Soothing and repairing composition for sensitive skin and application thereof in cosmetics

Abstract

The invention relates to the technical field of cosmetics, in particular to a soothing and repairing composition for sensitive skin and application of the soothing and repairing composition in cosmetics. According to the composition, the guaiacol extract, the mango leaf extract and the phytosterol serve as core active ingredients, a cell membrane receptor is stabilized through the phytosterol, the plant extract can act on an inflammation signal channel more accurately, and a remarkable synergistic interaction effect is generated through compounding of the guaiacol extract, the mango leaf extract and the phytosterol. The composition is mild in property and comprehensive in effect, and can be widely applied to cosmetics with the functions of resisting inflammation, relieving redness and repairing barriers.

Description

Technical Field

[0001] This invention belongs to the field of daily chemical products technology, specifically relating to a composition combining guaiac wood extract, mango leaf extract and phytosterols, and its application in relieving skin inflammation and repairing the skin barrier. Background Technology

[0002] Sensitive skin typically manifests as impaired skin barrier function, reduced tolerance to external physical and chemical stimuli, and a tendency to experience subjective discomfort such as redness, stinging, burning, and itching. Currently, soothing and repairing products for sensitive skin face the following technological bottlenecks: Limited efficacy, failing to balance immediate and long-term effects. Most soothing products on the market rely on single plant extracts (such as Centella asiatica and bisabolol). While some ingredients offer good immediate calming effects, their lack of ability to repair the skin's physical barrier leads to rapid loss of active ingredients, resulting in short-lasting soothing effects and an inability to fundamentally reduce skin sensitivity. Insufficient anti-inflammatory depth, failing to block the inflammatory cascade: Sensitive skin is often accompanied by complex cytokine imbalances, including the release of inflammatory factors such as TNF-α and IL-6. Existing soothing ingredients often only relieve surface redness and swelling, failing to precisely target deep inflammatory signaling pathways, leading to recurring inflammation. Furthermore, while many products add ceramides or common sterols to repair the barrier, these ingredients often merely accumulate mechanically on the skin's surface. How to achieve functional complementarity between lipid repair components and anti-inflammatory active components, so as to stabilize cell membrane receptors, enhance the penetration of active ingredients, and efficiently rebuild the physical structure of the stratum corneum, is a major challenge in the field of cosmetic research and development.

[0003] Guaiac tree, also known as guaiac wood, is a plant belonging to the genus *Guaiac*. Guaiac wood extract is primarily derived from the heartwood of the guaiac tree and contains components such as guaiacol, guaiacol, and α-guaiac glyceryl ether. Guaiac wood extract is rich in guaiazulene, a bicyclic sesquiterpene organic compound (C15H18) derived from guaiac oil. Guiazulene can rapidly lower skin surface temperature, inhibit capillary dilation (improving redness), and possesses powerful anti-inflammatory, soothing, antioxidant, and skin-repairing effects.

[0004] Mango leaves contain a variety of beneficial plant compounds, including polyphenols and terpenes. Terpenes contribute to good vision and immunity, and some studies have shown that these compounds can improve gut bacteria, helping to treat or prevent diseases such as obesity, diabetes, heart disease, and cancer. Furthermore, mangiferin in mango leaves has anti-inflammatory properties. The main component of mango leaf extract is mangiferin, a natural product derived from the leaves of the mango plant (Anacardiaceae family). It possesses significant antioxidant, anti-inflammatory, antitussive, antiasthmatic, antiviral (such as HSV-2), blood sugar regulating, and cognitive improvement pharmacological activities. Industrial preparation typically involves ethanol reflux extraction, followed by separation and purification using macroporous adsorption resin.

[0005] Phytosterols are a class of natural active ingredients derived from plants. Due to their structural similarity to cholesterol naturally present in the skin, they are widely used in skincare products. As a core ingredient for repairing the skin barrier and relieving inflammation and itching, phytosterols can mimic the skin's own lipids, helping to rebuild a damaged stratum corneum and reduce transepidermal water loss (TEWL). This makes them ideal for sensitive skin, those with rosacea, and those with a damaged skin barrier. Furthermore, phytosterols have significant anti-irritant effects, relieving redness, itching, and stinging caused by external environmental factors. They are often used as adjunctive therapy in the treatment of atopic dermatitis, eczema, and other conditions. Studies have shown that phytosterols can inhibit collagenase activity, slow collagen loss, and promote fibroblast regeneration, thus playing a preliminary anti-aging role. In cosmetic formulations, they are often used as natural emulsifiers or stabilizers, increasing product permeability and fluidity.

