An antioxidant peptide derived from pearl oyster and its applications

Abstract

The present invention relates to an antioxidant peptide derived from pearl oyster and its application. The sequence of the antioxidant peptide derived from pearl oyster is NSVAA (ASN-SER-VAL-ALA-ALA). The molecular weight of this antioxidant peptide is 460.2281 Da. Through research, it is found that this antioxidant peptide has good antioxidant activity and protective effect on cell oxidative damage, can be used to prepare antioxidants and cell oxidative damage protectants, and further used to prepare cosmetics, drugs, etc.

Description

Technical Field

[0001] The present invention relates to the field of active peptides, and more specifically, to an antioxidant peptide derived from pearl oyster and its application. Background Art

[0002] Any aerobic organism will produce free radicals. The body's antioxidant defense system plays an important role in scavenging reactive oxygen species (ROS) and preventing cell damage. However, excessive ROS production can lead to oxidative damage, initiate the oxidation of biomolecules such as DNA, RNA, and membrane lipids, and further may cause body disorders, resulting in premature aging or the occurrence of diseases such as cancer, atherosclerosis, diabetes, and cardiovascular diseases. Therefore, it is necessary to ingest an adequate amount of antioxidants to prevent or mitigate the oxidative stress caused by ROS. Although antioxidants such as butylated hydroxytoluene (BHT), tert-butylhydroquinone (TBHQ), and butylated hydroxyanisole (BHA) can reduce the free radical level in foods, they have potential toxic effects on human health. Developing natural antioxidants has important research significance.

[0003] Research has shown that antioxidant peptides have advantages such as high safety and environmental friendliness, and have become a research hotspot in recent years. Je et al. (Je, J.; Qian, Z.; Byun, H.; Kim, S., Purification and characterization of an antioxidant peptide obtained from tuna backbone protein by enzymatic hydrolysis. Process Biochem. 2007, 42, (5), 840 - 846.) prepared a peptide segment (VKAGFAWTANQQLS) with antioxidant activity by enzymatically hydrolyzing tuna backbone protein; Ahn et al. (Chang-Bum, Ahn; Jeong-Gyun, Kim.; Jae-Young, Je., Purification and antioxidant properties of octapeptide from salmon byproduct protein hydrolysate by gastrointestinal digestion. Food Chem. 2014, 147.) obtained an antioxidant active peptide (FLNEFLHV) with hepatoprotective effect by hydrolyzing the pectoral fin protein of salmon processing by-products.

[0004] The existing literature "Study on the Relationship between Protein Degradation and Antioxidant Activity in Pinctada martensii" studied the antioxidant activity of the enzymatic hydrolysate of Pinctada martensii (also known as pearl oyster), but it did not study which active components (bioactive peptides) in the enzymatic hydrolysate played the antioxidant role.

[0005] Therefore, it is necessary to conduct more in-depth research on the antioxidant active components of pearl oyster. Summary of the Invention

[0006] The primary objective of the present invention is to overcome the deficiency in the research on the antioxidant active components of pearl oyster in the above-mentioned existing technology, and to provide an antioxidant peptide derived from pearl oyster. This antioxidant peptide derived from pearl oyster has good antioxidant activity and protective effect on cell oxidative damage, can be used to prepare antioxidants and cell oxidative damage protectants, and can further be used to prepare cosmetics, drugs, etc.

[0007] A further objective of the present invention is to provide the application of the above antioxidant peptide in the preparation of antioxidants.

[0008] A further objective of the present invention is to provide the application of the above in the preparation of cell oxidative damage protectants.

[0009] The above objectives of the present invention are achieved through the following technical solutions:

[0010] An antioxidant peptide derived from pearl oyster has a sequence as shown in SEQ ID NO: 1.

[0011] The inventor of the present invention extracted an antioxidant peptide from pearl oyster, and its sequence is NSVAA (ASN - SER - VAL - ALA - ALA). The molecular weight of this antioxidant peptide is 460.2281 Da. Through research, it is found that this antioxidant peptide has good antioxidant activity and protective effect on cell oxidative damage, can be used to prepare antioxidants and cell oxidative damage protectants, and can further be used to prepare cosmetics, drugs, etc.

[0012] The application of the above antioxidant peptide in the preparation of antioxidants is also within the protection scope of the present invention.

[0013] The antioxidant peptide provided by the present invention has high antioxidant activity, and it can be added to cosmetics or drugs as a natural antioxidant.

