A polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair efficacy and uses thereof

Abstract

This invention provides a polypeptide composition and its application with anti-inflammatory, antioxidant, and skin barrier repair effects, relating to the field of polypeptide technology. The polypeptide composition, by weight, comprises the following raw materials: 5-8 parts of small molecule active peptides from fish maw, 3-5 parts of collagen cyclic dipeptide, 3-5 parts of tea oil polysaccharide, 3-5 parts of bamboo leaf polysaccharide, and 2-6 parts of moringa leaf polysaccharide. This invention is the first to creatively combine active peptides and polysaccharides in a scientific manner, achieving synergistic effects and significantly enhancing anti-inflammatory, antioxidant, and skin barrier repair effects. Experimental examples have verified that the polypeptide composition of this invention can significantly enhance the activity of HACAT cells and promote the effective repair of HACAT cell-damaged barriers. Furthermore, the polypeptide composition of this invention can inhibit anti-inflammatory factors IL-1β and TNF-α, effectively suppressing inflammatory responses and exhibiting significant skin barrier repair, anti-inflammatory, and antioxidant effects, showing promising application prospects.

Description

Technical Field

[0001] This invention relates to the field of peptide technology, and in particular to a peptide composition and its application that has anti-inflammatory, antioxidant and skin barrier repair effects. Background Technology

[0002] Skin barrier dysfunction and inflammation are common pathological features of various skin diseases, such as atopic dermatitis, eczema, and allergic dermatitis. Damage to the skin barrier leads to increased transepidermal water loss and easier invasion of external irritants, which in turn triggers immune cell activation and chronic inflammation. The persistent inflammatory response further damages the barrier structure, creating a vicious cycle. Sensitive skin, a highly sensitive skin condition with complex causes, is currently considered to be primarily caused by impaired skin barrier function. Therefore, maintaining the stability of the skin barrier structure and function is crucial for reducing skin inflammation, preventing pathogen invasion, and preventing skin diseases.

[0003] Inflammation plays a crucial role in regulating physiological functions. When the degree of inflammation exceeds the clearance capacity of macrophages, macrophages also begin to secrete pro-inflammatory factors and reactive oxygen species, accelerating skin inflammation and damage. Therefore, chronic inflammation not only causes disease in the body but also accelerates skin aging. For example, inflammation affects the skin barrier, increasing epidermal moisture loss and affecting the growth of keratinocytes, making it more difficult for the barrier to recover after damage. Inflammation breaks down the extracellular matrix, causing skin collapse, while inhibiting collagen synthesis, making the skin loose. Inflammation leads to increased tyrosinase activity, exacerbating melanin production.

[0004] Currently, treatments for skin barrier repair and anti-inflammation mainly include glucocorticoids, immunosuppressants, and natural plant extracts. However, all have significant limitations. For example, long-term use of glucocorticoids and immunosuppressants can lead to skin atrophy, telangiectasia, drug resistance, and significant side effects, and they cannot fundamentally repair the damaged barrier. While natural medicines based on plant active ingredients are generally safe, current plant extracts have not shown ideal repair effects on skin barrier damage. Therefore, most commercially available barrier repair products primarily supplement lipid components such as ceramides and cholesterol, which can temporarily improve dry skin but are ineffective in repairing the barrier under inflammatory conditions. Furthermore, existing natural ingredients in this field often focus on a single function, such as single anti-inflammation or single repair, and cannot simultaneously address both barrier damage and inflammation. Summary of the Invention

[0005] Therefore, this invention proposes a polypeptide composition and its application that has anti-inflammatory, antioxidant and skin barrier repair effects.

[0006] The technical solution of this invention is implemented as follows: A polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair effects, comprising the following ingredients by weight: 5-8 parts of small molecule active peptides from fish maw, 3-5 parts of collagen cyclic dipeptide, 3-5 parts of tea oil polysaccharide, 3-5 parts of bamboo leaf polysaccharide, and 2-6 parts of moringa leaf polysaccharide.

[0007] Furthermore, the polypeptide composition comprises, by weight, the following raw materials: 7 parts of small molecule active peptides from fish maw, 4 parts of collagen cyclic dipeptide, 4 parts of tea oil polysaccharide, 4 parts of bamboo leaf polysaccharide, and 5 parts of moringa leaf polysaccharide.