[0006] While guaiac wood extract and mango leaf extract are traditionally recognized as having anti-inflammatory potential, their stability and bioavailability under complex inflammatory environments still need improvement. Phytosterols, as components of the skin's natural barrier, have not yet been fully explored and applied in their auxiliary effects on active ingredients and their targeted inhibition of specific inflammatory factors in different proportions. Therefore, developing a soothing and repairing composition that can both immediately reduce inflammatory responses and effectively rebuild the skin's physical barrier, with significant synergistic effects among its components, has significant scientific research value and market potential.

[0007] Prior art CN115317417A provides a composition for repairing acne-prone and sensitive skin containing guaiac extract, comprising 1-50 parts guaiac extract, 1-50 parts myrtle extract, 1-10 parts asiaticoside, and 1-50 parts sophorolipid. This skincare product is gentle and non-irritating, reducing the bacterial flora effect of harmful bacteria, disrupting the biofilm formed by harmful bacteria, promoting the growth of probiotics, strengthening the microbial barrier, and repairing skin tissue, thereby preventing acne. It also has a good repairing effect on acne-prone and sensitive skin, and has whitening effects. It can be applied to the care of sensitive skin, promoting rapid skin healing and strengthening the skin barrier. Prior art CN116869875A discloses a soothing composition, its preparation method, and its application. One soothing composition comprises the following components: a soothing mixed extract, butylene glycol, 1,2-hexanediol, and water. The raw materials of the soothing mixed extract, by mass parts, include 10-30 parts of peony root, 5-10 parts of violet, 2-6 parts of guaiac wood, and 5-10 parts of purslane. A method for preparing the soothing composition involves mixing the components and stirring until homogeneous. An application of the soothing composition involves adding it to soothing skincare products. The soothing composition of this application has a good effect on improving the skin's microecological barrier and enhancing the skin barrier's tolerance to external stimuli. Existing technology CN116549359A discloses an acne-removing composition for optimizing skin oil quality, its preparation method, and its application, belonging to the field of cosmetic technology. This invention provides an acne-removing composition comprising the following components in parts by weight: 0.1-5 parts mango leaf extract, 0.1-10 parts guaiac extract, 0.1-10 parts acetylglucosamine, 0.1-10 parts yeast extract, and 0.01-5 parts EUK-134. This composition optimizes sebum composition as a whole, maintains a stable ratio of saturated to unsaturated fatty acids in sebum, inhibits sebum peroxidation, and achieves gentle acne removal and repair of the sebum barrier. Furthermore, this acne-removing composition exhibits excellent antibacterial properties. Simultaneously, this acne-removing composition can be added as an active ingredient to cosmetics, achieving a gentle and non-irritating formula. Moreover, the preparation method of this acne-removing composition is simple, the raw materials are readily available, and it is easy to implement in actual production.

[0008] The main objective of this invention is to provide a synergistic composition that can quickly relieve redness and stinging in sensitive skin while repairing the damaged skin barrier. The core problem of sensitive skin lies in the vicious cycle of alternating damage to the skin barrier and excessive inflammatory response. Existing soothing ingredients often target inflammation alone (such as Centella Asiatica) or the skin barrier alone (such as ceramides). This invention constructs a three-dimensional network of immediate calming, deep anti-inflammatory, and long-lasting repair through a triple composition derived from plants. Summary of the Invention

[0009] The purpose of this invention is to provide a synergistic composition that can quickly relieve redness and stinging in sensitive skin, while repairing the damaged skin barrier.

[0010] One aspect of the present invention provides a soothing and repairing composition for sensitive skin, the active ingredients of the composition comprising: guaiac extract, mango leaf extract and phytosterols.

[0011] Further, by weight, it includes the following components: guaiac extract: 5-35 parts; mango leaf extract: 1-20 parts; phytosterols: 0.5-15 parts.

[0012] Furthermore, the weight parts of each component are as follows: Guaiac extract: 15-25 parts; Mango leaf extract: 5-12 parts; Phytosterols: 2-8 parts.

[0013] Furthermore, the phytosterol is selected from one or more of β-sitosterol, stigmasterol, campesterol, and brassosterol.

[0014] Furthermore, the weight percentages of the components in the phytosterols are: 45% β-sitosterol, 25% stigmasterol, and 20% campesterol.

[0015] Furthermore, the composition further includes a carrier system selected from liposomes, nanoemulsions, microcapsules, or polyol solvent systems, for encapsulating or dissolving the active ingredient.

[0016] Another aspect of the present invention provides a cosmetic comprising any of the compositions described above, wherein the composition comprises 0.1%-10.0% by mass in the finished cosmetic product.

