Molecular Docking Studies and in-vitro Acetylcholinesterase Inhibition by Terpenoids and Flavonoids.

Terpenoids and flavonoids were evaluated for Acetylcholinesterase inhibition using in-silico and in-vitro methods. Insilico docking method is carried out using AutoDock 4.2 tools and in-vitro AChE inhibition was based on Ellman method. The protein structure (amino acid sequence) of human AChE is similar to AChE from electric eel was used for the evaluation. The crystal structure of AChE was downloaded from RCSB protein data bank. Terpenoids used for docking study were Ambrein, Geraniol, Limonene. Linalool, and ferulic acid whose lowest binding energy (kcal/mol) was found to be -9.54 kcal/mol, -5.22 kcal/mol, -5.46 kcal/mol, -5.16 kcal/mol, -5.17 kcal/mol and their supporting IC50 values obtained through in-vitro enzyme inhibition studies were 91 μg/ml ± 0.12, 200 μg/ml ± 0.21, 195 μg/ml ± 0.43, 200 μg/ml ± 0.24, 185 μg/ml ± 0.56 respectively. Flavonoids used for the docking studies were Quercetin, Curcumin, Myricetin, Kaempferol, and Luteolin whose lowest binding energy was found to be -8.34kcal/mol, -8.21 kcal/mol, -8.28 kcal/mol,-7.16 kcal/mol and -8.56 kcal/mol respectively. Tacrine was used as a standard and its lowest binding energy was found to be -7.17 kcal/mol and its corresponding IC50 value was found to be 155 μg/ml ± 0.11. This study revealed the acetylcholine esterase inhibition potential of different commercially available terpenoids and flavonoids.