Mild tightening, whitening and spot-fading plant composition and preparation method thereof

Abstract

The invention discloses a mild tightening, whitening and spot-fading plant composition and a preparation method thereof, and belongs to the technical field of cosmetics. The composition comprises the following components in parts by weight: 15-22 parts of a silybum marianum extract, 4-9 parts of a tuber melanosporum extract, 12-18 parts of an abelmoschus esculentus fruit extract, 5-10 parts of a chlorella fermentation product and 3-8 parts of a bakusnea leaf extract. The composition achieves the effects of multi-channel whitening (covering melanin generation, oxidation, transport and metabolism whole links), anti-inflammatory repair and tightening and moisturizing through the synergistic effect of multiple components, is mild and low in irritation, is suitable for various skin types including sensitive skin and can be widely used for preparing cosmetics, the adding amount is 0.1 wt%-20 wt%, and the skin whitening effect is good. The product efficacy and the skin tolerance can be effectively considered.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, specifically to a gentle, firming, whitening, and spot-fading plant-based composition and its preparation method. Background Technology

[0002] As consumers increasingly demand safety and efficacy in skincare products, plant-derived ingredients have become a hot research topic due to their gentle and low-irritant properties. However, existing firming, whitening, and spot-fading products have the following drawbacks: Single efficacy and poor synergy: Most products rely on a single active ingredient (such as niacinamide or vitamin C derivatives) to achieve whitening, or rely on synthetic polymers to achieve firming, making it difficult to simultaneously achieve the triple effects of firming, whitening, and fading spots. Moreover, there is a lack of synergy between ingredients, resulting in limited effects. Insufficient gentleness: Some products add alcohol, fragrances, and irritating preservatives in pursuit of quick results, which can easily cause redness and stinging in sensitive skin, especially for skin with a damaged barrier and poor compatibility. Balancing skin tolerance and efficacy is difficult: Traditional whitening ingredients (such as hydroquinone derivatives) can inhibit melanin, but long-term use can easily lead to dry skin and thinning of the stratum corneum, which contradicts the skin barrier protection required for firmness.

[0003] Therefore, there is an urgent need to develop a cosmetic product that can achieve multi-component synergistic effects through multiple pathways, providing gentle firming, whitening, and spot-fading benefits. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention aims to provide a gentle firming, whitening and spot-fading plant composition and its preparation method. The composition has the technical effects of multi-pathway synergistic whitening, anti-inflammatory repair, firming and moisturizing.

[0005] The present invention is achieved through the following technical solution: providing a gentle firming, whitening and spot-fading plant composition, which, by weight, includes 15-22 parts of milk thistle extract, 4-9 parts of black truffle extract, 12-18 parts of okra fruit extract, 5-10 parts of chlorella fermentation product, and 3-8 parts of purslane leaf extract.

[0006] Preferably, the mild firming, whitening, and spot-fading plant composition comprises, by weight, 17-20 parts milk thistle extract, 6-7 parts black truffle extract, 13-15 parts okra fruit extract, 7-9 parts chlorella fermentation product, and 5-7 parts senna leaf extract.

[0007] The preparation method of the okra fruit extract is as follows: S1: Select fresh okra berries, wash them, slice them to a thickness of 2-4 mm, dry them at a low temperature (40-50℃) until the moisture content is <8%; pulverize them and pass them through a 60-80 mesh sieve to obtain okra berry powder.

[0008] S2: Add a 30%-45% ethanol solution to the coffee okra fruit powder, with a liquid-to-mass ratio of (10-15) mL / g; extract with ultrasound at 150-200W for 1-1.5 hours, and filter to obtain the filtrate; repeat the above extraction process on the filter residue, combine the filtrates, concentrate by rotary evaporation to obtain the extract, and freeze-dry the extract to obtain the final product.

[0009] On the other hand, the present invention provides a method for preparing a gentle firming, whitening and spot-fading plant composition, wherein milk thistle extract, black truffle extract, okra fruit extract, chlorella fermentation product and senna leaf extract are mixed evenly in the specified amounts to obtain the composition.

[0010] The present invention also provides the use of a mild firming, whitening and spot-fading plant composition in the preparation of cosmetics, the cosmetics comprising the aforementioned mild firming, whitening and spot-fading plant composition, wherein the amount of the mild firming, whitening and spot-fading plant composition in the cosmetics is 0.1wt%-20wt%, preferably 1wt%-10wt%.

[0011] The cosmetic may also contain at least one of the following: moisturizer, thickener, antioxidant, emulsifier, preservative, penetration enhancer, solvent, pH adjuster, and fragrance.

[0012] Milk thistle extract, rich in silymarin (flavonoids: silymarin, isosilymarin, etc.), repairs the skin barrier, combats photoaging, and has anti-inflammatory and soothing effects. For skin whitening: it competitively inhibits tyrosinase, downregulates MITF gene expression, and eliminates ROS. For skin care: it promotes ceramide synthesis, inhibits MMP-1 activity (reducing collagen degradation), and lowers TNF-α release.

[0013] Black truffle extract mainly contains ergothioneine, polysaccharides, amino acids, phenolic compounds and other components. It repairs the skin barrier, reduces wrinkles and firms the skin, improves dullness and whitens the skin: ergothioneine (a strong antioxidant) scavenges free radicals and inhibits tyrosinase activity; for skin care: polysaccharides increase skin hydration, amino acids promote keratinocyte proliferation, and phenolic compounds inhibit elastase (anti-wrinkle).

[0014] Okra fruit extract, rich in mucopolysaccharides (okra polysaccharides), flavonoids, vitamin C, and dietary fiber, can aid in whitening and brightening skin tone, as well as providing powerful moisturizing, barrier repair, and soothing and anti-allergic effects. Whitening: Chlorophyll (antioxidant) reduces UV-induced pigmentation, and small molecule peptides downregulate MITF and TYR gene expression, promoting stratum corneum renewal. Skincare: Polysaccharides (molecular weight 2000~5000Da) are easily absorbed, and amino acids replenish skin nutrition and inhibit ROS damage.

[0015] Chlorella fermentation products are rich in algal polysaccharides, oligopeptides, amino acids, nucleic acids, vitamin B12, chlorophyll, and active minerals such as magnesium and zinc. In cosmetics, algal polysaccharides form films to lock in moisture and strengthen the skin barrier; oligopeptides and nucleic acids synergistically stimulate type I collagen synthesis, smoothing fine lines and improving elasticity; chlorophyll and vitamin B12 scavenge free radicals, inhibit tyrosinase, brighten skin tone, and provide antioxidant and anti-aging benefits; mineral ions soothe inflammation, regulate the skin's microecology, and reduce irritation. This product is water-soluble, stable, light-colored, and has excellent compatibility, making it suitable for addition to serums, masks, lotions, sunscreens, and other products. It achieves multiple effects in one, including moisturizing, whitening, repairing, and anti-aging, meeting the modern skincare demand for natural, safe, and highly effective products.

[0016] Kaempferia galanga leaf extract mainly contains flavonoids (kaempferol, quercetin), polyphenols, and tannins. It has anti-inflammatory and soothing properties, astringent and oil-controlling effects, and improves redness. It blocks melanin transport, inhibits enzyme activity, and fades dark spots. For whitening: flavonoids inhibit tyrosinase, blocking the transfer of melanin from melanocytes to keratinocytes; for skin care: tannins tighten pores, and polyphenols can inhibit IL-1β release (anti-inflammatory), reducing the risk of post-inflammatory hyperpigmentation.

[0017] Beneficial effects This invention provides a gentle, firming, whitening, and spot-fading plant composition and its preparation method. The composition has multi-pathway synergistic effects of whitening, anti-inflammatory repair, firming, and moisturizing.

[0018] This multi-pathway synergistic whitening formula covers the entire melanin production chain. *Smilax glabra* leaf extract directly targets and inhibits tyrosinase, reducing melanin production at its source. *Silybum marianum* and *Tuber nigricans* extracts powerfully scavenge free radicals during melanin synthesis (DOPA → DOPAquinone), preventing melanin oxidation and protecting cells from irritation. *Silybum marianum* and *Smilax glabra* leaf extracts also reduce inflammation caused by skin irritation, preventing inflammation-induced pigmentation. *Chlorella vulgaris* fermentation product and *Okra maculata* fruit extract promote cell renewal, gently moisturize and condition the stratum corneum, helping existing melanin to shed with aging keratinocytes, reducing melanin deposition.

