Compositions effective in reducing post-sun damage and their use in sun care products

Abstract

The application discloses a composition for effectively reducing after-sun damage and application thereof in sunscreen products, and particularly belongs to the technical field of skin care product raw materials. The composition is composed of dark black giant seaweed extract, centella asiatica extract, haematococcus pluvialis extract and oldenlandia diffusa extract, wherein the haematococcus pluvialis extract is prepared by an alkaline ultrasonic alcohol precipitation extraction process, and active ingredients are effectively reserved. The composition has excellent antioxidant, anti-inflammatory and photoprotective properties, and can be applied to the preparation of skin care products with antioxidant, anti-inflammatory, moisturizing and soothing effects, and is particularly suitable for sunscreen products for reducing after-sun damage, can reduce the use amount of physical / chemical sunscreen agents, and reduces skin irritation.

Description

Technical Field

[0001] This invention belongs to the field of skin care raw material technology, specifically, it relates to a composition that can effectively reduce sun damage and its application in sun protection products. Background Technology

[0002] With increasing attention being paid to skin damage caused by external light radiation such as ultraviolet (UV) and blue light, the demand for sunscreen and after-sun repair skincare products is growing. Existing sunscreens mostly rely on physical sunscreens (such as titanium dioxide and zinc oxide) or chemical sunscreens (such as ethylhexyl methoxycinnamate) to achieve photoprotection. However, physical sunscreens tend to feel heavy and leave a white cast, while chemical sunscreens may irritate sensitive skin. Furthermore, most products only focus on "blocking light radiation," offering limited ability to repair post-sun exposure skin oxidative damage, inflammatory reactions (such as redness and stinging), and decreased cell vitality.

[0003] Furthermore, the efficacy of single plant extracts in existing skincare products is relatively limited: for example, while Haematococcus pluvialis extract has strong antioxidant properties, its anti-inflammatory and skin barrier repair capabilities are insufficient; while Centella asiatica extract can soothe inflammation, it lacks strong photoprotective effects. It is impossible to achieve a comprehensive post-sun damage improvement effect of "antioxidant-anti-inflammatory-photoprotection-repair" through a single or few ingredients, making it difficult to meet consumers' needs for gentle and highly effective post-sun protection and repair.

[0004] Therefore, developing a multi-component synergistic composition that can reduce sun damage from multiple dimensions has become a key need in the skincare industry. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a composition that can effectively reduce sun damage and improve the skin's photoprotective effect, as well as its application in sunscreen products.

[0006] To achieve the above objectives, the present invention discloses the following technical solutions: In a first aspect, the present invention provides a composition for effectively reducing sun damage, the composition comprising the following components: extracts of *Gastrodia elata*, *Centella asiatica*, *Haematococcus pluvialis*, and *Hedyotis diffusa*.

[0007] Preferably, the composition contains the following components in parts by weight: 15-20 parts of dark black seaweed extract; Centella asiatica extract 2-4 parts; 1-2 parts of Haematococcus pluvialis extract; 6-8 parts of Hedyotis diffusa extract.

[0008] More preferably, the composition contains the following components in parts by weight: 18 parts of *Gastrodia elata* extract; Centella Asiatica extract 3 parts; 1.5 parts of Haematococcus pluvialis extract; Seven parts of Hedyotis diffusa extract.

[0009] More preferably, the preparation method of the light black giant seaweed extract includes the following steps: Step 1. Take dried Haematococcus pluvialis and add it to a 1.5-2.5wt% NaOH aqueous solution. Stir and mix evenly to form a suspension. Step 2. Sonicate the suspension for 10-15 minutes, then extract the mixture after sonication at 80-85℃ for 2-3 hours. Centrifuge the extracted mixture to collect the supernatant, discard the precipitate, and obtain an extract containing polysaccharides. Step 3. Add anhydrous ethanol to the extract. After the addition is complete, let it stand at 4°C for 16-18 hours. Centrifuge the mixture after alcohol precipitation to collect the precipitate. Step 4. Dry the precipitate and then freeze-dry it to obtain Haematococcus pluvialis extract.

