Plant sunscreen synergist, preparation method and application

Abstract

The invention relates to the field of cosmetics, in particular to a plant sunscreen synergist as well as a preparation method and application thereof. The plant sunscreen synergist is composed of a scutellaria baicalensis extract, a tea leaf extract and a ligusticum wallichii extract, and when the weight ratio of the scutellaria baicalensis extract to the tea leaf extract to the ligusticum wallichii extract is 3: 1: 1, the synergist has the absorption effect of effective coverage of different UV wave bands, and the ultraviolet ray absorption effect is optimal.

Description

Technical Field

[0001] This invention relates to the field of cosmetics, specifically to a plant-based sunscreen enhancer, its preparation method, and its application. Background Technology

[0002] Cosmetic sunscreens are the core active ingredients in sunscreens, sun lotions, and other products, designed to protect the skin from damage caused by ultraviolet rays (UVA and UVB). They are divided into chemical sunscreens and plant-based sunscreens.

[0003] Chemical sunscreens work by "absorbing and converting" ultraviolet (UV) radiation. The molecular structure of these ingredients absorbs specific wavelengths of UV radiation (mainly UVA and / or UVB). After absorbing energy, the molecules change from their ground state to an excited state, releasing the energy as a low-grade heat, thus preventing direct UV damage to skin cells. However, some chemical ingredients (such as benzophenone-3 and octocrylene) may pose a risk of irritation or sensitization to sensitive skin. A few ingredients (such as avobenzone) have poor photostability and require the use of other stabilizers. Furthermore, some ingredients (such as ethylhexyl methoxycinnamate) are considered by research to have potential impacts on aquatic ecosystems such as coral reefs.

[0004] Unlike chemical sunscreens, plant-based sunscreens not only block ultraviolet rays but also have anti-inflammatory and repairing effects on the skin, thereby reducing erythema and achieving a sun protection effect. Furthermore, plant-based sunscreens are generally of safe and reliable origin, with a lower probability of causing adverse reactions, making them more popular with consumers.

[0005] However, plant-based sunscreens have certain limitations, such as limited UV absorption capacity and incomplete wavelength coverage. Therefore, research into solutions to these limitations is of great significance. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a plant-based sunscreen synergist, its preparation method, and its application.

[0007] The plant-based sunscreen enhancer described in this invention is composed of Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract.

[0008] The Scutellaria baicalensis extract was obtained using an aqueous solution containing butylene glycol and sodium metabisulfite as the extraction solvent. The concentrations of butylene glycol and sodium metabisulfite in the aqueous solution were 12-30 wt% and 0.1-0.8 wt%, respectively.

[0009] The extract of Ligusticum chuanxiong was obtained using an aqueous solution containing butylene glycol and ethanol as the extraction solvent. The concentrations of butylene glycol and ethanol in the aqueous solution were 15-30 wt% and 15-35 wt%, respectively.

[0010] The extraction temperatures for both Scutellaria baicalensis extract and Ligusticum chuanxiong extract were 45-60℃, and the extraction time for both was 2-6 hours.

[0011] Tea extract was obtained using an aqueous solution containing butylene glycol and sodium metabisulfite as the extraction solvent. The weight ratio of water, butylene glycol, and sodium metabisulfite in the aqueous solution was (75-85):(18-23):(0.3-0.8). The extraction temperature and time were 50-60℃ and 1.5-2.5 h, respectively.

[0012] After extraction, the extracts of the above three substances may include post-processing steps, which may include at least one of the following processes: filtration, addition of preservatives, and decolorization. For example, after extracting Scutellaria baicalensis with an extraction solvent, post-processing may include microporous membrane filtration and the addition of preservatives. After extracting Ligusticum chuanxiong with an extraction solvent, post-processing may include filtration using a microporous membrane. After extracting tea leaves with an extraction solvent, post-processing may include decolorization and microporous filtration.

[0013] Scutellaria baicalensis extract (whose main active ingredients are baicalin and baicalein) is a commonly used anti-inflammatory and antioxidant ingredient in sunscreen products. Its mechanism of action includes: absorbing ultraviolet rays (especially UVA / UVB bands), scavenging free radicals (reducing oxidative stress damage), inhibiting tyrosinase activity (indirectly reducing melanin production), and anti-inflammatory and soothing (relieving redness and pain of the skin after sun exposure).

