Dendrite extension by methanol extract of Ashwagandha (roots of Withania somnifera) in SK-N-SH cells

Extension of dendrites and axons in neurons may compensate for and repair d amaged neuronal circuits in the dementia brain. Our aim in the present stud y was to explore drugs activating neurite outgrowth and regenerating the ne uronal network. We found that the methanol extract of Ashwagandha (roots of Withania somnifera; 5 mu g/ml) significantly increased the percentage of c ells with neurites in human neuroblastoma SK-N-SH cells. The effect of the extract was dose- and time-dependent mRNA levels of the dendritic markers M AP2 and PSD-95 by RT-PCR were found to be markedly increased by treatment w ith the extract, whereas those of the axonal marker Tau were not. Immunocyt ochemistry demonstrated the specific expression of MAP2 in neurites extende d by the extract. These results suggest that the methanol extract of Ashwag andha promotes the formation of dendrites. NeuroReport 11:1981-1985 (C) 200 0 Lippincott Williams & Wilkins.