Flavonoids from Carduus pycnocephalus as opioid and cannabinoid receptors ligands: An in silico and in vitro studies

Abstract

Promising binding affinity of Carduus pycnocephalus L. total methanol extract to opioid and cannabinoid receptors and bioassay-guided fractionation resulted in the isolation of four flavonoids: luteolin-7-O-glucoside (1), kaempferol-3-O-rhamnoside (2), luteolin (3), and kaempferol-3-O-glucoside (4). This is the first time reporting flavonoids 1 and 3 in C. pycnocephalus. The binding affinity of these flavonoids to opioid and cannabinoid receptor subtypes (δ, κ, μ, CB1, and CB2) was evaluated in vitro, complemented by a molecular docking study.