[0008] Furthermore, the molecular weight of the small molecule active peptides in the fish maw is less than 1000 Da.

[0009] Furthermore, the molecular weight of the collagen cyclic dipeptide is less than 1000 Da.

[0010] Furthermore, the preparation method of the tea oil polysaccharide includes: Pretreated tea leaves were sprayed at 120-150℃ and 0.8-1.2MPa for 10-15 minutes to obtain pretreated tea leaves. The pretreated tea leaves were then added to deionized water at a material-to-liquid ratio of 1:10-20 g / mL, and the pH was adjusted to 4.5-5.5. 2.0-2.5% (by weight of the pretreated tea leaves) of cellulase was added, and enzymatic hydrolysis was carried out at 50-55℃ for 2-3 hours. The pH was then adjusted to 6.0-7.0, and a second enzymatic hydrolysis was carried out at 40-45℃ for 1-2 hours. The hydrolysate was collected, ethanol was added for low-temperature alcohol precipitation, centrifuged, and the precipitate was collected. The precipitate was redissolved with Sevage reagent to remove proteins, dialyzed, and freeze-dried to obtain tea leaf polysaccharide.

[0011] Furthermore, the preparation method of the bamboo leaf orchid polysaccharide includes: At a material-to-liquid ratio of 1:10-20 g / mL, *Ormosia edulis* was added to a solvent composed of D-xylose and choline chloride for ultrasonic-microwave extraction. The extract was collected, and the pH was adjusted to 4.5-5.5. Cellulase at 1.0-2.0% of the mass of *Ormosia edulis* was added, and enzymatic hydrolysis was carried out at 45-55℃ for 1-3 hours. The hydrolysate was collected, and ethanol was added for low-temperature alcohol precipitation. After centrifugation, the precipitate was collected, and the precipitate was redissolved with Sevage reagent to remove protein. After dialyzing, the precipitate was freeze-dried to obtain *Ormosia edulis* polysaccharide. The solvent composed of D-xylose and choline chloride has a molar ratio of D-xylose to choline chloride of 1:1-3 and a water content of 20%-25%. The ultrasonic-microwave synergistic extraction is specifically performed as follows: ultrasonic extraction is first performed at an ultrasonic frequency of 15-20KHz, an ultrasonic power of 80-100W, and a temperature of 40-50℃ for 30-40 minutes, followed by microwave extraction at a microwave power of 200-400W and a temperature of 60-70℃ for 20-30 minutes.

[0012] Furthermore, the preparation method of the Moringa leaf polysaccharide includes: Moringa leaves were ultra-finely pulverized and added to phosphate buffer solution at a material-to-liquid ratio of 1:10-20 g / mL. The mixture was treated at 75-85℃ for 5-10 min, then cooled to 15-20℃ for 5-10 min, and then heated to 30-40℃ for 5-10 min. The mixture was filtered and dried to obtain pretreated moringa leaf powder. The pretreated moringa leaf powder was then added to anhydrous ethanol at a material-to-liquid ratio of 1:10-20 g / mL and refluxed at 75-85℃ for 2-3 h. After centrifugation, the precipitate was collected. The precipitate was then added to deionized water at a material-to-liquid ratio of 1:10-20 g / mL and extracted at 80-100℃ for 2-3 h. The supernatant was collected and concentrated to 0.1-0.2 times its original volume. Ethanol was added, and alcohol precipitation was performed at low temperature. After centrifugation, the precipitate was collected, redissolved in Sevage reagent to remove protein, dialyzed, and freeze-dried to obtain moringa leaf polysaccharide.

[0013] Application of a polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair effects in the preparation of anti-inflammatory products.

[0014] Application of a polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair effects in the preparation of antioxidant products.

[0015] Application of a polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair effects in the preparation of skin barrier repair products.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention is the first to creatively combine active peptides (small molecule active peptides from fish maw, cyclic dipeptides from collagen) and polysaccharides (tea oil polysaccharides, bamboo leaf polysaccharides, moringa leaf polysaccharides) in a synergistic effect, significantly enhancing anti-inflammatory, antioxidant, and skin barrier repair efficacy. Experimental examples have verified that the peptide composition of this invention can significantly enhance the activity of HACAT cells and promote the effective repair of HACAT cell-damaged barriers. Furthermore, the peptide composition of this invention can inhibit anti-inflammatory factors IL-1β and TNF-α, effectively suppressing inflammatory responses and exhibiting significant skin barrier repair, anti-inflammatory, and antioxidant effects, showing promising application prospects. Detailed Implementation

[0017] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0018] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0019] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0020] The collagen cyclic dipeptide of this invention has a molecular weight of less than 1000 Da and was purchased from Henan Jiqian Biotechnology Co., Ltd.

