Assessment of the genotoxicity and cytotoxicity in environmentally exposed human populations to heavy metals using the cytokinesis-block micronucleus cytome assay.

Abstract

The cytokinesis-block micronucleus cytome (CBMN-Cyt) assay was developed as a system for evaluating DNA damage, cytostasis, and cytotoxicity. The aim of the present study was to estimate levels of micronuclei (MNi), nucleoplasmic bridges (NPBs), nuclear buds (NBUDs), cell death (apoptosis/necrosis), nuclear division index, and nuclear division cytotoxicity index values in the peripheral blood lymphocytes of environmentally exposed subjects to heavy metals from five Bosnian regions, characterized by different exposure to heavy metals. The study was performed using CBMN-Cyt assay, considering factors, such as age, gender and smoking habits and their possible effects on analyzed parameters. In total, 104 healthy subjects were selected (49.04% females and 50.96% males; average age, 35.41 years; 51.92% smokers and 48.08% nonsmokers). There was significant difference between the frequency of NBUDs in Tuzla as compared to the control group. Furthermore, there was observed a statistically significant difference for the frequency of NPBs between Zenica, Olovo, and Kakanj when compared with the controls. Males showed a significantly higher number of apoptotic cells than females in controls. There were significant differences between smokers and nonsmokers in the frequency of NPBs in controls (higher in nonsmokers) and necrotic cells in Olovo (higher in nonsmokers). The pack years of smoking significantly influenced the number of necrotic cells in controls and the frequency of NBUDs in the overall sample. The results of the present study provide evidence of significantly increased frequency of NPBs and NBUDs in exposed subjects, suggesting that these endpoints are highly sensitive markers for measuring genotoxicity.