Cytoprotective effect of the NAF from black soybean seed coat on Aβ-induced neurotoxicity in PC12 cells. (A) Protective effect of the NAF on Aβ-induced cytotoxicity in PC12 cell system. PC12 cells were pretreated for 48 h with various concentrations. After 48 h, the cells were treated with 25 μM Aβ for 3 h. (B) Inhibition of lactate dehydrogenase release of the NAF on Aβ-induced membrane injury in PC12 cell. Bars were represented with the mean ± SD (n = 3). Significant difference (p < 0.05 versus vitamin C) was observed on the Aβ-induced cell death. Different superscripts indicate significant difference among groups at p < 0.05.