Evaluation of cytotoxic effects of imidacloprid and acetamiprid on in vitro systems

Neonicotinoids, which have received attention in recent years due to their toxic effects on non-target organisms, particularly bees, are a nicotine-derived insecticide group that is widely used in many countries, including Turkey, though their use is restricted in some. The potential toxicity of pure forms and commercial formulations of imidacloprid and acetamiprid, two important members of the group, on the HT-29 human colorectal adenocarcinoma cell line was investigated in this study individually and in combination. For this purpose, time and dose dependent cell viability was evaluated with MTT and neutral red assays; glutathione, superoxide dismutase, catalase and malondialdehyde levels were measured for the evaluation of oxidative stress by spectrophotometric methods; flow cytometry measurements of annexin V binding rates, caspase 3/7 activity, and mitochondrial membrane potential were used to determine the apoptosis process; the comet assay was used to detect DNA damage. According to the results, imidacloprid and acetamiprid were shown to induce cytotoxicity in HT-29 cells under these experimental conditions via caspase-mediated apoptosis, mitochondrial membrane depolarization, DNA damage, and oxidative stress. In the results, it was found remarkable that DNA damage occured at low doses, whereas toxic effects were induced at lower concentrations in the mixtures, and the formulations are at the forefront in terms of toxicity.