Neuroprotective Effects of Niranthin against Scopolamine-Induced Cognitive Impairment: Behavioral, Biochemical, and Molecular Docking Studies

Abstract

Ethnopharmacological relevance: The ayurvedic and ethnobotanical literature indicates use of Phyllanthus to treat physical sensations, somatic signs of anxiety and CNS disorders. Niranthin, a lignan isolated from the aerial parts of the plant Phyllanthus amarus, exhibits a wide spectrum of pharmacological activities. Aim of the study: This investigation was intended to explore the anti-amnesic/ anti-Alzheimer potential of Niranthin and forecast possible role of similar class of compounds. Materials and methods: Niranthin was evaluated using established in vivo models, including the Morris Water Maze, Elevated Plus Maze, scopolamine-induced amnesia, and motor coordination tests. Its effect on cholinergic function was assessed through acetylcholinesterase inhibition. Molecular docking studies were performed to predict interactions with key Alzheimer’s disease targets, including acetylcholinesterase, butyrylcholinesterase, beta-secretase, tau protein kinase, and monoamine oxidases. Results: Niranthin significantly improved learning and memory in behavioral models and attenuated scopolamine-induced cognitive deficits. It demonstrated acetylcholinesterase inhibitory activity and showed potential involvement of the GABAergic system. Docking studies revealed strong binding affinity toward multiple targets associated with Alzheimer’s pathology. Additionally, Niranthin exhibited favorable physicochemical properties and predicted blood–brain barrier permeability Conclusion: The findings of present study suggest that Niranthin possesses promising multi-target neuroprotective properties against scopolamine-induced cognitive impairment. However, additional investigations including pharmacokinetic evaluation, chronic toxicity assessment, and validation in transgenic Alzheimer's disease models are required before therapeutic translation can be considered.