[0014] The core functions of Ligusticum chuanxiong extract (whose main active ingredients are tetramethylpyrazine and ferulic acid) are to inhibit melanin production (by inhibiting tyrosinase activity) and to provide antioxidant protection (by scavenging free radicals). In sunscreen products, it not only enhances the sun protection effect but also prevents post-sun pigmentation (such as age spots and dullness).

[0015] Tea extract (whose main active ingredients are tea polyphenols and catechins) is a commonly used antioxidant ingredient in sunscreen products. Its functions include: absorbing ultraviolet rays (especially UVA band), scavenging free radicals (reducing UV-induced oxidative damage), inhibiting collagen degradation (preventing photoaging), and enhancing the stability of sunscreen agents (such as when combined with titanium dioxide and zinc oxide to reduce their photocatalytic activity).

[0016] The plant-based sunscreen synergist of this invention is composed of Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract in a weight ratio of (1-3):(1-2):(1-2). The synergist obtained within the above-mentioned ratio range can effectively cover the entire ultraviolet spectrum and part of the visible blue light region. Furthermore, when the ratio of the three components is 3:1:1, the synergist can effectively cover and absorb UV light of different wavelengths, and its ultraviolet absorption effect is optimal.

[0017] The present invention also provides a method for preparing the plant-based sunscreen enhancer, including a step of mixing the three components.

[0018] The present invention also provides the application of the plant-based sunscreen enhancer in the preparation of cosmetics, wherein the cosmetics include the plant-based sunscreen enhancer and fermentation products.

[0019] The fermentation products mentioned above are obtained by crushing, boiling, cooling, fermenting, sterilizing, and filtering *Magnolia denudata* and *Dendrobium nobile*. The fermentation process employs anaerobic fermentation using *Lactobacillus casei* and *Lactobacillus rhamnosus*. The strain number of *Lactobacillus casei* is CICC 6107, and the strain number of *Lactobacillus rhamnosus* is CICC 6151.

[0020] The method for preparing the fermentation product includes: crushing *Magnolia denudata* and *Dendrobium nobile* at a weight ratio of 1:2-4, adding 10-40 times the weight of water to the crushed material, boiling, and cooling to room temperature to obtain a cooled product. Sugar and fermentation bacteria are then added, and the mixture is anaerobic fermented at 20-40℃ for 3-6 days. Fermentation is terminated by sterilization, and the mixture is filtered to obtain the fermentation product. The amount of sugar added is 0.1-1% of the weight of the cooled product, and the amount of fermentation bacteria added is 1×10⁻⁶. 10 -1×10 12 Count of bacteria / g of cooled material. The ratio of viable Lactobacillus casei to Lactobacillus rhamnosus in the fermentation bacteria was 1:0.5-2.

[0021] The aforementioned cosmetics, by weight percentage, comprise: 1-15% of the aforementioned plant-based sunscreen enhancer, 1-20% of fermentation products, 2-6% of oils, 2-3% of emulsifiers, 3-6% of polyols, and the balance being water.

[0022] The advantages of this invention compared to the prior art are:

[0023] This invention utilizes a specific preparation method to prepare the aforementioned Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract. Testing based on the UV absorption characteristics of these extracts revealed that all three extracts absorb in the UVB (280-315nm) band; they also absorb in the UVA (315-400nm) band, with Ligusticum chuanxiong extract showing slightly weaker absorption; in the blue light absorption band (400-500nm), Scutellaria baicalensis extract exhibits strong absorption, tea extract shows weak absorption, and Ligusticum chuanxiong extract shows virtually no absorption. Based on this research, it can be demonstrated that a broad-spectrum coverage of UVA, UVB, and part of the blue light region can be achieved by combining the three plant extracts in a certain proportion. Specifically, Scutellaria baicalensis extract exhibits strong absorption in both UVA and blue light regions, tea extract shows stable absorption in both UVA and UVB regions, and while Ligusticum chuanxiong extract shows weak absorption in the blue light region, it still possesses certain protective potential in the UVB region. Therefore, according to the research of this invention, the synergistic effect of the three components is expected to improve the overall performance of the plant-based sunscreen system. Furthermore, to further verify the influence of the compounding ratio on sunscreen performance, this invention selected different ratios of Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract to obtain plant-based sunscreen synergists, and tested the UV absorption effect of their aqueous solutions. The test showed that when the solution of the plant-based sunscreen synergist obtained by combining Scutellaria baicalensis extract: Ligusticum chuanxiong extract: tea extract = 3:1:1 (mass ratio) was scanned across the entire wavelength range of 200-600 nm using a Feyond-A300 microplate reader, the plant-based sunscreen synergist exhibited significant and continuous absorption peaks in both the UVB (280-315nm) and UVA (315-400nm) regions. Scutellaria baicalensis contributed the main blue light absorption (400-500nm), tea enhanced UVB stability, and Ligusticum chuanxiong supplemented mid-wave ultraviolet protection. The synergistic effect of the three components achieved effective coverage and high-efficiency protection of the entire ultraviolet spectrum and part of the visible blue light region.