[0014] Preferably, the application of the antioxidant peptide in the preparation of drugs.

[0015] More preferably, the application of the antioxidant peptide in the preparation of drugs for scavenging free radicals.

[0016] Preferably, the application of the antioxidant peptide in the preparation of cosmetics.

[0017] More preferably, the application of the antioxidant peptide in the preparation of anti - aging cosmetics.

[0018] More preferably, the content of the antioxidant peptide in the antioxidant is 0.005 - 1 mg / mL.

[0019] The application of the above antioxidant peptide in the preparation of a cell oxidative damage protectant is also within the scope of protection of the present invention.

[0020] Since the antioxidant peptide of the present invention also has a good protective effect on cell oxidative damage, it can be used as a cell oxidative damage protectant to achieve the protection and repair of cells.

[0021] Preferably, the cell oxidative damage protectant is a cosmetic with a repair function.

[0022] More preferably, the content of the antioxidant peptide in the cell oxidative damage protectant is 0.05 - 0.2 mg / mL.

[0023] Even more preferably, the content of the antioxidant peptide in the cell oxidative damage protectant is 0.1 - 0.2 mg / mL.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The antioxidant peptide of the present invention has good antioxidant activity and a protective effect on cell oxidative damage, can be used to prepare antioxidants and cell oxidative damage protectants, and can further be used to prepare cosmetics, drugs, etc. Description of the Drawings

[0026] Figure 1 It is a test result graph for evaluating the in vitro antioxidant capacity of the pearl oyster meat hydrolysate, <3 kDa fraction, and ≥3 kDa fraction in Example 1.

[0027] Figure 2 It is a test result graph for evaluating the in vitro antioxidant capacity of each fraction obtained by two-step purification of the <3 kDa fraction in Example 1.

[0028] Figure 3 It is a test result graph for evaluating the intracellular antioxidant activity of the antioxidant peptide of the present invention.

[0029] Figure 4 It is a test result graph for the protective effect of the antioxidant peptide of the present invention on AAPH-induced cell damage. Detailed Embodiments

[0030] In order to more clearly and completely describe the technical solution of the present invention, the following further details the present invention through specific examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention. Various changes can be made within the scope defined by the claims of the present invention.

[0031] The main materials and reagents used in each example are described as follows:

[0032] The meat of pearl oyster (also known as Pinctada martensii) was provided by Beihai Black Pearl Marine Biotechnology Co., Ltd. (Guangxi, China);

[0033] Neutral protease (10 kU / g) was purchased from Nanning Pangbo Bioengineering Co., Ltd. (Nanning, China);

[0034] Glutathione (GSH), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China);

[0035] DMEM medium, fetal bovine serum, phosphate buffered saline (PBS), and penicillin-streptomycin-neomycin antibiotic mixture were purchased from Thermo Fisher Scientific (China) Co., Ltd. (Shanghai, China);

[0036] 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was purchased from Beijing LanGeKe Technology Co., Ltd. (Beijing, China);

[0037] Other chemical reagents were of analytical grade.

[0038] Preparation, Identification and Synthesis of Antioxidant Peptides in Example 1

[0039] 1.1 Preparation of Pearl Oyster Meat Hydrolysate

[0040] The pearl oyster meat was minced into meat paste, added with ultrapure water (material-liquid ratio 1:1, w / w), and the pH was adjusted to 7.25. Neutral protease (enzyme-substrate ratio 0.4%, w / w) was added, and the enzymatic hydrolysis reaction was carried out at 50 °C for 3 h. After the enzymatic hydrolysis was completed, the enzyme was inactivated immediately at 90 °C for 15 min. After cooling to room temperature, it was centrifuged at 4000 r / min for 15 min to obtain the pearl oyster meat hydrolysate, which was stored at -20 °C for further analysis.

[0041] 1.2 Ultrafiltration Separation of Pearl Oyster Meat Hydrolysate

[0042] At room temperature, the pearl oyster meat hydrolysate was separated by an ultrafiltration membrane with a molecular weight cut-off of 3 kDa, and two components with different relative molecular weights were obtained: <3 kDa component and ≥3 kDa component. The two components were collected and freeze-dried respectively, and stored at -20 °C for further analysis.

[0043] Using the pearl oyster meat hydrolysate, <3 kDa component and ≥3 kDa component as samples, the in vitro antioxidant capacity was evaluated. The in vitro antioxidant capacity evaluation included the DPPH free radical scavenging capacity evaluation and the ABTS free radical scavenging capacity evaluation.

