A whitening soothing composition containing curcumin bisglucoside and application thereof

Abstract

The application discloses a whitening and soothing composition containing curcumin bisglucoside and application thereof, and belongs to the technical field of cosmetics. The whitening and soothing composition comprises curcumin bisglucoside, dunaliella salina extract, mulberry root extract and apple leaf extract, and the components are as follows in terms of mass parts: 5-15 parts of curcumin bisglucoside, 10-25 parts of dunaliella salina extract, 30-50 parts of mulberry root extract and 20-40 parts of apple leaf extract. The curcumin bisglucoside is scientifically compounded with three kinds of plant extracts, the components synergistically act, and the whitening and soothing effects are jointly exerted, so that the tyrosinase activity can be effectively inhibited, the melanin production can be reduced, meanwhile, the composition has excellent anti-inflammatory and soothing effects, and can significantly improve the problems of skin redness and sensitivity. The application also discloses a serum product containing the composition, the formula is mild, the safety is high, and the composition is suitable for various skin conditions, and is particularly suitable for the whitening care of sensitive skin.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and in particular to a whitening and soothing composition containing curcumin diglucoside and its application. Background Technology

[0002] Skin color is primarily determined by the amount and distribution of melanin. Excessive melanin production is the main cause of dull skin and age spots. Tyrosinase is the key rate-limiting enzyme in melanin synthesis, and inhibiting tyrosinase activity is one of the core pathways to achieving skin whitening effects. Currently, common whitening active ingredients on the market include niacinamide, vitamin C and its derivatives, arbutin, kojic acid, and tranexamic acid, but these ingredients have their own limitations, such as poor stability, skin irritation, and limited whitening effects.

[0003] Curcumin is a natural polyphenolic compound extracted from the rhizome of turmeric. It possesses various biological activities such as antioxidation, anti-inflammation, and whitening. However, its poor water solubility, low skin permeability, and susceptibility to oxidation and discoloration severely limit its application in cosmetics. Curcumin diglucoside, a glycosylated derivative of curcumin, significantly improves water solubility and stability through glucose modification while retaining the biological activity of curcumin, making it a promising new whitening ingredient. However, the whitening effect of a single ingredient is often limited, and it is difficult to simultaneously address skin sensitivity and redness that often accompany whitening processes.

[0004] During skin whitening treatments, inflammatory reactions often occur due to the stimulation of whitening ingredients or ultraviolet radiation, manifesting as redness, burning, stinging, and other sensitive symptoms. This inflammation, in turn, stimulates melanocyte activity, leading to increased pigmentation and the formation of "post-inflammatory hyperpigmentation." Therefore, developing compositions that simultaneously possess whitening and soothing anti-inflammatory effects, achieving a dual benefit of "whitening + repair," has become a current trend in whitening skincare products.

[0005] Plant extracts are widely used in whitening and soothing cosmetics due to their natural, gentle, and multi-target effects. Dunaliella salina is rich in active ingredients such as β-carotene and polysaccharides, possessing antioxidant properties and enhancing skin tolerance. Mulberry root extract contains flavonoids such as morin and resveratrol, which can inhibit tyrosinase activity and also have anti-inflammatory effects. Apple leaf extract is rich in polyphenols, possessing antioxidant, soothing, and anti-inflammatory properties. However, there are currently no reports of combining curcumin diglucoside with these three plant extracts in a specific ratio to synergistically enhance whitening and soothing effects. How to scientifically select active ingredients and optimize their proportions to achieve synergistic effects while ensuring product safety and gentleness is a pressing technical problem 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 a whitening and soothing composition containing curcumin diglucoside and its application.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a whitening and soothing composition containing curcumin diglucoside, the composition comprising curcumin diglucoside, Dunaliella salina extract, mulberry root extract, and apple leaf extract.

[0008] The curcumin diglucoside described in this invention is a compound formed by curcumin and two glucose molecules linked by a glycosidic bond, which can be synthesized by biological enzymatic methods or obtained commercially. The Dunaliella salina extract is an extract obtained by ester extraction, concentration, and drying of Dunaliella salina, rich in active ingredients such as β-carotene, Dunaliella salina polysaccharides, and glycerol. The mulberry root extract is an extract obtained from the dried roots of the mulberry plant (Morus alba), mainly containing flavonoids such as morin, resveratrol oxide, and morinol, as well as stilbene compounds. The apple leaf extract is an extract obtained from the dried leaves of the apple plant (Apple arborescens), rich in polyphenolic active ingredients such as phlorizin, phloretin, and chlorogenic acid.

