Neuroprotective Effect of Total and Sequential Extract of Scrophularia striata Boiss. in Rat Cerebellar Granule Neurons Following Glutamate- Induced Neurotoxicity: An In-vitro Study

Neuroprotective effect of the extract from aerial parts of Scrophularia striata Boiss (Scrophulariaceae) was investigated against glutamate-induced neurotoxicity on cultured rat pups Cerebellar Granule Neurons (CGNs). CGNs from 8 days old Sprague-Dawley rat were prepared and cultured. The experiments were performed after 8 days in culture. The plant was collected from the northeastern part (Ruin region) of Iran and air-dried at room temperature. The total extract was prepared with maceration of prepared powder in ethanol 80% for three times. Sequential extracts were obtained using dried and powdered aerial parts with increasingly polar solvents: petroleum ether, chloroform, ethyl acetate and methanol 80% solution. Cultured cells were exposed to 125 μM of glutamate for 12 h following a 24 h of incubation with test fractions at concentration of 10 mcg/mL. Morphological assay was performed using invert light microscope after fixation and staining with haematoxylin. Neuronal viability was measured using MTT assay. Statistical analysis was done using SPSS software. One way analysis of variance (ANOVA) was performed by Tukey post-hoc test. Values were considered statistically significant when p-value ≤ 0.05. Results of this study showed a significant neuroprotective activity of high polarity methanolic fraction of aerial parts of Scrophularia striata against glutamate-induced neurotoxicity in a dosedependent manner. Treatment with 10 mcg/mL of the fractions showed the best result.