[0019] Synergistic anti-inflammatory and repair effects: The anti-inflammatory components of okra combine with the repair peptides of truffles to accelerate the resolution of inflammation and the reconstruction of the skin barrier; the anti-inflammatory effects of milk thistle complement the oil-controlling effects of senna, reducing the occurrence of inflammatory skin problems such as acne.

[0020] Whitening and moisturizing balance: Milk thistle inhibits tyrosinase activity and reduces melanin production; polysaccharides from okra and black truffle provide long-lasting hydration and prevent skin dryness during the whitening process; Chlorella's moisturizing and repairing effects maintain healthy skin and enhance the longevity of whitening effects. Attached Figure Description

[0021] Figure 1 This is a comparison of fluorescence intensity in zebrafish during an antioxidant test. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only some preferred embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Unless otherwise specified, the experimental methods used in the embodiments are conventional or common methods in the art, and the materials and reagents used are commercially available unless otherwise specified.

[0024] The raw materials used in the examples and comparative examples are described below: Black truffle extract: purchased from Xi'an Shangcheng Biotechnology Co., Ltd.; Extract of *Sophora indicum* leaf: purchased from Ningxia Xiangcao Biotechnology Co., Ltd.; Milk thistle extract: purchased from Xi'an Dongfeng Biotechnology Co., Ltd.; Chlorella Ferment: Purchased from Shandong Freda Biotechnology Co., Ltd.

[0025] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0026] The preparation method of okra fruit extract (homemade) is as follows: S1: Select fresh okra berries, wash them, slice them to a thickness of 2-4 mm, dry them at 45℃ until the moisture content is <8%; grind them and pass them through a 60-mesh sieve to obtain okra berry powder.

[0027] S2: Add a 40% ethanol solution to the coffee okra fruit powder at a liquid-to-mass ratio of 10 mL / g; extract with ultrasound at 150 W for 1.5 h, and filter to obtain the filtrate; repeat the above extraction process on the filter residue, combine the filtrates, and concentrate them to extract by rotary evaporation under vacuum conditions of 40℃ and 0.1 MPa. Freeze-dry the extract to obtain the final product.

[0028] The preparation method of Chlorella fermentation product (self-made) is as follows: S1: Chlorella active fermentation stock solution was selected and rotary evaporated to extract under vacuum conditions of 40℃ and 0.1MPa.

[0029] S2: Freeze-dry the extract at -20℃ for 8 hours to obtain the final product.

[0030] Example 1 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 18g of milk thistle extract, 7g of black truffle extract, 14g of okra fruit extract, 8g of chlorella fermentation product, and 6g of senna leaf extract evenly.

[0031] Example 2 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 20g of milk thistle extract, 6g of black truffle extract, 15g of okra fruit extract, 7g of chlorella fermentation product, and 5g of senna leaf extract evenly.

[0032] Example 3 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 17g of milk thistle extract, 7g of black truffle extract, 13g of okra fruit extract, 9g of chlorella fermentation product, and 7g of senna leaf extract evenly.

[0033] Example 4 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 21g of milk thistle extract, 4g of black truffle extract, 15g of okra fruit extract, 10g of chlorella fermentation product, and 3g of senna leaf extract evenly.

[0034] Example 5 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 22g of milk thistle extract, 5g of black truffle extract, 12g of okra fruit extract, 9g of chlorella fermentation product, and 5g of senna leaf extract evenly.

[0035] Example 6 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 15g of milk thistle extract, 8g of black truffle extract, 17g of okra fruit extract, 5g of chlorella fermentation product, and 8g of senna leaf extract evenly.

[0036] Example 7 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 16g of milk thistle extract, 9g of black truffle extract, 18g of okra fruit extract, 6g of chlorella fermentation product, and 4g of senna leaf extract evenly.

[0037] Comparative Example 1 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 7g of *Ichthyophthirius multifiliis* extract, 14g of *Okra* fruit extract, 8g of *Chlorella vulgaris* fermentation product, and 6g of *Solanum lyratum* leaf extract evenly.

[0038] Comparative Example 2 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 18g of milk thistle extract, 14g of okra fruit extract, 8g of chlorella fermentation product, and 6g of senna leaf extract evenly.