[0024] This invention uses the above-mentioned plant-based sunscreen enhancers to prepare cosmetic products with excellent anti-ultraviolet effects. In addition, the cosmetic products also contain fermentation products obtained by co-fermentation of Magnolia officinalis and Dendrobium nobile with Lactobacillus casei and Lactobacillus rhamnosus. When combined with the plant-based sunscreen enhancers, they work synergistically to significantly improve the effect of the cosmetic products in protecting cells from ultraviolet damage. Attached Figure Description

[0025] Figure 1 : Flavonoid standard curve.

[0026] Figure 2 Absorption wavelength-absorbance standard curves of diluted solutions of Scutellaria baicalensis extract, tea extract and Ligusticum chuanxiong extract.

[0027] Figure 3Absorption wavelength-absorbance standard curve of plant sunscreen synergist diluted solution made from Scutellaria baicalensis extract, tea extract and Ligusticum chuanxiong extract in different proportions.

[0028] Figure 4 Cell survival rate in each group.

[0029] Figure 5 The percentage decrease in cell viability of product BH compared to product A. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0032] Example 1: Preparation of Scutellaria baicalensis extract, tea extract and Ligusticum chuanxiong extract

[0033] Preparation of Scutellaria baicalensis extract:

[0034] Extraction solvent: an aqueous solution containing 25 wt% 1,3-butanediol and 0.6 wt% sodium metabisulfite;

[0035] Extraction method: The powder (obtained by crushing Scutellaria baicalensis slices and passing them through a 50-mesh sieve) and the extraction solvent were mixed at a weight ratio of 1:8 and stirred at 55℃ and 80 rpm for 5 hours. After filtering out the residue through a 300-mesh filtration, the filtrate was filtered through a microporous membrane with a pore size of 0.45 micrometers to obtain the extract. The extract was then mixed with 0.3% p-hydroxyacetophenone by weight to obtain the Scutellaria baicalensis extract.

[0036] Preparation of tea extract: Refer to Example 1 of invention patent CN121081349A.

[0037] Preparation of Ligusticum chuanxiong extract:

[0038] Extraction solvent: an aqueous solution containing 25 wt% 1,3-butanediol and 20 wt% ethanol;

[0039] Extraction method: The powder (obtained by crushing and passing through a 50-mesh sieve) of Ligusticum chuanxiong in a weight ratio of 1:8 was mixed with the extraction solvent and stirred at 55℃ and 80 rpm for 5 hours. After filtering out the residue through a 300-mesh filtration, the filtrate was filtered through a microporous membrane with a pore size of 0.45 micrometers to obtain the extract, which is the Ligusticum chuanxiong extract.

[0040] Example 2: Effect Test of the Extract

[0041] I. Test for flavonoid content

[0042] The flavonoid content in the extract was determined by the NaNO2-Al(NO3)3-NaOH colorimetric method.

[0043] This invention utilizes a plant flavonoid content detection kit (catalog number AKPL015M-50S, storage conditions 2-8℃, specification 120T / 50S, containing reagents one to four) manufactured by Beijing Box Biotechnology Co., Ltd., and combines it with a Feyond-A300 enzyme-linked immunosorbent assay (ELISA) analyzer to complete quantitative analysis. The specific detection method is as follows:

[0044] Preheat the Feyond-A300 microplate reader for at least 30 minutes and adjust the wavelength to 510nm (the characteristic absorption peak of flavonoid-aluminum ion complex).

