Lamiaceae Family Plants as a Potential Anticholinesterase Source in the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is one of the most common and progressive neurodegenerative disorders with dementia in the world. The precise causes of AD are not fully understood yet, although several important features of its pathophysiology are well described. Current AD treatment is symptomatic and is mainly, but not exclusively, focused on the inhibition of cholinesterases (ChEs). There are four cholinesterase inhibitors approved by the U.S. Food and Drug Administration (FDA): tacrine, donepezil, rivastigmine, and galantamine. Among them, galantamine is a natural drug, and rivastigmine is a derivative of the natural drug physostigmine. In addition, only an NMDA (N-methyl-D-aspartate) receptor antagonist, memantine, is also approved by the FDA in the treatment of patients with moderate to severe AD. However, none of them provides a satisfactory treatment for Alzheimer's disease, and studies are still going on to find new potential drugs from both synthetic chemicals and natural sources. In this review, studies on the discovery of new cholinesterase inhibitors from natural sources, particularly from Lamiaceae family plants were evaluated, and a number of terpenoids and phenolics/flavonoids isolated are presented as potential drugs in the treatment of Alzheimer's disease.