[0009] Preferably, the composition comprises the following components in parts by weight: Curcumin diglucoside: 5-15 parts; Dunaliella salina extract: 10-25 parts; Mulberry root extract: 30-50 parts; Apple leaf extract: 20-40 parts.

[0010] The present invention, by selecting components within a specific mass range, produces a composition with significant whitening and soothing effects.

[0011] More preferably, the composition comprises the following components in parts by weight: Curcumin diglucoside: 10 parts; Dunaliella salina extract: 18 parts; Mulberry root extract: 40 parts; Apple leaf extract: 32 parts.

[0012] The present invention selects components within a specific mass range to obtain a composition with more significant whitening and soothing effects.

[0013] Secondly, the present invention provides the application of the whitening and soothing composition containing curcumin diglucoside described in the first aspect in the preparation of cosmetics with whitening and soothing effects.

[0014] Preferably, the cosmetic includes any one of serum, toner, lotion, cream, gel, spray, and mask.

[0015] Thirdly, the present invention provides a serum with whitening and soothing effects, the serum comprising the whitening and soothing composition containing curcumin diglucoside described in the first aspect.

[0016] Preferably, the essence also includes skin conditioning agents, thickeners, preservatives, and deionized water.

[0017] More preferably, the skin conditioning agent includes at least one of panthenol, allantoin, sodium hyaluronate, dipotassium glycyrrhizate, niacinamide, and tocopheryl acetate, which are used to further enhance the moisturizing, repairing and antioxidant effects of the product. The thickener includes at least one of carbomer, xanthan gum, sodium hydroxyethyl cellulose, acrylate copolymers, guar gum, stearic acid, cetyl alcohol, and sodium polyacrylate, used to adjust the viscosity and feel of the product. The preservative includes at least one of potassium sorbate, sodium benzoate, p-hydroxyacetophenone, phenoxyethanol, and methylparaben, used to ensure the microbiological safety of the product.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention, through extensive experimental screening, is the first to combine curcumin diglucoside with Dunaliella salina extract, mulberry root extract, and apple leaf extract in a specific ratio, resulting in a synergistic effect among the components. Curcumin diglucoside plays a core role in whitening and also possesses anti-inflammatory activity; Dunaliella salina extract focuses on repairing the skin barrier and enhancing skin tolerance; mulberry root extract inhibits melanin production through multiple targets while also exerting anti-inflammatory effects; and apple leaf extract focuses on antioxidant and immediate soothing properties, rapidly improving skin redness. These four ingredients work synergistically, exerting their effects through multiple pathways, including inhibiting melanin synthesis, scavenging free radicals through antioxidant action, inhibiting the release of inflammatory factors, and repairing the skin barrier. This significantly enhances both whitening and soothing effects, demonstrating excellent synergistic efficacy while substantially reducing skin irritation.

[0019] The whitening and soothing compositions of this invention all use naturally derived active ingredients. The formula is gentle and has undergone skin irritation testing, proving it is non-irritating and particularly suitable for sensitive skin. The serum product provided by this invention has a refreshing feel, is easily absorbed, and with long-term use, can significantly brighten skin tone, lighten dark spots, and improve skin sensitivity and redness, achieving both whitening and repairing effects. Detailed Implementation

[0020] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific compositions.

[0021] The raw materials and their sources for this invention are as follows: Curcumin diglucoside: prepared by the method described in Example 5 of Patent Publication No. CN119913089B; Dunaliella salina extract: from Qiushi (Shandong) Import & Export Trading Co., Ltd.; Mulberry root extract: from Guangzhou Bochi Biotechnology Co., Ltd.; Apple leaf extract: from Qiushi (Shandong) Import & Export Trading Co., Ltd.; Unless otherwise specified, all other materials and reagents used in this invention are commercially available.

