Silk peptide composition for inhibiting melanogenesis and SC1 polypeptide and application thereof

Abstract

The invention discloses a silk peptide composition for inhibiting melanogenesis as well as SC1 polypeptide and application thereof, the composition comprises at least one of peptide fragments DIPFFR, SITDLLR, DIPYHLR, YSSDSRDGSVSSSTG and EFDDIK, after silkworm cocoon raw materials are pretreated, papain is used for enzymolysis, the enzymolysis time is 10-12 hours, then filtration is performed, filtrate is collected, and the SC1 polypeptide is obtained. The obtained silk protein hydrolysate is a composition for inhibiting melanogenesis; the obtained composition can inhibit melanogenesis and can be used for developing products for preventing or improving light aging.

Description

Technical Field

[0001] This invention relates to the field of biotechnology, specifically to a silk peptide composition that inhibits melanin production, and also to an SC1 polypeptide that inhibits melanin production and the application of the polypeptide. Background Technology

[0002] Studies have clarified that ultraviolet (UV) radiation not only causes acute sunburn but is also a core environmental factor leading to skin pigmentation problems such as uneven skin tone, stubborn age spots, and even melanoma. The core mechanism of skin pigmentation lies in the fact that UV radiation (especially UVA and UVB) activates epidermal melanocytes, inducing the "melanogenesis" signaling pathway. During this process, the activity of the key rate-limiting enzyme tyrosinase is upregulated, catalyzing the conversion of tyrosine to dopa, which is further oxidized to dopaquinone, ultimately forming melanin granules. These melanins are then transported to surrounding keratinocytes, resulting in visible darkening of the skin and age spots. Currently, mainstream skin whitening strategies mainly rely on tyrosinase inhibitors (such as hydroquinone and arbutin) and antioxidants (such as vitamin C). However, these ingredients not only have limitations in effectiveness but also often suffer from side effects such as cytotoxicity, skin irritation, allergies, and poor product stability. Therefore, developing skin whitening solutions that are more natural, safer, and have more diverse mechanisms of action has become an urgent need in the industry.

[0003] Sericin, a component of silk fibroin, is becoming a new hot spot in the development of "green whitening" raw materials due to its natural origin and biocompatibility. Sericin is a water-soluble globular protein that encapsulates silk fibers, accounting for approximately 25%–30% of the total silk content. Its molecules are rich in polar amino acids (such as serine and aspartic acid), giving it excellent moisturizing and gentle properties. Preliminary studies have confirmed the significant potential of sericin in the field of whitening. For example, specific sericin components can competitively or in combination inhibit tyrosinase activity, directly blocking melanin biosynthesis at its source; some sericin peptides can also achieve multi-target intervention by downregulating the signaling pathway of melanocyte-stimulating factors (such as α-MSH) or inhibiting the transport process of melanosomes. Furthermore, the inherent UV absorption capacity and anti-inflammatory properties of sericin can effectively reduce UVB-induced melanin-promoting signals, playing a dual role in preventative whitening and post-sun repair.

[0004] While these studies reveal the broad application prospects of sericin, most sericin raw materials currently on the market are crude extracts or random hydrolysates, with unknown core whitening active peptide sequences, unclear structure-activity relationships, and ambiguous targets. This "mixed composition" leads to unstable product efficacy, large batch-to-batch variations, and the inability to establish clear quality control standards, severely restricting its application as a high-end cosmetic ingredient. Therefore, developing a sericin-derived active peptide with a well-defined structure, clear whitening mechanism, and controllable quality uniformity is crucial to breaking through current industry bottlenecks and realizing the high-value utilization of silk resources. Summary of the Invention

[0005] In view of this, one objective of the present invention is to provide a silk peptide composition that inhibits melanin production; a second objective of the present invention is to provide an SC1 polypeptide that inhibits melanin production; a third objective of the present invention is to provide a composition containing the SC1 polypeptide; a fourth objective of the present invention is to provide the use of the SC1 polypeptide in the preparation of a product that inhibits melanin production; and a fifth objective of the present invention is to provide the use of the composition or the SC1 polypeptide in the preparation of a product for preventing or improving photoaging.

