VGF and Parkinson disease: In conclusion KSM-66, W. somnifera root extract, demonstrated neuroprotective effects showing a capacity to increase the viability of SH-SY5Y cells, a Parkinson's Disease model, to increase glutathione peroxidase and thiol transferase enzyme activities, to modulate the expression of oxidative stress response proteins; peroxiredoxin I, VGF and vimentin, to increase intracellular ATP levels and to modulate redox regulation by decreasing glutathionylated protein levels.