title: Paraoxsonase2 (PON2) and oxidative stress involvement in pomegranate juice protection against cigarette smoke-induced macrophage cholesterol accumulation.
abstract: Exposure to cigarette smoke (CS) promotes various stages of atherosclerosis development. Macrophages are the predominant cells in early atherogenesis, and the polyphenolic-rich pomegranate juice (PJ) is known for its protective role against macrophage atherogenicity. The aim of the current study was to examine the atherogenic effects of CS on macrophages, and to evaluate the protective effects of PJ against CS-induced macrophage atherogenicity. Murine J774A.1 macrophages were treated with CS-exposed medium in the absence or presence of PJ. Parameters of lipid peroxidation in CS-exposed medium were measured by the lipid peroxides and thiobarbituric acid reactive substances (TBARS) assays. Atherogenicity of macrophages incubated with increasing concentrations of CS-exposed medium was assessed by cytotoxicity, oxidative stress determined by generation of reactive oxygen species (ROS) using DCFH-DA, activity of the cellular anti-oxidant paraoxonase2 (PON2), macrophage accumulation of cholesterol and triglycerides, as well as through high density lipoprotein (HDL)-mediated cholesterol efflux from the cells. CS exposure resulted in significant and dose-dependent increases in lipid peroxides and TBARS medium levels (up to 3 and 8-fold, respectively). Incubation of macrophages with CS-exposed medium resulted in dose-dependent increases in macrophage damage/injury (up to 6-fold), intracellular ROS levels (up to 31%), PON2 activity (up to 2-fold), and macrophage cholesterol content (up to 24%). The latter might be explained by reduced HDL-mediated cholesterol efflux from CS-exposed macrophages (by 21%). PJ protected macrophages from CS-induced increases in intracellular ROS levels and cholesterol accumulation, as well as the attenuated efflux of cholesterol. These data indicate that CS stimulates macrophage oxidation and activates PON2 as a possible compensatory response to the oxidative burden. CS impairs HDL-mediated cholesterol efflux from macrophages leading to cellular accumulation of cholesterol. The atherogenic and oxidative effects of CS are attenuated by PJ, a polyphenolic-rich anti-oxidant.
authors.affiliation: The Lipid Research Laboratory, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Efron 1, Bat Galim, Haifa 31096, Israel.
authors.forename: Oren
authors.initials: O
authors.lastname: Rom
authors.affiliation: The Lipid Research Laboratory, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Efron 1, Bat Galim, Haifa 31096, Israel. Electronic address: aviram@tx.technion.ac.il.
authors.forename: Michael
authors.initials: M
authors.lastname: Aviram
mesh_terms: D000818:Animals; D043303:Aryldialkylphosphatase / Q000378:metabolism*; D001628:Beverages; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000378:metabolism; D029561:Lythraceae / Q000737:chemistry*; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D051379:Mice; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D020011:Protective Agents / Q000494:pharmacology*; D012907:Smoking / Q000009:adverse effects*
chemical_list: D008077:Lipoproteins, LDL; D020011:Protective Agents; D002784:Cholesterol; D043303:Aryldialkylphosphatase
keywords: Cholesterol; Cigarette smoke; Macrophages; Oxidative stress; Paraoxonase2; Pomegranate juice