[0039] Comparative Example 3 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 18g of milk thistle extract, 7g of black truffle extract, 8g of chlorella fermentation product, and 6g of senna leaf extract evenly.

[0040] Comparative Example 4 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 18g of milk thistle extract, 7g of black truffle extract, 14g of okra fruit extract, and 6g of senna leaf extract evenly.

[0041] Comparative Example 5 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 18g of milk thistle extract, 7g of black truffle extract, 14g of okra fruit extract, and 8g of chlorella fermentation product evenly.

[0042] Comparative Example 6 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 25g of milk thistle extract, 2g of black truffle extract, 8g of okra fruit extract, 15g of chlorella fermentation product, and 2g of senna leaf extract evenly.

[0043] Comparative Example 7 A method for preparing a gentle, firming, whitening, and spot-fading plant composition involves mixing 10g of milk thistle extract, 12g of black truffle extract, 20g of okra fruit extract, 3g of chlorella fermentation product, and 10g of senna leaf extract evenly.

[0044] Table 1. Ingredients for Examples 1-7 and Comparative Examples 1-7 (by weight / g) Milk thistle extract Black truffle extract Okra fruit extract Chlorella fermentation products Senna leaf extract Example 1 18 7 14 8 6 Example 2 20 6 15 7 5 Example 3 17 7 13 9 7 Example 4 21 4 15 10 3 Example 5 22 5 12 9 5 Example 6 15 8 17 5 8 Example 7 16 9 18 6 4 Comparative Example 1 / 7 14 8 6 Comparative Example 2 18 / 14 8 6 Comparative Example 3 18 7 / 8 6 Comparative Example 4 18 7 14 / 6 Comparative Example 5 18 7 14 8 / Comparative Example 6 25 2 8 15 2 Comparative Example 7 10 12 20 3 10 Note: " / " indicates that the component was not added.

[0045] Performance verification tests of Examples 1-7 and Comparative Examples 1-7: The performance of the mild firming, whitening and spot-fading plant compositions prepared in Examples 1-7 and Comparative Examples 1-7 was verified.

[0046] Anti-inflammatory test: Sample preparation: Dissolve 5g of the mild firming, whitening and spot-fading plant composition prepared in Examples 1-7 and Comparative Examples 1-7 in 10mL of sterile deionized water for later use.

[0047] Reagents: Tumor necrosis factor-α (TNF-α) assay kit, interleukin-6 (IL-6) assay kit, interleukin-1β (IL-1β) assay kit; lipopolysaccharide (LPS, E. coli O111:B4 type, Sigma); high glucose DMEM culture medium (containing 4.5 g / L glucose and L-glutamine, Gibco); fetal bovine serum (FBS, Gibco); phosphate-buffered saline (PBS, pH 7.2, Solarbio). Consumables and instruments: 24-well cell culture plates (Corning); cell culture flasks (Corning); CO2 incubator (Thermo); low-speed centrifuge (Eppendorf); microplate reader (Bio-Tek).

[0048] Experimental Methods: RAW264.7 cells were seeded into culture flasks containing 10% fetal bovine serum and high-glucose DMEM medium and incubated at 37°C in a 5% CO2 incubator. The cell density of RAW264.7 cells in the logarithmic growth phase was adjusted to 5 × 10⁻⁶ cells / year. 5 Cells / mL. Seed 500 μL per well into a 24-well cell culture plate and pre-incubate at 37°C, 5% CO2, and saturated humidity for 24 h to allow the cells to adhere completely.

[0049] After pre-culture, the original culture medium in each well was aspirated, and the cells were gently washed once with PBS. The cells were then treated according to the following groups, with 6 replicates per group to ensure consistent initial conditions between groups: 1) Blank control group: 550 μL of DMEM culture medium containing 10% fetal bovine serum + 50 μL of PBS (pH 7.2) solution (serum-free DMEM dilution) was added to each well, for a total volume of 600 μL; 2) Model group (LPS induction group): 550 μL of DMEM culture medium containing 10% fetal bovine serum + 50 μL of LPS solution (concentration 1 μg / mL, serum-free DMEM dilution) was added to each well, for a total volume of 600 μL to construct an inflammation model; 3) Experimental group (sample intervention group): 550 μL of DMEM culture medium containing 10% fetal bovine serum + 10 μL of LPS solution (concentration 5 μg / mL) + 40 μL of sample solution (concentration: 0.5 g / mL) was added to each well, for a total volume of 600 μL to achieve simultaneous intervention of sample and inflammation induction.

