction processes (such as traditional water extraction, alcohol extraction, or hot reflux methods) generally suffer from the following defects: low extraction efficiency; the plant cell wall structure is intact, and conventional pulverization is insufficient to break the cell walls, resulting in insufficient dissolution rate of intracellular active ingredients; severe component damage; prolonged high-temperature operation easily leads to oxidative degradation or configurational transformation of heat-sensitive components such as flavonoids and polyphenols, for example, resveratrol in Polygonum cuspidatum root is easily isomerized and inactivated at high temperatures; and the problem of coexisting impurities. Crude extracts often contain macromolecular impurities such as starch, pectin, and plant proteins, which not only affect the efficiency of subsequent processes but also easily become the cause of precipitation, turbidity, or color changes during product storage.

[0005] 2. Research on multi-target synergistic formulation systems is weak. Although there has been considerable research on single plant components (such as the inhibition of tyrosinase by mulberry root bark extract), the following shortcomings still exist in the multi-pathway synergistic regulation for skin tone improvement: the mechanism of action is singular, with most products focusing only on tyrosinase inhibition, lacking simultaneous intervention on parallel pathways such as the generation of advanced glycation end products (AGEs), the scavenging of oxidative free radicals, and the micro-inflammation caused by Propionibacterium acnes; the compatibility science is insufficient, research on the synergistic effect between different plant extracts is lacking, simple physical mixing is difficult to achieve efficacy enhancement, and may even lead to imbalance in the formulation system due to differences in solubility and stability.

[0006] 3. Lagging fine purification and quality control technologies. Insufficient purification precision means that traditional one-time alcohol precipitation processes cannot remove impurities of different polarities in stages, resulting in the co-precipitation of target active ingredients and ineffective components, affecting the purity and efficacy of the final product; significant quality fluctuations are also evident, as the composition of plant raw materials varies due to factors such as origin and harvesting period, and there is a lack of effective means to standardize and control these differences through process design, leading to batch-to-batch quality inconsistencies.

[0007] 4. Challenges exist in improving formulation stability and bioavailability. Physical stability defects include wide particle size distribution and low interfacial film strength in emulsions formed by conventional emulsification processes, leading to stability issues such as stratification and oil separation. Poor component permeability is another concern; the molecular structure and solubility characteristics of plant active ingredients may limit their transdermal penetration efficiency, affecting bioavailability. Microbial control risks also exist; there is a conflict between the sterilization conditions of heat-sensitive systems and the protection of plant active ingredients, and traditional heat sterilization processes may damage system stability and lead to component degradation.

[0008] To address the aforementioned technical bottlenecks, this invention has established a complete process technology system, achieving full-chain innovation from raw material processing to end products, and providing a reliable technical path for developing efficient, stable, and safe plant-based whitening products. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a plant extract composition with synergistic whitening effects and its preparation method.

[0010] Another object of the present invention is to provide the use of the composition in cosmetics.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a brightening and whitening plant extract composition, comprising the following components by weight percentage: 3-6% of the root extract of *Symplocos buergeriana*. Pomegranate extract 1-3% 1-3% mulberry root bark extract Polygonum cuspidatum root extract 3-6% Polysorbate-20 30-40% Butylene glycol 30-40% Water content: 20-30%.

[0012] Preferably, the weight ratio of the extracts of *Symplocos buergeriana* root, pomegranate, mulberry root bark, and *Polygonum cuspidatum* root is (4-6):(1-3):(1-3):(4-6); more preferably, it is 5:2:2:5.

[0013] Secondly, the present invention provides a method for preparing the brightening and whitening plant extract composition, comprising the following steps: (1) Pretreatment: The four raw materials, namely, the root of *Symplocos buergeriana*, the root bark of pomegranate, the root bark of mulberry, and the root of Polygonum cuspidatum, were subjected to cryogenic embrittlement treatment at -15℃ to -25℃ for 1-2 hours. Then, they were immediately put into an air jet mill and pulverized at a low temperature of ≤45℃ to obtain ultrafine powder with a particle size distribution D90≤25μm. The ultrafine powder was placed in a microwave vacuum dryer and dried at 50-60℃ and a vacuum degree of -0.09MPa until the moisture content was ≤5% for later use. (2) Extraction: The ultrafine powders of the four plant materials are put into extraction tanks respectively, and 8-12 times the weight of citrate-disodium hydrogen phosphate buffer solution with pH 5.0-5.5 is added. After stirring and dispersing, a compound plant hydrolytic enzyme is added. The compound enzyme includes cellulase, pectinase and β-glucanase in a weight ratio of (3-5):(1-2):1. The total amount of enzyme added is 0.5-1.5% of the weight of the raw materials. The enzyme is enzymatically hydrolyzed at 45-50℃ for 2-3 hours, and then the temperature is raised to 85-90℃ and held for 10 minutes to inactivate the enzyme. (3) Centrifugation: The four plant extracts after enzymatic hydrolysis and inactivation were first subjected to primary solid-liquid separation in a horizontal spiral sedimentation centrifuge at 4500-6000 rpm to collect the light phase liquid; then, the light phase liquid was pumped into a tubular separator and subjected to fine centrifugation at a high speed of 12000-15000 rpm to completely remove submicron fine particles; finally, the supernatant after tubular centrifugation was passed through a deep filter column filled with a mixture of diatomaceous earth and perlite for deep filtration to obtain a highly clear extract. (4) Pure precipitation purification: The four extracts obtained in step (3) are transferred into the alcohol precipitation system respectively; under stirring, 90-95% food grade ethanol is slowly added so that the final concentration gradient of ethanol is successively increased to 50%, 65%, and 80% (v / v); when the final concentration of ethanol is 50% (v / v), the precipitate is discarded after standing and the supernatant is collected; ethanol is added to the supernatant to make the final concentration reach 65% (v / v), and after standing, the precipitate precipitated this time is collected; then, the collected precipitate is stirred and washed with pre-cooled 80% (v / v) ethanol solution, and centrifuged or filtered after washing and the washing liquid is discarded. (5) High-pressure homogenization: Take the precipitate of the four plant raw materials obtained in step (4) of the formula and redissolve it with an appropriate amount of water. Mix it with the formula amount of polysorbate-20, butanediol and the remaining water. After preliminary pre-emulsification, homogenize it using a high-pressure homogenizer. The homogenization pressure is 800-1000 bar, and the cycle is 3-5 times. The homogenization temperature is controlled at 45-55℃. This high-pressure process promotes the self-assembly of polysorbate-20 with water, butanediol and plant active ingredients to form a layered liquid crystal structure. (6) Membrane filtration: The high-pressure homogenized emulsion is purified by a tangential flow filtration system. The system uses a 0.1 μm ceramic membrane or a 500 kDa ultrafiltration membrane as the filter element and performs circulating filtration at a transmembrane pressure of 2.0-3.5 bar and a temperature of 15-25 °C until the clarity of the filtrate meets the requirements. This step can further homogenize the particle size distribution, remove potential aggregates, and achieve physical cold sterilization, which can significantly reduce the microbial load. (7) Defoaming and sterilization: The homogenized emulsion is transported to a vacuum defoaming tank to remove micro bubbles entrained in the system under a vacuum of -0.08 to -0.1 MPa for 20-30 minutes; after defoaming, the emulsion is passed through a tubular low-temperature instantaneous sterilizer and kept at 75-80℃ for 15-30 seconds, and then rapidly cooled to below 25℃ through a heat exchanger; (8) Filling: The final product is filled into irradiated sterilized packaging containers through an aseptic filling line in a Class C clean environment and sealed immediately.