[0022] Preparation of a whitening and soothing composition containing curcumin diglucoside Composition 1 Composed of the following components by mass: 5 parts of curcumin diglucoside; 10 parts of Dunaliella salina extract; 30 parts of mulberry root extract; 20 parts of apple leaf extract; Preparation method: Mix the above components evenly, seal, protect from light, and store at 4°C.

[0023] Composition 2 Composed of the following components by mass: 10 parts of curcumin diglucoside; 18 portions of Dunaliella salina extract; 40 parts of mulberry root extract; 32 parts of apple leaf extract; The preparation method is the same as that of composition 1.

[0024] Composition 3 Composed of the following components by mass: 15 parts of curcumin diglucoside; 25 parts of Dunaliella salina extract; 50 parts of mulberry root extract; 40 parts of apple leaf extract; The preparation method is the same as that of composition 1.

[0025] Comparative Example 1 Unlike composition 2, it lacks Dunaliella salina extract. The missing mass fraction is made up by mulberry root extract and apple leaf extract in a mass ratio of 5:4. The mass fractions of the remaining components and the preparation method are the same as those of composition 2.

[0026] Comparative Example 2 Unlike composition 2, it lacks mulberry root extract. The missing mass fraction is made up by Dunaliella salina extract and apple leaf extract in a mass ratio of 9:16. The mass fractions of the remaining components and the preparation method are the same as those of composition 2.

[0027] Comparative Example 3 Unlike composition 2, it lacks apple leaf extract. The missing mass fraction is made up by Dunaliella salina extract and mulberry root extract in a mass ratio of 9:20. The mass fractions of the remaining components and the preparation method are the same as those of composition 2.

[0028] Comparative Example 4 Composed of the following components by mass: 10 parts of curcumin diglucoside; Eight portions of Dunaliella salina extract; 25 parts of mulberry root extract; 57 parts of apple leaf extract; The preparation method is the same as that of composition 2.

[0029] Preparation of a serum with whitening and soothing effects serum base Composed of the following components by mass percentage: Panthenol: 5 wt% Allantoin: 0.2 wt%; Sodium hyaluronate: 0.1 wt% Dipotassium glycyrrhizate: 0.1 wt%; Nicotinamide: 0.9 wt% Carbomer: 0.2 wt% p-Hydroxyacetophenone: 0.5 wt% 1,3-Butanediol: 5.0 wt% Triethanolamine: Appropriate amount; Deionized water replenished to 100%; Preparation method: Disperse carbomer in deionized water and stir until it swells evenly; add 1,3-butanediol, panthenol, allantoin, sodium hyaluronate, dipotassium glycyrrhizate, and nicotinamide, heat to 75°C, and stir until dissolved evenly; cool to 45°C, add p-hydroxyacetophenone, and stir evenly; add triethanolamine to adjust the pH to 6.5, stir evenly, and cool to room temperature to obtain the final product.

[0030] Serum 1 Composed of the following components by mass percentage: Composition 1: 2.0 wt% The serum base was replenished to 100 wt%; Preparation method: Mix composition 1 with the serum base evenly to obtain the serum.

[0031] Serum 2 Composed of the following components by mass percentage: Composition 2: 2.0 wt% The serum base was replenished to 100 wt%; Preparation method: Mix composition 2 with the essence base evenly to obtain the essence.

[0032] Serum 3 Composed of the following components by mass percentage: Composition 3: 2.0 wt% The serum base was replenished to 100 wt%; Preparation method: Mix composition 3 with the essence base evenly to obtain the essence.

[0033] Comparison of serum 1 The only difference from Essence 2 is that the composition number is different, and Comparative Example 1 is used to replace Composition 2 with the same mass percentage.

[0034] Comparison of serum 2 The only difference from Essence 2 is that the composition number is different, and Comparative Example 2 is used to replace Composition 2 with the same mass percentage.

[0035] Comparison of serums 3 The only difference from Essence 2 is that the composition number is different, and Comparative Example 3 is used to replace Composition 2 by the same mass percentage.

[0036] Comparison of serum 4 The only difference from Essence 2 is that the composition number is different, and Comparative Example 4 is used to replace Composition 2 by the same mass percentage.