[0050] The treated blank control group and 24-well culture plates were returned to a 37℃, 5% CO2 incubator for another 24 hours of incubation. After incubation, the supernatant from each well was collected into sterile centrifuge tubes and centrifuged at 4℃, 1000 rpm for 5 minutes to remove residual cell debris. The supernatant was then used to measure the absorbance (OD value) of each well using an enzyme-linked immunosorbent assay (ELISA) reader, strictly following the instructions for the TNF-α, IL-6, and IL-1β detection kits. The actual concentrations of inflammatory factors (TNF-α, IL-6, IL-1β) in each well were calculated based on the standard curve. The inhibition rate of inflammatory factors was calculated based on the concentrations of each group using the following formula: Inflammatory factor inhibition rate (%) = [(Average concentration of inflammatory factors in the model group - Average concentration of inflammatory factors in the experimental group) / (Average concentration of inflammatory factors in the model group - Average concentration of inflammatory factors in the blank control group)] × 100%.

[0051] Table 2. Results of anti-inflammatory test (inhibition rate of inflammatory factors %) Group TNF-α inhibition rate (%) IL-6 inhibition rate (%) IL-1β inhibition rate (%) Example 1 68.5 64.2 72.8 Example 2 66.3 63.8 70.1 Example 3 67.9 64.5 71.5 Example 4 65.2 62.1 68.9 Example 5 66.8 61.9 69.7 Example 6 64.1 61.4 67.3 Example 7 63.7 60.8 66.5 Comparative Example 1 45.2 42.6 50.1 Comparative Example 2 52.4 48.7 55.3 Comparative Example 3 48.9 46.2 52.8 Comparative Example 4 50.1 47.5 53.9 Comparative Example 5 47.3 44.8 51.2 Comparative Example 6 38.6 35.1 42.7 Comparative Example 7 40.2 37.5 44.3 According to the results in Table 2: 1) The mild firming, whitening, and spot-fading plant compositions described in Examples 1-7 showed inhibition rates of 63.7%-68.5%, 60.8%-64.5%, and 66.5%-72.8% against inflammatory factors TNF-α, IL-6, and IL-1β, respectively, indicating that the compositions have a significant effect in inhibiting inflammatory factors; 2) Compared with Example 1, Comparative Examples 1-5 lacked the components milk thistle extract, black truffle extract, okra fruit extract, chlorella fermentation product, and senna leaf extract, respectively, and their inhibition rates against TNF-α, IL-6, and IL-1β decreased to 45.2%-52.4%, 42.6%-47.8%, and 50.1%-55.3%, respectively; it can be seen that the five components included in Example 1 can work together to achieve a multi-target anti-inflammatory effect, indicating that the combination prepared in Example 1 has a mild desensitizing effect. 3) Compared with Example 1, Comparative Examples 6 and 7 adjusted the weight ratio of each component in the composition. Comparative Example 6 significantly increased the amount of milk thistle extract. Excessive milk thistle extract may cause antagonism between components, while insufficient repair components lead to the inability to repair inflammatory damage in time, resulting in the continuous release of inflammatory factors and a significant decrease in the inhibition rate of inflammatory factors TNF-α, IL-6, and IL-1β. In Comparative Example 7, the amount of senna leaf extract was significantly increased and the amount of milk thistle extract was significantly decreased. While the anti-inflammatory ability was weakened, the excessive tannins in senna leaf extract may stimulate cells and aggravate inflammation, thus leading to a significant decrease in the inhibition rate of inflammatory factors.

[0052] 2. Antioxidant test: Sample preparation: Dissolve 5g of each of the compositions of Examples 1-7 and Comparative Examples 1-7 in 10mL of sterile deionized water to prepare a 0.5g / mL stock solution, and then dilute it with zebrafish culture medium to a 1% concentration (final concentration) for later use.

[0053] Experimental method: The 1% concentration sample was tested according to the "Standard Operating Procedure for Evaluation of Antioxidant Efficacy of Zebrafish".

