Abstract
The neuroprotective effect of Nigella sativa oil (NSO) and its fractions against beta amyloid (A beta)-induced cell death in primary rat cerebellar granule neurons was investigated. Primary cultures were pretreated for 5 h with NSO and its fractions - hexane fraction (HF), ethyl acetate fraction (EAF) and water fraction (WF) - before incubating with 10 mu MA beta(1-40) for 24 h. Cell viability was investigated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) and lactate dehydrogenase (LDH) assays. Results of the MTS assay showed that the WF and NSO were significantly protective against cell death induced by 10 mu M A beta(1-40) at 1, 10 and 100 mu g/mL probably because of antioxidant properties as determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical trapping method. HF and EAF had low DPPH scavenging effect and were only effective at 100 mu mg/mL. However, NSO and its fractions were weakly protective against cell membrane damage in the LDH assay. NSO and its fractions, especially the WF, may play a role in the prevention of A beta-induced cell death.