Mahnashi_2023_Biomed.Pharmacother_165_115144

The current study aims to quantify HPLC-DAD polyphenolics in the crude extracts of Desmodium elegans, evaluating its cholinesterase inhibitory, antioxidant, molecular docking and protective effects against scopolamine-induced amnesia in mice. A total of 16 compounds were identified which include gallic acid (239 mg g(-1)), p-hydroxybenzoic acid (11.2 mg g(-1)), coumaric acid (10.0 mg g(-1)), chlorogenic acid (10.88 mg g(-1)), caffeic acid (13.9 mg g(-1)), p-coumaroylhexose (41.2 mg g(-1)), 3-O-caffeoylquinic acid (22.4 mg g(-1)), 4-O-caffeoylquinic acid (6.16 mg g(-1)), (+)-catechin (71.34 mg g(-1)), (-)-catechin (211.79 mg g(-1)), quercetin-3-O-glucuronide (17.9 mg g(-1)), kaempferol-7-O-glucuronide (13.2 mg g(-1)), kaempferol-7-O-rutinoside (53.67 mg g(-1)), quercetin-3-rutinoside (12.4 mg g(-1)), isorhamnetin-7-O-glucuronide (17.6 mg g(-1)) and isorhamnetin-3-O-rutinoside (15.0 mg g(-1)). In a DPPH free radical scavenging assay, the chloroform fraction showed the highest antioxidant activity, with an IC(50) value of 31.43 microg mL(-1). In an AChE inhibitory assay, the methanolic and chloroform fractions showed high inhibitory activities causing 89% and 86.5% inhibitions with IC(50) values of 62.34 and 47.32 microg mL(-1) respectively. In a BChE inhibition assay, the chloroform fraction exhibited 84.36% inhibition with IC(50) values of 45.98 microg mL(-1). Furthermore, molecular docking studies revealed that quercetin-3-rutinoside and quercetin-3-O-glucuronide fit perfectly in the active sites of AChE and BChE respectively. Overall, the polyphenols identified exhibited good efficacy, which is likely as a result of the compounds' electron-donating hydroxyl groups (-OH) and electron cloud density. The administration of methanolic extract improved cognitive performance and demonstrated anxiolytic behavior among tested animals.