Oxidative Stress, Cytotoxicity, and Genotoxicity Induced by Methyl Parathion in Human Gingival Fibroblasts: Protective Role of Epigallocatechin-3-Gallate.

Organophosphorous (OP) compounds are pesticides frequently released into the environment because of extensive use in agriculture. Among these, methyl parathion (mPT) recently received attention as a consequence of illegal use. The predominant route of human exposure to mPT is via inhalation, but inadvertent consumption of contaminated foods and water may also occur.

Effects of single-wall carbon nanotubes in human cells of the oral cavity: geno-cytotoxic risk.

Single-wall carbon nanotubes (SWCNTs) are one of the most extensively produced carbon materials and the environmental, public and professional exposure is therefore dramatically increasing. Consequently the studies on bio-effects and safety of SWCNTs are highly needed. The goal of this study was investigate the effects in vitro of SWCNTs in cells of the oral cavity, never employed in this research field.

Interaction between single wall carbon nanotubes and a human enteric virus.

Activated single wall carbon nanotubes have been used for biomedical purposes as carriers for drugs, peptides, proteins and nucleic acids. A large volume of data speaks to their suitability to act as a carrier. The ability of two differently activated SWNTs (with carboxyl groups or with carboxyl groups and polyethylenimine (PEI)) to form a complex with the hepatitis A virus was evaluated.

[The birth of nanobiotechnologies: new nanomaterials, potential uses, toxic effects and implications for public health].

Nanotechnologies hold considerable promise of advances in many sectors especially the biomedical field, since the materials used are of the appropriate dimensions to interact with important biological matter such as proteins, DNA and viruses. In this field the use of nanotechnologies will probably be second in importance only to biotechnologies. However many characteristics of nanomaterials that make them so promising from a technological point of view may also lead to negative effects on the environment and human health.

Evidence for the role of nitric oxide in antiapoptotic and genotoxic effect of nicotine on human gingival fibroblasts.

Resistance to apoptosis is essential for cancer survival and plays a critical role in carcinogenesis. Growing evidence suggests that nicotine can act as a tumor promoter, impairing apoptotic process in certain types of human cancer cell lines. Our previous study revealed in human gingival fibroblasts (HGFs) a concomitant antiapoptotic and genotoxic effect of nicotine, manifested by the attenuation of staurosporine (STP)-induced apoptosis and the increase of micronucleus frequency.

Role of the mismatch repair system and p53 in the clastogenicity and cytotoxicity induced by bleomycin.

The mismatch repair (MMR) system and p53 protein play a pivotal role in maintaining genomic stability and modulate cell chemosensitivity. Aim of this study was to examine the effects of either MMR-deficiency or p53 inactivation, or both, on cellular responses to bleomycin. The MMR-deficient colon carcinoma cell line HCT116 and its MMR-proficient subline HCT116/3-6, both expressing wild-type p53, were transfected with an expression vector encoding a dominant-negative p53 mutant, or with the empty vector.

Individual susceptibility to DNA telomerase inhibitors: a study on the chromosome instability induced by 3'-azido-3'-deoxythymidine in lymphocytes of elderly twins.

The activation of telomerase in phytohemagglutinin-stimulated peripheral lymphocytes is thought to play a role in telomere maintenance and DNA repair. Considering the importance of this enzyme in both cancer and senescence, we studied the effects of the telomerase inhibitor 3'-azido-3'-deoxythymidine on the frequency of chromosomal aberrations and micronuclei induced in peripheral blood lymphocytes (PBL) of elderly monozygotic and dizygotic twins, evaluated with respect to the genotoxic effects induced in unrelated young subjects. Our results show that the cytogenetic damage induced by 3'-azido-3'-deoxythymidine in human PBL was mainly regulated by genetic factors and allowed the identification of hypersensitive subjects.

Aphidicolin and bleomycin induced chromosome damage as biomarker of mutagen sensitivity: a twin study.

The induction of chromosome damage in cultured human lymphocytes by in vitro treatments with aphidicolin (APC) and bleomycin (BLM) has been proposed as test of sensitivity to mutagens. To assess their validity, we have investigated whether the individual expression of induced chromosome damage has a genetic rather than an environmental basis. Metaphase analysis for chromosomal aberrations (CA) and micronucleus (MN) assay in cytokinesis-blocked cells have been performed in peripheral blood lymphocytes from 19 healthy male twins (9 monozygotic and 10 dizygotic pairs), aged 70-78 years, after APC, BLM and APC+BLM treatments.

Genotoxic and antiapoptotic effect of nicotine on human gingival fibroblasts.

Growing evidence suggests that nicotine, the addictive component of cigarettes, can have a direct role in tumor development by enhancing cell proliferation and impairing apoptotic process in certain types of human cancer cell lines. Since the correlation between apoptosis and DNA damage is already well documented, we investigated the response of human gingival fibroblasts (HGFs) to nicotine exposure by examining its effect on DNA damage induction and apoptotic process in parallel. To assess the genotoxicity of this drug, the cytokinesis-block micronucleus (CBMN) test was performed.

The role of oxidative stress in the in vitro induction of micronuclei by pesticides in mouse lung fibroblasts.

The involvement of the antioxidant enzymes catalase and glutathione peroxidase (both at 0.1 mg/ml) in defence against the genotoxicity of phosphamidon (80 microg/ml) and dieldrin (25 microM) was investigated in order to demonstrate that the two pesticides damage DNA through the generation of reactive oxygen species and therefore of oxidative stress. The pesticide genotoxicity was determined by the cytokinesis-block micronucleus test performed on primary mouse lung fibroblast cultures.