[0010] More preferably, in step 1, a certain amount of dried Haematococcus pluvialis is accurately weighed, placed in a container, and 1.5-2.5wt% NaOH aqueous solution is added at a material-to-liquid ratio of 1:25-30 (g / mL). The mixture is stirred thoroughly to form a suspension.

[0011] More preferably, in step 2, the suspension is ultrasonically treated for 10-15 minutes at an ultrasonic frequency of 28 kHz, the ultrasonically treated mixture is heated to 80-85°C in a water bath, and hot-extracted at 150-200 r / min for 2-3 hours. The extracted mixture is then centrifuged at 8000-10000 r / min for 10-15 minutes, the supernatant is collected, the precipitate is discarded, and an extract containing polysaccharides is obtained.

[0012] More preferably, in step 3, 4 times the volume of anhydrous ethanol is added to the extract. After the addition is complete, the mixture is allowed to stand at 4°C for 16-18 hours. The mixture after ethanol precipitation is centrifuged at 8000-10000 r / min for 10-15 minutes. After centrifugation, the supernatant is discarded and the precipitate is collected.

[0013] More preferably, in step 4, 70-80 v / v% ethanol aqueous solution is added to the precipitate, centrifuged at 8000-10000 r / min for 10-15 min, the supernatant is discarded, and the washing is repeated 1-2 times. The washed precipitate is dried at 60℃ for 2-3 h, and then freeze-dried under vacuum to obtain Haematococcus pluvialis extract.

[0014] In a second aspect, the present invention provides the use of the composition described in the first aspect in the preparation of skin care products having antioxidant, anti-inflammatory, moisturizing and / or soothing effects.

[0015] Thirdly, the present invention provides the use of the composition described in the first aspect in the preparation of sunscreen products that can effectively reduce sun damage.

[0016] In this invention: LESSONIA NIGRESCENS extract is rich in polysaccharides, minerals, and active peptides. On the one hand, it can form a gentle moisturizing film on the skin surface, increase skin hydration, enhance skin barrier function, and reduce dryness and flaking after sun exposure. On the other hand, it can help resist the direct damage of ultraviolet and blue light to skin cells, providing basic photoprotection support for the skin. It is the core ingredient of the composition for "barrier repair + basic photoprotection".

[0017] Centella Asiatica extract contains active substances such as asiaticoside and hydroxyasiaticoside, which can significantly inhibit the secretion of inflammatory factors (such as IL-6) in sun-exposed skin and relieve inflammatory reactions such as redness, stinging, and itching. At the same time, it can promote the activity of skin fibroblasts and accelerate the repair process of sun-damaged skin. It is a key component of the composition for "anti-inflammatory + repair".

[0018] Haematococcus pluvialis extract is rich in polysaccharides and possesses extremely strong antioxidant activity. It effectively eliminates free radicals such as DPPH generated in sun-exposed skin, reduces oxidative stress damage to skin cells, enhances the skin's resistance to ultraviolet and blue light, and lowers the rate of cell apoptosis induced by photoradiation. It is the core component of the composition, providing both potent antioxidant protection and robust photoprotection. The "ultrasound-assisted hot extraction + alcohol precipitation + freeze-drying" preparation process provided by this invention maximizes the preservation of polysaccharide activity, ensuring optimal efficacy.

[0019] Hedyotis diffusa extract contains active ingredients such as flavonoids and alkaloids, which have auxiliary anti-inflammatory and soothing effects: it can work synergistically with Centella asiatica extract to further inhibit the release of inflammatory factors and enhance the overall anti-inflammatory effect; at the same time, it can relieve skin discomfort caused by light radiation and reduce skin sensitivity to irritation. It is an important component of the composition with "synergistic anti-inflammatory effect + soothing effect".

[0020] This invention has found that the four components form a multidimensional synergistic system that targets the four core problems of sun damage: oxidation, inflammation, cell damage, and barrier disruption, achieving comprehensive effects in multiple dimensions and aspects. A single-component formula cannot achieve the same results.

