Olax subscorpioidea prevented scopolamine-induced memory impairment through the prevention of oxido-inflammatory damage and modulation of cholinergic transmission.

Ethnopharmacological Relevance: Olax subscorpioidea oliv. is a shrub plant of the Olacaceae family with reported usage in ethnomedicine as a nootropic agent for the management of Alzheimer's-like dementia.

Aim: The aim of this study is to investigate the nootropic potential of methanol extract of Olax subscorpioidea (MEOS) in scopolamine-induced Alzheimer's-like dementia.

Materials And Methods: Thirty male mice, assigned into six groups (n = 8), were used for this study. Group, I received distilled water, group II received scopolamine (1 mg/kg, i.p.), groups iii-v received 25, 50, and 100 mg/kg, p.o. of MEOS and scopolamine (1 mg/kg/i.p.), and group vi received donepezil 5 mg/kg, p.o.and scopolamine (1 mg/kg, i.p.). The animals were pre-treated with MEOS and Donepezil for 14 days, and scopolamine from the 8th to 14th day. Followed by cognitive, oxidative stress, neuroinflammation, and histology assessments.

Results: 100 mg/kg MEOS significantly reduced transfer latency and increased discrimination index in the elevated plus maze and novel object recognition test cognitive assessments. 100 mg/kg MEOS, significantly reduced oxidative stress, protect endogenous antioxidants, suppressed neuroinflammation, and acetylcholinesterase (ACHE) activity. The histomorphometry study of the hippocampus revealed that MEOS prevented extensive pyknosis, karyolysis, chromatolysis, and loss of hippocampal neurons that accompanied scopolamine treatment.

Conclusion: MEOS protected against Alzheimer's-like dementia via the suppression of neuroinflammation and oxidative stress associated with scopolamine-induced amnesic behavior.