[0017] Furthermore, the dosage form of the cosmetic is selected from serums, lotions, creams, or masks.

[0018] Another aspect of the invention provides the use of the aforementioned soothing and repairing composition in the preparation of cosmetics, the cosmetics having anti-inflammatory, soothing redness, skin irritation reduction, or skin barrier repair functions.

[0019] Furthermore, the cosmetic achieves its anti-inflammatory and soothing effects by downregulating the release of TNF-α, IL-6, IL-1β, and NO.

[0020] The cytotoxicity test in this invention is a conventional technique in the field. The mitochondria of the live cells to be tested contain succinate dehydrogenase, which can reduce exogenous MTT to water-insoluble blue-purple formazan crystals, which precipitate in the cells. Dead cells do not have this function. DMSO can dissolve the formazan in the cells. The absorbance value at a wavelength of 490 nm is measured using an enzyme-linked immunosorbent assay (ELISA) reader. Since the amount of crystal formation is directly proportional to the number of live cells, the absorbance value can directly reflect the number of live cells.

[0021] The guaiac extract used in this invention was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the mango leaf extract was purchased from Givaudan Flavors & Fragrances Co., Ltd.; β-sitosterol, stigmasterol, campesterol and associated lipids were purchased from Chengdu Purifa Technology Development Co., Ltd.; cholesterol was purchased from Shanghai Biochemical Reagent Corporation; LPS and other substances were purchased from Sigma.

[0022] The beneficial effects of this invention are as follows: (1) The present invention produces a significant synergistic effect by precisely combining phytosterols with plant extracts (guaiac wood and mango leaves). Through anti-inflammatory evaluation, it was found that the inhibition rate of a single component was only 17.3% or 51.0%, while the inhibition rate of the compounded composition against inflammatory factors was greatly increased to 86.3%.

[0023] (2) When dealing with external stimuli (such as lactic acid stinging), the composition of the present invention has the characteristics of fast onset and strong aftereffect. Within 1 minute of applying the compounded composition, a stinging relief rate of 55.8% can be achieved, quickly soothing sensitive discomfort, and can help lock in active ingredients, providing long-lasting barrier protection. The stinging relief rate can reach up to 98.5% within 10 minutes.

[0024] (3) The composition of the present invention has been verified by transdermal water loss rate, which shows that it can significantly accelerate the self-repair of damaged skin. The compound plant sterols have higher compatibility with the lipids of the stratum corneum of the skin, can quickly rebuild the physical defense layer, reduce transdermal water loss, and fundamentally improve sensitive skin. Detailed Implementation

[0025] This invention provides a soothing and repairing composition for sensitive skin and its application in cosmetics. To better illustrate the purpose, technical solution, and advantages of this invention, specific embodiments will be provided below for further explanation. The purpose is to provide a detailed understanding of the invention, not to limit it. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Unless otherwise specified, the experimental reagents and instruments used in the embodiments and comparative examples of this invention are commonly used and commercially available. Unless otherwise specified, the experimental methods used in the embodiments and comparative examples are conventional methods, and the raw materials used in parallel experiments are from the same batch.

[0026] Example A soothing and repairing composition for sensitive skin, wherein the active ingredients in the composition are formulated in the manner shown in Table 1 below.

[0027] Table 1. Active ingredient ratio table Components Example 1 (Balanced Type) Example 2 (High-potency repair type) Example 3 (Light and Soothing Type) Comparative Example 1 (without sterols) Comparative Example 2 (without extract) Guaiac extract 20 25 15 20 0 Mango leaf extract 8 12 5 8 0 β-sitosterol 5 8 2 0 5 Butylene glycol Supplement to 100 Supplement to 100 Supplement to 100 Supplement to 100 Supplement to 100 Efficacy Evaluation 1. Evaluation of anti-inflammatory activity (Inflammation Inhibition) 1.1 Evaluation of anti-inflammatory activity at the cellular level The mouse macrophage cell line RAW264.7 was purchased from the Cell Bank of the Chinese Academy of Sciences; the cell culture medium was DMEM medium containing 10% FBS; and the ELISA detection kit was purchased from Beyotime Biotechnology Co., Ltd.

[0028] RAW264.7 cells were cultured routinely in a cell culture incubator, with the culture medium changed every 2-3 days. When the cells reached approximately 90% confluence at the bottom of the culture flask, they were passaged. After 3-5 passages, healthy cells were used for experiments, seeded into 6-well plates at a density of 3 × 10⁶ cells per group. 5 Samples were cultured at 37°C and 5% CO2 for 24 hours. The samples were prepared according to the above active ingredient ratio table. Using DMEM as solvent, the samples were prepared to a concentration of 0.5% (the safe concentration after cytotoxicity testing). The samples were grouped as shown in Table 2 below.

