title: Protective effects of Korean mistletoe lectin on radical-induced oxidative stress.
abstract: The radical scavenging effects and protective activities against oxidative stress of Korean mistletoe (Viscum album coloratum) lectin were investigated in vitro and with a cellular system using LLC-PK(1) renal epithelial cells. The Korean mistletoe lectin (KML) showed 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with an IC(50) value of 42.6 microg/ml. It also exerted nitric oxide (NO), superoxide anion (O(2)(-)), and hydroxyl radical scavenging activities in concentration-dependent manners. These results suggest that KML is a promising antioxidant by scavenging free radicals. Furthermore, under the LLC-PK(1) cellular model, the cells showed declines in viability and increases in lipid peroxidation through oxidative stress induced by sodium nitroprusside (SNP) and pyrogallol, generators of NO and O(2)(-), respectively. However, KML significantly and dose-dependently inhibited cell cytotoxicity and lipid peroxidation. In addition, 3-morpholinosydnonimnie (SIN-1), a generator of peroxynitrite (ONOO(-)) formed by simultaneously releases of NO and O(2)(-), caused cytotoxicity, lipid peroxidation, and NO overproduction in the LLC-PK(1) cells while KML ameliorated ONOO(-)-induced oxidative damage. Furthermore, overexpressions of cyclooxygenase-2 and inducible NO synthase induced by SIN-1 were observed, but KML down-regulated the expression levels of both genes. KML also reduced SIN-1-induced nuclear factor kappa B expression and the phosphorylation of inhibitor kappa B alpha in LLC-PK(1) cells. These results indicate that KML has protective activities against oxidative damage induced by free radicals.
authors.affiliation: Department of Food Science and Nutrition, Pusan National University, Busan, Korea.
authors.forename: Boh Kyung
authors.initials: BK
authors.lastname: Kim
authors.forename: Mi Jin
authors.initials: MJ
authors.lastname: Choi
authors.forename: Kun Young
authors.initials: KY
authors.lastname: Park
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Cho
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018374:LLC-PK1 Cells; D037102:Lectins / Q000494:pharmacology*; D014784:Mistletoe / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D017931:DNA Primers; D037102:Lectins; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances