title: Cyto-genotoxic effects of smoke from commercial filter and non-filter cigarettes on human bronchial and pulmonary cells.
abstract: Cigarette smoke is a complex mixture of chemicals, some of which are known as carcinogens. The cyto-genotoxic effects of cigarette-smoke extract (CSE) from commercial cigarettes without (A and B) and with filter (C and D) were evaluated at different CSE concentrations on A549 and BEAS-2B cells. The particle content of the cigarette smoke and the metal composition of the CSE were also analyzed. The cells were exposed to 1-10% of the CSE from one cigarette per experiment. Cytotoxicity was evaluated by use of the MTT assay after 24h, and the lactate dehydrogenase (LDH) assay after 30min and 24h. The Fpg-modified comet assay was used to evaluate direct-oxidative DNA damage on cells exposed for 30min. As expected, unfiltered cigarette smoke (particularly from the B cigarette) contained a higher number of particles than filtered smoke. With smoke extract from the B cigarette we found a decrease in cell viability only in BEAS-2B cells. The results of the LDH test showed membrane damage for B-cigarette smoke extract, particularly in BEAS-2B cells. Extracts from unfiltered cigarette smoke induced significant direct DNA damage, to a larger extent in A549 cells. Filtered cigarette-smoke extract induced a significant direct DNA damage at 5-10%. A significant induction of oxidative DNA damage was found at the highest CSE concentration in both cell types (by smoke extracts from B and C cigarettes in A549 cells, and from A and D cigarettes in BEAS-2B cells). Smoke extracts from filter cigarettes induced less direct DNA damage than those from unfiltered cigarettes in A549 cells, probably due to a protective effect of filter. In BEAS-2B cells the smoke extract from the B-cigarette showed the highest genotoxic effect, with a concentration-dependent trend. These findings show a higher cyto-genotoxicity for smoke extracts from the B-cigarette and oxidative effects for those from the A and D cigarettes, particularly in BEAS-2B cells. Moreover, there was a higher responsiveness of A549 cells to genotoxic insult of CSE, and a cigarette-dependent genotoxicity in BEAS-2B cells. Our experimental model demonstrated to be suitable to sensitively detect early genotoxic response of different lung-cell types to non-cytotoxic concentrations of complex inhalable mixtures.
authors.affiliation: INAIL-Italian Workers' Compensation Authority, Research Area - Department of Occupational Medicine, Monteporzio Catone, Rome, Italy. d.cavallo@inail.it
authors.forename: Delia
authors.initials: D
authors.lastname: Cavallo
authors.forename: Cinzia L
authors.initials: CL
authors.lastname: Ursini
authors.forename: Anna M
authors.initials: AM
authors.lastname: Fresegna
authors.forename: Raffaele
authors.initials: R
authors.lastname: Maiello
authors.forename: Aureliano
authors.initials: A
authors.lastname: Ciervo
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ferrante
authors.forename: Giuliana
authors.initials: G
authors.lastname: Buresti
authors.forename: Sergio
authors.initials: S
authors.lastname: Iavicoli
mesh_terms: D001980:Bronchi / Q000187:drug effects*; D002460:Cell Line; D020552:Comet Assay; D004249:DNA Damage; D005374:Filtration; D006801:Humans; D008168:Lung / Q000187:drug effects*; D009152:Mutagenicity Tests; D012906:Smoke / Q000009:adverse effects*; D062789:Tobacco Products / Q000009:adverse effects*
chemical_list: D012906:Smoke