Occupational exposure to ionizing radiation (IR) can cause systemic acute and chronic effects on human health, including genetic instability that may be etiology of various diseases, including cancer. The aim of this study was to evaluate the possible toxicogenetic changes in haematological and biochemical parameters, and cytogenetic biomarkers (micronuclei and nuclear abnormalities) indicators of mutagenicity and apoptosis, as well as seek their correlation with lifestyle, age and gender. In accordance with the ethical aspects, 45 professionals (technicians and technologists in radiology) occupationally exposed to low doses of IR participated in this study. For control, 45 healthy individuals were not exposed to IR and/or genotoxic chemicals were included. Peripheral blood and oral epithelium samples were used in the toxic evaluations. The results suggested unchanged hematological biomarkers but a significant (P < 0.05) increases in the frequency of micronuclei, sprouts, binucleate cells and bridges, as well as karyolysis and karyorrhexis in professional radiology sector. Hepatic and nephritic toxicity were not observed. Without protection, a significant (P < 0.01) correlation (P < 0.05) was observed between toxicogenetic biomarkers with age, smoking, alcohol consumption, time and place of work. In conclusion, IR may be associated with genetic instability in health diseases, like cancer.

Isotretinoin (ITN), chemically known as 13-cis-retinoic acid, is a part of the broad group of compounds related to vitamin A. It is particularly employed in the treatment of nodular cystic acne and as an inhibitor of proliferation of neoplastic cells, by exerting a regulatory effect on the cell differentiation. This study aimed at investigating the possible oxidative effects of ITN and modulatory effects of vitamins A and C in mutant and non-mutant Saccharomyces cerevisiae strains. In addition, to reconfirm the oxidative effects, five in vitro antioxidant assays were also prepared taking the alpha-tocopherol analogue, trolox as a standard. In vivo study conducted on S. cerevisiae cells was carried out with ITN 20 µg/ml taking hydrogen peroxide (H 2 O 2) as stressor (STR), whereas ITN 5 to 50 µg/ml was considered for in vitro assays taking similar dose of trolox (TRO). Results show ITN to have oxidative effect in both in vitro and in vivo tests. In conclusion, ITN produced oxidative effects and there may be an hypervitaminosis effect with vitamins A and C, thus insinuation to genetic material.