[0044] The method for evaluating the DPPH free radical scavenging capacity is as follows:

[0045] Mix 100 μL of the sample solution (0.25 - 2 mg / mL) with 100 μL of the DPPH solution (0.2 mM, 95% ethanol), and react in the dark at room temperature for 30 min. Measure the absorbance A at a wavelength of 517 nm using a microplate reader (Enspire Xenon LightModule, 200 Perkin–Elmer, Beaconsfield, U.K.). t Meanwhile, measure the absorbance A using ethanol instead of the DPPH solution. c Measure the absorbance A using ultrapure water instead of the sample solution. 0 Calculate the DPPH radical scavenging rate according to formula (1).

[0046] DPPH radical scavenging rate / % = [1 - (A t - A c ) / A o × 100% (1)

[0047] Where: A t is the absorbance of the sample solution and DPPH solution system; A c is the absorbance of the sample solution and ethanol system; A 0 is the absorbance of the ultrapure water and DPPH solution system.

[0048] The method for evaluating the ABTS radical scavenging ability is as follows:

[0049] First, mix 5 mL of the ABTS solution (7 mM) with 88 μL of the potassium persulfate solution (140 mM), and react in the dark at room temperature for 12 h. Dilute to obtain an ABTS·+ working solution with an absorbance of 0.7 ± 0.02 (wavelength 734 nm). Take 100 μL of the ABTS·+ working solution and mix it with 100 μL of the sample solution (0.25 - 2 mg / mL). After reacting in the dark at room temperature for 10 min, measure the absorbance A t ' at a wavelength of 734 nm. Meanwhile, measure the absorbance A c ' using ultrapure water instead of the ABTS·+ working solution, and measure the absorbance A 0 ' using ultrapure water instead of the sample solution. Calculate the ABTS radical scavenging rate according to formula (2).

[0050] ABTS radical scavenging rate / % = [1 - (A t '- A c ') / A o '] × 100% (2)

[0051] Where: A t ' is the absorbance of the sample solution and ABTS·+ working solution system; A c' is the absorbance value of the sample solution and ultrapure water system; A 0 ' is the absorbance value of the ultrapure water and ABTS·+ working solution system.

[0052] The evaluation test results of the in vitro antioxidant capacity of pearl oyster meat hydrolysate, <3 kDa fraction and ≥3 kDa fraction are as Figure 1 shown, among which, Figure 1 (A) is the evaluation result of DPPH radical scavenging ability, Figure 1 (B) is the evaluation result of ABTS radical scavenging ability. From Figure 1 (A) and Figure 1 (B), it can be seen that pearl oyster meat hydrolysate, <3 kDa fraction and ≥3 kDa fraction can all effectively scavenge DPPH and ABTS radicals; at a concentration of 1 mg / mL, the DPPH and ABTS radical scavenging rates of the <3 kDa fraction are 49.97% and 71.93% respectively; the radical scavenging ability of the <3 kDa fraction at the same concentration is significantly better than that of pearl oyster meat hydrolysate and ≥3 kDa fraction (p<0.05). The above shows that the <3 kDa fraction has stronger antioxidant activity and will be used for further purification.

[0053] 1.3 Purification of <3 kDa fraction by high performance liquid chromatography

[0054] The <3 kDa fraction was purified in two steps using a preparative high performance liquid (LC-8, Shimadzu, Japan) system. In the first step, the <3 kDa fraction was loaded onto a well-equilibrated reversed-phase C18 glass column (20 mm×450 mm, 10 μm, Shimadzu). The chromatographic conditions were: mobile phase (solution A: double distilled water + 0.1% TFA; solution B: methanol + 0.1% TFA); gradient elution: solution B 0 - 45 min: 5% - 10%, flow rate: 10 mL / min; detection wavelength: 214 nm. The separated fractions were collected, freeze-dried and their in vitro antioxidant capacity (evaluation of DPPH radical scavenging ability and ABTS radical scavenging ability) was measured respectively to screen the fraction with the strongest activity for the next step of purification.

[0055] In the second step, the fraction with the strongest activity separated after the first step of purification was loaded onto a well-equilibrated reversed-phase C18 steel column (19 mm×250 mm, 5 μm, Waters). The chromatographic conditions were: mobile phase (solution A: double distilled water + 0.1% TFA; solution B: methanol + 0.1% TFA); gradient elution: solution B 0 - 60 min: 5% - 10%, detection wavelength: 214 nm. The separated fractions were collected, freeze-dried and their in vitro antioxidant capacity (evaluation of DPPH radical scavenging ability and ABTS radical scavenging ability) was measured respectively to screen the fraction with the strongest activity for mass spectrometry identification.

