부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.niox.2007.06.002 Byline: Byung-Hak Kim, In Jeong Lee, Hwa-Young Lee, Bang Yeon Hwang, Sang-Bae Han, Youngsoo Kim Keywords: Isoquercitrin gallate; Quercetin; Protein-bound 3-nitrotyrosine; Zymosan; Macrophages Abstract: Peroxynitrite, the coupling product of superoxide and nitric oxide (NO) radicals, plays as a pathogenic mediator in the oxidative stress-implicated diseases. Quercetin 3-O-[beta]-(2a[sup.3]galloyl)-glucopyranoside (Q-32) is an isoquercitrin gallate. In this study, Q-32 was found to inhibit zymosan-induced production of protein-bound 3-nitrotyrosine, a stable metabolite of peroxynitrite, in macrophages RAW 264.7, and its inhibitory mechanism was also documented to be different from that of its aglycone, quercetin. Both Q-32 and quercetin inhibited not only zymosan- but also phorbol 12-myristate 13-acetate-induced superoxide productions in the macrophages. Q-32 did not affect NO production and inducible NO synthase (iNOS) expression in zymosan-stimulated macrophages RAW 2647. However, quercetin inhibited zymosan-induced NO production as well as down-regulated zymosan-induced iNOS expression at the transcription level. Further, quercetin inhibited zymosan-induced nuclear factor (NF)-[kappa]B transcriptional activity but also NF-[kappa]B-dependent iNOS promoter activity. Taken together, Q-32 and quercetin could provide invaluable tools to investigate zymosan-induced oxidative stress with distinct antioxidant mechanisms. Author Affiliation: College of Pharmacy & Research Center for Bioresource and Health, Chungbuk National University, Cheongju 361-763, Republic of Korea Article History: Received 17 April 2007; Revised 10 June 2007