Figure 1: Effects of SNP on SH-SY56 cell viability and NO production. SHSY5Y cells were treated with 1, 1.5, 2, 2.5, 3, or 3.5 mM SNP for 24 h. (a) Cell viability was measured by the MTT assay, and (b) NO production was measured by the nitrite assay. Data represent the mean, and the bars represent the standard error of the mean (SEM). *** p < 0.001 compared with control (untreated SH-SY5Y cells).