[0014] Preferably, in step (1), the compressed air of the airflow pulverizer needs to be processed by a refrigerated dryer and a precision filter to ensure that its dew point is ≤ -40℃ and is free of oil and dust.

[0015] Preferably, in step (3), the filter material of the deep filter column is composed of diatomaceous earth and perlite in a weight ratio of 2:1, and the filter layer thickness is 5-10 cm.

[0016] Preferably, in step (6), the concentration factor of the tangential flow filtration is controlled at 1.5-2.0 times to ensure the stability of the solid content and viscosity of the final product.

[0017] Thirdly, the present invention provides the use of the composition in the preparation of cosmetics for brightening skin tone, whitening, anti-oxidation, or inhibiting Propionibacterium acnes.

[0018] The effects of each component in the brightening and whitening essence composition of this invention are as follows: Cyanotis arachnoidea root extract: contains abundant naphthoquinone compounds, which can effectively inhibit tyrosinase activity and block the melanin production pathway at its source.

[0019] Pomegranate (PUNICA GRANATUM) extract: rich in polyphenols such as ellagic acid, it has significant antioxidant and anti-glycation effects. It can scavenge free radicals, inhibit the formation of AGEs, and inhibit Propionibacterium acnes, effectively improving post-inflammatory hyperpigmentation.

[0020] Mulberry (Morus ALBA) root bark extract: The main active ingredients are mulberry ketone, resveratrol, etc., which have a strong inhibitory effect on tyrosinase and can simultaneously inhibit the proliferation and migration of melanocytes and block the transfer of melanin to keratinocytes.

[0021] Polygonum cuspidatum root extract: rich in stilbene compounds such as resveratrol and resveratrol glycosides, it has excellent antioxidant capacity, can reduce oxidative damage caused by ultraviolet rays, and relieve skin micro-inflammatory conditions.

[0022] Through in-depth research, this invention has discovered that the above four plant extracts produce significant synergistic effects when formulated in specific proportions: The root extract of *Symplocos edulis* and the root bark extract of *Morus alba* synergistically inhibited tyrosinase activity through different sites of action. Experiments showed that the inhibition rate of the two combined was significantly higher than the theoretical sum value, exhibiting a significant synergistic effect.

[0023] Polygonum cuspidatum root extract and pomegranate extract exhibit a complementary and synergistic effect in scavenging free radicals and inhibiting AGEs formation. The DPPH free radical scavenging rate of the combination of the two increased to 88%, which is more than 30% higher than that of the single components.

[0024] The combined action of pomegranate extract and Polygonum cuspidatum root extract significantly enhanced the inhibitory effect on Propionibacterium acnes, while effectively preventing post-inflammatory hyperpigmentation by inhibiting the release of inflammatory factors.

[0025] The four components work together to simultaneously regulate multiple signaling pathways such as MITF, NF-κB, and Nrf2, forming a networked regulatory pattern that achieves multidimensional inhibition of melanin synthesis, oxidative stress, and inflammatory responses at the gene expression level.

[0026] The preparation process of this invention, through the innovative design of a series of key technologies, constructs a complete, efficient, and precise process system. These innovations are mutually supportive and interconnected, jointly ensuring that the final product achieves unexpected technical effects.

[0027] 1. Innovation in raw material pretreatment: Integration of cryogenic embrittlement and low-temperature airflow ultrafine grinding This invention introduces a cryogenic embrittlement treatment at -15℃ to -25℃ before conventional pulverization, causing the plant cell walls to become brittle at ultra-low temperatures. Subsequently, airflow ultrafine pulverization (D90≤25μm) is immediately performed under low-temperature conditions of ≤45℃. High temperatures are avoided throughout this process, and the compressed air undergoes deep dehumidification and dust removal treatment.

[0028] This process maximizes the retention of active ingredients and completely avoids the damage to heat-sensitive components (resveratrol, polyphenols) caused by the localized high temperatures of mechanical pulverization, thereby increasing the initial content of active ingredients. Simultaneously, the cell wall disruption rate is >90%, creating an excellent material foundation for subsequent extraction, significantly shortening extraction time, and improving the dissolution rate of target components.

[0029] 2. Innovation in extraction technology: Compound enzyme-assisted low-temperature directional extraction This invention uses a buffer solution system with a specific pH (5.0-5.5) and combines cellulase, pectinase and β-glucanase (in a ratio of 3-5:1-2:1) to carry out enzymatic hydrolysis under mild conditions of 45-50℃, which precisely breaks down the structural polysaccharides of plant cell walls.

[0030] This process achieves efficient extraction at low temperatures, increasing the yield of total polyphenols and flavonoids by 40-60% compared to traditional hot extraction methods. It effectively decomposes impurities such as pectin and viscous polysaccharides, greatly improving the filtration performance and clarity of the extract and reducing the burden on subsequent purification.

[0031] 3. Innovation in purification technology: multi-stage gradient alcohol precipitation and targeted washing This invention innovates the traditional one-time alcohol precipitation into a refined gradient process of "50% impurity removal - 65% target collection - 80% washing and refining".

[0032] This gradient process, combined with targeted washing, can remove water-soluble macromolecular impurities (at 50%) and fat-soluble pigments and impurities (at 80% washing), increasing the purity of the target active ingredient to over 90%. Washing removes potential factors that could cause discoloration or precipitation during storage, which is crucial for the product's long-term stability.

