Assessment of Global DNA Methylation in SH-SY5Y Cells Exposed to the Neonicotinoid Insecticides Imidacloprid and Thiamethoxam

Neonicotinoid insecticides, known for their selectivity and low mammalian toxicity, have been widely used in recent years as alternatives to organophosphate insecticides. Although neonicotinoids are generally considered to be safe, data show that they can cause harmful effects on human and environmental health. Due to the lack of information on their mechanism of toxicity, the effects of imidacloprid and thiamethoxam on DNA methylation as the most used marker for epigenetic effects were investigated in human neuroblastoma (SH-SY5Y) cells. The cells were exposed to imidacloprid and thiamethoxam in concentrations of 100, 200, and 500 mu M for 24 hours, then global DNA methylation and expression of genes involved in global DNA methylation (DNMT1, DNMT3a and DNMT3b) were investigated. Global DNA methylation significantly increased after imidacloprid exposure at 100 mu M, and thiamethoxam exposures at 200 mu M and 500 mu M (>1.5-fold). Imidacloprid significantly decreased the expression of DNMT1 and DNMT3a, whereas thiamethoxam did not cause any significant changes in the expression of DNMT genes. Our findings suggested that alteration in global DNA methylation may be involved in the toxic mechanisms of imidacloprid and thiametoxam.

Automated summary

Neonicotinoid insecticides, commonly used as alternatives to organophosphate insecticides, have been found to have harmful effects on human and environmental health. This study investigated the effects of imidacloprid and thiamethoxam on DNA methylation in human neuroblastoma cells, revealing significant increases in global DNA methylation after exposure to both chemicals.