Skin-brightening composition extracted from plants and preparation method of skin-brightening composition

Abstract

The invention provides a skin-brightening composition extracted from plants and a preparation method of the skin-brightening composition, and belongs to the field of medical, dental or cosmetic preparations. The composition comprises the following components: a mulberry leaf extract, tea polyphenol, a licorice extract, carrot seed oil, winter fragrant peppermint oil, a plant emulsifier, soybean lecithin and cholesterol. According to the invention, a plurality of different plant-derived whitening components are compounded, so that the full-period guarantee effect of a multi-target synergistic-auxiliary component anti-inflammatory soothing-lipidosome efficient delivery-stable system is realized, and the composition can be added into a plurality of different specific products, such as essence, face cream, emulsion and the like; the balance of the whitening effect, the skin compatibility and the product stability is realized, and the obvious industrialization value is realized.

Description

Technical Field

[0001] This invention belongs to the field of medical, dental or cosmetic formulations, and particularly relates to a skin-brightening composition extracted from plants and its preparation method. Background Technology

[0002] Skin color is primarily determined by the content and distribution of melanin in the epidermis, and its synthesis and metabolism are precisely regulated. In melanocytes of the basal layer of the skin, tyrosine is converted into melanin through a series of biochemical reactions catalyzed by tyrosinase. The generated melanin granules are transported to surrounding keratinocytes through the dendritic structure of melanocytes, migrate to the skin surface with the differentiation of epidermal cells, and finally complete metabolism with the shedding of the stratum corneum.

[0003] When this balance is disrupted, pigmentation abnormalities occur. Ultraviolet radiation can significantly increase tyrosinase activity and accelerate melanin synthesis; inflammatory responses release various cytokines that stimulate melanocytes to become overactive; endocrine disorders, mental stress, and other factors can affect melanin transport and metabolism, leading to localized pigment deposition and the formation of age spots.

[0004] Even and radiant skin tone is an important indicator of healthy skin, and problems such as dullness and pigmentation caused by abnormal melanin metabolism have always been a key research focus in the field of skin care. Plant extracts, as an important source of natural active ingredients, have become one of the core directions of whitening skincare research due to their gentleness and effectiveness in regulating melanin balance.

[0005] Plants have developed complex defense systems through long-term evolution. Their extracts contain active ingredients such as polyphenols, flavonoids, and glycosides, which can regulate melanin metabolism through multiple pathways and have significant application value. Currently, commonly used whitening ingredients derived from plants include: 1. The following components can directly inhibit tyrosinase by blocking its synthesis at the source.

[0006] Arbutin The β-glucosinolate derivative derived from bearberry leaves has a phenolic hydroxyl group structure similar to tyrosine, which can competitively occupy the active site of tyrosinase.

[0007] Glabridin Isoflavones in licorice root possess a unique "dual-lock mechanism": they directly inhibit the formation of tyrosinase dimers and downregulate MITF gene expression, thereby reducing enzyme protein synthesis. In vitro experiments have shown that their inhibitory efficacy is 16 times that of kojic acid.

[0008] Mulberry Extract It is rich in mulberry glycoside G and resveratrol glycoside. It can not only inhibit tyrosinase activity, but also inhibit the binding of α-MSH to MC1R receptor, blocking the melanin synthesis instruction at the source of the signal.

[0009] 2. Ultraviolet radiation induces a large amount of reactive oxygen species (ROS), activating transcription factors such as AP-1 and NF-κB, thereby stimulating melanin production. The following ingredients have excellent antioxidant capabilities: Proanthocyanidins Its unique C4-C8 / C6 bonding mechanism forms a super-strong electron donor. ESR analysis shows that its efficiency in removing DPPH free radicals is 8 times that of vitamin E.

[0010] Tea polyphenol complex (Camellia sinensis) EGCG (epigallocatechin gallate), as the core ingredient, can absorb 280-320nm ultraviolet rays (equivalent to SPF5 physical protection value) and activate the Nrf2 / ARE pathway, promoting the expression of superoxide dismutase (SOD) and glutathione peroxidase (GPx).

