title: Silybin counteracts lipid excess and oxidative stress in cultured steatotic hepatic cells.
abstract: OBJECTIVE
  To investigate in vitro the therapeutic effect and mechanisms of silybin in a cellular model of hepatic steatosis.
  
  
  METHODS
  Rat hepatoma FaO cells were loaded with lipids by exposure to 0.75 mmol/L oleate/palmitate for 3 h to mimic liver steatosis. Then, the steatotic cells were incubated for 24 h with different concentrations (25 to 100 μmol/L) of silybin as phytosome complex with vitamin E. The effects of silybin on lipid accumulation and metabolism, and on indices of oxidative stress were evaluated by absorption and fluorescence microscopy, quantitative real-time PCR, Western blot, spectrophotometric and fluorimetric assays.
  
  
  RESULTS
  Lipid-loading resulted in intracellular triglyceride (TG) accumulation inside lipid droplets, whose number and size increased. TG accumulation was mediated by increased levels of peroxisome proliferator-activated receptors (PPARs) and sterol regulatory element-binding protein-1c (SREBP-1c). The lipid imbalance was associated with higher production of reactive oxygen species (ROS) resulting in increased lipid peroxidation, stimulation of catalase activity and activation of nuclear factor kappa-B (NF-κB). Incubation of steatotic cells with silybin 50 μmol/L significantly reduced TG accumulation likely by promoting lipid catabolism and by inhibiting lipogenic pathways, as suggested by the changes in carnitine palmitoyltransferase 1 (CPT-1), PPAR and SREBP-1c levels. The reduction in fat accumulation exerted by silybin in the steatotic cells was associated with the improvement of the oxidative imbalance caused by lipid excess as demonstrated by the reduction in ROS content, lipid peroxidation, catalase activity and NF-κB activation.
  
  
  CONCLUSIONS
  We demonstrated the direct anti-steatotic and anti-oxidant effects of silybin in steatotic cells, thus elucidating at a cellular level the encouraging results demonstrated in clinical and animal studies.
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Vecchione
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Grasselli
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Voci
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Baldini
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: Ignazio
authors.initials: I
authors.lastname: Grattagliano
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: David Qh
authors.initials: DQ
authors.lastname: Wang
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Portincasa
authors.affiliation: Giulia Vecchione, Elena Grasselli, Adriana Voci, Francesca Baldini, Laura Vergani, DISTAV, Department of Earth, Environment and Life Sciences, University of Genova, 16132 Genova, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Vergani
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015153:Blotting, Western; D002334:Carnitine O-Palmitoyltransferase / Q000187:drug effects / Q000378:metabolism; D002374:Catalase / Q000187:drug effects / Q000378:metabolism; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D005234:Fatty Liver; D005470:Fluorometry; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D066292:Lipid Droplets / Q000187:drug effects / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D015227:Lipid Peroxidation / Q000187:drug effects; D008856:Microscopy, Fluorescence; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D019301:Oleic Acid / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects*; D010168:Palmitates / Q000494:pharmacology; D047492:Peroxisome Proliferator-Activated Receptors / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D000077385:Silybin; D012838:Silymarin / Q000494:pharmacology*; D013053:Spectrophotometry; D051780:Sterol Regulatory Element Binding Protein 1 / Q000187:drug effects / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D016328:NF-kappa B; D010168:Palmitates; D047492:Peroxisome Proliferator-Activated Receptors; D017382:Reactive Oxygen Species; D012838:Silymarin; D051780:Sterol Regulatory Element Binding Protein 1; D014280:Triglycerides; D014810:Vitamin E; D019301:Oleic Acid; D000077385:Silybin; D002374:Catalase; D002334:Carnitine O-Palmitoyltransferase
keywords: Lipid droplets; Lipid metabolism; Mitochondrial β-oxidation; Non-alcoholic fatty liver disease; Oxidative stress; Silybin; Steatotic hepatocytes