[0029] Table 2. Anti-inflammatory evaluation test

[0030] After removing the culture medium, the cells were washed once with D-Hanks reagent. The normal control group was replaced with fresh culture medium, while the model control group was replaced with fresh culture medium containing 0.5 μg / mL LPS. The test sample groups were replaced with fresh culture medium containing 0.5% sample and 0.5 μg / mL LPS. The cells were then cultured at 37℃ in 5% CO2 for 24 h. After culture, 200 μL of cell supernatant was collected in a centrifuge tube and analyzed according to the ELISA kit instructions. The downregulation rate was calculated using the following formula: Downregulation rate (%) = (T model control group - T sample group) / (T model control group - normal control group) × 100%, where T represents the average of three measurements. The results are shown in Table 3.

[0031] Table 3. Effect of samples on LPS-induced release of RAW264.7 cytokines (inhibition rate %) Components TNF-α IL-6 IL-1β NO Normal control - - - - Model comparison - - - - Example 1 84.9 82.6 86.3 76.2 Example 2 90.4 89.3 90.7 80.2 Example 3 78.6 73.7 73.8 63.1 Comparative Example 1 46.4 58.2 51.0 46.2 Comparative Example 2 20.3 24.7 17.3 16.9 As can be seen from the data in the table, Comparative Example 1 showed an inhibition rate of 51.0% against IL-1β, while Comparative Example 2 showed an inhibition rate of only 17.3%. However, Example 1 of the present invention, at the same or better activity concentration, showed a significantly increased inhibition rate of 86.3%, far exceeding the effect of simply adding the two components together. Example 2 also exhibited a more potent effect, possibly by stabilizing cell membrane receptors with phytosterols, allowing the guaiac and mango leaf extracts to act more precisely on inflammatory signaling pathways, resulting in a significant synergistic effect. Furthermore, the composition of the present invention not only effectively scavenges oxidative stress products such as NO, but also inhibits the cascade reaction of core inflammatory factors such as TNF-α and IL-6, thereby exhibiting effects of reducing redness and providing deep soothing relief.

[0032] 2. Anti-Erythema & Soothing 2.1 Lactic acid sting test Thirty participants, aged 18-40 years, diagnosed with sensitive skin by clinicians, were recruited. All participants signed informed consent forms. A self-controlled left-right method was used. After washing and drying their faces with water, participants sat quietly for 30 minutes in a temperature- and humidity-controlled laboratory (temperature 22±2℃, humidity 50±5%). A 10% lactic acid solution (Sigma, diluted with distilled water) was applied to the left and right sides of the participants' noses and corners of their mouths, inducing a stinging sensation with a cotton swab. Subsequently, samples (1-3) from the embodiments of this invention were applied to the left side of the participants using a cotton swab, and an equal amount of physiological saline was applied to the right side using the same method. At 1, 3, 5, and 10 minutes after application, participants rated the intensity of the stinging sensation. The rating criteria are shown in Table 4 below.

[0033] Table 4. Stinging Pain Evaluation Criteria score pain 0 points No feeling 1-3 points Mild sensation, occasionally stinging or itching 4-6 points Moderate sensation, persistent stinging and burning, but tolerable. 7-10 points Severe sensation, intense burning and pain, unbearable. After the experiment, the average scores of each group of subjects were recorded, and the pain relief rate was calculated using the following formula: Relief rate (%) = (Pre-application score - Post-application scores at various time points) / (Pre-application score) × 100%; The results are shown in Table 5.

[0034] Table 5. Stinging pain relief rate (%) Group 1min 3min 5min 10min Example 1 42.5 68.2 85.3 94.2 Example 2 55.8 78.3 92.1 98.5 Example 3 35.2 52.6 70.8 82.5 Comparative Example 1 38.6 55.4 68.2 72.3 Comparative Example 2 14.2 18.1 22.1 28.9 Therefore, Example 2 showed a 55.8% relief rate within one minute of application, significantly better than other groups, demonstrating that the high content of guaiac extract has a strong immediate calming effect. Furthermore, compared with Comparative Example 1, although there was some initial effect, the increase in relief rate slowed down after 5 minutes. The example group containing phytosterols performed better in the later stages, proving that phytosterols, by supplementing intercellular lipids, help lock in the active ingredients and provide long-lasting barrier protection. The experimental results confirm that this composition can significantly reduce the skin's sensitivity threshold to chemical stimuli and has a good soothing effect.