[0006] To achieve the above objectives, the present invention provides the following technical solution: 1. A silk peptide composition for inhibiting melanin production, said composition comprising at least one of the peptides DIPFFR, SITDLLR, DIPYHLR, YSSDSRDGSVSSSTG, and EFDDIK.

[0007] Preferably, the composition of the present invention is prepared by pretreating silkworm cocoon raw materials, enzymatically hydrolyzing them with papain for 10-12 hours, then filtering and collecting the filtrate, and the resulting silk fibroin hydrolysate is a composition that inhibits melanin production.

[0008] Preferably, the papain is hydrolyzed for 12 hours according to the present invention.

[0009] 2. An SC1 polypeptide that inhibits melanin production, wherein the amino acid sequence of the SC1 polypeptide is Asp-Ile-Pro-Tyr-His-Leu-Arg.

[0010] 3. A composition containing the SC1 polypeptide, wherein the composition is in the form of a cream, gel, lotion, solution or serum.

[0011] 4. The use of the composition or the SC1 polypeptide in the preparation of products that inhibit melanin production.

[0012] 7. Use of the composition or the SC1 polypeptide in the preparation of products for preventing or improving photoaging.

[0013] 8. Preferably, the prevention or improvement of photoaging includes inhibiting pigmentation, reducing erythema, or delaying cell aging.

[0014] The beneficial effects of this invention are as follows: This invention discloses a composition for inhibiting melanin production, its SC1 peptide, and its applications. The composition contains at least one of the peptides DIPFFR, SITDLLR, DIPYHLR, YSSDSRDGSVSSSTG, and EFDDIK. After pretreatment of silkworm cocoon raw materials, the mixture is enzymatically hydrolyzed using papain for 10-12 hours. The mixture is then filtered, and the filtrate is collected. The resulting silk fibroin hydrolysate is the composition for inhibiting melanin production. The obtained composition can inhibit melanin production and has good biocompatibility. It can effectively inhibit early photoaging phenomena, such as pigmentation and erythema, and significantly delay cell aging. It can be used to develop products for preventing or improving photoaging, which is of great significance for cosmetic development. Attached Figure Description

[0015] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 To observe the microstructure of degummed silk fibroin using scanning electron microscopy; Figure 2 A statistical chart showing the concentration, extraction rate, and maximum molecular weight of silk protein; Figure 3 SDS-PAGE was used to determine the molecular weight of sericin. Figure 4 The inhibitory effects of different extraction methods on melanin; Figure 5 This describes the process of producing silk protein hydrolysates using the P-1 method. Figure 6 The effect of SEH on cell viability; Figure 7 To evaluate the skincare efficacy of SEH; Figure 8 This is the result of pigment detection; Figure 9 Find Vmax, Km, and the Michaelis-Menten curve for the Michaelis-Menten equation; Figure 10 The effect of SEH treatment on the structure of the key enzyme tyrosinase (TYR); Figure 11 The results of detecting the content of melanin-related genes α-MSH, WNT2 / 2B, MITF, TYR, TYRP1, and DCT after SEH treatment; Figure 12 Ridge map induced by UV irradiation after SEH processing; Figure 13 To identify and quantify peptides in descending order of abundance; Figure 14 The results are from the clustering dendrogram analysis. Figure 15 To analyze the expression levels of key receptors using RNA-seq expression profiling; Figure 16 Heatmap of binding energy between core peptide and highly expressed receptor; Figure 17 Results of virtual structure analysis of the interaction between SC1 and TRPV4; Figure 18 mRNA expression results of key melanin production regulators Figure 19 To detect the effect of SC1 on MITF protein, a key regulator of melanin synthesis, using Western blot. Figure 20 To observe the results of SC1-induced UV suppression on the number of melanosomes and melanin granules using transmission electron microscopy; Figure 21 SC1 inhibits UV-induced melanin expression. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0017] Example 1: Extraction and hydrolysis of silk protein Rinse the silkworm cocoons three times with pure water and cut them into pieces about 1 cm long. 2 After the silk was broken into small pieces, different methods were used to extract the silk protein: the material-to-liquid ratio was 2%, and the silk protein was extracted using papain (800,000 U / L, 40℃) for 12 h and 8 h (P-1 and P-2, respectively), high temperature and high pressure (120℃) for 2 h, 1 h and 0.5 h (HTHP-1, HTHP-2 and HTHP-3, respectively), and neutral soap (0.5%), sodium carbonate (1%) and malic acid (1%) (NS, SC and MA, respectively). After processing, the silk protein was filtered to obtain SEH, and finally freeze-dried for storage.