[0033] 4. Innovation in formulation technology: High-pressure homogenization-induced construction of liquid crystal emulsion systems This invention involves homogenization under ultra-high pressure of 800-1000 bar and temperature control at 45-55°C. This process is not merely emulsification, but also utilizes ultra-high shear energy and cavitation energy to drive the self-assembly of polysorbate-20, butylene glycol, water, and plant active ingredients to form a layered liquid crystal structure.

[0034] The resulting liquid crystal system exhibits extremely high physical stability (heat resistance, centrifugation resistance), overcoming the drawback of conventional emulsions' tendency to separate. The liquid crystal structure is similar to the skin's lipid bilayer, significantly promoting the skin penetration of active ingredients and possessing sustained-release properties, thus prolonging the duration of action.

[0035] 5. Innovation in terminal refining: Dual protection of membrane filtration and low-temperature instantaneous sterilization Before filling, this invention integrates two terminal treatment steps: "tangential flow membrane filtration (0.1μm or 500kDa)" and "tubular low-temperature instantaneous sterilization (75-80℃, 15-30 seconds)".

[0036] Membrane filtration achieves physical cold sterilization and removes potential aggregates, while low-temperature flash sterilization inactivates microorganisms (including membrane-permeable viruses) and inactivates enzyme activity in one step. The synergy of these two methods ensures the product's excellent microbiological safety and physicochemical stability. The entire end-processing is completed under low-temperature or flash conditions, minimizing the damage to active ingredients and emulsion structure caused by traditional single heat sterilization.

[0037] It is evident that the innovative preparation process of this invention is a systematic engineering project. It begins with molecular-level cell disruption of the raw materials, enhances efficiency through biomimetic enzymatic hydrolysis, achieves precise purification via gradient alcohol precipitation, constructs a smart delivery system using high-pressure homogenization, and finally locks in quality through dual-terminal protection. This process not only solves the common problem in the industrialization of plant extracts—the difficulty of simultaneously achieving efficiency, purity, stability, and activity—but also synergistically generates a 1+1>2 effect, ultimately resulting in the composition of this invention exhibiting outstanding performance in terms of efficacy, stability, and bioavailability. Detailed Implementation

[0038] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0039] Example 1: Preparation of plant extract composition 1. Raw material preparation and pretreatment Take 1 kg each of dried roots of *Symplocos buergeriana*, pomegranate root bark, mulberry root bark, and *Polygonum cuspidatum*, and place them in a -20℃ freezer for 1.5 hours to embrittle. Immediately put the embrittled raw material into a liquid nitrogen-protected air jet mill and pulverize it at a temperature below 40°C until the particle size D90 = 20 μm; The ultrafine powder was placed in a microwave vacuum dryer and dried at 55℃ and -0.09MPa until the moisture content was 4.5%, thus obtaining the raw material ultrafine powder for later use.

[0040] 2. Extraction process The four types of raw material ultrafine powders were respectively put into a 500L extraction tank; Add 10 times its weight of a citrate-disodium hydrogen phosphate buffer solution with pH=5.2; Add a compound plant hydrolytic enzyme (cellulase: pectinase: β-glucanase = 4:1.5:1), with the enzyme addition amount being 1% of the total raw material; Enzymatic hydrolysis was carried out slowly with stirring at 48°C for 2.5 hours. The enzyme was inactivated by raising the temperature to 88°C and holding it for 10 minutes, resulting in four different extracts.

[0041] 3. Purification process The four extracts were first subjected to primary separation at 5000 rpm using a horizontal spiral sedimentation centrifuge. The collected light phase liquid is then purified by centrifugation at 13,000 °C using a tubular separator. The supernatant is then subjected to deep filtration through a deep filtration column (diatomaceous earth: perlite = 2:1, filter layer thickness 8cm); Transfer the clarified extract to an alcohol precipitation tank and slowly add 93% food-grade ethanol; first adjust to a 50% ethanol concentration, let stand for 3 hours, and discard the precipitate; continue adding ethanol to a 65% concentration, let stand for 3 hours, and collect the precipitate; wash the precipitate with a pre-cooled 80% ethanol solution, centrifuge, and discard the washing solution.

[0042] 4. Formulation preparation The four purified precipitates in the formula were reconstituted with an appropriate amount of ultrapure water and mixed with polysorbate-20, butylene glycol and the remaining water in the formula. The specific proportions of each component were as follows: *Symplocos buergeriana* root extract: 5%, pomegranate extract: 2%, mulberry root bark extract: 2%, *Polygonum cuspidatum* root extract: 5%, polysorbate-20: 36%, butylene glycol: 30%, water: 20%. After initial pre-emulsification, the mixture is homogenized four times at 900 bar using a high-pressure homogenizer, with the temperature controlled at 50°C. After homogenization, the emulsion was terminally purified at 2.5 bar and 20°C using a tangential flow filtration system (0.1 μm ceramic membrane). The refined emulsion was defoamed under vacuum (-0.09MPa, 25 minutes); Finally, the tube-type low-temperature instantaneous sterilizer is used to maintain the temperature at 78°C for 20 seconds and then rapidly cools it to 22°C. Aseptic filling is performed in a Class C clean environment.

[0043] Example 2: The preparation method is the same as in Example 1, except that the specific proportions of each component are as follows: 5% of *Symplocos buergeriana* root extract, 1% of pomegranate extract, 1% of mulberry root bark extract, 5% of *Polygonum cuspidatum* root extract, 36% of polysorbate-20, 30% of butylene glycol, and 22% of water.

[0044] Example 3: The preparation method is the same as in Example 1, except that the specific proportions of each component are as follows: 3% of *Symplocos buergeriana* root extract, 2% of pomegranate extract, 2% of mulberry root bark extract, 3% of *Polygonum cuspidatum* root extract, 36% of polysorbate-20, 30% of butylene glycol, and 24% of water.

[0045] Comparative Example 1: The preparation method is the same as in Example 1, except that only the root of Indigofera tinctoria is used. The specific proportions of each component are: Indigofera tinctoria root extract 5%, polysorbate-20 36%, butylene glycol 30%, and water 29%.

[0046] Comparative Example 2: The preparation method is the same as in Example 1, except that only pomegranate is used. The specific proportions of each component are: pomegranate extract 2%, polysorbate-20 36%, butylene glycol 30%, and water 32%.

[0047] Comparative Example 3: The preparation method is the same as in Example 1, except that only mulberry root bark is used. The specific proportions of each component are: 2% mulberry root bark extract, 36% polysorbate-20, 30% butylene glycol, and 32% water.

[0048] Comparative Example 4: The preparation method is the same as in Example 1, except that only the root of Polygonum cuspidatum is used. The specific proportions of each component are: Polygonum cuspidatum root extract 5%, polysorbate-20 36%, butylene glycol 30%, and water 29%.