[0021] The beneficial effects of this invention are: 1. The composition provided by the present invention can effectively remove free radicals from sun-exposed skin, effectively relieve sun-exposed inflammation, significantly reduce the damage of light radiation to skin cells, and improve sun-exposed skin problems from multiple dimensions; 2. The core component of the composition provided by this invention is a natural plant extract, which is free from the irritation of chemical sunscreens and the heaviness of physical sunscreens. At the same time, its excellent photoprotection performance can reduce the amount of physical / chemical sunscreens added in sunscreen products, further reducing the risk of skin irritation. It is suitable for various skin types such as sensitive skin, dry skin, and oily skin, and can be widely used in various skin care products such as sunscreen lotion, after-sun repair lotion, and moisturizing cream. Detailed Implementation

[0022] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] Unless otherwise specified, the test methods used in the examples and comparative examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified; and the percentages mentioned in the examples and comparative examples are mass percentages unless otherwise specified.

[0024] In this invention: Lessonia Nigrescens Extract: Lessonia Nigrescens extract, model: ZnPro-ll, purchased from Qingdao Ocean University Marine Oligosaccharide Technology Co., Ltd. Centella Asiatica Extract: Centella Asiatica extract, purchased from Shandong Freda Biotechnology Co., Ltd. Hedyotis diffusa extract: Hedyotis diffusa extract, purchased from Guangzhou Gana Biotechnology Co., Ltd.; Haematococcus pluvialis: purchased from Yunnan Aierfa Biotechnology Co., Ltd.

[0025] Preparation of Haematococcus pluvialis extract Step 1. Accurately weigh a certain amount of dried Haematococcus pluvialis, place it in a container, add 1.5-2.5wt% NaOH aqueous solution at a material-to-liquid ratio of 1:25-30 (g / mL), stir thoroughly to mix evenly and form a suspension; Step 2. Sonicate the container containing the suspension in an ice-water bath for 10-15 minutes at an ultrasonic frequency of 28 kHz. Place the ultrasonically treated mixture in a constant temperature water bath at 80 ℃ and heat and extract at 150 r / min for 2 hours. Centrifuge the extracted mixture at 8000-10000 r / min for 10-15 minutes, collect the supernatant, discard the precipitate, and obtain an extract containing polysaccharides. Step 3. Slowly add 4 times the volume of anhydrous ethanol to the extract while stirring slowly with a glass rod. After the addition is complete, let it stand in a refrigerator at 4°C for 16-18 hours to allow the polysaccharide to fully precipitate. Centrifuge the mixture after ethanol precipitation at 8000-10000 r / min for 10-15 min. After centrifugation, discard the supernatant and collect the precipitate. Step 4. Add 70-80 v / v% ethanol aqueous solution to the precipitate to cover it, centrifuge again at 8000-10000 r / min for 10-15 min, discard the supernatant, repeat washing 1-2 times, transfer the washed precipitate to a 60℃ oven and dry for 2-3 h, then freeze dry under vacuum to obtain Haematococcus pluvialis extract.

[0026] Compositions to reduce sun damage Weigh the raw materials according to the mass proportions in Table 1, mix them evenly, and obtain the composition for reducing sun damage.

[0027] Table 1. Raw material mass fractions

[0028] Performance testing 1. Antioxidant test: The compositions 1-7 prepared above were diluted with deionized water to obtain test sample solutions 1-7 with a concentration of 50 μg / mL, and then subjected to DPPH free radical scavenging ability tests. The ability to scavenge DPPH free radicals reflects, to some extent, the antioxidant capacity of a substance.