[0056] After the first step of purification, three peaks were separated and labeled as fraction F1, fraction F2, and fraction F3, respectively. The results are shown in Figure 2 (A). As can be seen from Figure 2 (A), fraction F1 had the highest response value and the best scavenging rates for DPPH and ABTS free radicals, which were 65.02% and 73.06% (1 mg / mL), respectively. Therefore, fraction F1 was selected for enrichment and the second step of purification.

[0057] After the second step of purification of fraction F1, five peaks were obtained and labeled as fraction F1-1, fraction F1-2, fraction F1-3, fraction F1-4, and fraction F1-5, respectively. The results are shown in Figure 2 (B). As can be seen from Figure 2 (B), fraction F1-1 had the highest scavenging rates for DPPH and ABTS free radicals, which were 69.12% and 75.34% (1 mg / mL), respectively. Therefore, fraction F1-1 was enriched for further mass spectrometry identification to determine its peptide profile composition.

[0058] 1.4 Mass spectrometry identification of fraction F1-1 and bioinformatics evaluation of peptides

[0059] Fraction F1-1 was identified by LC-MS / MS. The lyophilized powder was dissolved and loaded onto an Easy NLC 1200 system (ThermoFisher) and separated by a reversed-phase C18 column (2 μm, 75 μm × 25 cm, Acclaim PepMap RSLC). MS data were acquired on a ThermoFisher Q Exactive mass spectrometer (ThermoFisher, USA) equipped with a Nano Flex ion source. Data acquisition conditions: ion spray voltage (1.9 KV), interface heater temperature (275 °C). The PEAKS Studio8.5 (Bioinformatics Solutions Inc., Waterloo, Canada) software was used to process the raw mass spectrometry data of the original map file, and the peptide sequence was retrieved from the Pinctada martensi species protein database on Uniprot to determine the primary structure of the peptide segment.

[0060] Bioinformatics evaluation of the identified peptides: Predict the potential toxicity of the peptides through ToxinPred (https: / / webs.iiitd.edu.in / raghava / toxinpred / multi_submit.php); Analyze the resistance of the peptides to gastrointestinal digestion by simulating enzymatic digestion with pepsin (pH = 1.3 and > 2.0) and trypsin in ExPASy peptide cutter (https: / / web.expasy.org / peptide_cutter / ) (the lowest probability is 20%), and simulate and calculate the hydrophobicity of the peptides through Pepdraw (http: / / www.pepdraw.com / ).

[0061] After identifying the component F1-1 and conducting bioinformatics evaluation of the peptides, antioxidant peptides were screened out, and their sequence is NSVAA (ASN-SER-VAL-ALA-ALA). This antioxidant peptide is non-toxic and can completely resist the simulated enzymatic digestion of pepsin and trypsin. Its hydrophobicity is +9.75 Kcal / mol, showing strong hydrophobicity. This antioxidant peptide contains hydrophobic amino acids ALA and VAL, which are key factors for the ability to scavenge free radicals, indicating that this antioxidant peptide has good ability to scavenge free radicals (DPPH and ABTS free radicals), and thus has good antioxidant activity. The identification results of the antioxidant peptides and their peptide characteristics are shown in Table 1.

[0062] Table 1 Identification results of antioxidant peptide (NSVAA) and its peptide characteristics

[0063]

[0064] 1.5 Synthesis of antioxidant peptides

[0065] Nanjing Jie Peptide Biotechnology Company synthesized the antioxidant peptide (NSVAA) by solid-phase synthesis method. The purity of the antioxidant peptide is > 98%, and it is further used to study its antioxidant ability at the cellular level.

[0066] Example 2 Evaluation of intracellular antioxidant activity of antioxidant peptides

[0067] 2.1 Cell culture

[0068] The HepG2 cells used were between passages 20 and 35. The cells were cultured in a basal medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin-neomycin antibiotic mixture. The cells were cultured in an incubator at 37 °C and 5% CO 2 The medium was changed every other day, and the cells were passaged when they grew to 80% - 90%.

