title: Fatty acids decrease catalase activity in human leukaemia cell lines.
abstract: Fatty acid (FA) may disturb the redox state of the cells not only by an increase in reactive oxygen species (ROS) generation but also due to a reduction in antioxidant enzyme activities. The effect of various FAs (palmitic, stearic, oleic, linoleic, gamma-linolenic and eicosapentaenoic acids (EPAs)) on Jurkat and Raji cells, (human T and B leukaemic cell lines was investigated). The following measurements were carried out: FA composition of the cells, cell proliferation and activities of catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD). The protective effect of alpha-tocopherol on cell death was also investigated. Each cell line presented a specific FA composition. All the tested FAs reduced catalase activity. The toxic effect of FA was abolished by the pre-incubation with physiological concentrations of alpha-tocopherol. The findings support the proposition that the increase in oxidative stress induced by FA partially occurs due to a reduction in catalase activity. In spite of the decrease in the enzyme activity, catalase protein and mRNA levels were not changed, suggesting a post-translational regulation.
authors.affiliation: School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil. karenina@usp.br <karenina@usp.br>
authors.forename: Anna K
authors.initials: AK
authors.lastname: Azevedo-Martins
authors.forename: R
authors.initials: R
authors.lastname: Curi
mesh_terms: D002374:Catalase / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D005227:Fatty Acids / Q000494:pharmacology / Q000502:physiology*; D005231:Fatty Acids, Unsaturated / Q000502:physiology; D006801:Humans; D019169:Jurkat Cells; D007938:Leukemia / Q000201:enzymology* / Q000378:metabolism; D015448:Leukemia, B-Cell / Q000201:enzymology; D015458:Leukemia, T-Cell / Q000201:enzymology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D002374:Catalase