[0029] The testing method is as follows: Accurately weigh the DPPH reagent and prepare a 0.04 mg / mL DPPH solution using 50% v / v ethanol aqueous solution. Under light-protected conditions, add the DPPH solution and different test samples to a 96-well plate, mix thoroughly, and incubate at room temperature in the dark for 30 minutes. Measure the absorbance at 517 nm using a microplate reader. Each measurement requires three groups: the test sample solution, the blank, and the control. Each group should have three replicates, as detailed below: Sample set: 100 μL of sample solution to be tested + 100 μL of DPPH solution Blank group: 100 μL of test sample solution + 100 μL of 50 v / v% ethanol aqueous solution Control group: 100 μL 50 v / v ethanol aqueous solution + 100 μL DPPH solution Calculate the DPPH removal rate using the following formula: DPPH clearance rate = [1 - (sample group - blank group) / control group] × 100% The test results are shown in Table 2: Table 2 Antioxidant Test Results Sample solution to be tested 1 (corresponding to composition 1) 87.73% Sample solution 2 (corresponding to composition 2) 88.20% Sample solution 3 to be tested (corresponding to composition 3) 86.92% Sample solution 4 to be tested (corresponding to composition 4) 71.59% Sample solution 5 to be tested (corresponding to composition 5) 76.42% Sample solution 6 to be tested (corresponding to composition 6) 80.68% Sample solution to be tested 7 (corresponding to composition 7) 73.68% Results analysis: As can be seen from the results in Table 2, compositions 1-3 have excellent DPPH free radical scavenging ability. Compared with compositions 4-7, it was found that the lack of any one component would reduce the free radical scavenging rate of the composition. This indicates that the extracts of *Gastrodia elata*, *Centella asiatica*, *Hedyotis diffusa*, and *Haematococcus pluvialis* in the composition complement each other to achieve a good antioxidant effect.

[0030] 2. Anti-inflammatory test: This study used Ana-1 macrophages as the research subject and detected the effect of compositions 1-7 on the secretion of the inflammatory factor IL-6 by ELISA.

[0031] The testing method is as follows: Ana-1 macrophages were processed at a rate of 1×10⁻⁶. 4 Cells were seeded per well in a 96-well plate and incubated at 37°C with 5% CO2 for 24 h. To induce an inflammatory response with LPS, 1 mg / mL LPS solution was diluted to 3 μg / mL and added to each well at 50 μL / well. The plates were then incubated at 37°C with 5% CO2 for 4 h. Using complete culture medium as the diluent, compositions 1-7 were diluted to 100 μg / mL and added to each well at 100 μL / well. The control group consisted of diluent and 50 v / v ethanol aqueous solution. Each group was repeated in 6 wells and incubated at 37°C with 5% CO2 for 24 h. Finally, IL-6 levels were detected by ELISA. A standard curve regression equation was calculated based on the known concentration of the standard and the measured OD value. The OD value of the sample wells was substituted into the equation to calculate the concentration of the measured sample, and then multiplied by the dilution factor to obtain the actual IL-6 concentration of the original sample.

[0032] The inhibition rate of the sample against IL-6 was calculated using the following formula: Inhibition rate (%) = (1 - IL-6 content in sample group / IL-6 content in control group) × 100% The test results are shown in Table 3: Table 3 Anti-inflammatory test results Composition 1 70.53 Composition 2 71.19 Composition 3 70.71 Composition 4 32.30*** Composition 5 28.12*** Composition 6 41.03*** Composition 7 39.15*** Note: "*" indicates a significant difference compared to composition 2, P<0.05, "**" P<0.01, "***" P<0.001.

[0033] Results analysis: According to the test results in Table 3, compositions 1-7 all have a certain inhibitory effect on IL-6. Among them, compared with composition 2, the anti-inflammatory properties of compositions 4-7 are significantly reduced. This indicates that the formulation system composed of extracts of *Gastrodia elata*, *Centella asiatica*, *Hedyotis diffusa*, and *Haematococcus pluvialis* has excellent performance in anti-inflammatory and soothing aspects. The components in the system achieve an indispensable synergistic effect and can effectively inhibit the expression of inflammatory factors.

[0034] 3. Light protection test:

[0035] This test examined the cell viability of compositions 1-7. The survival rate of human immortalized keratinocytes (HaCat) after irradiation with ultraviolet and blue light can reflect, to some extent, the protective effect of the substance against ultraviolet and blue light.

[0036] The testing method is as follows: First, the cell safety test concentration of the composition is determined by the MTT assay for cytotoxicity.

[0037] According to 2×10 4 Immortalized keratinocyte suspension was seeded into 96-well plates at a density of 100 μL / well and incubated at 37°C in a 5% CO2 incubator for 24 h. Using complete culture medium as a diluent, compositions 1-7 were diluted to a concentration of 100 μg / mL and added to the cells at 100 μL / well. For the positive and negative control groups, the same volume of 50% v / v ethanol aqueous solution was added instead of the drug. Cells were incubated at 37°C in a 5% CO2 incubator for 24 h. Cells from compositions 1-7 and the positive control group were then irradiated with UV light for 20 min and blue light for 3 h, respectively. The negative control group received no light treatment. All cells were then incubated for another 24 h. Finally, the changes in cell viability were assessed using an MTT assay.

