In Vitro Effects of the Organochlorine Pesticide β-Hexachlorocyclohexane on Bovine Peripheral Blood Mononuclear Cells

摘要

Abstract The β-hexachlorocyclohexane (β-HCH) is a very stable and accumulable isomer of Lindane, a well known organochlorine pesticide. The HCHs were banned in all developed countries but to date high concern still exists for environment, animal and human health due to contaminated sites. In this study, several in vitro tests [cell viability (XTT), trypan blue exclusion (TBE), lactate dehydrogenase release (LDH) and bromodeoxyuridine (BrdU) incorporation assays] were performed to investigate the toxic effects of exposure to β- HCH (from 0.1 to 1000 μM) on bovine peripheral blood mononuclear cells (PBMCs). All the trials were performed incubating PBMCs for 2 and 7 days. At high concentrations (i.e. 1000 μM), the β-HCH approximately halved the number of living cells regardless the exposure time, significantly decreased the cell viability assessed by the XTT assay, and compromised the proliferation potential of PBMCs. At lower β-HCH exposure levels (0.1 to 100 μM), particularly after 7 days of exposure, a progressive decrease of cell viability has been observed. These adverse effects were significant at concentrations observed in the blood of cattle reared in polluted areas. The LDH results suggest that β-HCH does not clearly affect the integrity of the cell membrane in the range of exposure levels tested. All in all, these findings warn about the risk posed by the long-term exposure to β-HCH of farm animals reared in rural areas polluted by β-HCH. Further research is needed to deepen our knowledge about the mechanisms through which β-HCH affects the PBMCs functionality.