Phytochemicals for the Improvement of Cognitive Function through Cholinergic Anti-inflammatory Pathway

Cognition is the interdisciplinary scientific study of the brain and its processes, which include the intelligence and behaviour of living beings. Humans are generally equipped with a capacity for cognitive function at birth, but some conditions, such as infection and oxidative stress, lead to impaired cognition. Herbal drugs/phytochemicals are utilized in order to get better cognitive functions and alleviate symptoms associated with impaired cognition function. Yet, there still remains no complete cure for cognitive dysfunction, with most current treatments offering symptomatic relief. This has prompted us to review the importance of phytochemicals and the mechanism by which they may augment cognitive functions. For the present review, a comprehensive literature search was conducted by referring to the research and review articles published by authentic journals and available on web databases. Indeed, numerous plant-based drugs have traditionally been used to combat learning and memory-associated deficits, but many available drugs are potentially toxic alkaloidal cholinesterase inhibitors. Findings by various researchers exhibited that many plant-based drugs act through a different mechanisms, such as inhibition of acetylcholinesterase (AChE), activation of antioxidant defence, and augmenting the blood flow to the brain. The aim of the present review is to highlight the importance of phytochemicals in the modulation of cholinergic anti-inflammatory pathways (CAP) in neurodegenerative disease. For this, available literature was critically analysed. Through a comprehensive review of the recent research findings, this article concludes that medicinal plants serve as reservoirs of various successful drugs for cognition improvement, which belong to different classes of secondary metabolites. We also observe that phytochemicals can modulate cholinergic anti-inflammatory pathways (CAP) in neurodegenerative disease, although the mechanism of action of most natural/herbal extracts and their compounds is not yet fully explored.