[0018] The microstructure of degummed silk fibroin was observed using a scanning electron microscope (Hitachi SU3500, Japan). The results showed that the sericin in silk fibroin could be effectively removed by methods such as papain hydrolysis and high temperature and pressure. Figure 1 Sericin concentration was determined using the BCA protein quantification kit (Beyotime P0012, China).

[0019] The sericin removal rate is calculated using the following formula: Degumming rate (%) = (Initial mass of dried cocoons − Mass of dried cocoons after degumming) / Initial mass of dried cocoons × 100% Statistical results are as follows Figure 2 As shown in the figure. The results indicate that the efficiency of papain hydrolysis for 12 hours and high temperature and high pressure extraction can reach over 25%.

[0020] The molecular weight of sericin was determined by SDS-PAGE: A sericin sample with an equal solid content was mixed with loading buffer, boiled for 5 min, and then electrophoresed in a 12% separating gel. After Coomassie brilliant blue staining, the sample was scanned and recorded using a Patch-clamp imaging system (Canon, Japan). SDS-PAGE results showed that papain hydrolysis of silk fibroin was the most effective in producing a low molecular weight peptide library, exhibiting the most thorough and consistent degradation, with the product components mainly concentrated below 25 kDa. Figure 3 ).

[0021] Example 2: Screening for the anti-melanin production activity of silk fibroin B16F10 melanocytes were treated with the sericin peptide libraries obtained by the eight methods in Example 1 for 12 h. The melanin content in the cells was expressed as "melanin per unit protein". The content was detected by dissolving half of the cells in 1 M NaOH at 80°C for 1 h and measuring the absorbance at 405 nm using a ELISA reader (Synergy H4, USA); the protein concentration of the other half of the cells was measured using the BCA method.

[0022] Semi-quantitative melanin content = melanin absorbance ÷ protein concentration.

[0023] The results showed that, except for the NS library, all other libraries significantly inhibited melanin synthesis (P < 0.05). Among them, the P-1 library derived from papain hydrolysis showed the strongest inhibitory effect, even better than the positive control arbutin. Figure 4 Based on the above experimental results, the P-1 method was ultimately chosen to produce silk protein hydrolysate (SEH) for subsequent experiments. Figure 5 Further safety assessment of SEH in the NIH3T3 fibroblast model was conducted. Logarithmic-phase cells were seeded into 96-well plates until 80% confluence. After 24 h of sericin treatment, cells were incubated with CCK-8 for 30 min. Absorbance was measured at 450 nm, and cell viability was calculated. The results showed that SEH had no significant toxicity to NIH3T3 fibroblasts, and that SEH concentrations below 5.73 mg / mL had no significant effect on cell viability. Figure 6 This indicates that SEH has good biosafety.