[0035] 3. Skin Barrier Repair Validation: This embodiment uses the Transdermal Water Loss Test (TEWL) to verify the role of phytosterols in rebuilding the skin's physical defense layer. Guaiac extract (20 parts) and mango leaf extract (8 parts) were premixed to prepare an extraction mixture. Different types of phytosterols (5 parts) were added to prepare test samples. The specific ratios are shown in Table 6 below.

[0036] Table 6. Sterol Ratio Group Active components Sterol composition Test Example 1 Extract mixture + campesterol Camphor sterol monomers with a purity of ≥95% Test Example 2 Extract mixture + stigmasterol Stigmasterol monomers with a purity of ≥95% Test Example 3 Extract mixture + complex phytosterols β-Sitosterol (45%) + Stigmasterol (25%) + Campesterol (20%) + Associated Lipids (10%) Test Example 4 Extract mixture + cholesterol Animal-derived cholesterol Test Example 5 Extract mixture only / Selected subjects from the aforementioned pool were chosen. Five 2×2cm areas were selected on the inner side of the subjects' left forearms. TEWL values ​​were measured using a Dermalab skin analyzer and recorded as initial TEWL values. Subsequently, 3M transparent tape was repeatedly applied and peeled off 20 times, and TEWL values ​​were collected and recorded as day D0. Following this, the corresponding test sample was applied twice daily to the selected areas, once in the morning and once in the evening at fixed times, for 7 consecutive days. TEWL values ​​for each area were monitored on days 1, 3, and 7, and the recovery rate (%) was calculated using the following formula: Recovery rate (%) = (D0 TEWL - TEWL after application) / (D0 TEWL - Initial TEWL) × 100%; The results are shown in Table 7.

[0037] Table 7. Effects of different sterol components on skin barrier recovery rate (recovery rate, %) Group D1 D3 D7 Test Example 1 12.4±1.5 28.6±2.2 52.4±2.8 Test Example 2 10.8±1.2 25.4±1.9 48.6±3.1 Test Example 3 24.5±2.1 48.2±1.5 78.4±2.2 Test Example 4 15.2±1.8 32.1±2.6 58.5±2.5 Test Example 5 5.4±0.8 12.5±1.4 28.2±1.5 Therefore, while Test Example 5 exhibits anti-inflammatory effects, its repair rate of the physical barrier is slow. The addition of phytosterols significantly enhances the repair rate. Furthermore, Test Example 3 demonstrates a significantly better repair effect than Test Example 1 or Test Example 2, indicating that a mixture of β-sitosterol, stigmasterol, and campesterol in the specified proportions more readily integrates with the lipids of the stratum corneum. Conclusion: In summary, the composite phytosterols selected in this invention achieve optimal compatibility and functional complementarity with guaiac wood and mango leaf extracts, thereby accelerating barrier reconstruction.

[0038] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A soothing and repairing composition for sensitive skin, characterized in that, The active ingredients of the composition include: guaiac wood extract, mango leaf extract and phytosterols.

2. The composition according to claim 1, characterized in that, By weight, it includes the following components: Guaiac wood extract: 5-35 parts; Mango leaf extract: 1-20 parts; Phytosterols: 0.5-15 parts.

3. The composition according to claim 2, characterized in that, The weight parts of each component are as follows: Guaiac extract: 15-25 parts; Mango leaf extract: 5-12 parts; Phytosterols: 2-8 parts.

4. The composition according to claim 1, characterized in that, The phytosterols are selected from one or more of β-sitosterol, stigmasterol, campesterol, and brassosterol.

5. The composition according to claim 4, characterized in that, The weight percentages of the components in the phytosterols are: 45% β-sitosterol, 25% stigmasterol, and 20% campesterol.

6. The composition according to claim 4, characterized in that, The composition further includes a carrier system selected from liposomes, nanoemulsions, microcapsules, or polyol solvent systems, for encapsulating or dissolving the active ingredient.

7. A cosmetic comprising the composition according to any one of claims 1-6, characterized in that, The composition has a mass percentage content of 0.1%-10.0% in the finished cosmetic product.

8. The cosmetic product according to claim 7, characterized in that, The dosage form of the cosmetic is selected from serum, lotion, cream or mask.

9. The use of the soothing and repairing composition according to any one of claims 1-6 in the preparation of cosmetics, characterized in that, The cosmetic has anti-inflammatory, redness-soothing, skin-reducing, or skin-barrier-repairing functions.

10. The application according to claim 9, characterized in that, The cosmetic achieves its anti-inflammatory and soothing effects by downregulating the release of TNF-α, IL-6, IL-1β, and NO.

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