Title:Molecular Targets of Tannic Acid in Alzheimer's Disease
Volume: 14
Issue: 8
Author(s): Nady Braidy*, Bat-Erdene Jugder, Anne Poljak, Tharusha Jayasena, Seyed Mohammad Nabavi, Perminder Sachdev and Ross Grant*
Affiliation:
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney,Australia
- Sydney Medical School, University of Sydney, Sydney,Australia
Keywords:
Tannic acid, Alzheimer’s disease, Aβ pathology, tau, β-secretase, neurons.
Abstract: Tannic acid (TA) is a naturally occurring plant-derived polyphenol found in several herbaceous
and woody plants, including legumes, sorghum, beans, bananas, persimmons, rasberries, wines
and a broad selection of teas. Clinically, TA has strong antioxidant/free radical scavenging, antiinflammatory,
anti-viral/bacterial, and anti-carcinogenic properties. While the aetiology of Alzheimer’s
disease (AD) remains unclear, this complex multifactorial neurodegenerative disorder remains the most
common form of dementia, and is a growing public health concern worldwide. The neuroprotective effects
of TA against AD have been shown in several in vitro and in vivo models of AD. Apart from its
potent antioxidant and anti-inflammatory roles, evidence suggests that TA is also a natural inhibitor of
β-secretase (BACE1) activity and protein expression. BACE1 is the primary enzyme responsible for the
production and deposition of Aβ peptide. TA also destabilises neurotoxic amyloid beta (Aβ) fibrils in
vitro. Apart from its effects on the Aβ cascade, TA can also inhibit the in vitro aggregation of tau peptide,
a core component of intracellular neurofibrillary tangles (NFTs). This review summarizes the relevance
of TA and TA-related vegetable extracts (tannins) in the pathogenesis of AD and its enzymatic
targets. It also highlights the significance of TA as an important lead compound against AD.