Preliminary investigation on the effect of methanol leaf extract of Duranta repens on enzymes of cholinergic and monoaminergic systems critical to neurodegeneration in rats in vitro

Purpose: To evaluate the neurological effects of Duranta repens leaf extract by assessing its impact on monoamine oxidase-B (MAO-B) and acetylcholinesterase (AchE). Methods: Rat brain homogenates were used as enzyme sources. The activity of MAO-B was determined spectrophotometrically using a kinetic method based on benzylamine as substrate, while the ability of the extract to inhibit AchE activity was assessed using enzyme-linked immunosorbent assay (ELISA). Results: Compared to the standard drug (donepezil) the extract demonstrated high potency (IC50 = 9.30 mg/dL for the extract and 36.90 mg/dL for donepezil) in inhibiting AchE activity. Similarly, it exhibited a strong inhibitory effect against MAO-B (IC50 = 2.45 mg/dL for the extract and 11.50 mg/dL for donepezil). Conclusion: The findings suggest that D. repens leaf extract has significant potential in reducing neuron loss. Further investigations to identify the specific phytoconstituents responsible for the inhibitory effects of the extract on MAO and AchE would be required.