[0049] Comparative Example 5: Traditional water extraction and alcohol precipitation process 1. Mix the four plant materials in a dry weight ratio of 5:2:2:5, grind them at room temperature using a regular grinder until they pass through a 20-mesh sieve (about 850μm), and dry them in a 60℃ oven until the moisture content is ≤8%.

[0050] 2. Put the mixed raw materials into the extraction tank, add 10 times the weight of purified water, heat to 90℃, reflux and extract twice, 2 hours each time, combine the two extracts and sieve through a 100-mesh sieve.

[0051] 3. Concentrate the filtrate under reduced pressure at 70°C to 1 / 5 of its original volume. Slowly add 95% ethanol to the concentrate while stirring, and adjust the final ethanol concentration to 70% (v / v). Let it stand for 24 hours and collect all the precipitate.

[0052] 4. Dry the precipitate in a 70℃ oven to constant weight, then pulverize it through an 80-mesh sieve to obtain crude plant extract.

[0053] 5. Redissolve the dried crude extract in water and mix it with the excipients in the following proportions: 14% plant extract (by dry weight), 36% polysorbate-20, 30% butylene glycol, and 20% water.

[0054] 6. Homogenize three times using a standard homogenizer at 200 bar pressure, then sterilize at 121°C for 20 minutes.

[0055] Comparative Example 6: Based on Example 1, ordinary mechanical crushing was used to achieve a similar particle size (D90≈25μm), the cryogenic embrittlement step was omitted, and the remaining steps were the same as in Example 1.

[0056] Comparative Example 7: A single alcohol precipitation (65% ethanol concentration) was used, omitting the 50% impurity removal and 80% ethanol washing steps, and the remaining steps were the same as in Example 1.

[0057] Comparative Example 8: The process was the same as in Example 1, using a standard homogenization process (pressure 200 bar, 3 cycles).

[0058] Comparative Example 9: After homogenization, the membrane is not filtered through a tangential flow filtration system; the remaining steps are the same as those in Example 1.

[0059] To scientifically study the synergistic effects of four plant extracts under specific ratios and preparation processes, this invention provides the following experimental data: I. Synergistic Study on Whitening Efficacy Experimental methods: Step 1: Solution Preparation 1. Tyrosinase solution: Prepare a tyrosinase working solution with a concentration of 250 U / mL using pre-cooled PBS buffer, keep it on ice for later use, and prepare it fresh each time.

[0060] 2. Substrate solution: Prepare a 2.5 mM L-DOPA solution using PBS buffer and store it protected from light.

[0061] 3. Sample solution: Prepare a stock solution of 200 μg / mL using PBS buffer (containing no more than 1% DMSO for dissolution) for all samples to be tested (including the present invention group, the control group, and the positive control), and dilute as needed.

[0062] Step 2: Establishment of the reaction system and addition of samples Add the reagents to the 96-well plate in the order and amount shown in the table below, with 3 replicates for each sample.

[0063] Hole type PBS buffer (μL) Sample solution (μL) Tyrosinase working solution (μL) L-DOPA solution (μL) effect Sample measurement well 40 20 20 20 Determine the inhibitory effect of the sample on the enzyme. Sample background well 60 20 0 20 Subtract the sample's own color Enzyme activity control wells 60 0 20 20 Represents 100% enzyme activity Blank control hole 80 0 0 20 Correcting the background Step 3: Incubation and Reaction Place the well plates containing PBS buffer, sample solution, and tyrosinase working solution in a 37°C microplate reader and incubate for 10 minutes.

[0064] Then, 20 μL of L-DOPA solution is automatically and quickly added by the microplate reader and mixed immediately.

[0065] The reaction continued at 37°C, and the absorbance was immediately read at a wavelength of 475 nm every 30 seconds for 10 minutes.

[0066] Step 4: Data Acquisition and Processing 1. Take the linear portion of the absorbance value change with time within the reaction time interval (usually 0-10 minutes) and calculate its reaction rate (ΔOD / min).

[0067] 2. Calculate the tyrosinase inhibition rate using the following formula: ; Vsample: The reaction rate of the sample well is measured.

[0068] V Sample Background: The reaction rate of the sample background pores.

[0069] V enzyme control: The reaction rate of the enzyme activity control well.

[0070] Synergistic effect analysis: Theoretical summation calculation: The theoretical summation is calculated according to the Loewe summation model (quality-weighted average).

[0071] Synergy effect index calculation: ; An index greater than 1.2 is generally considered to indicate a significant synergistic effect.

[0072] Quality control: The entire operation is carried out in the dark or in low light, because L-DOPA is sensitive to light.

[0073] Ensure that the inhibition rate of the positive control (arbutin, 200 μg / mL) is within a reasonably accepted range (e.g., 55%-65%) to demonstrate the effectiveness of the experimental system.

[0074] All experiments were independently repeated three times. Data are expressed as mean ± standard deviation and statistical significance was tested (e.g., t-test).

[0075] Table 1 Results of Tyrosinase Inhibition Rate Test Sample group Formula ratio (C:A:M:P)* Measured inhibition rate (%) Theoretical sum (%) Synergy Index Example 1 5:2:2:5 78.5 ± 1.3 50.4 1.56 Example 2 5:1:1:5 70.2 ± 1.8 48.7 1.44 Example 3 3:2:2:3 65.0 ± 1.5 52.1 1.25 Comparative Example 1 - 35.4±1.2 - - Comparative Example 2 - 20.1±0.8 - - Comparative Example 3 - 40.2±1.5 - - Comparative Example 4 - 25.3±1.0 - - Positive control (arbutin) - 60.5±1.3 - - *C:A:M:P = *Symplocos buergeriana* root: pomegranate: mulberry root bark: Japanese knotweed root As shown in the table above, the four plant extracts of this invention do not simply add up, but rather exhibit a strong synergistic effect. Furthermore, the synergistic effect is maximized when the ratio is 5:2:2:5. The combination of the four plant extracts in Examples 1-3 demonstrates significantly superior efficacy compared to each individual component and the positive control group, achieving unexpected technical results.

[0076] II. Study on the Synergistic Effect of Antioxidant Capacity Experimental methods: This invention employs two complementary classical methods to comprehensively evaluate antioxidant capacity: DPPH free radical scavenging experiment (electron transfer mechanism) and ORAC oxygen free radical absorption capacity experiment (hydrogen atom transfer mechanism).

