Exploring the therapeutic utility of apocynin in multifactorial neurodegenerative Alzheimer’s disease in a preclinical animal model

Abstract

Aim:Alzheimer’s disease (AD) devastates learning and memory, the defining faculties of the human species. Extracellular amyloid beta (Aβ) deposits and intracellular hyperphosphorylated tau are hallmarks of AD pathology. The exact cause of the disease remains unknown, but a lot of data support AD to be a multifactorial disease. Given the central roles of oxidative stress and neuroinflammation in AD pathogenesis, apocynin, a potent antioxidant and anti-inflammatory agent, was selected for investigation. Apocynin is an aromatic ketone, a naturally occurring methoxy-substituted catechol known to possess numerous biological activities, namely anti-oxidant, anti-inflammatory, etc. The present study assessed apocynin’s potential against an Aβ_1–42-induced sporadic AD rat model.
Methods:In the present study, Wistar rats were subjected to intrahippocampal administration of 200 µmol/L of Aβ_1–42 peptide in right hemisphere. Further were treated with apocynin 50, 150, and 300 mg/kg per orally for 28 days. The study examined the neurobehavioral aspects using the Barnes Maze test (BMT). Hippocampus was examined for the antioxidant (SOD, GSH, catalase, and LPO), inflammatory (TNF-α) parameters, RAGE, caspase-3, PGC-1α expression, and IHC analysis for Aβ load, adult hippocampal neurogenesis markers (BDNF, Ki67, DCX, NeuN), at the end of 28 days.
Results:Apocynin administration demonstrated significant improvement in cognitive functions, diminished oxidative stress and inflammatory response triggered by Aβ administration. Apocynin additionally instigated adult hippocampal neurogenesis and triggered mitochondrial biogenesis.
Conclusions: These primary results strongly advocate apocynin’s nootropic, neurotrophic and neuroprotective potential in an Aβ induced neurotoxicity in rats.

Keywords

Alzheimer’s / apocynin / PGC-1α / DCX / Ki-67 / caspase / neurogenesis

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