Evaluation of the Neuroprotective Activity of Ethanolic Leaf Extract of Smilax glabra Roxb against Scopolamine Induced Dementia in Wistar Rats

Abstract

Background: Alzheimer’s Disease (AD) is a common neurological condition characterised by progressive deficits in cognition, memory, and behavior. Its pathology involves cholinergic dysfunction, neuronal loss, and oxidative damage. Existing drugs provide only symptomatic relief without stopping progression, spurring interest in plants with antioxidant and neuroprotective effects. Smilax glabra Roxb., a traditional remedy, shows promise against inflammation and oxidative stress. Objectives: This study assessed the neuroprotective effects of ethanolic root extract from Smilax glabra Roxb. (SGE) in scopolamine-induced dementia using Wistar rats. Materials and Methods: Rats (5 groups) included normal control, scopolamine-induced dementia (2 mg/kg i.p.), rivastigmine standard, and three Smilax glabra Roxb. doses (oral, 30 days). Behavioral evaluations on days 15 and 30 used rotarod (motor coordination), elevated plus maze (anxiety), open field (exploration), closed chamber, and Morri’s water maze (spatial memory). Brains were examined for total protein, antioxidant enzymes (catalase, superoxide dismutase), Acetylcholinesterase (AChE), lipid peroxidation, and histopathology. Results: Smilax glabra Roxb. significantly alleviated scopolamine-induced impulsivity, boosted home-return latency, curbed anxiety, and enhanced coordination. It elevated catalase, superoxide dismutase, and brain protein levels; lowered lipid peroxidation and AChE activity. Histology showed intact neurons and less degeneration in SGE groups. Conclusion: Smilax glabra Roxb. demonstrates neuroprotection in this dementia model via reduced oxidative stress, cholinesterase inhibition, and neuronal preservation, suggesting its value as a natural AD therapy candidate needing clinical validation.