2.11. Neuroprotection Studies in the SH-SY5Y Human Neuroblastoma Cell Line

Cells were pre-incubated with the corresponding compound at 1 μM in neuroblastoma culture medium. After 24 h, the medium was removed and replaced with 1% FBS neuroblastoma culture media containing the corresponding compound at 1 µM and the toxic stimuli, namely a mixture of rotenone and oligomycin A (R/O, 30 μM/10 μM, respectively), okadaic acid (OA) at 20 nM or a high concentration of KCl (70 mM). Cells were co-incubated for further 24 h with the R/O mixture or KCl solution, or 18 h with the OA solution. Melatonin (1 µM) or nimodipine (1 µM) were used as positive control and reference compounds in the R/O, OA or high concentration of potassium models, respectively. Control cells were incubated with the same amount of dimethyl sulfoxide (DMSO) without any drug. After the co-incubation period, cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction method [56]; basal condition was considered as 100% survival.