[0024] Example 3: SEH inhibits melanin production during UV-induced photoaging. To evaluate the skincare efficacy of SEH, a small-scale, double-blind, half-face study was conducted. The participants were a 45-year-old male and a 25-year-old female. For 28 consecutive days, participants applied a cream containing 0.2% SEH to one side of their face (Table 1), while the other side of their face was treated with a completely SEH-free cream as a control. The results showed that, within the 4-week trial period, standardized imaging and time-series analysis revealed benign changes in skin pigmentation, UV spots, melasma, and redness, indicating that SEH effectively reduced pigmentation and erythema, and the tested area consistently showed better results than the control area. Figure 7 and Figure 8 These findings suggest that SEH can effectively inhibit early photoaging phenomena, such as pigmentation and erythema.

[0025] Table 1, Formula Table serial number Element Percentage (%) (Experimental Group) Percentage / % (control group) 1 glycerin 1.8 1.8 2 Xanthan Gum 0.2 0.2 3 Hydrogenated polydecene 0.4 0.4 4 Bis-PEG-15 methyl ether polydimethylsiloxane 1 1 5 Polydimethylsiloxane 1 1 6 SEH 0.2 0 7 pure water 95.4 95.6 Meanwhile, its direct effect on the key enzyme, tyrosinase (TYR), was further investigated. The assay used tyrosine and L-DOPA as substrates in a 96-well system: 100 µL 0.1 M phosphate buffer (pH 6.8) + 20 µL tyrosinase + 20 µL sericin, pre-incubated at 37 ℃ for 10 min, then 20 µL of substrate was added to initiate the reaction; readings were taken at 475 nm every min for 30 min. The concentration of L-DOPA was varied, and Vmax and Km were calculated using the Michaelis-Menten equation. The Michaelis-Menten curves showed that SEH is a potent mixed-type TYR inhibitor, significantly reducing the enzyme's maximum reaction rate (Vmax) and altering its affinity for the substrate (Km). Figure 9 (Table 2). Spectroscopic analysis confirmed that SEH can directly bind to tyrosinase (TYR) and its essential Cu. 2 ⁺ ions ( Figure 10 The above results indicate that SEH can block melanin production pathways at both the gene and protein levels, thereby alleviating UV-induced melanin deposition.

[0026] Table 2. Results of Lineweaver–Burk Double Reciprocal Chart equation Vmax (mol / L / s) Km (mol / L) 11.00mM Dopa Y = 0.0003229*X + 0.9468 4.508e-3 2.861e-2 7.48mM Dopa Y = 0.0003070*X + 1.100 5.09mM Dopa Y = 0.0001911*X + 0.9969 1.60mM Dopa Y = 8.909e-005*X + 0.9193 1.09mM Dopa Y = 6.252e-005*X + 0.8384 0.74mM Dopa Y = 4.557e-005*X + 1.040 50.00mM Dopa + 17.5mg / mL SEH Y = 0.002753*X + 0.2022 5.676e-5 3.443e-3 22.22mM Dopa + 17.5mg / mL SEH Y = 0.002248*X + 0.5264 4.39mM Dopa + 17.5mg / mL SEH Y = 0.0002270*X + 0.5281 0.39mM Dopa + 17.5mg / mL SEH Y = 0.0001428*X + 0.9746 0.17mM Dopa + 17.5mg / mL SEH Y = 0.0001046*X + 1.071 0.08mM Dopa + 17.5mg / mL SEH Y = 8.586e-005*X + 0.5132 0.03mM Dopa + 17.5mg / mL SEH Y = 5.482e-005*X + 0.6430 Example 4: UV radiation activates melanin-related pathways in cells To further investigate the molecular mechanism of SEH's inhibitory effect on pigmentation, human primary melanocytes were divided into three groups: a blank control group without any treatment, a UV irradiation group, and a group pretreated with 2 mg / mL SEH before UV irradiation. The UV irradiation conditions were UVA 75 mJ / cm². 2 +UVB 75 mJ / cm 2After processing, transcriptome analysis was performed. The specific analysis methods are as follows: Three groups were set up: WT blank, 1 mg / mL SEH pretreatment + UV, and UV treatment alone (dose as above). Total RNA was extracted, and libraries were constructed and sequenced using the Illumina platform. Differentially expressed genes were screened using DESeq2, enriched using gseGO and gseKEGG with clusterProfiler (V3.5.1); box plots were drawn using ggplot2, and ternary plots were plotted using ggtern (V3.5.0). Calculations were performed on a Dawning high-performance computer. The results showed that SEH significantly downregulated key melanin production-related genes such as α-MSH, WNT2 / 2B, MITF, TYR, TYRP1, and DCT. Figure 11 Ridge mapping analysis showed that UV irradiation induced upregulation of the melanoma signaling pathway, while this pathway was not detected in the SEH / UV comparison, indicating that SEH effectively inhibited UV-induced activation of this pathway. Figure 12 ).