[0045] Prepare the standard diluent according to the kit instructions (dilute the 10 mg / mL rutin standard solution with reagent five to 1.0 mg / mL, 0.8 mg / mL, 0.4 mg / mL, 0.2 mg / mL, 0.1 mg / mL, and 0.05 mg / mL respectively). Set up the test tubes in sequence (add 80 μL of the diluent of the sample to be tested, namely Scutellaria baicalensis extract, Ligusticum chuanxiong extract, or tea extract, the diluent is made by diluting the three extracts with deionized water to 10 wt%), control tubes (80 μL sample to be tested + 20 μL reagent one), standard tubes (80 μL standard diluent of the corresponding concentration + 20 μL reagent one), and blank tubes (80 μL distilled water + 20 μL reagent one). Add 20 μL of reagent 1 to each tube and mix well. Let stand at room temperature for 5 min. Then add 20 μL of reagent 2 (only for the test tube and standard tube), 160 μL of reagent 3, and 120 μL of reagent 4 (120 μL for the test tube and standard tube, and 140 μL for the control tube). Mix well and develop color at 37 °C for 45 min. Cool to room temperature.

[0046] After color development, transfer 200 μL of reaction solution to a 96-well plate and measure the absorbance at 510 nm using a Feyond-A300 microplate reader. Record the absorbance as A assay (assay tube), A control (control tube), A standard (standard tube), and A blank (blank tube). Calculate ΔA assay (A assay - A control) and ΔA standard (A standard - A blank). Plot a flavonoid standard curve with the concentrations of the standard dilutions (1.0, 0.8, 0.4, 0.2, 0.1, 0.05 mg / mL) on the x-axis and the corresponding ΔA standard on the y-axis (see...). Figure 1 The standard equation y=kx+b was obtained by fitting the data. The concentration of flavonoids x (mg / mL) in the sample (extract) was calculated by substituting the ΔA measurement into the equation. The results are shown in Table 1.

[0047] Table 1: Flavonoid concentrations of different extracts

[0048] According to the test results in Table 1, Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract all have high concentrations of flavonoids.

[0049] II. Testing of DPPH free radical inhibition rate

[0050] Test Principle: 1,1-Diphenyl-2-trinitrophenylhydrazine (DPPH) is a stable, long-lived free radical. Its ethanol solution is deep purple and exhibits strong absorption around 517 nm. In the presence of a free radical scavenger, the light absorption of the DPPH ethanol solution decreases due to the pairing of unpaired electrons with the DPPH. The degree of fading of the DPPH ethanol solution is linearly related to the number of electrons it accepts, thus allowing evaluation of the test sample's ability to scavenge free radicals, i.e., its antioxidant activity.

[0051] Test method: Using methanol as solvent, prepare DPPH solution A (60 mg / L), sample solution B, and positive control solution (ascorbate palmitate). Add the solutions to 96-well plates, setting up "sample wells" (160 μL solution B + 40 μL solution A), "sample control wells" (160 μL solution B + 40 μL methanol), "negative control wells" (40 μL solution A + 160 μL methanol), and "positive control wells" (160 μL solution C + 40 μL solution A). Measure the OD value at 517 nm using a microplate reader. After adding solutions A and B, incubate in the dark for 20 min before measurement.

[0052] Sample solution B above: extracts of Ligusticum chuanxiong, Scutellaria baicalensis, and tea were obtained, and diluted with methanol. The final concentrations are expressed as solid content concentrations (mg / mL).

[0053] The DPPH radical inhibition rate (%) of each group was calculated based on absorbance using the formula: [OD negative control – (OD sample – OD sample control)] / OD negative control × 100%. The samples were diluted to different concentrations to calculate the DPPH radical inhibition rate, and the IC50 values ​​obtained at different concentrations were calculated using Graphpad Prism 8 software. 50 IC50 of different samples 50 The results are shown in Table 2.

[0054] Table 2: IC50 of different samples 50 value According to the test results in Table 2, the Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract prepared in this invention all have low IC50 values ​​for DPPH free radical inhibition. 50 It has a value that can effectively inhibit DPPH and has good antioxidant properties.

