Deltamethrin induces apoptotic cell death in cultured cerebral cortical neurons

In this study we investigated the induction of apoptotic cell death and its potential mechanisms in cultured cortical neurons in response to deltamethrin exposure. The cultured cortical neurons were treated at 7 days with deltamethrin at concentrations of 10, 100, and 1000 nM, respectively. MTT assay showed that higher concentrations of deltamethrin (100 and 1000 nM) decreased neuronal viability in a time- and dose-dependent way. TUNEL staining revealed that numerous apoptotic cells appeared in the treated cultures compared to controls at 24, 48, and 72 h after treatment of 100 nM deltamethrin. Western blot analysis demonstrated that p53 and Bax expression were dramatically increased at the same time points, whereas Bcl-2 expression was significantly reduced at all time points after deltamethrin treatment. Further, we found that nitric oxide synthase inhibitor N(G)-nitro-L-arginine prevented deltamethrin-induced neuronal apoptosis and altered expression of p53, Bax, and Bcl-2. These results suggest that nitric oxide synthase might mediate deltamethrin-elicited neuronal apoptosis through modulating the expression of apoptosis-related genes.