Radical-scavenging activity,ACE-inhibiting capability and identification of rapeseed albumin hydrolysate

Albumin derived from rapeseed was hydrolyzed sequentially using alcalase and flavorzyme to produce antioxidant peptides.To identify antioxidant peptides,rapeseed albumin hydrolysate(RAH)was fractionated using size exclusion chromatography(G-25).The antioxidant activity and angiotensin I-converting enzyme(ACE)inhibiting activity of rapeseed peptides(RSP)purified from RAH were evaluated.The results revealed that RSP-4 had the highest ABTS radical-scavenging activity(TEAC value=0.24)and ACE-inhibiting capacity(IC50=0.19 mg/mL)compared to other fractions.Moreover,RSP-4 was identified as PFDSYFVC(977 D)by electrospray ionization(ESI)mass spectrometry and tandem mass spectrometry(MS/MS).©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Biochanin A and CPe-Ⅲ Peptide Improved Hepatic Infl ammation by Regulating the Hepatic Lipid Metabolic Pathways in Diet-Induced Obese Mice

Biochanin A(BCA) and CPe-Ⅲ peptide, which both exist in chickpea(Cicer arietinum L.), possess significant antihyperlipidemic properties. However, the actualmechanisms ofthose compounds in inhibiting the dysregulation oflipid metabolism and complicated inflammation have not been wellcharacterized. This study investigated the effects ofBCA, CPe-Ⅲ peptide, and combined BCA and CPe-Ⅲ peptide(BC) on the expression ofgenes involved in hepatic lipid and inflammation metabolism. Results demonstrated that BCA, CPe-Ⅲ peptide, and BC significantly attenuated hepatitis and hyperlipidemia by downregulating those genes involved in pro-inflammatory cytokines(TNF-α), hepatic fatty acid(FA) synthesis(ACC1 and FAS), cholesterolmetabolism(SREBP2, HMGCR, and PCSK9), and upregulating key regulators involved in FA oxidation(PPARα and FABP1), lipolysis(ATGL), LDLR, reverse cholesteroltransport(ABCA1, SR-B1, and LXRα), and cholesterolcatabolism(CYP7 A1). Moreover, they also altered the expression oflipid metabolism-related proteins, including SREBP2, PCSK9, LDLR, ABCA1, and CYP7 A1. Finally, these results revealed that the combination treatment ofBCA and CPe-Ⅲ peptide resulted in greater antihyperlipidemic activity compared with individualcompounds.

Investigating Interaction Between Biochanin A and Human Serum Albumin by Multi-spectroscopic and Molecular Simulation Methods

Biochanin A(BCA), the most abundant isoflavone in chickpeas, presents a wide range of biological activities, such as hypolipidaemic, anti-oxidative, antiproliferative, and estrogen-like effects. We investigated the interaction between BCA and human serum albumin(HSA) via several techniques. UV–Vis absorption spectroscopy verified the conformational variation of HSA after BCA addition, and fluorescence spectroscopy revealed the relevant binding parameters. Circular dichroism spectroscopy was used to estimate the secondary structural changes of HSA with and without BCA. Molecular docking and dynamics simulations were then applied to study the characteristics of HSA with BCA. Energy decomposition analysis was used to prove that Trp214 in subdomain ⅡA of HSA is the most likely binding site of BCA. Van der Waals forces and hydrophobic interactions may play important roles during the binding process. All of our results showed that BCA presents significant binding affinity to HSA, thus confirming that the role of HSA has as an efficient transporter of biomolecules.

EXTRACTION AND EVALUATION OF EDIBLE OIL FROM SCHIZOCHYTRIUM SP.USING AN AQUEOUS ENZYMATIC METHOD

Schizochytrium sp.,a marine microalga,is a potential source of edible oil due to its short growth cycle and rapid lipid accumulation,especially of docosahexaenoic acid.An approach to isolate edible microalgal oil from Schizochytrium sp.using aqueous enzymatic extraction(AEE)was developed.Parameters were optimized by single-factor experiments followed by Box-Behnken design.Proteases were effective in extracting oil.The maximum free oil recovery(49.7%±0.58%)and total oil recovery(68.1%±0.94%)were obtained under optimum conditions of liquid-to-solid ratio of 4.8:1,a 2.5%enzyme concentration of papain and an extraction time of 2.2 h.There was a significant difference(P<0.05)in polyunsaturated fatty acid composition between microalgal oil obtained by AEE and by Soxhlet extraction,with the former having superior physiochemical properties and higher concentrations of bioactive components including total phenolic compounds and total tocopherols.These findings indicate a potential application of AEE for extraction of oil from Schizochytrium sp.