[0027] Example 5: Identification of bioactive peptides in SEH targeting highly expressed receptors To investigate the correlation between the high efficacy of SEH in preventing UV-induced photoaging and its core active peptides, SEH was desalted and concentrated using C18 solid-phase extraction. Analysis was performed using Q Exactive high-resolution mass spectrometry (Thermo, Germany): precursor ions 350-1550 m / z, daughter ions from 110 m / z; DDA Top 20, dynamically excluded. Peptides were identified by comparing the spectra with the SilkDB database using SequestHT. A total of 105 peptides were identified in SEH, and their composition was determined by a bubble plot (…). Figure 13 The clustering dendrogram visually illustrates the origins and relative abundance of these peptides. Figure 14 The peptides in SEH mainly originate from Sericin 1, Fib L, Seroin 1, Fib H and P25 proteins; the five most abundant peptides are DIPFFR, SITDLLR, DIPYHLR, YSSDSRDGSVSSSTG and EFDDIK, all of which are derived from Sericin 1, Fib L and Seroin.

[0028] To delve deeper into potential peptide-receptor interactions, our focus was on several active membrane proteins in melanocytes. RNA-seq expression profiling revealed differential receptor expression in melanocytes, with TRPV4, IGF1R, PDGFRβ, and MC1R showing the highest expression abundance. Figure 15These five characteristic peptides were molecularly docked with the aforementioned receptors. The protein crystal structure was downloaded from PDB, and the 3D structure of the peptides was constructed using PyMol V2.5.5. Energy minimization was performed using the MMFF94 force field. After dehydration, deionization, and ligand removal, the whole protein was used as the docking cassette. The structure was converted to PDBQT using ADFRsuite, and a global search was performed using AutoDock Vina (exhaustiveness=32) to select the optimal conformation. The optimal conformation was then displayed using PyMol and DS Visualizer. The resulting binding energy heatmap showed that the binding energies of multiple peptide-receptor pairs ranged from -11.644 to -6.557 kcal / mol. Figure 16 Subsequently, complexes with binding energies below -10 kcal / mol—IGF1R-DIPFFR, PDGFRβ-EFDDIK, TRPV4-DIPFFR, TRPV4-DIPYHLR, TRPV4-EFDDIK, and TRPV4-SITDLLR—were selected for fine molecular docking to elucidate their microscopic mechanisms of action.

