Table 4.

Virtual screening studies employed to identify potential inhibitors for neurodegenerative diseases.

Author (Year of Publication)	Neurodegenerative Diseases	Method	Chemical Scaffold Under Study	Target	Significance of Study
Lin et al. (2016) [105]	Sporadic and familial forms of AD	VS by utilizing docking studies with the GOLD docking program	1.1 million compounds in the ZINC and in-house databases	GSK-3β	The results revealed that among the tested compounds, VB-008 (anandamide transport inhibitor) with a polar head and a long nonpolar tail and one h-bond in the hinge region with Asp133, exerted the strongest overall effect on the examined GSK-3β activity, tau aggregation, and neuroprotection.
Noeske et al. (2007) [106]	PD and multiple sclerosis	2D-pharmacophore-based VS	Six known mGluR1 antagonists	Metabotropic glutamate receptor 1 (mGluR1)	The most potent compound yielded an IC50 of 362 nM based on a coumarine scaffold which was further subjected to a hit optimization program, and a compound with an IC50 of 123 nM was obtained.
Daidone et al. (2012) [107]	PD and hypertension	VS of the ZINC database, docking-based screening and in vitro assay	In-house built database of known active and inactive DDC inhibitors	DOPA decarboxylase (DDC)	Authors found several competitive inhibitors of human DDC with Ki values in the low micromolar range. The most potent inhibitor with a Ki value of 500 nM emerged as a promising candidate for further lead optimization.
Lepailleur et al. (2014) [108]	AD	Common feature-based pharmacophore model to VS in combination with similarity based clustering method and molecular docking	17,194 compounds of the CERMN chemical library	Histamine H3-receptor (H3R) and serotonin 4-receptor (5HT4R)	Results from the binding experiments confirmed that benzo[h]-[1,6]naphthyridine derivative retrieved by this VS method exerts high affinity for both H3R and 5HT4R.
Ferreira et al. (2011) [109]	AD, PD	Four-point pharmacophore	macrocycle diterpene derivatives with the greater number of compounds known to have multidrug resistance (MDR) -reversing activity	Pgp	The final 4-point pharmacophore model demonstrated the essential role of hydrophobic interactions and the presence of electron acceptor features for Pgp modulators which could be utilized for the development of novel multi-resistance modulators.
Lu et al. (2011) [110]	AD	Pharmacophore-based virtual screening approach of NCI chemical databases followed by molecular docking	known AChEI	AChE	The identified hits by VS were subjected to molecular docking study using the LibDock program which obtained 9 hits with the highest scoring structures that have ability to block simultaneously the catalytic and peripheral anionic sites of the enzyme.