Plant Natural Products for Cognitive Impairment: A Review of the preclinical Evidence

Cognitive impairment (CI) is a highly complex central nervous system disorder commonly associated with aging. This condition is characterized by a progressive reduction of cognitive function. Modern synthetic drugs have been granted clinical approval for the treatment of CI. However, most of these drugs show insufficient efficacy and undesired side effects in clinical practice. Alternative drugs for CI are required to overcome these problems. Medicinal plants and their bioactive molecules remain the main sources for new drug discovery, and they have the potential to be developed as novel drugs for CI. Many reports have demonstrated the activity of other medicinal plants and their active metabolites for CI in various experiments. In this article, we summarize the potency of plant natural compounds for CI, focusing on cognitive-enhancing activity in amnesic-animal experimental models. We also discuss the pathophysiological basis of CI and propose potential therapeutic targets of CI using plant natural compounds. Additionally, we highlight promising natural compounds for CI and discuss their possible mechanisms of action. This review provides insight into the effort of discovery and development of pharmaceutical agents derived from medicinal plants to combat CI. © 2021 Helmi Helmi et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).