Evaluation of cytotoxicity and genotoxicity of pesticide mixtures on lymphocytes

Abstract

The cytotoxicity and genotoxicity of pesticide mixtures viz. endosulfan + chlorpyrifos, chlorpyrifos + profenofos, and endosulfan + profenofos were evaluated on cultured human peripheral blood lymphocytes using assays for cell viability, and genotoxicity using chromosomal aberrations test and comet assay. The LC values for cytotoxicity were 3.50 μM, 4.18 μM, and 10.5 μM for profenofos, endosulfan, and chlorpyrifos respectively. When combined in equimolar concentrations, the LC values for cytotoxicity were 1.4 μM, 1.8 μM, and 2.0 μM for endosulfan + chlorpyrifos, chlorpyrifos + profenofos, and endosulfan + profenofos, respectively. Higher concentrations of individual pesticides (0.5-4.0 μM) but very low concentrations of pesticide mixtures caused significant DNA damage. Additive index values indicated a synergistic effect of toxicity for endosulfan + chlorpyrifos combination (1.12 TTU). The binary mixture of chlorpyrifos + profenofos showed an additive toxicity (0.46 TTU) while an antagonistic effect was observed for endosulfan + profenofos combination. Synergism could be due to these complementary pesticides simultaneously acting in different ways, magnifying their efficacy, whereas an additive interaction would imply that the chemicals are acting by the same mechanism and at the same target. Analysis of toxicity of pesticide mixtures may serve as important biomarker for occupational and household exposure to pesticides, with different modes of action.

Chromosome Missegregation and Aneuploidy Induction in Human Peripheral Blood Lymphocytes In vitro by Low Concentrations of Chlorpyrifos, Imidacloprid and α‐Cypermethrin

“…Ability of induction of primary DNA damage was also demonstrated in human spermatozoan cells (Salazar‐Arredondo et al, ) again, at the concentrations higher than the dose tested in the present study. The third study further confirmed ability of chlorpyrifos to induce primary DNA damage and chromosome aberrations (CA) in lymphocytes isolated from healthy individuals following 2 h exposure in the range form 0,18 to 1,40 μg/mL, which corresponds to the concentrations tested in our study (Sultana Shaik et al, ). Freshwater organisms such as zebrafish (Wang et al, ), fish Channa punctatus (Bloch) (Ali et al, ) and molluscs (JanakiDevi et al, ) have been used to evaluate genotoxicity of chlorpyrifos in vivo .…”

Effects of endosulfan isomers on cytokine and nitric oxide production by differentially activated RAW 264.7 cells

“…These results suggest that the toxicity of endosulfan isomers varies with the cell type examined. Technical grade endosulfan products, or other mixtures of α and β endosulfans, have been examined extensively for cytotoxic potential [ [7] , [8] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] ]. Not surprisingly, these studies have shown that endosulfan exposure in vitro causes loss of cell viability that increases in severity as the concentration and duration of exposure increases.…”

Neonicotinoid insecticides differently modulate acetycholine‐induced currents on mammalian α7 nicotinic acetylcholine receptors

“…Thus, individuals would be exposed to mixtures of environmental pesticides rather than to one pesticide. In addition, low concentrations of pesticide mixtures can cause significant damage, similar to higher concentrations of individual pesticides (Sultana Shaik et al, ). Here, we found that clothianidin, acetamiprid and thiamethoxam, at the same low concentration (10μM), differently modulated ACh‐induced current amplitudes.…”