[0021] The small molecule active peptides of fish maw in this invention have a molecular weight of less than 1000 Da and were purchased from Hubei Haijia Biotechnology Co., Ltd.

[0022] Preparation Example 1 Methods for preparing tea oil polysaccharides include: Tea leaves were sprayed at 130℃ and 1.0MPa for 12 minutes to obtain pretreated tea leaves. The pretreated tea leaves were then added to deionized water at a material-to-liquid ratio of 1:15 g / mL, and the pH was adjusted to 5.0±0.1. Cellulase at 2.0% of the pretreated tea leaves' mass was added, and enzymatic hydrolysis was performed at 50℃ for 2 hours. The pH was then adjusted to 6.5±0.1, and a second enzymatic hydrolysis was performed at 40℃ for 1 hour. The hydrolysate was collected, and ethanol was added at a volume ratio of 4:1. Low-temperature alcohol precipitation was performed at 4℃ for 12 hours. After centrifugation, the precipitate was collected, redissolved with Sevage reagent to remove proteins, and dialyzed in a 2000 Da dialysis bag with deionized water at 4℃ for 48 hours, changing the water every 4 hours. The precipitate was then freeze-dried to obtain tea leaf polysaccharide.

[0023] Preparation Example 2 The preparation methods of bamboo leaf orchid polysaccharides include: Add *Ormosia rubescens* to a solvent composed of D-xylose and choline chloride (molar ratio of D-xylose to choline chloride 1:2, water content 20%) at a material-to-liquid ratio of 1:15 g / mL. First, ultrasonically extract for 30-40 min at a frequency of 15-20 kHz, a power of 80-100 W, and a temperature of 40-50℃. Then, microwave extract for 20-30 min at a power of 200-400 W and a temperature of 60-70℃. Collect the extract, adjust the pH to 5.0±0.1, add 1.5% (by weight) cellulase from *Ormosia rubescens*, and perform enzymatic hydrolysis at 50℃ for 2 h. Collect the hydrolysate, add ethanol (ethanol to hydrolysate volume ratio 4:1), and perform low-temperature alcohol precipitation at 4℃ for 12 h. Centrifuge, collect the precipitate, redissolve the precipitate in Sevage reagent to remove protein, and then... Dialyze the product in a dialysis bag using deionized water at 4°C for 48 hours, changing the water every 4 hours, and then freeze-dry to obtain bamboo leaf orchid polysaccharide.

[0024] Preparation Example 3 Methods for preparing Moringa leaf polysaccharides include: Moringa leaves were ultra-finely pulverized and added to phosphate buffer solution at a material-to-liquid ratio of 1:15 g / mL. The mixture was treated at 85℃ for 5 min, then at 15℃ for 8 min, and then at 35℃ for 8 min. After filtration and drying, pretreated moringa leaf powder was obtained. The pretreated moringa leaf powder was then added to anhydrous ethanol at a material-to-liquid ratio of 1:15 g / mL and refluxed at 80℃ for 2 h. After centrifugation, the precipitate was collected. The precipitate was then added to deionized water at a material-to-liquid ratio of 1:15 g / mL and extracted at 100℃ for 2 h. The supernatant was collected and concentrated to 0.2 times its original volume. Ethanol was added at a volume ratio of 4:1 (ethanol to concentrated supernatant). The mixture was subjected to low-temperature alcohol precipitation at 4℃ for 12 h. After centrifugation, the precipitate was collected. The precipitate was redissolved with Sevage reagent to remove proteins. The mixture was dialyzed in a 2000 Da dialysis bag with deionized water at 4℃ for 48 h, with the water changed every 4 h. The mixture was then freeze-dried to obtain moringa leaf polysaccharide.