[0077] 1. DPPH free radical scavenging experimental procedure: Step 1: Solution Preparation DPPH working solution: Accurately weigh DPPH and prepare a 0.1 mM solution with anhydrous ethanol. Store in the dark and prepare fresh before use.

[0078] Sample / control solution: Prepare a solution of all test samples to 200 μg / mL using an appropriate solvent (such as an ethanol / water mixture).

[0079] Step 2: Establishment of the reaction system Add samples to a 96-well plate according to the following system, with 6 replicates for each sample: Hole type Sample solution (μL) Anhydrous ethanol (μL) DPPH working solution (μL) effect Sample measurement well 50 - 150 Determine total scavenging capacity Sample bottom hole 50 150 - Subtract the sample's own color Blank control hole - 50 150 Represents 100% free radical content VC positive control well 50 - 150 Verify system effectiveness Step 3: Reaction and Detection After the sample was added, the well plate was sealed with a sealing film and allowed to stand at room temperature in the dark for 30 minutes to react.

[0080] Immediately after the reaction was completed, the absorbance of each well was measured at a wavelength of 517 nm using an ELISA reader.

[0081] Step 4: Data Processing Calculate DPPH radical scavenging rate: ; Sample A: Absorbance measured in the sample well.

[0082] Sample background: Absorbance of the sample background pores.

[0083] A. Blank: Absorbance of the blank control well.

[0084] 2. ORAC (Oxygen Radical Absorption Capacity) Experimental Procedure: Step 1: Solution Preparation Fluorescein working solution: Prepare a 70 nM fluorescein solution with phosphate buffer, store in the dark, and keep on ice.

[0085] AAPH solution: Prepare a 240 mM AAPH solution using phosphate buffer, prepare fresh each time, and keep on ice.

[0086] Trolox standard curve: Prepare a series of Trolox standard solutions of different concentrations using buffer solutions (typically 6.25, 12.5, 25, 50, 100 μM).

[0087] Sample solution: Dilute the sample to be tested to 200 μg / mL with buffer solution.

[0088] Step 2: Sample addition and reaction Add samples to the black 96-well plate according to the following system, with 3 replicates for each sample / standard: Add 25 μL of Trolox standard, the sample to be tested, or buffer (blank) to each well.

[0089] Then add 150 μL of fluorescein working solution.

[0090] Place the well plate in a 37°C fluorescence microplate reader and incubate for 10-15 minutes to allow the temperature to equalize.

[0091] The instrument automatically and rapidly injects 25 μL of AAPH solution to initiate the reaction.

[0092] Step 3: Fluorescence monitoring Immediately begin monitoring the fluorescence signal, with the following parameter settings: Excitation wavelength: 485 nm Emission wavelength: 528 nm Detection mode: Dynamic cycle Cycle time: Fluorescence intensity is read every 2 minutes. Total run time: 90 minutes (or until the fluorescence intensity of the blank wells decays to less than 5% of the initial value). Temperature: 37℃ Step 4: Data Processing Calculate the net AUC: Integrate the fluorescence intensity-time curve for each well and calculate the area under the curve (AUC).

[0093] ; Plot the standard curve: Plot the Trolox concentration on the x-axis and the corresponding net AUC on the y-axis to create a standard curve (usually linear).

[0094] Calculate the ORAC value: Based on the net AUC value of the sample, calculate the corresponding Trolox equivalent concentration from the Trolox standard curve. The final result is expressed as micromoles of Trolox equivalent per gram of sample (μmol TE / g).

[0095] 3. Synergistic effect analysis Theoretical summation calculation: The theoretical summation is calculated according to the Loewe summation model (quality-weighted average).

[0096] Synergy effect index calculation: ; 4. Quality Control The DPPH experiment requires ensuring that the absorbance of the blank well is stable and between 0.6 and 1.2.

[0097] The ORAC experiment requires a linear regression coefficient (R²) > 0.98 for the Trolox standard curve.

[0098] The DPPH clearance rate of the positive control VC and the ORAC value of Trolox should be within the expected range to prove the effectiveness of the experimental system.

[0099] Each experiment was repeated three times independently.

[0100] Table 2 Antioxidant Test Results Sample group DPPH removal rate (%) ORAC value (μmol TE / g) DPPH Synergistic Effect Index ORAC Synergistic Effect Index Example 1 82.3±1.0 11200±300 1.48 1.53 Example 2 73.5±1.2 9400±250 1.38 1.33 Example 3 69.0±1.5 8900±280 1.21 1.17 Comparative Example 1 35.2±1.0 3250±150 - - Comparative Example 2 65.3±1.2 8560±240 - - Comparative Example 3 40.5±0.9 3850±180 - - Comparative Example 4 55.8±1.1 6980±210 - - Positive control (VC) 92.1±0.8 13520±290 - - Table 2 evaluates the antioxidant capacity of the compositions of the present invention from different matrix dimensions using two methods. In both the DPPH and ORAC models, the compositions of the present invention exhibit significant synergistic antioxidant effects. For the comparative examples of single components, Comparative Example 2, containing only pomegranate extract, showed the highest DPPH scavenging rate among the single components. This is because pomegranate extract is rich in components that rapidly donate electrons (such as ellagic acid), which can quickly neutralize a large number of initial free radicals. Comparative Example 3, containing only Polygonum cuspidatum root extract, had a significantly higher ORAC value than its corresponding DPPH scavenging rate, indicating that components such as resveratrol are superior in long-term protection. The individual antioxidant data of Podophyllum heliotropium root extract and Morus alba root bark extract are generally average, but the flavonoids they contain (such as mulberry ketone in Morus alba root bark) may play an auxiliary role indirectly by regenerating other antioxidants (such as vitamin C and vitamin E) or chelating metal ions. Furthermore, the optimal ratio (5:2:2:5) was again confirmed as the key to maximizing synergy; the antioxidant efficacy of other ratios decreased significantly.

[0101] III. Synergistic Study on Anti-Glycation Efficacy Experimental methods: Step 1: Solution Preparation BSA solution: Prepare a BSA solution with a concentration of 20 mg / mL using PBS buffer.

[0102] Fructose solution: Prepare a 1.0 M fructose solution using PBS buffer.

[0103] Sample / Control Solution: Prepare a stock solution of 200 μg / mL using PBS buffer for all test samples and positive control (aminoguanidine).

[0104] Step 2: Establishment of the reaction system Establish the reaction system according to the table below in 1.5 mL centrifuge tubes (or by directly constructing the reaction system in a 96-well plate). Each sample should have 6 replicates.

