The toxicity of insecticide broflanilide on human SH-SY5Y cells

Broflanilide (BFL) is a new bis-amide insecticide that binds to γ-aminobutyric acid receptor, has attracted widespread attention because of its high efficiency, broad spectrum, and novel mechanism of action. It is widely used, which may pose short or long-term safety risks to humans or the environment. This study focuses on the toxic effects of commercial BFL formulation on the human neuroblastoma cell line (SH-SY5Y) in vitro. The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide method, flow cytometric analysis, fluorescent staining method, immunofluorescence, single-cell gel electrophoresis, and protein immunoblotting were carried out for this study. The results showed that the commercial BFL formulation could cause mitochondrial damage (the collapse of mitochondrial membrane potential and the opening of mitochondrial permeability transition pore), DNA damage (DNA single-strand breaks, DNA double-strand breaks, and oxidative DNA damage), alter the expression of related proteins, and induce mitochondria-mediated apoptosis. And the cytotoxicity of the BFL formulation is mainly caused by the active ingredient BFL. In conclusion, this study provides a theoretical basis for the damage of BFL to human cells. To our knowledge, this is the first report of the toxic effects of BFL or its formulation on human cells, which suggests the possible security risk of BFL on human beings and attracts more people's attention to its environmental toxicity effects.