[0011] Ferulic acid Phenylpropanoid compounds in rice bran and angelica can block the active site of tyrosinase by chelating with copper ions. More importantly, they can stabilize vitamins C and E, forming an "antioxidant synergistic network" that increases the photodamage protection efficacy to four times that of single-use products.

[0012] 3. Through melanin metabolism regulation: accelerating pigment shedding. Linoleic acid By activating PPARγ receptors, it promotes the degradation of melanosomes in keratinocytes.

[0013] Fruit acids It can specifically hydrolyze desmosomes between keratinocytes, accelerating the shedding of pigmented dead skin cells.

[0014] In the field of plant-based skin whitening, there are some misconceptions that need to be clarified: First, the belief that "natural ingredients are absolutely safe" is misleading. In fact, some plant extracts contain irritating substances and must be purified before they can be used. Second, the pursuit of "fast-acting whitening" is misleading. Such products may contain illegal additions of heavy metals or hormones, which may have significant short-term effects but can lead to serious consequences such as skin sensitivity and pigmentation rebound. Therefore, finding a plant-based skin-brightening composition with excellent comprehensive performance is one of the goals currently being pursued by the industry. Summary of the Invention

[0015] The purpose of this invention is to provide a skin-brightening composition extracted from plants and its preparation method, wherein all its components are derived from plants.

[0016] A skin-brightening composition, preferably comprising the following ingredients in parts by weight: Mulberry leaf extract 2-3 Tea polyphenols 0.3-0.5 Licorice extract 0.5-0.8 Carrot seed oil 2-3 Winter peppermint oil 1.0-1.5g Plant-based emulsifier 1.0-1.5 Soy lecithin 3-5 Cholesterol 0.6-1.

[0017] Preferably, the plant emulsifier is at least one of the following: sucrose polystearate, alkyl polysaccharide, or polyglycerol fatty acid ester.

[0018] Preferably, the soybean lecithin is hydrogenated or non-hydrogenated soybean lecithin.

[0019] Preferably, it also includes 4-6 parts of a component freeze-drying protectant; the freeze-drying protectant is mannitol and / or trehalose.

[0020] Preferably, it further includes 0.1-0.2 parts of an antioxidant, wherein the antioxidant is at least one fat-soluble antioxidant and one water-soluble antioxidant.

[0021] The present invention also provides a method for preparing the aforementioned skin-brightening composition, comprising the following steps: S1: The components are classified into fat-soluble components and water-soluble components based on their solubility; S2: The lipid-soluble components dissolve in anhydrous ethanol to form a lipid-soluble phase; the water-soluble components dissolve in water to form an aqueous phase. S3: Heat the aqueous phase, then inject the lipid-soluble phase into the aqueous phase; maintain a shear rate of at least 8000 rpm during the injection process; the heating temperature of the aqueous phase is higher than the phase transition temperature of soybean lecithin; After injection, stir to form a liposome solution; S4: The liposome solution is homogenized under high pressure or sonicated to reduce the particle size to ≤200 nm; a liposome suspension is obtained.

[0022] Preferably, it also includes the following steps: S5: Freeze-dry the liposome suspension to obtain porous liposome freeze-dried powder.

[0023] Preferably, step S5 is as follows: The liposome suspension was pre-frozen at a maximum of -80°C for at least 4 hours, then freeze-dried at a maximum of -40°C / 0.1 mBar for 24 hours; finally, it was further dried by continuously heating to a maximum of 10°C / 0.005 mBar to obtain porous liposome freeze-dried powder.

[0024] Preferably, in step S4, when high-pressure homogenization is used, the pressure is ≥600 bar.

[0025] The present invention also provides the application of the aforementioned skin-brightening composition in the preparation of cosmetics, including but not limited to dosage forms such as serums, creams, lotions, and lyophilized powders.

[0026] This invention achieves a whitening effect by synergistically targeting different whitening pathways, specifically: Mulberry leaf extract: Contains flavonoids, alkaloids and polysaccharides. It inhibits melanin production by competitively binding to the active site of tyrosinase, while scavenging free radicals to reduce pigmentation caused by oxidative stress. Its polysaccharide components can also enhance the moisture content of the stratum corneum and improve dull skin tone caused by dryness.