[0055] III. Test of Ultraviolet Absorption Effect

[0056] Diluted extracts of Scutellaria baicalensis, tea, and Ligusticum chuanxiong (1 wt% solid content) were prepared using DMSO and added to 96-well plates at a volume of 200 μL per well, with three replicates for each sample. The UV absorption spectra in the 200-600 nm wavelength range were scanned using a Feyond-A300 enzyme-linked immunosorbent assay (ELISA) reader to investigate the absorption of the diluted extracts in the UVA, UVB, and blue light bands. 200 μL of anhydrous ethanol was used as a blank control, with three replicates per well. After subtracting the blank control values, an absorption wavelength-absorbance standard curve was plotted. (See figure). Figure 2 .

[0057] Figure 2 In the diagram, the wavelengths on the horizontal axis are classified as long-wave UVA, medium-wave UVB, short-wave UVC, and vacuum UVD. Among them, UVA is the longest of the three, ranging from 320 to 400 nanometers. UVB ranges from 280 to 320 nm, and UVC ranges from 100 to 280 nm (most UVC is absorbed by the ozone layer and does not reach the Earth; among them, the wavelength range of 100 to 200 nm is also called vacuum UVD). The longer the wavelength, the stronger the penetrating power.

[0058] According to Figure 2Test results show that Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract all absorb in the UVB (280-315nm) band; in the UVA (315-400nm) band, all three also absorb, with Ligusticum chuanxiong extract showing slightly weaker absorption; in the blue light absorption band (400-500nm), Scutellaria baicalensis extract shows strong absorption, tea extract shows weak absorption, and Ligusticum chuanxiong extract shows virtually no absorption. Specifically, Scutellaria baicalensis extract exhibits strong absorption in the UVA and blue light regions, tea extract shows stable absorption in both UVA and UVB regions, and while Ligusticum chuanxiong extract shows weak absorption in the blue light region, it still possesses some protective potential in the UVB region.

[0059] Example 3: Testing the UV absorption effect of different proportions of extracts

[0060] According to the test results of Example 2 above, the three extracts have different absorption effects in different wavelength bands and have a certain complementary effect. Therefore, this example studies the ultraviolet absorption effect of the three plant extracts after being compounded in a certain proportion.

[0061] In this embodiment, Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract were mixed sequentially in weight ratios of 3:1:1, 1:1:1, 1:2:1, and 1:1:2 to obtain plant-based sunscreen synergists 1, 2, 3, and 4, respectively. These synergists were then diluted with anhydrous ethanol to a solid content of 1 wt%, and this diluted solution was used as the test sample. The solution was added to a 96-well plate with a volume of 200 μL per well, and three replicates were set for each sample. The UV absorption spectrum in the 200-600 nm wavelength range was scanned using a Feyond-A300 enzyme-linked immunosorbent assay (ELISA) reader to observe the absorption of different sunscreen synergists in the UVA, UVB, and blue light bands. 200 μL of anhydrous ethanol was used as a blank control, and three replicates were set up. The average value of the results was recorded. Then, the absorbance values ​​of the blank control group were subtracted from each group to obtain the UV absorbance of the sunscreen synergists with different proportions. The results are shown in Table 3, and a standard curve of absorption wavelength versus absorbance was plotted. Figure 3 .

[0062] Table 3: UV absorbance of sunscreen synergists in different proportions

[0063] According to Table 3 and Figure 3Test results show that the plant-based sunscreen synergists 1, 2, 3, and 4, obtained by combining the above weight ratios of 3:1:1, 1:1:1, 1:2:1, and 1:1:2, can all achieve broad-spectrum coverage of UVA, UVB, and some blue light regions. In particular, when Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract are combined in a weight ratio of 3:1:1, the resulting plant-based sunscreen synergist exhibits significant and continuous absorption peaks in both the UVB (280-315nm) and UVA (315-400nm) regions. Scutellaria baicalensis contributes the main blue light absorption (400-500nm), tea enhances UVB stability, and Ligusticum chuanxiong supplements mid-wave ultraviolet protection. The three synergistically achieve effective coverage and high-efficiency protection of the entire ultraviolet spectrum and some visible blue light regions.