[0069] 2.2 Cytotoxicity assay

[0070] The effect of antioxidant peptides on the viability of HepG2 cells was determined by the MTT method. HepG2 cells were seeded in a 96-well plate at a cell density of 1×10 4 cells / well and cultured at 37°C and 5% CO 2 for 24 h. In the sample treatment group, 100 μL of medium containing antioxidant peptides (0.025, 0.05, 0.1, 0.25, 0.5, 1 mg / mL) was added, and fresh medium without antioxidant peptides was used as the blank group. After continued culture for 24 h, the medium was discarded, 100 μL of MTT solution (0.5 mg / mL) was added, and the cells were incubated in the dark for 4 h. The MTT solution was discarded, 100 μL of DMSO was added, and the mixture was shaken for 10 min to completely dissolve the blue-violet crystals. The cell viability was measured and calculated at a wavelength of 490 nm using an enzyme-linked immunosorbent assay (ELISA) reader.

[0071] 2.3 Determination of intracellular antioxidant activity

[0072] Intracellular antioxidant activity was characterized by the CAA method. The principle of the CAA method is to introduce the fluorescent probe DCFH-DA into HepG2 cells. Intracellular lipase degrades the fluorescent probe DCFH-DA into DCFH, which is oxidized to fluorescent DCF under the induction of AAPH, while antioxidant peptides can protect the probe from oxidation. The specific procedure is as follows: In a 96-well plate, HepG2 cells were seeded at a cell concentration of 6×10 4 cells / well and cultured at 37°C and 5% CO 2 for 24 h. In the sample treatment group, 50 μL of DCFH-DA working solution (50 μM) and 50 μL of antioxidant peptide solution (0.005, 0.01, 0.025, 0.05, and 0.1 mg / mL) were added. In the control group and the blank group, 50 μL of 50 μM DCFH-DA solution and 50 μL of sterile water were added, respectively. After incubation for 1 h, the cells were washed with 100 μL of PBS. In the sample treatment group and the control group, 100 μL of AAPH working solution (600 μM) was added, and fresh medium was added to the blank group. The fluorescence value was measured at an excitation wavelength of 485 nm and a measurement wavelength of 528 nm, once every 5 min for 1 h. At the same time, glutathione (GSH) was used as a positive control. The CAA was calculated by the area-under-the-curve (AUC) of the fluorescence curve, as shown in formula (3). The half-maximal effective concentration (EC 50 ) of the sample corresponding to CAA equal to 50 was also calculated.

[0073]

[0074] Wherein: AUC t , AUC c and AUC o are the fluorescence curve areas of the sample treatment group, the control group, and the blank group, respectively.

[0075] The cytotoxicity assay results of Step 2.2 are as shown in Figure 3 (A). Compared with the blank control group, if the cell survival rate is higher than 90%, it is considered that the sample has no toxic effect on cells at this concentration. As shown in Figure 3 (A), the survival rates of HepG2 cells in the sample treatment group are all higher than 90%. The results indicate that the antioxidant peptide has no toxic effect on cells. Therefore, the intracellular antioxidant activity assay was carried out.

[0076] The intracellular antioxidant activity assay results of Step 2.3 are as shown in Figure 3 (B). As can be seen from Figure 3 (B), the antioxidant activity of the antioxidant peptide is concentration-dependent; by further calculation, the EC 50 value of the antioxidant peptide is 0.096 mg / mL, which is comparable to the EC 50 value of 0.030 mg / mL of the positive control (GSH), and is lower than the EC 50 value of 0.13 mg / mL of the reported antioxidant peptide from pine nuts (Liang, R.; Zhang, Z.; Lin, S., Effects of pulsed electric field on intracellular antioxidant activity and antioxidant enzyme regulating capacities of pine nut (Pinus koraiensis) peptide QDHCH in HepG2 cells. Food Chem. 2017, 237, 793 - 802.) and much lower than the EC 50 value of 2.85 mg / mL of the reported antioxidant peptide from corn (Wang, L.; Ding, L.; Yu, Z.; Zhang, T.; Ma, S.; Liu, J., Intracellular ROS scavenging and antioxidant enzyme regulating capacities of corn gluten meal-derived antioxidant peptides in HepG2 cells. Food Res. Int. 2016, 90, 33 - 41.). The above shows that the antioxidant peptide of the present invention has good intracellular antioxidant activity.