[0054] Zebrafish pretreatment: Two days after fertilization, Albino strain zebrafish were randomly divided into groups of 15 each and placed in 24-well plates. 500 μL of culture medium was added to each well and the plates were pre-incubated for 12 hours. Inflammation and oxidative stress induction: 50 μL LPS solution (final concentration 1 μg / mL) was added to all wells except the blank control group, and the mixture was incubated at 37℃ for 6 h to construct an oxidative stress model; Sample intervention: 50 μL of 1% concentration sample was added to the wells of the experimental group (Examples 1-7, Comparative Examples 1-7), and 50 μL of culture medium was added to the model control group. The incubation was continued for 24 h. Detection: The DCFH-DA fluorescent probe method was used. The fluorescence intensity of each well was detected by a microplate reader (fluorescence intensity is positively correlated with ROS level), and the ROS scavenging rate (antioxidant efficacy %) was calculated using the following formula: Antioxidant efficacy (%) = [(average fluorescence intensity of model group - average fluorescence intensity of experimental group) / (average fluorescence intensity of model group - average fluorescence intensity of blank control group)] × 100%.

[0055] Table 3 Results of Antioxidant Test Group Antioxidant efficacy (%) p-value Significance determination Example 1 28.4 <0.001 Extremely significant Example 2 29.1 <0.001 Extremely significant Example 3 29.2 <0.001 Extremely significant Example 4 25.8 <0.001 Extremely significant Example 5 26.5 <0.001 Extremely significant Example 6 24.3 <0.01 Significant Example 7 25.1 <0.01 Significant Comparative Example 1 21.7 <0.01 Significant Comparative Example 2 18.3 <0.05 Significant (weak) Comparative Example 3 20.5 <0.05 Significant (weak) Comparative Example 4 19.1 <0.05 Significant (weak) Comparative Example 5 22.4 <0.05 Significant (weak) Comparative Example 6 13.8 <0.05 Significant (weak) Comparative Example 7 12.5 <0.05 Significant (weak) Blank control group 0 - - Model control group 0 - - Table 3 shows that: 1) The antioxidant efficacy of Examples 1-7 reached 24.3%-29.2%, indicating that Examples 1-7 had significant (or highly significant) antioxidant effects. 2) Compared with Example 1, Comparative Examples 1-5 lacked certain components, and their antioxidant efficacy decreased to 18.3%-22.4%. The complementary antioxidant mechanisms among the components may be the reason for the reduced antioxidant activity of Comparative Examples 1-5: for example, ergothioneine from *Tuber nigricans* extract can directly and effectively scavenge ROS; silymarin from *Smilax china* extract can provide sustained antioxidant capacity; polysaccharides and chlorophyll from *Okra* fruit extract and *Chlorella vulgaris* fermentation products can inhibit ROS generation; and flavonoids and polyphenols from *Solanum lyratum* leaf extract can block the oxidative stress chain reaction. Therefore, a full-chain antioxidant network of "scavenging-inhibition-blocking" can be formed among different antioxidant active components. The reason for the reduced antioxidant efficacy of Comparative Examples 6-7 compared to Example 1 may be that the ratio of antioxidant activities among the components is unbalanced, and different concentrations of components may affect each other's antioxidant effects.

[0056] Application examples Application Examples 1-7 and Comparative Application Examples 1-7 of the present invention provide a moisturizing skin care lotion, the composition of which is shown in Table 4; wherein, Application Examples 1-7 and Comparative Application Examples 1-7 respectively use the mild firming, whitening and spot-fading plant composition prepared in Examples 1-7 and Comparative Examples 1-7.

[0057] Table 4 Ingredients of Moisturizing Skin Lotion Raw material name mass percentage / % Whitening and anti-aging compositions suitable for sensitive skin prepared in Examples 1-7 or Comparative Examples 1-7 6.00 Carbomer 0.50 Cetearyl alcohol 1.60 glycerin 2.00 Butylene glycol 2.00 Panthenol 0.50 Sodium hyaluronate 0.20 Lysine 0.05 Histidine 0.05 sterile deionized water margin The preparation method of the moisturizing skin care lotion is as follows: Carbomer and sodium hyaluronate are added to sterile deionized water and heated to 40°C until completely dissolved under magnetic stirring at 350 rpm; then cetearyl alcohol, glycerin, butylene glycol, panthenol, lysine, and histidine are added, and the mixture is heated and stirred until dissolved; then the mild firming, whitening, and spot-fading plant composition prepared in the examples or comparative examples is added, and the mixture is stirred at 2000 rpm for 10 min using a vacuum emulsifying high-speed mixer, and the product is discharged to obtain the moisturizing skin care lotion.