[0027] Tea polyphenols: With EGCG as the core, they have both strong antioxidant effects (scavenging free radicals and blocking melanin oxidation and maturation) and the ability to inhibit tyrosinase expression. At the same time, they can reduce the transport of melanosomes to keratinocytes, help inhibit the release of inflammatory factors, and reduce the risk of inflammation-induced pigmentation.

[0028] Licorice extract: Contains glycyrrhizin and dipotassium glycyrrhizate. Glycyrrhizin effectively inhibits tyrosinase activity and blocks melanin transport, while dipotassium glycyrrhizate exerts anti-inflammatory and soothing effects, reducing skin sensitivity caused by active ingredients or external stimuli and enhancing the gentleness of the formula.

[0029] Carrot seed oil: Rich in beta-carotene, vitamin E and phytosterols. Beta-carotene is converted into vitamin A to repair the skin barrier, phytosterols inhibit the release of inflammatory mediators to relieve irritation, and vitamin E and tea polyphenols form an antioxidant network to protect fat-soluble components and improve dry and dull skin.

[0030] Winter peppermint belongs to the genus *Satureja montana* of the Lamiaceae family; although named "peppermint," it is not a species of the genus *Mentha* (such as spearmint and peppermint). This invention has discovered that winter peppermint essential oil, when used alone, has the effect of inhibiting tyrosinase activity; and when combined with other ingredients with the same effect (such as mulberry leaf extract and licorice extract), it can significantly enhance the effect; it also has anti-inflammatory effects.

[0031] Plant-based emulsifiers, such as sucrose polystearate and alkyl polysaccharides, can reduce the interfacial tension between oil and water to form a uniform primary emulsion. They can also synergistically regulate the stability of liposome membranes with soybean lecithin. Furthermore, plant-derived ingredients have high biocompatibility, reducing the risk of skin irritation.

[0032] Soy lecithin: As the core framework of liposomes, it self-assembles into vesicles through hydrophilic heads and hydrophobic tails, encapsulating fat-soluble and water-soluble active ingredients. Its natural phospholipid structure is similar to that of skin lipids, which can enhance transdermal efficiency and is easily metabolized by the skin, resulting in high safety.

[0033] Cholesterol: It is embedded in the gaps between soybean lecithin molecules, reducing the fluidity of liposome membranes and preventing leakage of active ingredients caused by membrane structure rupture during storage. At the same time, it enhances compatibility with the stratum corneum of the skin, further improving the stability and transdermal effect of the carrier.

[0034] Freeze-drying protectants: Mannitol or trehalose form a glassy state to encapsulate liposomes during freeze-drying, reducing the damage to the membrane structure caused by ice crystal growth, maintaining the integrity of liposomes, and improving the resolubility of freeze-dried powder, ensuring the encapsulation rate and particle size stability of active ingredients after resolubilization.

[0035] Antioxidants: A combination of fat-soluble (such as vitamin E) and water-soluble (such as vitamin C derivatives) is used. The fat-soluble components protect the liposome membrane and fat-soluble components from lipid peroxidation, while the water-soluble components scavenge free radicals in the aqueous phase. This dual-blocking of the oxidative degradation of active ingredients significantly extends the shelf life.

[0036] In summary, this invention achieves full coverage of the whitening pathway and a closed-loop anti-inflammatory and soothing effect in terms of its ingredients: In terms of skin whitening, mulberry leaf extract, licorice extract, and winter pepper oil work together to inhibit tyrosinase activity; tea polyphenols and winter pepper oil provide dual antioxidant protection; licorice extract additionally blocks melanin transport, and multiple targets work together to improve whitening efficiency.

[0037] In terms of anti-inflammatory and soothing effects, carrot seed oil (barrier repair, anti-inflammatory), winter peppermint oil (powerful anti-inflammatory), licorice extract (dipotassium glycyrrhizate for soothing), and gentle emulsifiers form a closed loop from "reducing irritants" to "blocking inflammatory responses" and then to "repairing the barrier," thus addressing the pain point of highly active whitening ingredients easily causing sensitivity.

