Phytochemical Profile, Antioxidant, Anticholinergic and Antibacterial Properties of Flowers of Abelmoschus esculentus (Okra)

The aim of this research was to investigate the antioxidant, and anticholinergic properties, phenolics profile and antibacterial activities of Abelmoschus esculentus ethanol extract. The analysis of phenolic compounds was performed with LC-MS/MS. The antioxidant capacity (radical scavenging, metal-reducing power and total antioxidant activity) was assessed by DPPH, ABTS, Cu2+-Cu+ reducing (CUPRAC), Fe3+-Fe2+ reducing and ferric thiocyanate methods. The antibacterial activity was determined by disc diffusion and MIC (Minimum inhibitory concentration) methods and the anticholinergic property was predicted by inhibition of acetylcholinesterase (AChE). Acetohydroxamic acid was determined as the main phenolic compound with the highest amount in the flower extract. Also, quercetin, myricetin, fumaric acid, vanillic acid, ellagic acid, 4-hydroxybenzoic acid, salicylic acid, caffeic acid, kaempferol, butein, protocatechic acid, catechin hydrate, oleuropein and other components were detected, respectively. The ethanolic extract of the plant has 29.41% DPPH radical scavenging activity, 20.59% ABTS radical scavenging activity, and also moderate metal reduction potential. Also, the extract showed an inhibition effect on the AChE with IC50 values (0.18 mg mL(-1)). The ethanol extract of the plant showed antibacterial effect on Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium at different levels. These results suggested that extract of the flowers of A. esculentus extract might play a role in the treatment of some diseases with its antioxidant, anticholinergic, and antibacterial activity.