[0037] Efficacy test Test Example 1: Tyrosinase Inhibitory Activity Test 1.1 Reagents and Instruments Reagents: mushroom tyrosinase, L-DOPA, sodium dihydrogen phosphate, disodium hydrogen phosphate, dimethyl sulfoxide; Instruments: Multifunctional microplate reader (SpectraMaxi3x, Molecular Devices), 96-well plate (Corning), constant temperature water bath, high-precision pipette.

[0038] 1.2 Solution Preparation Phosphate-buffered saline (PBS): Accurately weigh 3.12 g of sodium dihydrogen phosphate and 7.17 g of disodium hydrogen phosphate, add deionized water to dissolve and bring the volume to 1000 mL, adjust the pH to 6.8, filter through a 0.22 μm filter membrane for sterilization, and store at 4 °C for later use. Tyrosinase solution: Take mushroom tyrosinase and prepare an enzyme solution of 100 U / mL with PBS buffer. Prepare fresh before use. L-DOPA substrate solution: Accurately weigh L-DOPA and prepare a 2.5 mmol / L substrate solution with PBS buffer. Store in the dark and use immediately after preparation. Sample solution: Take the compositions of Compositions 1-3 and Comparative Examples 1-4 respectively, dissolve them in DMSO to prepare a stock solution of 1 mg / mL, and then dilute it with PBS buffer to a concentration of 50 μg / mL. 1.3 Test Procedure The reaction was carried out using a 96-well plate, with a total reaction volume of 200 μL per well. The samples were added in the following order: Sample group: Add 140 μL of PBS buffer, 20 μL of sample solution and 20 μL of tyrosinase solution in sequence, and gently pipette to mix. Control group (no sample): Add 160 μL of PBS buffer and 20 μL of tyrosinase solution sequentially, and gently mix by pipetting. Blank group (enzyme-free): Add 160 μL of PBS buffer and 20 μL of sample solution in sequence, and gently mix by pipetting. Pre-incubate the 96-well plate in a 37°C constant temperature water bath for 10 minutes; Add 20 μL of L-DOPA substrate solution to each well quickly, and immediately place the well in a microplate reader. Measure the absorbance continuously at 475 nm wavelength, taking a reading every 30 seconds for a total of 10 minutes. Each sample was set up with 3 replicates, and the experiment was repeated 3 times and the average value was taken.

[0039] 1.4 Calculation Method Plot a kinetic curve with reaction time on the x-axis and absorbance on the y-axis. Calculate the enzyme reaction rate by taking the slope within the linear range of the reaction. The formula for calculating the tyrosinase inhibition rate is as follows: Inhibition rate (%) = [1 - (slope of sample group - slope of blank group) / (slope of control group - slope of blank group)] × 100% The results are shown in Table 1.

[0040] Table 1 Effect of the composition on tyrosinase activity Composition 1 74.1 Composition 2 76.8 Composition 3 69.8 Comparative Example 1 54.2 Comparative Example 2 46.6 Comparative Example 3 50.3 Comparative Example 4 55.8 As shown in Table 1, compositions 1-3 of the present invention all exhibit significant inhibitory effects on tyrosinase. Among them, composition 2 shows the highest tyrosinase inhibition rate, reaching 76.8%, which is significantly higher than the other pairs. The tyrosinase inhibition rates of each pair decreased to varying degrees due to the absence of a certain component or proportions exceeding the scope of the present invention. This indicates that the four components work synergistically within the specific ratio range of the present invention to exert excellent whitening and soothing effects.

[0041] Test Example 2: Anti-inflammatory and soothing efficacy test of the composition 2.1 Reagents and Instruments Cell line: RAW264.7 mouse mononuclear macrophages (Chinese Academy of Sciences Cell Bank); Reagents: DMEM high glucose medium, fetal bovine serum, penicillin-streptomycin antibiotics, lipopolysaccharide, CCK-8 cytotoxicity assay kit, mouse IL-6 ELISA kit, PBS buffer, 0.25% trypsin-EDTA digestion solution; Instruments: CO2 incubator (ThermoFisher), clean bench, inverted microscope, multi-functional microplate reader, centrifuge, 96-well cell culture plate.