[0077] Study on the Protective Effect of Antioxidant Peptide against AAPH-Induced Cell Damage in Example 3

[0078] 3.1 Effects of Different Concentrations of AAPH on Cell Viability

[0079] Cells were seeded into 96-well plates at a concentration of 1×10 4 cells / well and cultured in an incubator at 37 °C with 5% CO 2 and 95% air for 48 h. In the AAPH damage group, 150 μL of fresh medium containing a series of different concentrations of AAPH (final concentration 0.025 - 25 mM) was added, and in the control group, an equal volume of fresh medium without AAPH was added. After continued culture for 24 h, the cell survival rate was measured by the MTT method, and the results are shown in Figure 4 (A). As can be seen from Figure 4 (A), compared with the control group, the cell survival rate in the AAPH damage group decreased, and there was a dose-effect relationship. Considering that the intensity of oxidative damage in actual situations is often different, damage models with cell survival rates of 50% and 80% were constructed using 10 mM and 0.25 mM AAPH, respectively, and on this basis, the protective effect of antioxidant peptide on cells with different degrees of oxidative damage was compared.

[0080] 3.2 Protective Effect on Oxidatively Damaged Cells

[0081] Cells were seeded into 96-well plates at a concentration of 1×10 4 cells / well and cultured for 24 h. In the sample treatment group, 100 μL of fresh medium containing the sample (0.025, 0.05, 0.1, and 0.2 mg / mL) was added, and an equal volume of fresh medium was added to the control group and the AAPH damage group. After treatment for 24 h, 50 μL of fresh medium containing AAPH (final concentration 10 and 0.25 mM) was added to the sample treatment group and the AAPH damage group, and an equal volume of fresh medium was added to the control group. After continued culture for 24 h, the cell survival rate was measured by the MTT method. The results of the protective effect of antioxidant peptide on the oxidative damage of HepG2 cells induced by 10 mM and 0.25 mM AAPH are shown in Figure 4 (B) and Figure 4 (C). In the figure, ## indicates p < 0.01 when comparing the AAPH damage group with the blank control group; # indicates p < 0.05 when comparing the AAPH damage group with the blank control group; ** indicates p < 0.01 when comparing the sample treatment group with the AAPH damage group; * indicates p < 0.05 when comparing the sample treatment group with the AAPH damage group. As can be seen from Figure 4As can be seen from (B), compared with the control group, the AAPH damage group could significantly reduce the cell survival rate (p < 0.01), indicating that the cell oxidative damage model was successfully established. In the cell oxidative damage model with a cell survival rate of 50% constructed by 10 mM AAPH, the antioxidant peptide at a concentration of 0.1 mg / mL increased the cell survival rate from 50.77% to 69.38%, higher than the cell survival rate of 56.37% in the GSH positive control group at the same concentration; the antioxidant peptide at a concentration of 0.2 mg / mL increased the cell survival rate from 50.77% to 70.55%, higher than the cell survival rate of 57.60% in the GSH positive control group at the same concentration. From Figure 4 As can be seen from (C), in the cell oxidative damage model with a cell survival rate of 80% constructed by 0.25 mM AAPH, the antioxidant peptide at a concentration of 0.2 mg / mL increased the cell survival rate from 79.41% to 100.09%, and was higher than the cell survival rate of 92.08% in the GSH positive control group at the same concentration. The above shows that the ability of the antioxidant peptide to protect against cell oxidative damage is particularly prominent.

[0082] Through Examples 1 to 3, it is shown that the antioxidant peptide of the present invention can not only scavenge DPPH free radicals and ABTS free radicals, has good in vitro antioxidant activity, but also has good intracellular antioxidant activity and cell oxidative damage protection effect.

[0083] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An antioxidant peptide derived from pearl oyster, characterized in that, the antioxidant peptide is the sequence shown in SEQ ID NO:

1.

2. Use of the antioxidant peptide according to claim 1 in the preparation of an antioxidant.

3. Use of the antioxidant peptide according to claim 1 in the preparation of an antioxidant drug.

4. Use of the antioxidant peptide according to claim 1 in the preparation of an antioxidant cosmetic.

5. According to the use described in claim 4, characterized in that, the antioxidant cosmetic is an anti-aging antioxidant cosmetic.

6. According to the use described in claim 2, the content of the antioxidant peptide in the antioxidant is 0.005 - 1 mg / mL.

7. Use of the antioxidant peptide according to claim 1 in the preparation of a cell oxidative damage protectant.

8. According to the use described in claim 7, characterized in that, the cell oxidative damage protectant is a cosmetic with a repair function.

9. According to any one of the uses described in claims 7 - 8, the content of the antioxidant peptide in the cell oxidative damage protectant is 0.05 - 0.2 mg / mL.

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