title: Antioxidant and antiglycation properties of triterpenoid saponins from Aralia taibaiensis traditionally used for treating diabetes mellitus.
abstract: Our previous study has demonstrated that the antidiabetic activity of the extract of root bark of Aralia taibaiensis (EAT) was correlated with its combined antioxidant and antiglycation properties. To confirm further the constituents responsible, 12 triterpenoid saponins were isolated from EAT and examined for their antioxidant and antiglycation activities. The antioxidant activities of the pure compounds and EAT were evaluated by studying the inhibition of lipid peroxidation in rat liver microsomes induced by ascorbate/Fe(2+), cumine hydroperoxide (CHP) or CCl(4)/reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH). The antioxidant capacities were also evaluated by studying the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. The antiglycation activities of the pure compounds and EAT were evaluated by hemoglobin-delta-gluconolactone (delta-Glu) assay, bovine serum albumin (BSA)-glucose assay and N-acetyl-glycyllysine methyl ester (GK peptide)-ribose assay. EAT outperformed other compounds in all the assays. The compounds with best antioxidant (TA7, TA24 and TA35) and antiglycation (TA21, TA9 and TA24) activities in different assays were screened out. The results suggest that the antioxidant and antiglycation properties of EAT could be explained, at least in part, by the synergistic effect of pure compounds isolated from it.
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Xi
authors.forename: Chunxu
authors.initials: C
authors.lastname: Hai
authors.forename: Haifeng
authors.initials: H
authors.lastname: Tang
authors.forename: Aidong
authors.initials: A
authors.lastname: Wen
authors.forename: Hongli
authors.initials: H
authors.lastname: Chen
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Liang
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Chen
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D027983:Aralia / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000378:metabolism; D004357:Drug Synergism; D016166:Free Radical Scavengers / Q000494:pharmacology; D017127:Glycation End Products, Advanced / Q000037:antagonists & inhibitors / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D010851:Picrates / Q000378:metabolism; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012503:Saponins / Q000494:pharmacology*; D014315:Triterpenes / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D017127:Glycation End Products, Advanced; D007004:Hypoglycemic Agents; D010851:Picrates; D010936:Plant Extracts; D012503:Saponins; D014315:Triterpenes; C004931:1,1-diphenyl-2-picrylhydrazyl