[0025] Example 1 A polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair effects, comprising the following ingredients by weight: 7 parts fish maw small molecule active peptide, 4 parts collagen cyclic dipeptide, 4 parts tea oil polysaccharide, 4 parts bamboo leaf orchid polysaccharide, and 5 parts moringa leaf polysaccharide.

[0026] Example 2 A polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair effects, comprising the following ingredients by weight: 5 parts fish maw small molecule active peptide, 3 parts collagen cyclic dipeptide, 3 parts tea oil polysaccharide, 3 parts bamboo leaf orchid polysaccharide, and 2 parts moringa leaf polysaccharide.

[0027] Example 3 A polypeptide composition with anti-inflammatory, antioxidant and skin barrier repair effects, comprising the following ingredients by weight: 8 parts fish maw small molecule active peptide, 5 parts collagen cyclic dipeptide, 5 parts tea oil polysaccharide, 5 parts bamboo leaf orchid polysaccharide, and 6 parts moringa leaf polysaccharide.

[0028] Comparative Example 1 The difference from Example 1 is that it lacks small molecule active peptides from fish maw, and the missing peptides are allocated according to the proportions of the other four substances. Otherwise, it is the same as Example 1.

[0029] Comparative Example 2 The difference from Example 1 is that collagen cyclic dipeptide is missing, and the missing component is allocated according to the proportions of the other four substances; otherwise, it is the same as Example 1.

[0030] Comparative Example 3 The difference from Example 1 is that it lacks tea oil polysaccharide, and the missing component is distributed according to the proportions of the other four substances. Otherwise, it is the same as Example 1.

[0031] Comparative Example 4 The difference from Example 1 is that it lacks bamboo leaf orchid polysaccharide, and the missing polysaccharide is distributed according to the proportions of the other four substances. Otherwise, it is the same as Example 1.

[0032] Comparative Example 5 The difference from Example 1 is that Moringa leaf polysaccharide is missing, and the missing component is allocated according to the proportions of the other four substances. Otherwise, it is the same as Example 1.

[0033] Test Example 1 - Antioxidant Capacity Test The DPPH free radical scavenging rate of the compositions prepared in Examples 1-3 and Comparative Examples 1-5 was determined. Experimental method: Prepare an ethanol solution of DPPH with a concentration of 200 μmol / L. Dilute the compositions prepared in Examples 1-3 and Comparative Examples 1-5 to 1 mg / mL. Take 2 mL of the sample to be tested and mix with 8 mL of DPPH ethanol solution. After shaking evenly, place in the dark at 25°C for 30 min in the dark. Collect the supernatant and measure the absorbance at a wavelength of 517 nm. Record it as A0. Take 2 mL of anhydrous ethanol and perform the same operation as above, measure the absorbance, and record it as A1; Take 2 mL of deionized water and perform the same operation as above, measure the absorbance and record it as A2; Use 2 mL of a vitamin C solution with a concentration of 1 mg / mL as a positive control; Three parallel experiments were set up for each group to calculate the average value. The free radical scavenging capacity of different samples was calculated according to the DPPH scavenging rate formula.

[0034] Calculation formula: DPPH clearance rate = [1 (A0 [A1) / A2]×100%.

[0035] The results are shown in Table 1.

[0036] Table 1

[0037] As can be seen from Table 1, the compositions of Examples 1-3 of the present invention have a high DPPH scavenging rate and good antioxidant capacity.

[0038] Test Example 2 - Skin Barrier Repair Capacity Test 1. Effect test on the decrease in viability of human immortalized epidermal cells (HACAT cells) induced by bacterial lipopolysaccharide; Experimental Methods: HaCaT cells were cultured in DMEM complete medium containing 10% fetal bovine serum (FBS) in a humidified, 5% CO2 incubator at 37°C. The medium was changed every 24 hours. Cells were passaged at 80%-90% confluence, maintaining logarithmic growth. After passage 3 and stabilization, HaCaT cells were diluted to 2×10⁶ cells / mL. 5 Bacterial lipopolysaccharide (BLP) was inoculated into 96-well plates at a concentration of 100 μL / well, and divided into 10 groups: control group, bacterial lipopolysaccharide group, Examples 1-3 groups, and Comparative Examples 1-5 groups. Examples 1-3 and Comparative Examples 1-5 groups were treated with the compositions prepared in Examples 1-3 and Comparative Examples 1-5 for 2 h. The control group and bacterial lipopolysaccharide group were treated with an equal volume of phosphate buffer. Except for the control group, the other groups were treated with bacterial lipopolysaccharide to a final concentration of 4 μg / mL and incubated for 22 h. The effect of each group on HACAT cell viability was detected using CCK8 reagent.

