title: Silybin-Phosphatidylcholine Complex Protects Human Gastric and Liver Cells from Oxidative Stress.
abstract: OBJECTIVE
  Silybin is the main component of silymarin with antioxidant, anti-inflammatory and cytoprotective actions. Our aim was to compare the effect of silybin used as single substance, silybin-phosphatidylcholine complex (SilPho), and derivatives of silybin (MannpSil, GalpSil, GlcpSil, LactpSil) on MKN28 and HepG2 cell viability and cell death, in vitro, after induction of oxidative stress.
  
  
  METHODS
  Oxidative stress was induced by incubating HepG2 and MKN28 cells with xanthine oxidase in the presence of its substrate xanthine. Cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide assay. Determination of Malondialdehyde (MDA) in MKN28 cells was performed by high-performance liquid chromatography. Quantitative analysis of apoptotic cells was carried-out using annexin.
  
  
  RESULTS
  SilPho and new silybin glycoconjugates did not affect cell viability, while silybin induced about 50% cell death in both MKN28 and in HepG2 cells. Pre-treatment of cells with silybin and new silybin glycoconjugates (before oxidative stress induction) did not affect cell viability, while SilPho had a protective effect. Exposure of MKN28 cells to oxidative stress caused a two-fold increase in cellular MDA concentration compared to untreated cells. Moreover, pre-treatment with SilPho, but not with silybin, significantly prevented oxidative stress-induced increase in cellular Malondialdehyde. Moreover, silybin induced apoptosis potentiated by oxidative stress, while SilPho did not induce any effect. Oxidative stress caused cell death primarily by necrosis, antagonized by SilPho.
  
  
  CONCLUSIONS
  The protective effect of SilPho is partially due to inhibition of radical oxidative species.
authors.affiliation: Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy alessandro.federico@unina2.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Federico
authors.affiliation: Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Dallio
authors.affiliation: Department of Chemical Sciences, University of Naples Federico II, Naples, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: DI Fabio
authors.affiliation: Department of Chemical Sciences, University of Naples Federico II, Naples, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: Zarrelli
authors.affiliation: Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Zappavigna
authors.affiliation: Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Stiuso
authors.affiliation: Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: Tuccillo
authors.affiliation: Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Caraglia
authors.affiliation: Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
authors.forename: Carmela
authors.initials: C
authors.lastname: Loguercio
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D010713:Phosphatidylcholines / Q000494:pharmacology*; D000077385:Silybin; D012838:Silymarin / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D010713:Phosphatidylcholines; D012838:Silymarin; C067772:IdB 1016; D000077385:Silybin
keywords: Silybin; cell necrosis; oxidative stress