The Preparation Of Se-enriched Peanut Protein And Its Mechanism On Alcohol-induced Hepatic Injury In Mice

With the rapidly devepment of Se-enrich products,some problems comes,such as the non-regulated technical standards,lacking of high value-added production,uncertainty of the products'biological effect and so on.In this study,we take Se-enriched peanut to do some reaserch,as establishing Se speciation detection method,exploring the relationship beween selenium enrichment and nutritional components accumulation,optimizing Se-enrich peanut protein(SePP)preparation process,and clearing its biological effect.The main results and conclusionsare following:(1)The study revealed that mixed enzymes(protease and lipase,2:1 w/w)in Na2S2O3,assisted by 1 h ultrasonic processing could effectively extract Se speciation from defatted peanut powder.Separation of organic Se by HPLC was achieved by using pentafluoropropionic anhydride at a concentration of 0.1%in 2%methanol as mobile phase.Selenomethionine is the dominant Se species in peanut,accounting for 65%of the total Se.The analysis of nutrition qualities and antioxidant activity invarious Se concetrion selenium-enriched peanuts turned out that Se enrichment changed the accumulation of protein,polysaccharide,mineralsin peanuts,and under the same protein concentration,the variation tendency of selenium content and the antioxidant activity was consistent.(2)Se mainly distributed in peanut protein,but not in peanut oil.High hydrostatic pressure of 300 MPa and 5 min,combined with water bath in 40? extracting 6 h could efficiently remove peanut oil.Alkali-soluble protein occupied 55%Se-enriched peanut protein,and showed potent antioxidative effect with its high Se content.Single factor experiment couped with Box-Behnken surface response design was couduted to obtain the optimum conditions for the protein extraction.That was 50? of extraction temperature,5.5 of the acid precipitator pH,9.0 for the extracting solution pH,95 min of extraction time and 11 mL/g of liquid-to-solid ratio.During the peanut-protein preparation,nearly 37%of Se losses were due to the complexity of the multi-stage process.The loss ascribed to volatilization,dissolution,degradation,or other physical modes of transfer or loss.(3)To investigate the effects of SePP and Se compounds on alcohol-induced liver disease(ALD)and gut microbiota composition in mice,thesix intervention groups were as follows:peanut protein control,three Se dose-dependent SePP groups(PL,PM,PH),selenomethionine group(OSe),and sodium selenite group.Compared with the ALD model,the PM,PH and OSe groups restored alcohol-induced alterationsin liver histopathology and serum chemistry,as well as markedly ameliorated glutathione peroxidase activitiesand serum insulin levels.In addition,treatment with SePP and selenomethionine defended against ALD.As revealed by 16S rRNA gene sequencing,SePP or selenomethionine treatment reversed diversity loss and community alterations in the gut microbiota of the ALD group,as well as increased the relative population of Peptococcaceae,Lachnospiraceae,Clostridiaceae,Roseburia and reduced the population of Verrucomicrobia.(4)The protective function and its mechanism of SePP and selenomethionine on ALD was conducted on cell level.It turned out that 500?M alcohol led to AML-12 cell viability significant reduction and promoted cell death.10?M selenomethionine and same Se doses SePP showed no cytotoxicity and could reverse cell viability and cell death to normal level,especially SePP.What's more,SePP and selenomethionine could also inhibited ethanol-induced hepatic ADH and CYP2E1 activation,decreased ROS level,and restored mitochondrial membrane potential and GSH level.Further mechanistic investigations reveal that activation of Nrf-2 via the p38 pathway and induction of autophagy by SePP contribute to its hepato protective activity.In conclusion,selenomethionine-dominated SePP is the suitable high value-added peanut product,and has potential applications as a nutraceutical for ALD prevention.