In vitro evaluation of monoamine oxidase and acetylcholinesterase enzyme activities of Capparis cartilaginea Decne

The genus Capparis is recognised for its neuroprotective potential; however, the biological activity of Capparis cartilaginea Decne. (C. cartilaginea) remains insufficiently explored. This study evaluated the in vitro inhibitory activity of the combined fractions of C. cartilaginea leaves and their isolated flavonoids against monoamine oxidase A (MAO-A) and B (MAO-B) using liver and brain mitochondrial preparations. The fractions inhibited both isoforms in a concentration-dependent manner, with the most pronounced MAO-B inhibition observed in liver mitochondria (97.9% at 2.0 mg/mL), exceeding the activity of the reference inhibitor deprenyl (91.8%). Among the isolated flavonoids, narcissin exhibited the strongest MAO-B inhibition (Ki = 0.34 ± 0.06 μmol/L), followed by rutin, manghaslin, and nicotiflorin. No significant acetylcholinesterase (AChE) inhibition was detected. These findings suggest that C. cartilaginea and its flavonoid constituents represent promising leads for the development of MAO-B-targeted neuroprotective agents.