[0105] Reaction components Model control group (μL) Sample measurement group (μL) Sample background group (μL) Blank control group (μL) BSA solution (20 mg / mL) 100 100 100 0 Fructose solution (1.0 M) 100 100 0 0 Sample solution (200 μg / mL) 0 50 50 0 PBS buffer 50 0 100 250 Total volume 250 250 250 250 Step 3: Incubation reaction Gently vortex the above mixture until well combined.

[0106] Seal the tube opening with sealing film (or use a 96-well plate sealing film), place it in a 37°C constant temperature incubator, and incubate in the dark for 7 days.

[0107] Key control points: The entire incubation process must be kept in the dark and at a constant temperature to ensure the reproducibility of results.

[0108] Step 4: Fluorescence detection After incubation, dilute the reaction solution in each tube appropriately (e.g., dilute 5 times with PBS) to avoid excessively strong fluorescence signals that exceed the detection linear range.

[0109] Transfer the diluted solution to a black 96-well plate, adding 200 μL to each well.

[0110] The specific fluorescence intensity of AGEs was detected using a fluorescent microplate reader. The detection parameters were as follows: Excitation wavelength (Ex): 370 nm Emission wavelength (Em): 440 nm Read the fluorescence intensity (RFU) value of each well.

[0111] Data processing: Calculate the inhibition rate of AGEs formation: ; Sample F: Average fluorescence intensity of the sample measurement group (including BSA + fructose + sample) F Sample Background: The average fluorescence intensity of the sample background group (including BSA+ samples, without fructose), used to subtract the sample's own fluorescence.

[0112] F model: The average fluorescence intensity of the model control group (containing BSA + fructose, no sample) represents 100% AGEs generation.

[0113] F blank: The average fluorescence intensity of the blank control group (PBS buffer only), used to correct for background fluorescence.

[0114] Synergy effect index calculation: ; Quality control and verification: System effectiveness verification: Ensure that the AGEs inhibition rate of the positive control aminoguanidine (200 μg / mL) is >75%, proving that the experimental system is fully effective.

[0115] Model establishment was successful: The fluorescence intensity of the model control group (BSA + fructose) must be significantly higher than that of the blank control group (usually more than 10 times higher), indicating that AGEs were successfully generated.

[0116] Background subtraction: A "sample background group" must be set to exclude the interference of the sample's own color or fluorescence on the final result.

[0117] Repeatability and statistics: All experiments were independently repeated three times. Data were expressed as mean ± standard deviation and statistical significance was tested (e.g., one-way ANOVA).

[0118] Table 3 Results of anti-glycation effect test Sample group AGEs inhibition rate (%) Theoretical sum (%) Synergy Index Example 1 72.8±2.0 49.5 1.47 Example 2 61.0±1.6 47.1 1.30 Example 3 57.5±1.8 50.3 1.14 Comparative Example 1 15.3±0.8 - Comparative Example 2 45.2±1.5 - - Comparative Example 3 18.5±1.0 - Comparative Example 4 35.8±1.2 - - Positive control (aminoguanidine) 82.6±1.3 - - As shown in Table 3, among the four plant extracts, pomegranate extract is the core anti-glycation agent. This is because pomegranate contains abundant ellagic acid and other polyphenols, which have a strong carbonyl scavenging ability and can directly react with reducing sugars, competitively inhibiting the binding of sugars to protein amino groups, thus blocking the formation of AGEs at the source. Polygonum cuspidatum root extract showed a good individual inhibition rate of 35.8%. The glycation process is closely related to oxidative stress (formation of glycation oxidation products) and micro-inflammation. Polygonum cuspidatum root is rich in resveratrol, which indirectly inhibits the formation and accumulation of AGEs by scavenging free radicals and inhibiting inflammation. The individual anti-glycation effects of mulberry root bark extract and *Symplocos buergeriana* root extract are relatively weak; their main function is to inhibit tyrosinase. However, Examples 1-3, which use the four plant extracts in combination, showed excellent AGEs inhibition rates. A very strong synergistic effect was produced among the four components, and the synergistic effect was optimal when the ratio of the four components was 5:2:2:5.

[0119] IV. Synergistic Study on Inhibition of Propionibacterium acnes Experimental methods: Step 1: Preparation of bacterial culture 1. Resuscitation and passage: Streak cryovials of Propionibacterium acnes on RCM agar plates and incubate in an anaerobic environment at 37°C for 48-72 hours until single colonies are formed.

[0120] 2. Preparation of bacterial suspension: Pick 3-5 single colonies with the same morphology, inoculate them into RCM broth, and anaerobic culture for 24-48 hours until the late logarithmic growth phase (McFrankenstein turbidity about 0.5).

[0121] 3. Standardized bacterial culture: Dilute the bacterial culture with sterile RCM broth to approximately 1×10⁻⁶. 6 CFU / mL was used as the working bacterial suspension. Calibration with a McFarland turbidimeter and verification via plate count are recommended.

[0122] Step 2: Sample Solution Preparation 1. Prepare all test samples into a high-concentration stock solution (e.g., 20 mg / mL) using an appropriate sterile solvent (e.g., DMSO) and perform sterile filtration (0.22 μm filter membrane).

[0123] 2. In a 96-well plate, perform serial two-fold dilutions of the sample stock solution using RCM broth. Typically, 10-12 concentration gradients are set, for example, from 1024 μg / mL to 1 μg / mL.

[0124] Step 3: Sample addition and inoculation The following reaction system was established in a 96-well U-plate, with 3 replicates for each sample / concentration: Hole type RCM broth (μL) Sample dilution solution (μL) Working bacterial suspension (μL) Final bacterial concentration (CFU / mL) Sample test well 80 100 20 <![CDATA[~5×10 5 ]]> Growth control wells 180 0 20 <![CDATA[~5×10 5 ]]> Solvent control well 80 100 (containing an equal amount of solvent) 20 <![CDATA[~5×10 5 ]]> Culture medium blank well 200 0 0 - Step 4: Anaerobic culture 1. Seal the 96-well plate with a special plate cover or sealing film to prevent evaporation and maintain an anaerobic environment.

[0125] 2. Immediately place the entire 96-well plate into the anaerobic digester and activate the anaerobic gas-generating bag as required.

[0126] 3. Place the anaerobic container in a 37℃ constant temperature incubator and anaerobic culture for 48 hours.

[0127] Step 5: Result Interpretation 1. Visual Interpretation: After culturing, carefully remove the 96-well plate and observe it against a white background. The lowest sample concentration that completely inhibits bacterial growth (no precipitate or turbidity at the bottom of the well) is taken as the MIC value of that sample.

