Celastrus paniculatus oil ameliorates NF-KB mediated neuroinflammation and synaptic plasticity in the scopolamine-induced cognitive impairment rat model

Abstract

Background and aim: Traditionally, Celastrus paniculatus Willd. (CP) oil has been utilized as a tranquilizer and memory enhancer. The present study investigated the neuropharmacological activity and efficacy of CP oil in ameliorating scopolamine-induced cognitive impairment in rats.

Experimental procedure: Cognitive deficiency was induced in rats by administration of scopolamine (2 mg/kg intraperitoneal injection) for a period of 15 days. Donepezil served as a reference drug and CP oil was tested as both preventive and curative treatments. Animals' behaviour was assessed through the Morris water maze (MWM), novel object preference (NOR), and conditioned avoidance (CA) tests. Oxidative stress parameters, bioamine concentration (dopamine, noradrenaline, and 5-hydroxytryptamine), nerve growth factor (NGF), interleukin-6 (IL-6), nuclear factor kappa B (NF-кB), and tumor necrosis factor-alpha (TNFα) were estimated. Synaptophysin immunohistochemistry was performed.

Results: Our results showed that CP oil ameliorated behavioural deficits. It reduced latency to find a hidden platform in MWM. Reduced novel object exploration time and discrimination index (p < 0.05) in the NOR. Reduced step-down latency and normalized conditioned avoidance response (p < 0.001) in the CA test. CP oil increased dopamine, serotonin, norepinephrine, superoxide dismutase (SOD), glutathione, and catalase levels. It decreased malondialdehyde (MDA), acetylcholinesterase activity, IL-6, NF-кB (P < 0.001), TNFα, and NGF levels. Treatment showed approximate typical reactivity to synaptophysin.

Conclusion: Our data is suggestive that CP oil treatment improves behavioural test outcomes, increases biogenic amine concentration, and decreases acetylcholinesterase activity, and neuroinflammatory biomarkers. It also restores synaptic plasticity. It thus improves cognitive functions against scopolamine-induced amnesia in rats by improving cholinergic function.

Keywords: Acetylcholinesterase activity; Alzheimer’s disease; Biogenic amines; Cognition; Nerve growth factor; Neuroinflammation; Oxidative stress; Synaptophysin.