[0029] Example 6: SC1 peptide targets TRPV4 membrane receptor Based on molecular docking simulations, all-atom simulations were performed using AMBER 22. Peptide charges were calculated using antechamber+Gaussian 09 HF / 6-31G*, and the force field was GAFF2 (peptide) / ff14SB (protein). A 10 Å truncated octahedral water cell was used with TIP3P, neutralized with Na⁺ / Cl⁻, and optimized with 2500 steps of steepest descent followed by 2500 steps of conjugated gradient energy optimization. The temperature was increased from 0 to 298.15 K by 200 ps, ​​followed by NVT of 500 ps and NPT equilibration of 500 ps. Finally, NPT was produced in 100 ns (298.15 K, 1 atm), truncated by 10 Å, with long-range electrostatic PME, hydrogen bond confinement using SHAKE, and the trajectory saved every 10 ps. SC1 (DIPYHLR derived from Sericin 1) formed 29 interactions with TRPV4, exhibiting extremely strong peptide-receptor combinatorial interactions: these interactions included hydrogen bonds, charge attraction, and other non-covalent bonds (Table 3). The SC1 peptide (DIPYHLR) was identified as a characteristic component of SEH with anti-melanogenesis activity. First, a virtual structural analysis of the interaction between SC1 and TRPV4 was performed: a banded model and surface visualization revealed their binding conformation; further interaction mapping revealed that the two are bound by multiple stabilizing forces, including van der Waals forces, salt bridges, conventional hydrogen bonds, and π-cationic bonds, which collectively explain the observed high affinity. Figure 17 These different types of interactions suggest that the complex has a stable structure and can effectively regulate TRPV4 channel activity.

[0030] Table 3. Interaction information between TRPV4 and DipyhLR Category Types From To 1 Hydrogen Bond; Electrostatic Salt Bridge; Attractive Charge peptide:ASP1 A:ASP369 2 Electrostatic Attractive Charge peptide:ARG7 A:ASP333 3 Hydrogen Bond Conventional Hydrogen Bond A:TYR283 peptide:ARG7 4 Hydrogen Bond Conventional Hydrogen Bond A:ASN322 peptide:ASP1 5 Hydrogen Bond Conventional Hydrogen Bond A:ASN367 peptide:ASP1 6 Hydrogen Bond Conventional Hydrogen Bond A:LYS382 peptide:TYR4 7 Hydrogen Bond Conventional Hydrogen Bond peptide:HIS5 A:GLY381 8 Hydrogen Bond Conventional Hydrogen Bond peptide:ARG7 A:ALA330 9 Hydrogen Bond Conventional Hydrogen Bond peptide:ARG7 A:ASP333 10 Hydrogen Bond Conventional Hydrogen Bond peptide:ARG7 A:ALA330 11 Hydrogen Bond Conventional Hydrogen Bond peptide:ARG7 A:ASP333 12 Hydrogen Bond Conventional Hydrogen Bond peptide:ARG7 A:HIS5:O 13 Hydrogen Bond Carbon Hydrogen Bond A:PRO275 peptide:ARG7 14 Hydrogen Bond Carbon Hydrogen Bond A:PHE282 peptide:ARG7 15 Hydrogen Bond Carbon Hydrogen Bond A:LYS379 peptide:TYR4 16 Hydrogen Bond Carbon Hydrogen Bond A:LYS382 peptide:TYR4 17 Hydrogen Bond Carbon Hydrogen Bond peptide:ASP1 A:ASP369 18 Hydrogen Bond Carbon Hydrogen Bond peptide:HIS5 A:THR380 19 Electrostatic Pi-Cation A:LYS382 peptide:HIS5 20 Electrostatic Pi-Cation A:LYS442 peptide:TYR4 21 Electrostatic Pi-Anion A:GLU444 peptide:HIS5 22 Hydrophobic Alkyl A:PRO275 peptide:ILE2 23 Hydrophobic Alkyl A:PRO275 peptide:PRO3 24 Hydrophobic Alkyl A:LYS276 peptide:LEU6 25 Hydrophobic Alkyl A:ALA330 peptide:PRO3 26 Hydrophobic Alkyl peptide:ARG7 A:ILE331 27 Hydrophobic Pi-Alkyl A:TYR283 peptide:PRO3 28 Hydrophobic Pi-Alkyl peptide:HIS5 A:LYS382 29 Hydrophobic Pi-Alkyl peptide:HIS5 A:LYS442 Example 7: SC1 inhibits the expression of key genes involved in UV-induced melanin production. Gene-level results showed that the SC1 treatment group significantly downregulated the mRNA expression of key melanin production regulators such as C-kit, MITF, and TYR induced by UV. Figure 18 Western blot analysis was performed to detect the effect of SC1 on MITF protein. The specific method involved peptide pretreatment followed by UV irradiation. After 6 h, the cells were washed twice with cold PBS. A lysis buffer containing inhibitor was added, and the cells were incubated on ice for 30 min. Cells were scraped off, incubated at 4°C and 12,000 rpm for 10 min, and the supernatant was collected for BCA quantification. An equal volume of protein was mixed with loading buffer, incubated at 95°C for 5 min, and then SDS-PAGE was performed. The cells were then transferred to a PVDF / NC membrane, blocked with 5% skim milk / BSA-TBST for 1 h, incubated with primary antibody (CST, 12590) overnight at 4°C, washed with TBST, and incubated with secondary antibody (CST, 5127) for 1 h. ECL chemiluminescence was performed, and the images were acquired using a gel imaging system and quantified using ImageJ. The results showed that ≥75 μM SC1 reduced MITF protein expression by more than 50% compared to the UV group. Figure 19 ).

