White sesame seed water-soluble fraction enhances human neuroblast cell viability via an anti-apoptotic mechanism

Defatted sesame seed flour is recovered as a byproduct after oil extraction and is usually considered a waste product. Previously, we showed that water-soluble fractions purified from defatted white and gold sesame seed flour exhibited good antioxidant activity in vitro. We also identified ferulic acid and vanillic acid as the bioactive antioxidants in both white and gold sesame seed water-soluble fractions (WS-wsf and GS-wsf, respectively). In this study, we hypothesized that WS-wsf and GS-wsf may have neuroprotective effects due to their antioxidant potential. Treatment with WS-wsf for 24 hours enhanced human neuroblastoma SH-SY5Y cell viability and proliferation, while GS-wsf, ferulic acid, and vanillic acid did not show similar effects. In addition, WS-wsf (1-3 mg/mL) significantly and dose-dependently protected SH-SY5Y cells against camptothecin-induced apoptosis, suggesting the involvement of an anti-apoptosis mechanism in the neuroprotective effects of WS-wsf. In fact, treatment with WS-wsf significantly decreased the mRNA expression levels of pro-apoptotic Bax and p53 genes. WS-wsf also enhanced Bcl-2 protein level and Akt phosphorylation. Taken together, this study showed that WS-wsf has interesting neuroprotective potential via an anti-apoptotic mechanism, which is independent from its antioxidant capacity.