[0128] 2. Microplate reader-assisted interpretation: To improve accuracy, absorbance can be read at a wavelength of 600 nm. The lowest concentration where the absorbance value increases by less than 90% compared to the growth control well is determined as the MIC.

[0129] Synergistic effect analysis: 1. Calculate the fractional inhibitory concentration index (FIC Index). FIC = Σ(actual concentration of component i in the combined MIC / monomeric MIC of component i).

[0130] 2. Criteria for Determining Synergistic Effects FIC Index ≤ 0.5: Synergistic effect. 0.5 < FIC Index ≤ 1.0: Additive effect. 1.0 < FIC Index ≤ 2.0: Irrelevant effect; FIC Index > 2.0: Antagonistic effect.

[0131] Quality control: Strain activity: The growth control wells must be clearly turbid to indicate good bacterial growth.

[0132] Sterile control: The blank wells of the culture medium must remain clear to prove that the culture medium is sterile.

[0133] Solvent effect: The growth of the solvent control wells should be consistent with that of the growth control wells, proving that the solvent has no antibacterial effect.

[0134] Positive control: The MIC value of clindamycin should be within the CLSI recommended quality control range (e.g., 0.06-0.25 μg / mL) to prove the effectiveness of the experimental system.

[0135] Repeatability: All experiments should be repeated independently at least three times.

[0136] Table 4. Results of antibacterial effect test Sample group MIC (μg / mL) of Propionibacterium acnes Synergy Index Example 1 62.5 0.48 Example 2 125 0.92 Example 3 375 1.25 Comparative Example 1 ＞1000 Comparative Example 2 500 - Comparative Example 3 >1000 - Comparative Example 4 800 - Positive control (clindamycin) 0.5 - As shown in Table 4, the composition of the present invention exhibits a clear synergistic antibacterial effect only when the ratio of the four plant extracts is 5:2:2:5. This synergy may stem from the synergistic effect of multiple targets, such as pomegranate extract (which directly disrupts bacterial membranes) and Polygonum cuspidatum root extract (which inhibits quorum sensing and has anti-inflammatory properties). Mulberry root bark and Podophyllum oleracea root extract may have played a supporting role by altering the microenvironment.

[0137] V. Verification of the effectiveness of the preparation process Table 5 Comparison of key indicators for different preparation processes Test metrics Example 1 Comparative Example 5 Total polyphenol yield (mg / g raw material) 48.5 ± 1.2 25.3 ± 2.1 Total flavonoid yield (mg / g raw material) 35.8 ± 0.9 18.7 ± 1.5 Purity of active ingredient (HPLC, %) 92.5 ± 0.8 65.8 ± 2.5 Tyrosinase inhibition rate (%) 78.5 ± 1.5 62.0 ± 2.0 3-month activity retention rate (HPLC, %) 95.2 ± 0.5 68.5 ± 3.0 Emulsion particle size D90 (nm) 158 ± 5 Unable to stabilize emulsification Transdermal absorption rate (24h, %) 45.2 ± 2.1 15.3 ± 1.8 The yield of total polyphenols and total flavonoids in Example 1 is more than 90% higher than that of traditional processes. This significant improvement stems from the synergistic effect of "cryogenic embrittlement-ultrafine pulverization" and "compound enzyme-assisted low-temperature directional extraction." The former gently and effectively breaks down the cell walls of the fabric, while the latter precisely hydrolyzes the cell wall structure at optimal temperature and pH, allowing for the full dissolution of active ingredients. The purity of the active ingredients in Example 1 reaches 92.5%, while the traditional process only achieves 65.8%. This is because the present invention uses a gradient alcohol precipitation and washing step, which precisely separates the target active agent (precipitated under 65% ethanol) from water-soluble impurities (discarded under 50% ethanol) and lipid-soluble impurities (discarded under 80% ethanol washing). The process in Example 1 yields a nearly pure extract, while the traditional process still yields a crude extract. Furthermore, the process of Example 1 maximizes the extraction and retention of active ingredients, resulting in a significantly higher tyrosinase inhibition rate than that of the conventional process in Comparative Example 5. It also greatly promotes the penetration and transport of active ingredients through the stratum corneum.

[0138] Table 6 Comparison of effects of different preparation processes Test metrics Example 1 Comparative Example 6 Comparative Example 7 Comparative Example 9 Retention rate of heat-sensitive component (resveratrol) (%) 98.5 85.2 96.8 97.1 Product Clarity (NTU) ＜10 15 85 20 Liquid crystal structure formation (polarizing microscope) Typical Maltese Cross Partial formation Partial formation none Emulsion stability at room temperature (months) ＞12 ＞12 6 3 As shown in Table 6, ordinary mechanical pulverization generates a large amount of frictional heat. Localized high temperatures can lead to the degradation, isomerization, or oxidation of heat-sensitive components such as resveratrol. The cryogenic embrittlement process of this invention achieves ultra-fine cell disruption with almost no heat effect and low oxidation, maximizing the preservation of the plant's natural activity and laying the foundation for efficient extraction and high efficacy in subsequent processes. Regarding product clarity, 1 < 10, exhibiting extremely high clarity, while the comparative example 7, using a single-stage alcohol precipitation, reaches as high as 85, showing significant turbidity. This is because the traditional 70% single-stage alcohol precipitation is a crude process, where impurities of different polarities co-precipitate with the target precipitate. This invention employs a refined process of 50% impurity removal, 65% target collection, and 80% washing. 50% ethanol preferentially precipitates large-molecule polysaccharides and starches, 65% ethanol precisely precipitates target flavonoids and polyphenols, and 80% ethanol washing effectively removes lipid-soluble pigments, waxes, and other hydrophobic impurities attached to the surface of the target precipitate. The turbidity of Comparative Example 7 was due to the failure to remove these fat-soluble impurities, which not only affect the product's appearance but are also the culprits behind precipitation, discoloration, and oxidation during storage. The gradient process of this invention ensures high purity and physical stability of the product. The product of Example 1 exhibits a room temperature storage stability of >12 months, while Comparative Example 9 only shows 3 months. Example 1 showed a typical Maltese cross structure under a polarized light microscope, proving the formation of laminar liquid crystals, while Comparative Example 9 did not show this result. It is evident that ordinary homogenization can only form unstable traditional emulsions, where droplets easily aggregate and mature, leading to short-term stratification. High-pressure homogenization-induced liquid crystallization is not only a physically stable packaging process but also an innovation that improves product bioavailability and achieves long-lasting sustained release.