[0038] In terms of process, the soybean lecithin-cholesterol liposomes of this invention achieve "precise encapsulation of active ingredients and improved transdermal efficiency". The small particle size (≤200nm) and skin-compatible carrier ensure that the ingredients reach the target site (melanocytes, epidermal basal layer) directly, reducing ineffective loss.

[0039] The combination of compound antioxidants (protection of active ingredients), liposome encapsulation (physical barrier), and freeze-drying process (moisture removal and freeze-drying protectant) maintains the stability of active ingredients throughout the entire lifecycle from preparation and storage to use, significantly extending the shelf life.

[0040] Liposome suspensions can be used directly in serums and lotions; lyophilized powders can be compounded with solvents to suit "high-activity instant skincare" scenarios, and can also be prepared in the form of lyophilized agents; meeting the dosage form needs of different skin types (sensitive skin, dry skin, oily skin).

[0041] This invention combines various plant-derived whitening ingredients to achieve synergistic effects across multiple targets, including anti-inflammatory and soothing auxiliary ingredients, efficient liposome delivery, and a stable system that ensures a full-cycle effect. It achieves a balance between whitening efficacy, skin compatibility, and product stability, and has clear industrialization value. Detailed Implementation

[0042] To better understand the present invention, the present invention will be further described below with reference to specific serial numbers. The terminology used in the serial numbers is for describing specific embodiments and does not constitute a limitation on the scope of protection of the present invention.

[0043] In the specific implementation methods, unless otherwise specified, the experimental methods used are all conventional methods, and the materials and reagents used are all commercially available unless otherwise specified.

[0044] Unless otherwise specified, percentages, % and so on in the specific implementation method are assumed to be mass percentages.

[0045] The raw materials used in this invention are as follows: Mulberry leaf extract: INCI name MORUS ALBA leaf extract, containing ≥5% 1-deoxynojirimycin (1-DNJ) and ≥10% flavonoids; Tea polyphenols: INCI famous tea (CAMELLIA SINENSIS) polyphenols.

[0046] Licorice: Licorice (Glycyrrhiza uralensis) extract.

[0047] Carrot seed oil: INCI name: carrot (DAUCUS CAROTA SATIVA) seed oil.

[0048] Sea buckthorn oil: INCI name: sea buckthorn (HIPPOPHAE RHAMNOIDES) oil.

[0049] Rosehip oil: INCI name: Rosa Canina (dogtooth rose) fruit oil.

[0050] Spearmint essential oil: INCI name: Spearmint (MENTHA VIRIDIS) leaf oil.

[0051] Field peppermint oil: INCI name: field peppermint (MENTHA ARVENSIS) leaf oil.

[0052] Winter Peppermint Essential Oil: refers to the whole plant distillation extract of Satureja montana, a species belonging to the Lamiaceae family.

[0053] Example 1 The preparation of the skin-brightening composition includes the following steps: S1: The components are divided into fat-soluble components and water-soluble components according to their solubility, and each component is weighed according to the proportions in Table 1 below.

[0054] S2: The fat-soluble components are dissolved in anhydrous ethanol, with the amount of anhydrous ethanol being 5 times the total mass of the fat-soluble components. The mixture is stirred in a water bath at 40-60℃ until it is completely dissolved, forming a fat-soluble phase. The water-soluble components are dissolved in purified water, with the amount being 90% of the total mass of the aqueous phase. The solution is heated to 65°C and stirred until homogeneous to form the aqueous phase. S3: Keep the temperature of the aqueous phase between 65-75℃, and slowly inject the lipophilic phase into the aqueous phase at 65-75℃, while maintaining a high-speed shearing of 8000rpm during the injection process; After injection, continue stirring at 500 rpm for 30 minutes to form a crude liposome solution; S4: Homogenize the crude liposome solution by circulating it at 600 bar until the particle size is ≤200 nm; to obtain a liposome suspension. S5: The liposome suspension was tangentially filtered using an ultrafiltration membrane with a molecular weight cutoff of 100 kDa and concentrated to a liposome concentration of 10%; then sealed and stored for later use.

