Evaluation of acetylcholinesterase and monoamine oxidase inhibitory activities of the aqueous extract and flavonoids of Capparis cartilaginea Decne

Capparis cartilaginea Decne . (Capparaceae) is a medicinal plant with a long history of use in traditional medicine. Despite its ethnopharmacological relevance, its neuropharmacological properties remain underexplored . In our previous work, seven glycosylated flavonoids were isolated and structurally elucidated from the aqueous leaf extract, including derivatives of kaempferol, quercetin, and isorhamnetin [ 1 ]. In the present study, the neuropharmacological potential of the aqueous extract and selected flavonoids was evaluated through the inhibition of acetylcholinesterase (AChE), monoamine oxidase A (MAO-A), and monoamine oxidase B (MAO-B), enzymes associated with neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. The aqueous extract exhibited no significant inhibitory activity against AChE at concentrations ranging from 0.005 to 0.5 mg/mL. In contrast, both the extract and isolated flavonoids showed concentration-dependent inhibition of MAO-A and MAO-B, with a markedly greater effect on MAO-B. The inhibition was observed in the range of 0.01 to 2 mg/mL. Based on their selective MAO-B inhibitory profiles, four flavonoids were selected for enzyme kinetics analysis: kaempferol-3- O -rutinoside (nicotiflorin), quercetin-3- O -rutinoside (rutin), quercetin 3-(2G-rhamnosylrutinoside) (manghaslin), and isorhamnetin-3- O -rutinoside (narcissin). These compounds demonstrated inhibition constants (Ki) in the nanomolar range, indicating potent and selective inhibition of MAO-B. These findings suggest potential pharmacological value and support further research into their application in neurological disorders. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany