title: Antioxidant and antiglycation activities of the synthesised dipeptide, Asn-Trp, derived from computer-aided simulation of yam dioscorin hydrolysis and its analogue, Gln-Trp.
abstract: Previous studies have shown that the Trp residue contributes to a high oxygen radical absorbance capacity (ORAC). Therefore, in this study, a Trp-containing dipeptide derived from a computer-aided simulation of pepsin hydrolysis of the yam tuber, dioscorin-namely, Asn-Trp (NW), and its analogue, Gln-Trp (QW)-were synthesised to compare their antioxidant and antiglycation activities with carnosine, homocarnosine, or glutathione (GSH). The antioxidant assays included hydroxyl radical-scavenging activity, anti-AAPH-induced hemolysis, and ORAC activity. NW had a significantly higher antioxidant activity than had QW and performed much better than carnosine, homocarnosine, or GSH. Using bovine serum albumin (BSA)/galactose or BSA/glucose as experimental models, NW had better antiglycation effects than had QW, as detected by an anti-N(ε)-(carboxymethyl)lysine (anti-CML) antibody. Moreover, NW and QW (50-200 μM) showed protection against methylglyoxal-induced cell deaths in human umbilical vein endothelial cells. These results suggest that NW, derived from computer-aided simulation of dioscorin hydrolysis, exhibits antioxidant and antiglycation activities, which thus shows the benefits of the yam tuber as an antioxidant-rich food.
authors.affiliation: School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chuan-Hsiao
authors.initials: CH
authors.lastname: Han
authors.forename: Yin-Shiou
authors.initials: YS
authors.lastname: Lin
authors.forename: Shyr-Yi
authors.initials: SY
authors.lastname: Lin
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Hou
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D017076:Computer-Aided Design; D027742:Dioscorea / Q000737:chemistry*; D004151:Dipeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D006031:Glycosylation / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis
chemical_list: D000975:Antioxidants; D004151:Dipeptides
keywords: Antioxidant activity; Asn-Trp; Hemolysis; N(ε)-(carboxymethyl)lysine (CML); Oxygen radical absorbance capacity (ORAC); Yam tuber dioscorin