Essential Oils as Treatment Strategy for Alzheimer's Disease: Current and Future Perspectives.

Alzheimer's disease is a multifarious neurodegenerative disease that causes cognitive impairment and gradual memory loss. Several hypotheses have been put forward to postulate its pathophysiology. Currently, few drugs are available for the management of Alzheimer's disease and the treatment provides only symptomatic relief. Our aim is to review the relevant in vitro, in vivo, and clinical studies focused toward the potential uses of essential oils in the treatment of Alzheimer's disease. Scientific databases such as PubMed, ScienceDirect, Scopus, and Google Scholar from April 1998 to June 2018 were explored to collect data. We have conducted wide search on various essential oils used in different models of Alzheimer's disease. Out of 55 essential oils identified for Alzheimer's intervention, 28 have been included in the present review. A short description of in vivo studies of 13 essential oils together with clinical trial data of Salvia officinalis, Salvia lavandulifolia, Melissa officinalis, Lavandula angustifolia, and Rosmarinus officinalis have been highlighted. In vitro studies of remaining essential oils that possess antioxidant and anticholinesterase potential are also mentioned. Our literary survey revealed encouraging results regarding the various essential oils being studied in preclinical and clinical studies of Alzheimer's disease with significant effects in modulating the pathology through anti-amyloid, antioxidants, anticholinesterase, and memory-enhancement activity.