Zingiber officinale ameliorates Alzheimer's disease and Cognitive Impairments: Lessons from preclinical studies

Alzheimer's disease (AD) is a neurodegenerative condition mostly communal in people of advanced years accompanying various dysfunctionalities especially cognitive impairments. A number of cellular damages, such as amyloid-beta aggregation, tau protein hyperphosphorylation, some neurotransmitter imbalances, apoptosis, oxidative stress, and inflammatory responses are responsible for AD incidence. As a reason for inadequate efficacy, side effects, and pharmacokinetic problems of conventional drugs used for AD, the discovery of novel therapeutic agents with multi-targeted potential is desirable. Protective properties of phytochemicals combat numerous diseases and their vast acceptance and demand in human beings encouraged scientists to assess their effective activities. Zingiber officinale, gingerol, shogaol, and borneol were evaluated against memory impairments. Online databases including; Web of Science, Scopus, Embase, Pubmed, ProQuest, ScienceDirect, and Cochrane Library were searched until 3th February 2020. In vitro, in vivo, and clinical studies are included after screening their eligibility. Mostly interventive mechanisms such as; oxidative stress, neuroinflammation, and apoptosis are described. Correlation between the pathogenesis of AD and signaling pathways is explicated. Results and scores of cognition measurements are clarified due to in vivo studies and clinical trials. Some traditional aspects of consuming ginger in AD are also mentioned in the present review. In accumulation ginger and its components possess great potency for improving and abrogating memory dysfunctions but conducting further studies to evaluate their pharmacological and pharmaceutical aspects is required.