Neurobehavioral and Neurochemical Effect of Azadirachta Indica on Stress Induced Anxiety in Mice

Abstract

Background: Anxiety disorders represent a major global mental health burden characterized by exaggerated fear and stress responses. Neurochemical imbalances involving GABA, serotonin, dopamine, and noradrenaline underlie these conditions. Synthetic anxiolytics such as benzodiazepines and SSRIs, though effective, often produce adverse effects. Hence, herbal alternatives like Azadirachta indica (Neem) are being explored for safer therapy. Objective: To evaluate the anxiolytic and neuroprotective potential of ethanolic extract of Azadirachta indica leaves in stress induced anxiety in mice, with emphasis on behavioral and biochemical correlates. Methods: Leaves of A. indica were authenticated and extracted using Soxhlet apparatus with ethanol. Phytochemical screening confirmed the presence of alkaloids, flavonoids, phenols, tannins, and carbohydrates. Swiss albino mice were divided into five groups: positive control, negative control, standard (diazepam 4 mg/kg), and test groups (100 mg/kg and 200 mg/kg extract). Anxiety was induced by immobilization stress. Behavioral assays included Elevated Plus Maze, Light–Dark Box, Open Field Test, and Actophotometer. Biochemical parameters—plasma nitrate (Griess assay), iNOS, AChE, and GABA were quantified, and histopathological evaluation of brain tissue was performed. Results: The extract produced dose dependent anxiolytic effects, increasing time spent in open arms and light zones while reducing locomotor activity. Biochemically, A. indica lowered plasma nitrate and AChE levels, elevated iNOS and GABA concentrations, and restored neuronal morphology. The 200 mg/kg dose showed results comparable to diazepam, confirming modulation of nitric oxide and GABAergic pathways. Conclusion: The ethanolic extract of Azadirachta indica exhibits significant anxiolytic and neuroprotective activity through antioxidant and neurotransmitter modulating mechanisms. These findings validate its traditional use and suggest its potential as a natural alternative for managing anxiety disorders.