[0055] Table 1. Whitening Composition Ratio Table 1 (continued) Whitening Composition Ratio Example 2 The antioxidant properties of each skin-brightening composition prepared in Example 1 were tested, specifically including: DPPH methanol solution is violet in color and has a strong absorbance at 517 nm. If it binds to the sample, it will reduce the absorbance at 517 nm, thus determining the sample's ability to scavenge DPPH free radicals.

[0056] The specific method is as follows: (1) Take the sample from Example 1, mix it with sterile water, and prepare an equal volume (2 mL) of the test solution with a concentration of 2% and 2 × 10 4 Mix the mol / L DPPH solution thoroughly (Al); (2) Take equal volumes of anhydrous ethanol (the solvent for the analyte) and 2×10 4 Mix the mol / L DPPH solution thoroughly (A2); (3) Take an equal volume of anhydrous ethanol and mix it with the test solution (A3); (4) After reacting for 40 min, the absorbance values ​​of tubes A1, A2 and A3 were measured at 517 nm.

[0057] The formula for calculating the clearance rate is: Clearance rate (%) = [1 - (A1 - A3) / A2] × 100% The test results are shown in Table 2.

[0058] Table 2 Antioxidant Test Results According to the experimental data in Table 2, the contribution of the six different oils or essential oils to antioxidant activity is as follows: winter peppermint oil > field peppermint oil > spearmint oil > carrot seed oil > sea buckthorn oil > rosehip oil; and according to the comparison of serial numbers 1, 19, and 10, winter peppermint and carrot seed oil have a synergistic effect.

[0059] Example 3 To examine the whitening ability of each sample, a tyrosinase inhibition experiment was conducted for comparison; the specific method is as follows: The corresponding reagents and different volumes of the sample to be tested were added sequentially to the sample wells of the 96-well microplates corresponding to the 10 samples prepared in Example 1. After adding tyrosinase, the microplates were incubated at 37°C for 10 min, followed by the addition of L-tyrosine substrate solution, and the reaction was allowed to proceed for another 10 min. The absorbance (OD value) was then measured at a wavelength of 475 nm using a microplate reader.

[0060] Each sample was diluted with PBS solution to a concentration of 4%, and the results are shown in Table 3 below.

[0061] The formula for calculating the inhibition rate of tyrosinase activity is as follows: Tyrosinase inhibition rate (%) = The control group consisted of a mixture of tyrosinase and substrate. The blank group consisted of PBS solution.

[0062] Table 3 Results of tyrosinase inhibition According to the experimental results in Table 3, the contribution of winter pepper essential oil to tyrosinase inhibition is: winter pepper oil > carrot seed oil > sea buckthorn oil > rosehip oil and pepper. Among them, peppermint oil and spearmint oil have little contribution, and winter pepper oil and carrot seed oil have a synergistic effect.

[0063] Example 4 To compare different dosage forms, the following experiments were added.

[0064] The preparation of the skin-brightening composition includes the following steps: S1: The components are divided into fat-soluble components and water-soluble components according to their solubility, and each component is weighed according to the proportions in Table 4 below.

[0065] S2: The fat-soluble components are dissolved in anhydrous ethanol, with the amount of anhydrous ethanol being 5 times the total mass of the fat-soluble components. The mixture is stirred in a water bath at 40-60℃ until it is completely dissolved, forming a fat-soluble phase. The water-soluble components are dissolved in purified water, with the amount being 90% of the total mass of the aqueous phase. The solution is heated to 65°C and stirred until homogeneous to form the aqueous phase. S3: Keep the temperature of the aqueous phase between 65-75℃, and slowly inject the lipophilic phase into the aqueous phase at 65-75℃, while maintaining a high-speed shearing of 8000rpm during the injection process; After injection, continue stirring at 500 rpm for 30 minutes to form a crude liposome solution; S4: Homogenize the crude liposome solution by circulating it at 600 bar until the particle size is ≤200 nm; to obtain a liposome suspension. S5: Pre-freeze the liposome suspension at -80℃ for 4 hours to form a solid ice crystal framework; Transfer to a freeze dryer and freeze-dry at -40℃ and 0.1 mBar for 24 hours to remove free water by sublimation; Gradually increase the temperature to 10℃ and maintain at 0.005mBar for 6 hours to remove bound water and obtain porous liposome lyophilized powder, which is then sealed and stored for later use.

[0066] Table 4. Whitening Composition Ratio The DPPH clearance rate and tyrosinase inhibition of the porous liposome lyophilized powders prepared in Example 4 were tested using the same methods as in Examples 2 and 3. However, since the preparation in Example 4 is a solid lyophilized powder, it needs to be reconstituted beforehand; the test concentration for DPPH scavenging rate is 4%, and the test concentration for tyrosinase inhibition is 8%, as shown in Table 5 below.

[0067] Table 5 Test results for different dosage forms Compared with samples 1, 2, and 3 of Examples 4, the proportions of the core components in samples 11, 12, and 13 are completely identical. However, due to the doubling of the test concentration and the slightly lower proportion of added antioxidants and lyophilization protectants (less than 50%), the actual content of the core components is slightly higher. This results in a slight increase in the DPPH free radical scavenging rate and tyrosinase inhibition rate. It can be considered that the preparation of lyophilized powder has no negative impact on its performance.

[0068] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A skin-brightening composition, characterized in that, The following components are included in parts by weight: Mulberry leaf extract 2-3 Tea polyphenols 0.3-0.5 Licorice extract 0.5-0.8 Carrot seed oil 2-3 Winter peppermint oil 1.0-1.5g Plant-based emulsifier 1.0-1.5 Soy lecithin 3-5 Cholesterol 0.6-1.

2. The skin-brightening composition according to claim 1, characterized in that, The plant emulsifier is at least one of the following: sucrose polystearate, alkyl polysaccharide, or polyglycerol fatty acid ester.

3. The skin-brightening composition according to claim 1, characterized in that, The soybean lecithin is either hydrogenated or non-hydrogenated.

4. The skin-brightening composition according to claim 1, characterized in that, It also includes 4-6 parts of a component freeze-drying protectant; the freeze-drying protectant is mannitol and / or trehalose.

5. The skin-brightening composition according to claim 1, characterized in that, It also includes 0.1-0.2 parts of an antioxidant, wherein the antioxidant is at least one fat-soluble antioxidant and one water-soluble antioxidant.

6. A method for preparing the skin-brightening composition according to any one of claims 1-5, characterized in that, Includes the following steps: S1: The components are classified into fat-soluble components and water-soluble components based on their solubility; S2: The lipid-soluble components dissolve in anhydrous ethanol to form a lipid-soluble phase; the water-soluble components dissolve in water to form an aqueous phase. S3: Heat the aqueous phase, then inject the lipid-soluble phase into the aqueous phase; maintain a shear rate of at least 8000 rpm during the injection process; the heating temperature of the aqueous phase is higher than the phase transition temperature of soybean lecithin; After injection, stir to form a liposome solution; S4: The liposome solution is homogenized under high pressure or sonicated to reduce the particle size to ≤200 nm; a liposome suspension is obtained.

7. The method for preparing the skin-brightening composition according to claim 6, characterized in that, It also includes the following steps: S5: Freeze-dry the liposome suspension to obtain porous liposome freeze-dried powder.

8. The method for preparing the skin-brightening composition according to claim 7, characterized in that, Step S5 is as follows: The liposome suspension was pre-frozen at a maximum of -80°C for at least 4 hours, then freeze-dried at a maximum of -40°C / 0.1 mBar for 24 hours; finally, it was further dried by continuously raising the temperature to a maximum of 10°C / 0.005 mBar. Porous liposome lyophilized powder.

9. The method for preparing the skin-brightening composition according to claim 6, characterized in that, In step S4, when high-pressure homogenization is used, the pressure is ≥600 bar.

10. The application of the skin-brightening composition according to claims 1-5 in the preparation of cosmetics, characterized in that, The cosmetic product is at least one of the following: serum, face cream, lotion, skin lotion, essential oil, and freeze-dried agent.

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