| Hsiao G, Ko FN, Lin CN and Teng CM |
------>authors3_c=None ------>paper_class1=1 ------>Impact_Factor=None ------>paper_class3=2 ------>paper_class2=1 ------>vol=1298 ------>confirm_bywho=sheujr ------>insert_bywho=??? ------>Jurnal_Rank=None ------>authors4_c=None ------>comm_author=0 ------>patent_EDate=None ------>authors5_c=None ------>publish_day=None ------>paper_class2Letter=None ------>page2=130 ------>medlineContent= ------>unit=E0100 ------>insert_date=19991209 ------>iam=1 ------>update_date= ------>author=??? ------>change_event=5 ------>ISSN=None ------>authors_c=None ------>score=500 ------>journal_name=Biochimica et Biophysica Acta ------>paper_name=Antioxidant properties of isotorachrysone isolated from Rhamnus nakaharai. ------>confirm_date=20030320 ------>tch_id=088002 ------>pmid=8948496 ------>page1=119 ------>fullAbstract=Isotorachrysone inhibited iron-induced lipid peroxidation with an IC50 value of 1.64 +/- 0.08 microM in rat brain homogenates, and was comparable in potency to butylated hydroxytoluene and was more potent than alpha-tocopherol or desferrioxamine. The mechanism of antioxidant properties were then examined. Isotorachrysone could scavenge the stable free radical diphenyl-p-picrylhydrazyl. And it was an efficient direct scavenger of water-soluble peroxyl radicals with stoichiometry factor of 0.53 +/- 0.05 in the aqueous phase and also toward lipid-soluble peroxyl radicals in tissue homogenates. The oxygen consumption during peroxidation induced by radicals on human erythrocyte ghosts was suppressed by isotorachrysone. Furthermore, it was reactive towards superoxide anion with a second-order rate constant of 5.06 +/- 0.65 x 10(5) M-1 S-1. But it did not react with hydrogen peroxide detected within the sensitivity limit of our assay. Using ascorbate/iron ion/H2O2 as a hydroxyl radical generating system and deoxyribose as a probe, isotorachrysone was effective with hydroxyl radicals with a second-order rate constant of 3.88 +/- 0.54 x 10(11) M-1 S-1 under stimulation by iron-EDTA. On the other hand, isotorachrysone retarded the peroxidation of human low density lipoprotein (LDL) initiated by both aqueous and lipophilic peroxyl radicals. And it also suppressed copper-catalyzed human LDL oxidation, as measured by fluorescence intensity, electrophoretic mobility, and thiobarbituric acid-reactive substances formation in a concentration-dependent manner. Our results show that isotorachrysone is potentially an effective and versatile antioxidant, and can help protecting LDL against oxidation. ------>tmu_sno=None ------>sno=342 ------>authors2=None ------>authors3=None ------>authors4=None ------>authors5=None ------>authors6=None ------>authors6_c=None ------>authors=Hsiao G, Ko FN, Lin CN and Teng CM ------>delete_flag=0 ------>SCI_JNo=None ------>authors2_c=None ------>publish_area=None ------>updateTitle=Antioxidant properties of isotorachrysone isolated from Rhamnus nakaharai. ------>language= ------>check_flag=0 ------>submit_date= ------>country=None ------>no= ------>patent_SDate=None ------>update_bywho= ------>publish_year=1996 ------>submit_flag= ------>publish_month=None |