Flavonoid Profile, Biological Potentials, and In Silico Approaches of Methanol Extracts on AChE: Amaranthus retroflexus L.

Abstract

This study investigated the flavonoid compounds and their biological activities in methanol extracts obtained from root, stem, leaf, and flower parts of Amaranthus retroflexus L. Flavonoids in the extracts were characterized for the first time by liquid chromatography-highresolution mass spectrometry (LC-HRMS), and a total of eight flavonoid derivatives were identified. The extracts' total antioxidant status (TAS) and total oxidant status (TOS) were determined, and the results were expressed as mM Trolox equivalent/L and µM H₂O₂ equivalent/L. According to our findings, all extracts showed high antioxidant activity, with a TAS value >2.0, mainly the root extract, which exhibited the highest activity, with a value of 3.632 mM Trolox equivalent/L. In addition, all extracts showed in vitro inhibition of acetylcholinesterase (AChE) enzyme. In DNA protection tests performed by gel electrophoresis, it was observed that the extracts could effectively protect plasmid DNA against oxidative damage. In silico evaluations assessed the binding affinities, dynamic stability, and pharmacokinetic profiles of luteolin-7-rutinoside, rutin, hyperoside, and quercitrin to AChE. ADMET analyses, molecular docking, and MD simulation (100 ns) revealed that luteolin-7-rutinoside and rutin exhibited high binding affinity and stable stability, but all compounds required structure optimization and formulation strategies due to poor absorption and high risk of drug-induced liver injury (DILI).