[0064] Example 4: Application of plant-based sunscreen synergists

[0065] I. Preparation of cosmetic products

[0066] The cosmetic product was prepared according to the weight percentages in Table 4; among which, the plant sunscreen synergist was a mixture of Scutellaria baicalensis extract, tea extract and Ligusticum chuanxiong extract in a weight ratio of 3:1:1; the oil was isopropyl palmitate, triethylhexanoate and squalane in a weight ratio of 1:1:2; the emulsifier was sodium di(lauramide-glutamine)lysine and Tween-60 in a weight ratio of 1:0.8; and the polyol was 1,2-propanediol, glycerin and 1,3-butanediol in a weight ratio of 1:0.5:2.

[0067] Table 4: Composition of Cosmetic Products

[0068] The preparation methods of the fermentation products used in products A, C, and D are as follows:

[0069] The flowers of *Magnolia denudata* and the stems of *Dendrobium nobile* were pulverized at a weight ratio of 1:2. Then, 15 times the weight of water was added to the pulverized mixture. After boiling, the mixture was cooled to room temperature to obtain a cooled product. Sucrose and fermentation bacteria (0.9% of the weight of the cooled product) were added, and the mixture was anaerobic fermented at 35°C for 5 days. Fermentation was then terminated by sterilization, and the product was filtered through a 0.22-micron pore size membrane to obtain the fermentation product. The amount of fermentation bacteria added was 6.54 × 10⁻⁶. 11 The fermentation bacteria consist of *Lactobacillus casei* CICC 6107 and *Lactobacillus rhamnosus* CICC6151 in a live bacteria ratio of 1:0.5.

[0070] The preparation method of the fermentation product used in Product B is as follows:

[0071] The flowers of *Magnolia denudata* and the stems of *Dendrobium nobile* were pulverized at a weight ratio of 1:2. Then, 16 times the weight of water was added to the pulverized mixture. After boiling, the mixture was cooled to room temperature to obtain a cooled product. Sucrose and fermentation bacteria were added at a weight ratio of 0.85% of the cooled product. Anaerobic fermentation was carried out at 37°C for 6 days. Fermentation was then terminated by sterilization. The product was filtered through a 0.22-micron pore size membrane to obtain the fermentation product. The amount of fermentation bacteria added was 7.57 × 10⁻⁶. 11 The fermentation bacteria consist of *Lactobacillus casei* CICC 6107 and *Lactobacillus rhamnosus* CICC 6151 in a live bacteria ratio of 1:2.

[0072] Product E differs from Product A only in the preparation method of the fermentation product. The fermentation bacteria used is *Lactobacillus casei* CICC 6107, and the amount of fermentation bacteria added is maintained at 6.54 × 10⁻⁶. 11 bacteria / g of chilled material.

[0073] Product F differs from Product A only in the preparation method of the fermentation product. The fermentation bacteria used is *Lactobacillus rhamnosus* CICC 6151, and the amount of fermentation bacteria added is maintained at 6.54 × 10⁻⁶. 11 bacteria / g of chilled material.

[0074] Product G differs from Product A only in the preparation method of the fermentation product. The fermentation bacteria consist of *Lactobacillus casei* CICC 6107 and *Lactobacillus rhamnosus* CICC 6151 in a viable count ratio of 1:0.1, while the amount of fermentation bacteria added remains at 6.54 × 10⁻⁶. 11 bacteria / g of chilled material.

[0075] Product H differs from Product A only in the preparation method of the fermentation product. The fermentation bacteria consist of *Lactobacillus casei* CICC 6107 and *Lactobacillus rhamnosus* CICC 6151 in a viable count ratio of 1:5, while the amount of fermentation bacteria added remains at 6.54 × 10⁻⁶. 11 bacteria / g of chilled material.

[0076] The preparation method of the above cosmetic product is as follows: water and emulsifier are stirred at 50°C and 100 rpm for 0.3 hours to obtain mixture 1; polyol is heated to 70°C, oil is added, and stirred at 80 rpm for 0.5 hours to obtain mixture 2; mixture 2 is added to mixture 1, stirred at 60°C and 100 rpm for 0.5 hours, cooled to 40°C, plant sunscreen synergist and fermentation product are added, stirred at 40°C and 100 rpm for 0.5 hours, and allowed to stand at room temperature for 0.5 hours to obtain the cosmetic product.

[0077] II. Testing cosmetic products

[0078] The above products were tested for their protective effect against UVB-induced cell damage (cell survival rate) to verify the ability of the cosmetic products in this application to protect cells from UV damage.