[0042] 2.2 Cell Culture RAW264.7 cells were cultured in DMEM high-glucose medium containing 10% fetal bovine serum and 1% penicillin-streptomycin, and placed in an incubator at 37°C, 5% CO2, and saturated humidity. Cells were passaged every 2-3 days, and cells in the logarithmic growth phase were used for experiments.

[0043] 2.3 Cytotoxicity assay (CCK-8 assay) Log-phase RAW264.7 cells were digested with 0.25% trypsin to adjust the cell concentration to 1×10⁻⁶. 5 Cells were seeded at a density of 100 μL / mL in 96-well plates and incubated for 24 h to allow the cells to adhere to the plate. Discard the old culture medium and add fresh culture medium containing different concentrations of samples (compositions 1-3, comparative examples 1-4), 100 μL per well. The final sample concentrations are 12.5, 25, 50, 100, and 200 μg / mL, respectively. Three replicates are set up for each concentration. At the same time, a blank control group (only culture medium is added without cells) and a normal control group (cells are added without samples) are also set up. After culturing for another 24 hours, add 10 μL of LCK-8 solution to each well, avoiding the generation of air bubbles; Incubate in an incubator for 2 hours, and then measure the absorbance at 450 nm using a microplate reader. Cell viability (%) = (OD value of sample group - OD value of blank group) / (OD value of normal control group - OD value of blank group) × 100% Based on the cytotoxicity results, the concentration with a cell viability rate >90% was selected as the working concentration for subsequent anti-inflammatory experiments.

[0044] 2.4 Anti-inflammatory activity test The cytotoxicity test results showed that the cell viability of all samples was ≥90% at a concentration of 50 μg / mL, with no obvious cytotoxicity. Therefore, this concentration was selected as the working concentration.

[0045] RAW264.7 cells in logarithmic growth phase were selected and the cell concentration was adjusted to 2 × 10⁻⁶.5 1 mL of the solution was seeded into each well of a 24-well plate and cultured for 24 h to allow the cells to adhere. Discard the old culture medium and add 500 μL of fresh culture medium containing the sample (final concentration 50 μg / mL) for 2 h of pretreatment; Add LPS solution to bring the final LPS concentration to 1 μg / mL and continue culturing for 24 h. Collect the cell supernatant, centrifuge at 3000 rpm for 10 min at 4℃, and take the supernatant; Follow the instructions for the mouse IL-6 ELISA kit: Set up standard wells and sample wells, and add 50 μL of standard at different concentrations to the standard wells; Add 50 μL of the supernatant to be tested to the sample well; Add 100 μL of enzyme-labeled reagent to each well, seal the plate, and incubate at 37°C for 60 min. Discard the liquid, spin dry, fill each hole with washing solution, let stand for 30 seconds and then discard, repeat washing 5 times; Add 50 μL of color developer A to each well, then add 50 μL of color developer B, gently shake to mix, and develop color at 37°C in the dark for 15 min. Add 50 μL of stop solution to each well and measure the absorbance at 450 nm wavelength using an ELISA reader within 15 min. The concentration of IL-6 in each sample was calculated based on the standard curve; Formula for calculating IL-6 release inhibition rate: Inhibition rate (%) = (1 - IL-6 concentration in the sample group / IL-6 concentration in the LPS model group) × 100% The average of the experimental results is shown in Table 2.

[0046] Table 2. Effects of the composition on anti-inflammatory and soothing effects. Composition 1 52.2 Composition 2 55.8 Composition 3 50.5 Comparative Example 1 38.2 Comparative Example 2 40.8 Comparative Example 3 43.7 Comparative Example 4 46.6 As shown in Table 2, compositions 1-3 of the present invention significantly inhibited the release of the inflammatory cytokine IL-6 induced by LPS in mouse monocytes and macrophages. Among them, composition 2 showed the highest IL-6 release inhibition rate, reaching 55.8%, which was significantly higher than that of the other pairs. The IL-6 release inhibition rates of the other pairs were all lower than those of the compositions of the present invention, further verifying the synergistic soothing effect of the four components in the formulation of the present invention.

