Study On The Enzymatic Preparation And Anti-aging Activities Of Cucumaria Frondosa Extracts

Seven edible sea cucumbers with low economic value were used to screen a high-quality sea cucumber protein source-cucumaria frondosa,and the peptide-rich sea cucumber extract was prepared by enzymatic hydrolysis,separation and purification for evualuation of stability and bioavailability.The peptide profile of the extract was identified by UPLC-QTOF-MS/MS.Drosophila and D-galactose-induced mice were used as model organisms to evaluate the anti-aging effects of the extracts.?1?Seven edible sea cucumbers with low economic value were hydrolyzed by three proteases including protamex,flavorzyme and papain for 4,8 and 12 hours to obtain the sea cucumber extracts,respectively.Assays for reducing power,hydroxyl radical scavenging capacity and oxygen radical absorption capacity were conducted to determine their antioxidant activities.The different sea cucumber extracts were classified in terms of extract yields,protein recovering ratios,and antioxidant activities by clustering analysis.The extract yields and protein recovering ratios of cucumaria frondosa,acaudina leucoprocta,holothuria tubulosa,holothuria scabra,and thelenata anax extracts were superior to those of stichopus variegates and holothuria keferstein extracts.And the antioxidant capacity of extract of cucumaria frondosa was the highest.The extract yields,protein recovering ratios,and antioxidant activities of the sea cucumber extracts prepared by protamex were the higest among all extracts.In terms of optimal extraction parameters,the extract yields were41.24%⁵5.57%.The protein recovering ratios were 65.06%⁹8.4%.The antioxidant activity values including reducing power values,OH values and ORAC values were 3.41³.41?mol trolox equiv/g dry sea cucumber,28.83⁹6.65?mol trolox equiv/g dry sea cucumber,38.99¹33.08?mol trolox equiv/g dry sea cucumber,respectively.It can provide theory and method support for the processing of functional foods with sea cucumber extract as the core ingredients.?2?Cucumaria frondosa was used as raw material,the foaming and enzymolysis process was optimized with the yield of enzymolysis product,protein recovery rate and ORAC value,and the optimal preparation process of sea cucumber extract was determined.The product yield was 55.54%,the protein recovery was 88.85%,and the ORAC value was 198.96?mol Trolox equiv/g dry sea cucumber.The protein content of the peptide-rich extract?CFE?obtained by ultrafiltration purification,concentration under reduced pressure,and freeze-drying was 88.40%,and the ORAC value was 371.98?mol trolox equiv/g powder.The stability of CFE was studied and it was found that metal ions such as Fe²⁺,Zn²⁺and acidic environment inhibited its antioxidant activity;heating could increase its ORAC value;under heating conditions,sugars greatly enhanced the antioxidant activity of the extract.The model of digestive gastrointestinal tract digestion was constructed in vitro.CFE was compared with dried sea cucumber powder,foamed sea cucumber and cooked sea cucumber meat.The results showed that the order of bioavailability and antioxidant activity was:CFE>cooked sea cucumber meat>foamed sea cucumber meat>dry sea cucumber powder,which demonstrated the superiority of foaming and brewing technology and the advantages of preparing CFE in bioavailability.?3?CFE prepared by enzymatic hydrolysis and purified by ultrafiltration was examined for its ability to prolong lifespan of fruit flies and resist oxidative stress in D-galactose-induced aging mice.CFE possessed peptides with small molecular weights?mainly<3 kDa?,Ala,Val and Leu at the N-terminal end and aromatic/hydrophobic/acidic amino acids in sequence.We provided the first in vivo evidence that CFE significantly prolonged the lifespan of fruit flies and improved learning and memory damage of D-gal-induced aging mice.The mechanism underlying its protective effect might be associated with the ability to up-regulate Klotho expression,activate SOD and GSH-Px,inhibit lipid and protein peroxidation,and down-regulate acetylcholinesterase activity.CFE could be used as a health-promoting ingredient for coping with age-associated diseases.