[0058] Performance test of the moisturizing skin lotion prepared in the application example Human closed patch test: The specific test method is in accordance with the "Cosmetic Safety Technical Specifications" (2015 edition). The test is conducted using human skin patch test. The scoring criteria are detailed in Table 5.

[0059] Table 5 Scoring Criteria

[0060] degree of reaction Rating levels Skin reaction － 0 negative reaction ± 1 Suspicious reaction, only slight erythema ＋ 2 Weak positive reaction (erythema): erythema, infiltration, edema, and papules may be present. ＋＋ 3 Strong positive reaction (herpes): erythema, infiltration, edema, papules, vesicles; the reaction may extend beyond the test area. ＋＋＋ 4 Extremely strong positive reaction: obvious erythema, severe infiltration, edema, confluent herpes, reaction extending beyond the test area. Thirty volunteers, aged 20-50 years (average age 31.3 years), were recruited and signed informed consent forms. Using a suitable patch tester, a closed patch test method was employed. An equal volume of 25 μL of the test substance (measured by pipette) was placed in the patch tester, which was then applied to the volunteer's arm with hypoallergenic adhesive tape. The tape was gently pressed to ensure even application to the skin. The test substance was removed after 24 hours. Skin reactions were observed at 0.5, 24, and 48 hours after patch removal. Adverse skin reactions were recorded and are shown in Table 6.

[0061] Table 6. Results of Adverse Skin Reactions from Patch Testing

[0062] Table 6 shows that in all application cases and the control group, the skin reaction scores of all 30 volunteers at each observation time point (0.5, 24, and 48 hours) were 0, with no adverse reactions such as mild erythema, edema, or papules. This indicates that none of the tested samples caused skin irritation or allergic reactions. These results consistently confirm that, regardless of whether the five plant extracts are fully contained or under different formulation conditions, the prepared composition exhibits excellent skin mildness and safety at a 6% addition level, without causing visible damage to the skin barrier, making it suitable for various skin types, including sensitive skin. The negative results of the patch test further support the technical claim of the plant composition's "mild" properties, providing a reliable safety basis for its practical application in whitening and spot-fading cosmetics.

[0063] Whitening performance test Experimental Methods: Seventy healthy volunteers aged 20-45 years with a clear desire for skin whitening were recruited as subjects. The subjects were randomly divided into 14 groups of 5 people each, corresponding to the application examples 1-7 and the control application examples 1-7, for a total of 14 test samples.

[0064] Intervention method: Subjects used the corresponding group's skin lotion twice daily, morning and evening, for 4 consecutive weeks. Each time, an appropriate amount of lotion was applied evenly to the facial skin.

[0065] Assessment tool: Objective quantitative detection was performed using the Hexameter MX18 skin red melanin analyzer.

[0066] Melanin content record: The average melanin content before use is recorded as T1, and the value detected after 4 weeks is recorded as T2.

[0067] Inhibition rate calculation: Melanin inhibition rate N=(T1-T2) / T1×100%, accurate to two decimal places.

[0068] Statistical analysis: Data analysis software was used to test the significance of differences between groups. A p < 0.05 was considered statistically significant.

