〔Abstract〕 Objective To observe the effect of sodium fluoride(NaF) and 2-(2-benzofuranyl) 2-imidazoline(2-BFI) on mitochondrial morphology, function, and apoptosis of SH-SY5 Y cells, and to explore the protective effect of 2-BFI on NaF-induced injury. Methods Different concentrations of NaF(0.5, 1.0, 1.5, 2.0, 4.0 mmol/L) were used to treat SH-SY5Y cells for 24 h,and then Cell Counting Kit-8( CCK-8) assay was used to screen the proliferation ability of SH-SY5Y cells; SH-SY5Y cells were treated with Na F and different concentrations of 2-BFI( 2. 5,5. 0,10. 0,20. 0,40. 0 μmol/L) for 24 h,and the proliferation ability of SH-SY5Y cells was detected by CCK-8 assay. The transmission electron microscope was used to observe the mitochondrial morphology,the mitochondrial function was detected by ATP detection kit and Mito-Tracker Red CMXRos kit,cell apoptosis was detected by TUNEL staining,and the expressions of Bcl-2,Bax,and cleaved caspase-3 protein were detected by Western blot. Results The cell survival rate of SH-SY5Y gradually decreased with the increase of Na F concentration.The selected Na F was 2. 0 mmol/L. 2-BFI treatment for 24 h could improve the cell survival rate. At 10 mmol/L,the cell survival rate was higher( 99. 169%),and 10 mmol/L was selected as the 2-BFI follow-up experimental concentration. Compared with the control group,the mitochondrial morphology of the Na F group changed,ATP levels and mitochondrial membrane potential( Δψm) decreased,the apoptosis rate increased,Bcl-2 protein content decreased,expression of Bax and cleaved caspase-3 protein increased. Compared with Group Na F,2-BFI administration improved mitochondria morphology,increased ATP levels and Δψm,reduced cell apoptosis rate,increased Bcl-2 protein content,and reduced Bax,cleaved caspase-3 protein expression. Conclusion 2-BFI can improve mitochondrial morphology and function,reduce cell apoptosis,and play neuroprotective role in fluorosis SH-SY5Y cells.