[0039] The results are shown in Table 2.

[0040] Table 2

[0041] As shown in Table 2, the compositions prepared in Examples 1-3 of this invention can significantly improve the problem of decreased HACAT cell viability caused by bacterial lipopolysaccharide.

[0042] 2. Test on the repair effect of bacterial lipopolysaccharide on the barrier damage of human immortalized epidermal cells (HACAT cells); Experimental method: Following the method described above, HaCaT cells were diluted to 5 × 10⁻⁶. 5 Cells were inoculated at a density of 1 mL / well in 12-well plates, divided into 10 groups: control group, bacterial lipopolysaccharide group, Examples 1-3, and Comparative Examples 1-5. A scratch was made on the bottom of each well using a pipette tip, and the cell scratches at 0 h were recorded using an inverted microscope. Except for the control and bacterial lipopolysaccharide groups, the other groups received the corresponding intervention for 2 h. The control and bacterial lipopolysaccharide groups received an equal volume of phosphate-buffered saline (PBFS). Except for the control group, which received an equal volume of PBFS, the other groups received bacterial lipopolysaccharide to a final concentration of 4 μg / mL and incubated for 46 h. Finally, the changes in cell scratches in each group were observed and recorded using an inverted microscope after 48 h, and the cell scratch repair status was calculated based on the scratch area at 0 h and 48 h.

[0043] Cellular scratch repair capacity (%) = scratch area at 48h / scratch area at 0h × 100%.

[0044] The results are shown in Table 3.

[0045] Table 3

[0046] As can be seen from Table 2, the compositions prepared in Examples 1-3 of the present invention can significantly repair scratches.

[0047] Test Example 3 - Anti-inflammatory Capacity Test Tests on the inflammatory effects of bacterial lipopolysaccharide on human immortalized epidermal cells (HACAT cells); Experimental method: Following the method described above, HaCaT cells were diluted to 2 × 10⁻⁶. 5 Cells were inoculated at 100 μL / well in 96-well plates, and divided into 10 groups: control group, bacterial lipopolysaccharide group, Examples 1-3 groups, and Comparative Examples 1-5 groups. Except for the control group and the bacterial lipopolysaccharide group, the other groups were treated with the corresponding substances for 2 h. The control group and the bacterial lipopolysaccharide group were inoculated with an equal volume of phosphate buffer. Except for the control group, which was inoculated with an equal volume of phosphate buffer, the other groups were inoculated with bacterial lipopolysaccharide to a final concentration of 4 μg / mL and incubated for 22 h. Cell supernatants were collected from each group, centrifuged, and the IL-1β and TNF-α levels in the supernatants were detected using an ELISA kit.

[0048] The results are shown in Table 4.

[0049] Table 4

[0050] As can be seen from Table 3, the compositions prepared in Examples 1-3 of this invention can significantly reduce the content of inflammatory factors IL-1β and TNF-α, and have excellent anti-inflammatory ability.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polypeptide composition having anti-inflammatory, antioxidant and skin barrier repair efficacy, characterized in that, By weight, it includes the following ingredients: 5-8 parts small molecule active peptides of fish maw, 3-5 parts cyclic dipeptides of collagen, 3-5 parts tea oil polysaccharides, 3-5 parts bamboo leaf polysaccharides, and 2-6 parts moringa leaf polysaccharides.

2. The polypeptide composition having anti-inflammatory, antioxidant and skin barrier repair efficacy as claimed in claim 1, wherein, The polypeptide composition comprises, by weight, the following raw materials: 7 parts of small molecule active peptides from fish maw, 4 parts of collagen cyclic dipeptide, 4 parts of tea oil polysaccharide, 4 parts of bamboo leaf polysaccharide, and 5 parts of moringa leaf polysaccharide.

3. The polypeptide composition having anti-inflammatory, antioxidant and skin barrier repair efficacy as claimed in claim 1, wherein, The molecular weight of the small molecule active peptides in the fish maw is less than 1000 Da.