[0069] Table 7 Results of melanin inhibition rate Group Melanin inhibition rate N (%) p-value Significance determination Application Example 1 22.35 ＜0.01 Significant Application Example 2 21.87 ＜0.01 Significant Application Example 3 21.52 ＜0.01 Significant Application Example 4 20.73 ＜0.01 Significant Application Example 5 19.21 ＜0.01 Significant Application Example 6 19.38 ＜0.01 Significant Application Example 7 18.94 ＜0.01 Significant Comparative Application Example 1 14.26 ＜0.05 Significant (weak) Comparative Application Example 2 15.83 ＜0.05 Significant (weak) Comparative Application Example 3 15.17 ＜0.05 Significant (weak) Comparative Application Example 4 14.41 ＜0.05 Significant (weak) Comparative Application Example 5 13.75 ＜0.05 Significant (weak) Comparative Application Example 6 11.42 ＜0.05 Significant (weak) Comparative Application Example 7 12.19 ＜0.05 Significant (weak) According to the melanin inhibition rate data in Table 7, the inhibition rate of Application Examples 1-7 (complete formula group) (18.94%-22.35%) was significantly higher than that of Control Application Examples 1-7 (11.42%-16.19%), and the statistical significance was generally stronger (p<0.01). This significant difference may mainly stem from the multi-pathway synergistic whitening mechanism constructed by the five plant ingredients in the complete formula. Specifically, milk thistle extract and senna leaf extract reduce melanin production and deposition at the source by inhibiting tyrosinase activity and blocking the transport of melanin to keratinocytes, respectively; the potent antioxidant components in black truffle extract (such as ergothioneine) can effectively scavenge free radicals and prevent the oxidation process during melanin synthesis from deepening; at the same time, okra fruit extract and chlorella fermentation products accelerate the metabolic shedding of generated melanin by promoting stratum corneum renewal. In contrast, the comparative application groups, lacking any ingredient (such as the extract of *Eucommia ulmoides* leaf in Comparative Example 5) or exhibiting severely imbalanced proportions (such as Comparative Examples 6 and 7), disrupted this synergistic network. This could not only render certain whitening pathways (such as antioxidant or transport blocking) ineffective or reduce their function, but also potentially lead to antagonistic effects due to imbalanced proportions between ingredients. For example, excessive amounts of a single ingredient might inhibit the activity of other components, or insufficient repair and moisturizing capabilities could result in a decline in skin barrier function, indirectly affecting the overall and sustained whitening effect. Therefore, a complete and optimized formula, by covering the entire chain of melanin production, oxidation, transport, and metabolism, achieves significantly superior synergistic whitening efficacy compared to partial or imbalanced formulas.

[0070] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A gentle, firming, whitening, and spot-fading plant-based composition, characterized in that, The composition comprises, by weight, 15-22 parts milk thistle extract, 4-9 parts black truffle extract, 12-18 parts okra fruit extract, 5-10 parts chlorella fermentation product, and 3-8 parts senna leaf extract.

2. The gentle, firming, whitening, and spot-fading plant composition according to claim 1, characterized in that, The composition comprises, by weight, 17-20 parts milk thistle extract, 6-7 parts black truffle extract, 13-15 parts okra fruit extract, 7-9 parts chlorella fermentation product, and 5-7 parts senna leaf extract.

3. The gentle, firming, whitening, and spot-fading plant composition according to claim 1, characterized in that, The preparation method of the okra fruit extract is as follows: S1: Select fresh okra berries, wash them, slice them to a thickness of 2mm-4mm, dry them at 40℃-50℃ until the moisture content is <8%; pulverize them and pass them through a 60-80 mesh sieve to obtain okra berry powder; S2: Add a 30%-45% ethanol solution to the coffee okra fruit powder, with a liquid-to-mass ratio of (10-15) mL / g; extract with ultrasound at 150W-200W for 1-1.5 hours, and filter to obtain the filtrate; repeat the above ethanol solution extraction process on the filter residue, combine the filtrates, concentrate by rotary evaporation to obtain an extract, and freeze-dry the extract to obtain the final product.

4. The method for preparing the mild, firming, whitening, and spot-fading plant composition according to any one of claims 1-3, characterized in that, Mix milk thistle extract, black truffle extract, okra fruit extract, chlorella fermentation product and senna leaf extract evenly according to the specified amounts to obtain the final product.

5. Use of the mild firming, whitening, and spot-fading plant composition according to any one of claims 1-3 in the preparation of cosmetics.

6. The use according to claim 5, characterized in that, The mild, firming, whitening, and spot-fading plant composition is used in the cosmetic at an amount of 0.1wt%-20wt%.

7. The use according to claim 6, characterized in that, The gentle, firming, whitening, and spot-fading plant composition is used in the cosmetic at an amount of 1wt%-10wt%.

8. The use according to claim 5, characterized in that, The cosmetic may also contain at least one of the following: moisturizer, thickener, antioxidant, emulsifier, preservative, penetration enhancer, solvent, pH adjuster, and fragrance.

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