[0139] Table 7 Comparison of sterilization effects of different preparation processes Test metrics Example 1 Comparative Example 8 Microbial survival rate (log decrease) >6 (sterile) 4-5 Bacterial endotoxins (EU / mL) ＜0.25 1.5 Retention rate of active ingredients after sterilization 99.1 98.5 Particle aggregation none slight As shown in Table 7, the dual process of membrane filtration and low-temperature instantaneous sterilization effectively ensures the microbial safety of the product. Even if microorganisms permeate through the membrane due to extreme conditions (such as minor membrane damage), the subsequent instantaneous sterilization can immediately inactivate them, ensuring a foolproof sterile state. While sufficiently killing microorganisms, it minimizes damage to heat-sensitive plant components. In addition, membrane filtration can also remove fine aggregates present in endotoxin particles.

[0140] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A brightening and whitening botanical essence composition, characterized by, By weight percentage, the following components are included: Radix Indigoferae Pulchellae 3-6%, Punica granatum extract 1-3%, Mulberry root extract 1-3%, Polygonum cuspidatum root extract 3-6%, Polysorbate-20 30-40%, Butylene glycol 30-40%, Water 20-30%.

2. The composition of claim 1, wherein, The weight ratio of the Radix Indigoferae Pulchellae extract, Punica granatum extract, Mulberry root extract, and Polygonum cuspidatum root extract is (4-6):(1-3):(1-3):(4-6).

3. The composition according to claim 1 or 2, characterized in that, The weight ratio of the Radix Indigoferae Pulchellae extract, Punica granatum extract, Mulberry root extract, and Polygonum cuspidatum root extract is 5:2:2:

5.

4. A method of preparing the lightening and whitening botanical essence composition according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: (1) Pretreatment: The Radix Indigoferae Pulchellae, Punica granatum root bark, Mulberry root bark, and Polygonum cuspidatum root are respectively subjected to cryogenic embrittlement treatment at -15 to -25°C for 1-2 hours, and then immediately put into an airflow pulverizer for pulverization at a low temperature of ≤45°C to obtain raw material ultrafine powder with a particle size distribution D90≤25μm; the ultrafine powder is placed in a microwave vacuum drying machine and dried at 50-60°C and a vacuum degree of -0.09MPa until the moisture content is ≤5%, ready for use; (2) Extraction: The ultrafine powder of the four kinds of plant raw materials is respectively put into an extraction tank, 8-12 times by weight of a citric acid-disodium hydrogen phosphate buffer solution with a pH of 5.0-5.5 is added, and after stirring and dispersing, a composite plant hydrolytic enzyme is added, the composite enzyme includes cellulase, pectinase, and β-glucanase with a weight ratio of (3-5):(1-2):1, and the total amount of enzyme added is 0.5-1.5% of the weight of the raw material; enzymolysis is carried out at 45-50°C for 2-3 hours, and then the temperature is raised to 85-90°C for 10 minutes to inactivate the enzyme; (3) Centrifugation: the four plant extraction liquids after enzyme inactivation are respectively subjected to primary solid-liquid separation by a horizontal screw sedimentation centrifuge at 4500-6000rpm, and the light phase liquid is collected; then, the light phase liquid is pumped into a tubular separator and subjected to fine centrifugation at a high speed of 12000-15000rpm to completely remove sub-micron fine particles; finally, the supernatant after tubular centrifugation is subjected to deep filtration through a deep filtration column filled with a mixed filter material of diatomite and perlite to obtain a highly clarified extraction liquid; (4) Pure sedimentation and refinement: the four extraction liquids obtained in step (3) are respectively transferred into an alcohol precipitation system; under stirring, 90-95% edible grade ethanol is slowly added, and the final concentration of ethanol is gradually increased to 50%, 65%, and 80% (v / v) in sequence; when the final concentration of ethanol is 50% (v / v), the precipitate is discarded after standing, and the supernatant is collected; the supernatant is further added with ethanol to reach a final concentration of 65% (v / v), and after standing, the precipitate separated at this time is collected; then, the collected precipitate is washed by stirring with pre-cooled 80% (v / v) ethanol solution, and after washing, centrifugation or filtration is performed, and the washing liquid is discarded; (5) High pressure homogenization: the formula amount of the precipitate of the four plant raw materials obtained in step (4) is re-dissolved with an appropriate amount of water, mixed with the formula amount of polysorbate-20, butanediol and the remaining water, and then subjected to preliminary pre-emulsification, and then subjected to homogenization by using a high pressure homogenizer; the homogenization pressure is 800-1000 bar, the circulation is 3-5 times, and the homogenization temperature is controlled at 45-55°C; this high pressure process promotes the self-assembly of polysorbate-20, water, butanediol and plant active ingredients to form a lamellar liquid crystal structure; (6) Membrane filtration: the emulsion after high pressure homogenization is subjected to terminal refinement by a tangential flow filtration system; the system uses a 0.1 μm ceramic membrane or a 500 kDa ultrafiltration membrane as a filtration element, and is subjected to circulation filtration at a transmembrane pressure of 2.0-3.5 bar and a temperature of 15-25°C until the filtrate reaches the required clarity; this step further homogenizes the particle size distribution, removes potential aggregates, and at the same time realizes physical cold sterilization, significantly reducing the microbial load; (7) Defoaming and sterilization: the homogenized emulsion is transported to a vacuum defoaming tank, and the fine bubbles entrained in the system are removed at a vacuum degree of -0.08~-0.1 MPa for 20-30 minutes; after defoaming, the emulsion is passed through a tubular low-temperature instantaneous sterilization machine at 75-80°C for 15-30 seconds, and then rapidly cooled to below 25°C by a heat exchanger; (8) Filling: the final product is filled into an irradiation sterilized packaging container through a sterile filling line in a C-class clean environment, and then sealed immediately.

5. The method of claim 4, wherein, In step (1), the compressed air of the jet mill needs to be treated by a freeze dryer and a precision filter to ensure that the dew point is ≤ -40°C and there is no oil and dust.

6. The method of claim 4, wherein, In step (3), the filter material of the deep filtration column is composed of diatomite and perlite mixed at a weight ratio of 2:1, and the filter layer thickness is 5-10 cm.

7. The method of claim 4, wherein, In step (6), the concentration multiple of the tangential flow filtration is controlled at 1.5-2.0 times to ensure the stability of the solid content and viscosity of the final product.

8. Use of the composition of any one of claims 1-3, or the composition obtained by the method of any one of claims 4-7, in the preparation of a cosmetic for lightening skin color, whitening, anti-glycation, antioxidant or inhibiting propionibacterium acnes.