title: Grape seed procyanidins prevent oxidative injury by modulating the expression of antioxidant enzyme systems.
abstract: In the present paper, we report the effect of a grape seed procyanidin extract (GSPE) on antioxidant enzyme systems (AOEs). Gene expression was tested using the hepatocarcinoma cell line HepG2 by exposing it to several GSPE doses between 0 and 100 mg/L for 24 h. We evaluated mRNA expression and enzyme activity levels using real time RT-PCR and spectrophotometry. The results suggested a transcriptional GSPE regulation of glutathione related enzymes caused by an increase both in mRNA and in enzyme activity levels overall at 15 mg/L. We also assessed the GSPE effect on AOEs in cells submitted to oxidative stress. Under oxidative conditions (1 mM H(2)O(2), 1 h), we found a decrease in GSH content and an increase in MDA, and we suggested a posttranslational regulation of GPx/GR mRNAs and a transcriptional enhancement of GST mRNA. The GSPE pretreatment (15 mg/L, 23 h) before HepG2 submission to H(2)O(2) (1 mM, 1 h) showed an increase of the mRNA of GPx/GR with respect to the H(2)O(2) group, whereas the GSH content was similar to the control group. However, the GPx/GR enzyme activities were not increased. We hypothesize that GSPE probably improves the cellular redox status via glutathione synthesis pathways instead of regulation of the GPx and/or GR activities protecting against oxidative damage.
authors: Departament de Bioquímica i Biotecnologia, Unitat d'Enologia del Centre de Referència en Tecnologia dels Aliments de la Generalitat de Catalunya, Universitat Rovira i Virgili, 43007 Tarragona, Spain.
authors: Francesc
authors: F
authors: Puiggros
authors: Niurka
authors: N
authors: Llópiz
authors: Anna
authors: A
authors: Ardévol
authors: Cinta
authors: C
authors: Bladé
authors: Lluís
authors: L
authors: Arola
authors: M Josepa
authors: MJ
authors: Salvadó
mesh_terms: D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000235:genetics; D005980:Glutathione Reductase / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics; D018197:Hepatoblastoma; D006801:Humans; D008113:Liver Neoplasms; D018384:Oxidative Stress / Q000187:drug effects*; D044945:Proanthocyanidins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000737:chemistry*; D013482:Superoxide Dismutase / Q000235:genetics; D027843:Vitis / Q000737:chemistry*
chemical_list: D044945:Proanthocyanidins; D012333:RNA, Messenger; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase