Figure 1.

Dose-dependent effects of DA on SH-SY5Y cell-viability. SH-SY5Y cells were treated without (control) or with varying concentrations of DA (100–400 μM) for 24 h in the presence or absence of NAC (2.5 mM), and the cell viability was measured by (a) trypan blue assay or (b) estimation of LDH activity, as described in Section 3. Values are the means ± SD of six observations. Statistically significant differences in cell death among the groups exist at P < 0.001 as shown by asterisks (∗) (in (a), F  (4,25) = 1177.09, P < 0.001; in (b), F  (4,25) = 898.99. P < 0.001).