[0047] Test Example 3: Effect of the Composition on Hyaluronidase Inhibition Rate 3.1 Reagents and Instruments Reagents: Hyaluronidase, sodium hyaluronate, acetic acid, sodium acetate, p-dimethylaminobenzaldehyde, acetylacetone, hydrochloric acid, sodium hydroxide, dimethyl sulfoxide; Instruments: Multifunctional microplate reader, 96-well plate, constant temperature water bath, high-precision pipette, vortex mixer, EP tube (or test tube).

[0048] 3.2 Solution Preparation Acetic acid-sodium acetate buffer (pH 5.0): Accurately weigh 13.6g of sodium acetate, dissolve it in deionized water, adjust the pH to 5.0 with glacial acetic acid, bring the volume to 1000mL, and store at 4℃ for later use. Hyaluronidase solution: Take hyaluronidase and prepare an enzyme solution of 1200 U / mL with acetate-sodium acetate buffer. Prepare fresh before use. Sodium hyaluronate substrate solution: Accurately weigh sodium hyaluronate and prepare a 0.5 mg / mL substrate solution with acetate-sodium acetate buffer. Store at 4°C for later use. Acetylacetone reagent: Accurately weigh 0.5 mL of acetylacetone, add 50 mL of 0.5 mol / L sodium carbonate solution, mix well, and use immediately. DMAB reagent: Accurately weigh 1.6g of p-dimethylaminobenzaldehyde, add 15mL of concentrated hydrochloric acid, then add 105mL of isopropanol, mix well, and store at 4℃ protected from light for later use. Sample solution: Take the compositions of Compositions 1-3 and Comparative Examples 1-4 respectively, dissolve them in DMSO to prepare a stock solution of 1 mg / mL, and dilute with acetate-sodium acetate buffer to a final concentration of 100 μg / mL during testing. The final concentration of DMSO shall not exceed 1%.

[0049] 3.3 Test Procedure The hyaluronidase inhibition rate was determined using the Elson-Morgan method, following these steps: Sample group: Add 25 μL of acetate-sodium acetate buffer, 25 μL of sample solution and 25 μL of hyaluronidase solution in sequence, mix gently by pipetting, and incubate in a water bath at 37°C for 20 min. Enzyme control group: Add 25 μL of acetate-sodium acetate buffer, 25 μL of acetate-sodium acetate buffer, and 25 μL of hyaluronidase solution in sequence, mix gently by pipetting, and incubate in a water bath at 37°C for 20 min. Blank control group: Add 50 μL of acetate-sodium acetate buffer and 25 μL of acetate-sodium acetate buffer in sequence, mix gently by pipetting, and incubate in a water bath at 37°C for 20 min; After incubation, add 25 μL of sodium hyaluronate substrate solution to each reaction tube, gently mix by pipetting, and continue incubation in a 37°C water bath for 40 min. The reaction was terminated by adding 10 μL of 0.4 mol / L sodium hydroxide solution to each reaction tube; Add 25 μL of acetylacetone reagent to each reaction tube, vortex to mix, heat in a 100°C water bath for 15 min, and immediately place in ice water to cool for 5 min. Add 200 μL of DMAB reagent to each reaction tube, vortex to mix, and let stand at room temperature for 10 min for color development; After the reaction was completed, 200 μL of the reaction solution was transferred to a 96-well plate, and the absorbance value at 585 nm was measured using an ELISA reader. Each sample was set up with 3 replicates, and the experiment was repeated 3 times and the average value was taken.

[0050] 3.4 Calculation Method The formula for calculating the hyaluronidase inhibition rate is as follows: Inhibition rate (%) = [1 - (OD value of sample group - OD value of blank group) / (OD value of enzyme control group - OD value of blank group)] × 100% The experimental results are shown in Table 3.

[0051] Table 3. Inhibitory effect of the composition on hyaluronidase Composition 1 60.4 Composition 2 67.2 Composition 3 64.7 Comparative Example 1 48.1 Comparative Example 2 47.5 Comparative Example 3 57.3 Comparative Example 4 52.6 As shown in Table 3, compositions 1-3 of the present invention all exhibit significant inhibitory effects on hyaluronidase. Among them, composition 2 shows the highest hyaluronidase inhibition rate, reaching 67.2%, which is significantly higher than the other pairs. The hyaluronidase inhibition rates of each pair decreased to varying degrees, indicating that the four components have a synergistic effect on hyaluronidase inhibition within the specific ratio range of the present invention.

