title: Treatment with oligonol, a low-molecular polyphenol derived from lychee fruit, attenuates diabetes-induced hepatic damage through regulation of oxidative stress and lipid metabolism.
abstract: We have identified the effects of oligonol, a low-molecular polyphenol derived from lychee fruit, on oxidative stress and lipid metabolism in a type 2 diabetic model. Oligonol was orally administered at 10 or 20 mg per kg body weight per d for 8 weeks to db/db mice, and its effects were compared with those of the vehicle in db/db and m/m mice. Serum and hepatic biochemical factors, and protein and mRNA expression related to lipid metabolism were measured. In the oligonol-administered group, there were significant reductions of reactive oxygen species (ROS), lipid peroxidation, and the TAG and total cholesterol concentrations in both the serum and liver. Additionally, oligonol attenuated oxidative stress through the inhibition of advanced glycation endproduct formation and its receptor expression. Furthermore, augmented expressions of NF-κBp65 and inducible NO synthase were down-regulated to the levels of m/m mice in the group treated with oligonol at 20 mg/kg. Regarding lipid metabolism, lower hepatic lipid resulted from the down-regulation of sterol regulatory element-binding protein-1 and its target gene of lipogenic enzymes in the liver of db/db mice. The present results suggest that oligonol has protective effects against ROS-related inflammation and excess lipid deposition in the type 2 diabetic liver.
authors.affiliation: Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Jeong Sook
authors.initials: JS
authors.lastname: Noh
authors.forename: Chan Hum
authors.initials: CH
authors.lastname: Park
authors.forename: Takako
authors.initials: T
authors.lastname: Yokozawa
mesh_terms: D000818:Animals; D015415:Biomarkers; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D002784:Cholesterol; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D048909:Diabetes Complications; D005638:Fruit / Q000737:chemistry; D005786:Gene Expression Regulation / Q000502:physiology; D050356:Lipid Metabolism / Q000187:drug effects*; D032125:Litchi / Q000737:chemistry*; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008107:Liver Diseases / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control*; D008239:Lysine / Q000031:analogs & derivatives; D051379:Mice; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D009929:Organ Size; D018384:Oxidative Stress / Q000187:drug effects*; D047493:PPAR alpha; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000378:metabolism; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D051782:Sterol Regulatory Element Binding Protein 2 / Q000235:genetics / Q000378:metabolism; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014280:Triglycerides
chemical_list: D015415:Biomarkers; D047493:PPAR alpha; D010636:Phenols; D012333:RNA, Messenger; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2; D051996:Transcription Factor RelA; D014280:Triglycerides; C514283:oligonol; D002392:Catechin; D002784:Cholesterol; D052247:Nitric Oxide Synthase Type II; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D008239:Lysine