Genotoxic effects of imidacloprid in human lymphoblastoid TK6 cells

Abstract

Among neonicotinoid insecticides, the fastest growing class of insecticides worldwide over the past decade, imidacloprid (IMI) is the most widely used one. The effects of IMI on human health, especially on genetic toxicity have gradually aroused more attention. In this study, a combined in vitro approach employing the thymidine kinase (TK) gene mutation assay, the comet assay and the micronucleus test was taken to assess the genotoxicity of IMI. The mechanism behind IMI was also explored by measuring reactive oxygen species (ROS) in the human lymphoblastoid TK6 cells. The cells were treated with 0.01, 0.1, 1, 5, and 10 μg/mL IMI, and ROS generation was measured by the use of 2,7,-dichlorofluorescin diacetate (DCFH-DA) assay. IMI significantly increased the micronucleus (MN) frequency, TK mutations and DNA damage with a dose-effect relationship, and the lowest effective concentration in those tests was 0.1 μg/mL. However, no obvious change of intracellular ROS was observed for any concentrations. The results indicate that IMI has potential genotoxic effects on TK6 cells, but ROS does not seem to be involved as a mechanism of genotoxicity under the experimental conditions.

Keywords:

• Imidacloprid
• TK gene mutation
• micronucleus test
• alkaline comet assay
• reactive oxygen species

Disclosure statement

The authors declare that they have no conflicts of interest.

Additional information

Funding

This study was supported by the Natural Science Foundation of China [Grant Nos. 81630085 and 817733870], the Science and Technology Commission of Shanghai Municipality [Grant No. 17ZR1415800], and the Pediatrcis, Shanghai Municipal Commission of Health and Family Planning, Developing plan of important weak disciplines [Grant No. 2016ZB0103].