[0052] Test Example 4: Safety Test 4.1 Test Subjects We are recruiting 30 healthy volunteers, regardless of gender, aged 20-45 years (mean age 31.5 years). Inclusion criteria: no history of skin diseases, no use of corticosteroids or immunosuppressants within the past month, no use of antihistamines within the past week, and no skin lesions, erythema, papules, or other abnormalities on the forearm. Exclusion criteria: pregnant or breastfeeding women, individuals with allergies, and those currently participating in other clinical trials. All volunteers must sign an informed consent form.

[0053] 4.2 Test Materials Spot tester, hypoallergenic medical tape, serum 1-3, control serum 1-4, serum matrix, deionized water (negative control), 0.2% sodium dodecyl sulfate (SDS, positive control).

[0054] 4.3 Test Methods Clean the skin on the flexor side of the subject's forearm before the experiment and apply the patch after it dries. 0.02 mL of the test sample was added dropwise onto the filter paper of the spot tester. The negative control was deionized water and the positive control was 0.2% SDS. Secure the spot tester to the flexor side of the subject's forearm with low-sensitivity tape and gently press it to ensure close contact with the skin. Remove the patch applicator 24 hours after application, gently wipe away any remaining test substance with a dry cotton ball, and mark each patch site. Observe the skin reaction at each site under natural light at 0.5h, 24h, and 48h after removing the patch applicator, and score and record the adverse skin reaction according to the grading standard of adverse skin reaction in the "Cosmetic Safety Technical Specifications" (2015 edition).

[0055] 4.4 Evaluation Criteria Skin Reaction Grading Standards: Level 0: No response; Grade 1: Mild erythema, faintly visible, smaller than the tested area; Grade 2: Obvious erythema covering the entire affected area, which may be accompanied by mild edema; Grade 3: Erythema, edema, papules, extending beyond the tested area; Grade 4: Erythema, edema, papules, vesicles, bullae, with the affected area significantly extending beyond the test area; A reaction of grade 1 or higher is considered a positive skin irritation.

[0056] The test results showed that, except for the positive group, the skin reaction grades of the other sample groups and the blank group were all 0, indicating that the essence and essence base provided by the present invention are safe and non-irritating.

[0057] Test Example 5: Human Efficacy Evaluation Trial 5.1 Test Subjects We are recruiting 75 qualified healthy volunteers, regardless of gender, aged 22-45. Inclusion criteria: dull skin tone (ITA° value <40), facial redness and sensitivity (a* value >15), no participation in other efficacy clinical trials within the past 3 months, and no use of whitening or anti-allergy skincare products within the past month. Exclusion criteria: pregnant or breastfeeding women, those with serious systemic diseases, those with acute facial inflammation or skin diseases, and those allergic to any ingredient in the test product. All volunteers must sign an informed consent form.

[0058] 5.2 Experimental Grouping and Methods This study employed a randomized, double-blind, controlled trial design, randomly assigning 75 volunteers to each group of 15. The experimental group used Serum 2, while the control groups used Comparison Serum 1, Comparison Serum 2, and Comparison Serum 3, respectively. The control group used the serum base. Directions for use: After cleansing morning and evening, apply an appropriate amount of serum evenly to the face and gently massage until absorbed. Use continuously for 8 weeks. During the trial period, avoid using other whitening or anti-allergy skincare products and avoid sun exposure.

[0059] 5.3 Test Indicators and Methods Tests were conducted before use (week 0) and at week 8. Before the test, the subjects sat quietly for 30 minutes in a constant temperature and humidity room (temperature 22±1℃, relative humidity 50±5%).

[0060] Skin tone whiteness test: The CR-400 colorimeter (KONICA MINOLTA) measures the ITA° value at four locations: the center of the forehead, left cheek, right cheek, and center of the jawline, and takes the average value. The higher the ITA° value, the whiter the skin tone.

[0061] Skin redness test: The CIELab color space parameters of the same area of ​​the face were measured using a CR-400 colorimeter (Konica Minolta), and the a* value was recorded and averaged. The higher the a* value, the more severe the redness.

