Cognition-Enhancing Effect of Artemisia Pallens Leaf Extract Against Scopolamine-Induced Amnesia in Rats

Abstract

Background: Cognitive impairment is a major feature of neurodegenerative disorders, with scopolamine widely used to induce experimental amnesia. Plant-derived phytochemicals are increasingly explored as safer alternatives to synthetic nootropics. Objective: To evaluate the cognition-enhancing potential of methanolic leaf extract of Artemisia pallens against scopolamine-induced amnesia in Wistar rats. Methods: A. pallens leaves were extracted using a Soxhlet apparatus with 80% methanol. Phytochemical screening, total phenolic content (Folin-Ciocalteu method), and total flavonoid content (AlCl₃ method) were determined. Rats were divided into five groups: vehicle, scopolamine (2 mg/kg, i.p.), A. pallens extract (100 and 200 mg/kg, p.o.) + scopolamine, and piracetam (20 mg/kg, p.o.) + scopolamine. Cognitive performance was assessed using the Elevated Plus Maze paradigm, with transfer latency as the behavioural index. Results: Phytochemical analysis confirmed the presence of alkaloids, phenolics, tannins, proteins, and flavonoids. The extract showed high phenolic (71.53 ± 1.51 mg GAE/g) and flavonoid (59.36 ± 0.64 mg QE/g) content. Scopolamine significantly impaired cognition, while A. pallens extract produced dose-dependent reductions in transfer latency (−41.7% and −50.8% at 24 h; −47.0% and −56.2% at 48 h for 100 and 200 mg/kg, respectively). Piracetam showed the strongest effect (−55.1% at 24 h; −59.9% at 48 h). Conclusion: Artemisia pallens leaf extract exhibits significant cognition-enhancing activity, likely mediated by its phenolic and flavonoid constituents. It may represent a potential phytotherapeutic agent for managing memory deficits.