[0038] The calculation formula is as follows: Cell viability percentage (%) = (Average OD value of sample wells / Average OD value of negative control group) × 100% The test results are shown in Table 4: Table 4. Results of light protection test

[0039] Note: "*" indicates a significant difference compared to composition 2, P<0.05, "**" P<0.01, "***" P<0.001.

[0040] Results analysis: As shown in Table 4, compared with the positive control group, the HaCat cells treated with compositions 1-3 showed significantly increased activity after exposure to ultraviolet and blue light, and were significantly higher than those of compositions 4-7. This indicates that the composition composed of extracts of *Gastrodia elata*, *Centella asiatica*, *Hedyotis diffusa*, and *Haematococcus pluvialis* can effectively resist damage from ultraviolet and blue light and play a role in photoprotection. The composition provided by this invention can be applied to skin care products with sun protection effects, reducing the use of physical and chemical sunscreens.

[0041] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composition for effectively reducing sun damage, characterized in that, The composition contains the following components in parts by weight: 15-20 parts of dark black seaweed extract; Centella asiatica extract 2-4 parts; 7 parts of Haematococcus pluvialis extract; 1.5 parts of Hedyotis diffusa extract; The preparation method of the Haematococcus pluvialis extract includes the following steps: Step 1. Take dried Haematococcus pluvialis and add it to a 1.5-2.5wt% NaOH aqueous solution. Stir and mix evenly to form a suspension. Step 2. Sonicate the suspension for 10-15 minutes, then extract the mixture after sonication at 80-85℃ for 2-3 hours. Centrifuge the extracted mixture to collect the supernatant, discard the precipitate, and obtain an extract containing polysaccharides. Step 3. Add anhydrous ethanol to the extract. After the addition is complete, let it stand at 4°C for 16-18 hours. Centrifuge the mixture after ethanol precipitation to collect the precipitate. Step 4. Dry the precipitate and then freeze-dry it to obtain Haematococcus pluvialis extract.

2. The composition according to claim 1, characterized in that, In step 1, a certain amount of dried Haematococcus pluvialis is accurately weighed, placed in a container, and 1.5-2.5wt% NaOH aqueous solution is added at a material-to-liquid ratio of 1:25-30g / mL. The mixture is stirred thoroughly to form a suspension.

3. The composition according to claim 1, characterized in that, In step 2, the suspension is ultrasonically treated for 10-15 minutes at an ultrasonic frequency of 28 kHz. The ultrasonically treated mixture is then heated in a water bath to 80-85°C and hot-extracted at 150-200 r / min for 2-3 hours. The extracted mixture is then centrifuged at 8000-10000 r / min for 10-15 minutes. The supernatant is collected, and the precipitate is discarded to obtain an extract containing polysaccharides.

4. The composition according to claim 1, characterized in that, In step 3, add 4 times the volume of anhydrous ethanol to the extract. After the addition is complete, let it stand at 4°C for 16-18 hours. Centrifuge the mixture after ethanol precipitation at 8000-10000 r / min for 10-15 minutes. After centrifugation, discard the supernatant and collect the precipitate.

5. The composition according to claim 1, characterized in that, In step 4, 70-80 v / v% ethanol aqueous solution is added to the precipitate, centrifuged at 8000-10000 r / min for 10-15 min, the supernatant is discarded, and the washing is repeated 1-2 times. The washed precipitate is dried at 60℃ for 2-3 h, and then freeze-dried under vacuum to obtain Haematococcus pluvialis extract.

6. The use of the composition according to any one of claims 1-5 in the preparation of skin care products having antioxidant, anti-inflammatory and / or moisturizing effects.

7. The use of the composition according to any one of claims 1-5 in the preparation of a skin care product having a soothing effect.

8. The use of the composition according to any one of claims 1-5 in the preparation of sun protection products that can effectively reduce sun damage.

Images