[0062] 5.4 Test Results ITA° value change rate = (Week 8 test value - Week 0 test value) / Week 0 test value × 100% a* value change rate = (Week 0 test value - Week 8 test value) / Week 0 test value × 100% The experimental results are shown in Table 4.

[0063] Table 4 Results of Human Efficacy Tests for Serums

[0064] As shown in Table 4, after 8 weeks of continuous use, the ITA° change rate of the experimental group (Essence 2) was 16.5%, significantly better than that of the control essence. Among them, the control essence group 2 (lacking mulberry root extract) had the lowest ITA° change rate, further confirming that mulberry root extract is the most crucial contributor to the whitening effect. This is consistent with the tyrosinase inhibitory activity of flavonoid components such as morin and resveratrol in mulberry root extract. The ITA° change rate of the blank group was 5.6%, and the net increase in efficacy of the experimental group compared to the blank group reached 10.9 percentage points, fully demonstrating that the composition of this invention has a significant whitening and enhancing effect.

[0065] The experimental group showed a 15.5% change rate in a* value, significantly better than the control serum. The control serum group 1 (lacking Dunaliella salina extract) had the lowest a* change rate, further confirming that Dunaliella salina extract is the most crucial contributor to anti-inflammatory and soothing effects, consistent with the anti-inflammatory activity of its rich β-carotene and Dunaliella salina polysaccharides. The control group showed a 6.4% change rate in a* value (panthenol, dipotassium glycyrrhizate, etc., in the matrix provided basic soothing effects). The experimental group showed a net increase of 9.1 percentage points compared to the control group, indicating that the composition of this invention, together with the soothing components in the matrix, exerts excellent soothing and redness-reducing effects.

[0066] It is worth noting that although Comparative Example 1 (Halogen-deficient Dunaliella salina) showed the best whitening effect among the default control group, it had the worst soothing effect; Comparative Example 2 (deficient mulberry root) and Comparative Example 3 (deficient apple leaf) both showed varying degrees of reduction in whitening and soothing effects. Only Composition 2 of the present invention, containing all four components, can achieve optimal results in both whitening and soothing dimensions, fully demonstrating that the four components work together within the specific ratio range of the present invention to exert a synergistic effect of whitening and soothing.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended 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. A whitening and soothing composition containing curcumin diglucoside, characterized in that, The composition includes curcumin diglucoside, Dunaliella salina extract, mulberry root extract, and apple leaf extract.

2. The composition according to claim 1, characterized in that, Includes the following components by weight: Curcumin diglucoside: 5-15 parts; Dunaliella salina extract: 10-25 parts; Mulberry root extract: 30-50 parts; Apple leaf extract: 20-40 parts.

3. The composition according to claim 2, characterized in that, The composition comprises the following components in parts by weight: Curcumin diglucoside: 10 parts; Dunaliella salina extract: 18 parts; Mulberry root extract: 40 parts; Apple leaf extract: 32 parts.

4. The use of the composition according to any one of claims 1-3 in the preparation of cosmetics having whitening and soothing effects.

5. The application as described in claim 4, characterized in that, The cosmetic formulation is any one of the following: serum, toner, lotion, cream, mask, gel, or spray.

6. A serum with whitening and soothing effects, characterized in that, The serum comprises the whitening and soothing composition containing curcumin diglucoside as described in any one of claims 1-3.

7. The essence as described in claim 6, characterized in that, The serum also includes skin conditioning agents, thickeners, preservatives, and deionized water.

8. The essence as described in claim 7, characterized in that, The skin conditioning agent includes at least one of panthenol, allantoin, sodium hyaluronate, dipotassium glycyrrhizate, nicotinamide, and tocopheryl acetate.

9. The essence as described in claim 7, characterized in that, The thickener includes at least one of carbomer, xanthan gum, sodium hydroxyethyl cellulose, acrylate copolymers, guar gum, stearic acid, cetyl alcohol, and sodium polyacrylate.

10. The essence as described in claim 7, characterized in that, The preservative includes at least one of potassium sorbate, sodium benzoate, p-hydroxyacetophenone, phenoxyethanol, and methylparaben.

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