[0079] Grouping: blank group, model group, positive control group and product AH group; each group was tested in parallel three times and the average value was calculated.

[0080] The testing procedure is as follows: HepG-2 cells in the logarithmic growth phase were taken and stored at a density of 2.5 × 10⁻⁶. 5 Cells / well were seeded into 96-well plates, and 250 μL of MEM basal medium was added. The plates were incubated at 37°C and 5% CO2 for 24 h. The medium was then discarded, and the plates were treated with the following: the blank control and model groups were treated with 250 μL of MEM basal medium; the positive control group was treated with 250 μL of MEM basal medium containing 110 μg / mL resveratrol; and the product AH group was treated with 250 μL of MEM basal medium containing 0.5 wt% product AH. All groups were incubated at 37°C and 5% CO2 for 3 h. Except for the blank control group, all other groups were irradiated under UVB lamps at a height of 10 cm, a duration of 1500 s, and a dose of 150 mJ / cm². 2 Then, the culture medium was discarded, and 250 μL of MEM basal medium was added to each well. The cells were incubated at 37°C and 5% CO2 for 24 hours. Cell viability was determined using the MTT assay. The results are shown below. Figure 4 Furthermore, based on the survival rate, the percentage decrease in survival rate of product BH compared to product A was calculated, and the results are shown in [see figure]. Figure 5 .

[0081] according to Figure 4-5 The test results show that the cosmetics prepared using plant-based sunscreen synergists and fermentation products can effectively inhibit ultraviolet (UV) damage to cells and have excellent cell protection effects. Test results for products A, C, and D show that the plant-based sunscreen synergists and fermentation products can work synergistically to significantly enhance the cosmetics' ability to inhibit UV damage to cells. Compared to product A, which uses only a single strain of *Lactobacillus casei* CICC 6107 and *Lactobacillus rhamnosus* CICC 6151 for fermentation, products D and E have poorer UV protection effects. The synergistic fermentation of these two strains can improve the UV protection ability of the fermented products to a certain extent, thus enhancing the cell protection effect of the cosmetics. Compared to product A, products F and G, by changing the ratio of fermentation bacteria in the fermentation products, result in product A having higher UV protection efficiency.

Claims

1. A plant-based sunscreen synergist, characterized in that, The plant-based sunscreen enhancer is composed of Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract.

2. The plant-based sunscreen synergist according to claim 1, characterized in that, Scutellaria baicalensis extract was obtained by extraction using an aqueous solution containing butylene glycol and sodium metabisulfite as the extraction solvent.

3. The plant-based sunscreen synergist according to claim 1, characterized in that, The extract of Ligusticum chuanxiong was obtained by using an aqueous solution containing butylene glycol and ethanol as the extraction solvent.

4. The plant-based sunscreen synergist according to claim 2 or 3, characterized in that, The extraction temperature for the above-mentioned Scutellaria baicalensis extract and Ligusticum chuanxiong extract was 45-60℃.

5. The plant-based sunscreen synergist according to claim 1, characterized in that, Tea extract was obtained using an aqueous solution containing butylene glycol and sodium metabisulfite as the extraction solvent.

6. The plant-based sunscreen synergist according to any one of claims 1-3 and 5, characterized in that, The weight ratio of Scutellaria baicalensis extract, tea extract and Ligusticum chuanxiong extract was (1-3):(1-2):(1-2).

7. The plant-based sunscreen synergist according to any one of claims 1-3 and 5, characterized in that, The weight ratio of Scutellaria baicalensis extract, tea extract and Ligusticum chuanxiong extract is 3:1:

1.

8. A method for preparing a plant-based sunscreen synergist according to any one of claims 1-7, characterized in that, This includes the step of mixing Scutellaria baicalensis extract, tea extract, and Ligusticum chuanxiong extract.

9. The application of a plant-based sunscreen synergist according to any one of claims 1-7 in the preparation of cosmetics, characterized in that, The cosmetics include the plant-based sunscreen enhancers and fermentation products.

10. The application according to claim 9, characterized in that, The fermentation products are obtained by crushing, boiling, cooling, fermenting, sterilizing and filtering Magnolia officinalis and Dendrobium nobile. The fermentation is carried out by anaerobic fermentation of Lactobacillus casei and Lactobacillus rhamnosus at a live cell ratio of 1:0.5-2.

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