title: Efficacy of sauchinone as a novel AMPK-activating lignan for preventing iron-induced oxidative stress and liver injury.
abstract: Iron-overload disorders cause hepatocyte injury and inflammation by oxidative stress, possibly leading to liver fibrosis and hepatocellular carcinoma. This study investigated the efficacy of sauchinone, a bioactive lignan, in preventing iron-induced liver injury and explored the mechanism of sauchinone's activity. To create iron overload, mice were injected with phenylhydrazine, and the effects on hepatic iron and histopathology were assessed. Phenylhydrazine treatment promoted liver iron accumulation and ferritin expression, causing hepatocyte death and increased plasma arachidonic acid (AA). Sauchinone attenuated liver injury (EC(50)=10 mg/kg) and activated AMPK in mice. Treatment of hepatocytes with iron and AA simulated iron overload conditions: iron + AA synergistically amplified cytotoxicity, increasing H(2)O(2) and the mitochondrial permeability transition. Sauchinone protected hepatocytes from iron + AA-induced cytotoxicity, preventing the induction of mitochondrial dysfunction and apoptosis (EC(50)=1 microM), similar to the result using metformin. Sauchinone treatment activated LKB1, which led to AMPK activation: these events contributed to cell survival. Evidence of cytoprotection by LKB1 and AMPK activation was revealed in the reversal of sauchinone's restoration of the mitochondrial membrane potential by either dominant negative mutant AMPKalpha or chemical inhibitor. In conclusion, sauchinone protects the liver from toxicity induced by iron accumulation, and sauchinone's effects may be mediated by LKB1-dependent AMPK activation.
authors.affiliation: College of Pharmacy, Seoul National University, Seoul 151-742, Korea.
authors.forename: Young Woo
authors.initials: YW
authors.lastname: Kim
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Sang Mi
authors.initials: SM
authors.lastname: Shin
authors.forename: Se Jin
authors.initials: SJ
authors.lastname: Hwang
authors.forename: Janie S
authors.initials: JS
authors.lastname: Brooks
authors.forename: Hee Eun
authors.initials: HE
authors.lastname: Kang
authors.forename: Myung Gull
authors.initials: MG
authors.lastname: Lee
authors.forename: Sang Chan
authors.initials: SC
authors.lastname: Kim
authors.forename: Sang Geon
authors.initials: SG
authors.lastname: Kim
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D001578:Benzopyrans / Q000737:chemistry / Q000494:pharmacology*; D004149:Dioxoles / Q000737:chemistry / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D007501:Iron / Q000008:administration & dosage / Q000633:toxicity*; D017705:Lignans / Q000737:chemistry / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects* / Q000293:injuries* / Q000473:pathology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D018384:Oxidative Stress / Q000187:drug effects*; D010659:Phenylhydrazines / Q000494:pharmacology; D032134:Saururaceae / Q000737:chemistry
chemical_list: D001578:Benzopyrans; D004149:Dioxoles; D017705:Lignans; D010659:Phenylhydrazines; C410958:sauchinone; C030299:phenylhydrazine; D016718:Arachidonic Acid; D007501:Iron; D055372:AMP-Activated Protein Kinases