4. The polypeptide composition having anti-inflammatory, antioxidant and skin barrier repair efficacy as claimed in claim 1, wherein, The molecular weight of the collagen cyclic dipeptide is less than 1000 Da.

5. The polypeptide composition having anti-inflammatory, antioxidant and skin barrier repair efficacy as claimed in claim 1, wherein, the polypeptide composition is a mixture of polypeptides having molecular weight in the range of 500- 1000 Da. The preparation method of the tea oil polysaccharide includes: Pretreated tea leaves were sprayed at 120-150℃ and 0.8-1.2MPa for 10-15 minutes to obtain pretreated tea leaves. The pretreated tea leaves were then added to deionized water at a material-to-liquid ratio of 1:10-20 g / mL, and the pH was adjusted to 4.5-5.

5. 2.0-2.5% (by weight of the pretreated tea leaves) of cellulase was added, and enzymatic hydrolysis was carried out at 50-55℃ for 2-3 hours. The pH was then adjusted to 6.0-7.0, and a second enzymatic hydrolysis was carried out at 40-45℃ for 1-2 hours. The hydrolysate was collected, ethanol was added for low-temperature alcohol precipitation, centrifuged, and the precipitate was collected. The precipitate was redissolved with Sevage reagent to remove proteins, dialyzed, and freeze-dried to obtain tea leaf polysaccharide.

6. The polypeptide composition with anti-inflammatory, antioxidant, and skin barrier repair effects as described in claim 1, characterized in that, The preparation method of the bamboo leaf orchid polysaccharide includes: At a material-to-liquid ratio of 1:10-20 g / mL, *Ormosia edulis* was added to a solvent composed of D-xylose and choline chloride for ultrasonic-microwave extraction. The extract was collected, and the pH was adjusted to 4.5-5.

5. Cellulase at 1.0-2.0% of the mass of *Ormosia edulis* was added, and enzymatic hydrolysis was carried out at 45-55℃ for 1-3 hours. The hydrolysate was collected, and ethanol was added for low-temperature alcohol precipitation. After centrifugation, the precipitate was collected, and the precipitate was redissolved with Sevage reagent to remove protein. After dialyzing, the precipitate was freeze-dried to obtain *Ormosia edulis* polysaccharide. The solvent composed of D-xylose and choline chloride has a molar ratio of D-xylose to choline chloride of 1:1-3 and a water content of 20%-25%. The ultrasonic-microwave synergistic extraction is specifically performed as follows: ultrasonic extraction is first performed at an ultrasonic frequency of 15-20KHz, an ultrasonic power of 80-100W, and a temperature of 40-50℃ for 30-40 minutes, followed by microwave extraction at a microwave power of 200-400W and a temperature of 60-70℃ for 20-30 minutes.

7. The polypeptide composition with anti-inflammatory, antioxidant, and skin barrier repair effects as described in claim 1, characterized in that, The preparation method of the Moringa leaf polysaccharide includes: Moringa leaves were ultra-finely pulverized and added to phosphate buffer solution at a material-to-liquid ratio of 1:10-20 g / mL. The mixture was treated at 75-85℃ for 5-10 min, then cooled to 15-20℃ for 5-10 min, and then heated to 30-40℃ for 5-10 min. The mixture was filtered and dried to obtain pretreated moringa leaf powder. The pretreated moringa leaf powder was then added to anhydrous ethanol at a material-to-liquid ratio of 1:10-20 g / mL and refluxed at 75-85℃ for 2-3 h. After centrifugation, the precipitate was collected. The precipitate was then added to deionized water at a material-to-liquid ratio of 1:10-20 g / mL and extracted at 80-100℃ for 2-3 h. The supernatant was collected and concentrated to 0.1-0.2 times its original volume. Ethanol was added, and alcohol precipitation was performed at low temperature. After centrifugation, the precipitate was collected, redissolved in Sevage reagent to remove protein, dialyzed, and freeze-dried to obtain moringa leaf polysaccharide.

8. The use of the polypeptide composition according to any one of claims 1-7 in the preparation of anti-inflammatory products.

9. The use of the polypeptide composition according to any one of claims 1-7 in the preparation of antioxidant products.

10. The use of the polypeptide composition according to any one of claims 1-7 in the preparation of a product for repairing the skin barrier.

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