Plant Terpenoids as the Promising Source of Cholinesterase Inhibitors for Anti-AD Therapy.

Plant-derived terpenes are the prolific source of modern drugs such as taxol, chloroquine and artemisinin, which are widely used to treat cancer and malaria infections. There are research interests in recent years on terpene-derived metabolites (diterpenes, triterpenes and sesquiterpenes), which are believed to serve as excellent cholinesterase inhibitors. As cholinesterase inhibitors are the current treatment for Alzheimer's disease, terpene-derived metabolites will have the potential to be involved in the future drug development for Alzheimer's disease. Hence, a bibliographic search was conducted by using the keywords "terpene", "cholinesterase" and "Alzheimer's disease", along with cross-referencing from 2011 to 2020, to provide an overview of natural terpenes with potential anticholinesterase properties. This review focuses on the extraction, chemical structures and anti-cholinesterase mechanisms of terpenes, which support and encourage future research on drug discovery and development in treating Alzheimer's disease.