[0031] Example 8: The anti-melanin production effect of SC1 in inhibiting UV stimulation Transmission electron microscopy was used to observe the number of melanosomes and melanin granules. Specifically, the cells were pretreated with 2.25 µM SC1 peptide for 6 h, the supernatant was discarded, and the cells were irradiated with UV light and incubated. Fixation was then performed in 2.5% glutaraldehyde-0.1 M phosphate buffer (pH 7.4) at 4°C for 2 h, followed by fixation with 1% osmium tetroxide for 1 h, graded ethanol dehydration, epoxy resin embedding, 70 nm ultrathin sections, uranium-lead double staining, and 80 kV TEM imaging. The results showed that UV irradiation significantly increased the number of melanosomes and melanin granules; while the SC1-treated group maintained normal cell morphology, and both melanosome density and maturity were significantly reduced. Figure 20 In in vitro experiments, melanin content determination showed that only 2.25 μM SC1 was needed to restore melanin production to the blank control level, completely reversing UV-induced excessive melanin synthesis. Figure 21 The above experimental results indicate that SC1 effectively inhibits melanin production by blocking the C-kit / MITF / TYR signaling pathway.

[0032] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A silk peptide composition for inhibiting melanin production, characterized in that: The composition comprises at least one of the peptides DIPFFR, SITDLLR, DIPYHLR, YSSDSRDGSVSSSTG, and EFDDIK.

2. The silk peptide composition for inhibiting melanin production according to claim 1, characterized in that: The composition is prepared by pretreating silkworm cocoon raw materials, enzymatically hydrolyzing them with papain for 10-12 hours, then filtering and collecting the filtrate. The resulting silk fibroin hydrolysate is a composition that inhibits melanin production.

3. The silk peptide composition for inhibiting melanin production according to claim 1, characterized in that: The papain was hydrolyzed over 12 hours.

4. An SC1 polypeptide that inhibits melanin production, characterized in that: The amino acid sequence of the SC1 polypeptide is Asp-Ile-Pro-Tyr-His-Leu-Arg.

5. A composition containing the SC1 polypeptide of claim 4, characterized in that: The composition is in the form of a cream, gel, lotion, solution, or serum.

6. The use of any one of the compositions of claims 1 to 3 or the SC1 polypeptide of claim 4 in the preparation of a product that inhibits melanin production.

7. Use of the composition according to any one of claims 1 to 3 or the SC1 polypeptide according to claim 4 in the preparation of products for preventing or improving photoaging.

8. The use according to claim 7, characterized in that: The prevention or improvement of photoaging includes inhibiting pigmentation, reducing erythema, or delaying cell aging.

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