The “Aged Garlic Extract” (AGE) and One of its Active Ingredients S-Allyl-LCysteine (SAC) as Potential Preventive and Therapeutic Agents for Alzheimer's Disease (AD)

Abstract

Alzheimer's disease (AD) is the most common form of dementia in the older people and 7(th) leading cause of death in the United States. Deposition of amyloid-beta (Aβ) plaques, hyperphosphorylation of microtubule associated protein tau (MAPT), neuroinflammation and cholinergic neuron loss are the major hallmarks of AD. Deposition of Aβ peptides, which takes place years before the clinical onset of the disease can trigger hyperphophorylation of tau proteins and neuroinflammation, and the latter is thought to be primarily involved in neuronal and synaptic damage seen in AD. To date, four cholinesterase inhibitors or ChEI (tacrine, rivastigmine, donepezil and galantamine) and a partial NMDA receptor antagonist (memantine) are the only approved treatment options for AD. However, these drugs fail to completely cure the disease, which warrants a search for newer class of targets that would eventually lead to effective drugs for the treatment of AD. In addition to selected pharmacological agents, botanical and medicinal plant extracts are also being investigated. Apart from its culinary use, garlic (Allium sativum) is being used to treat several ailments like cancer and diabetes. Herein we have discussed the effects of a specific 'Aged Garlic Extract' (AGE) and one of its active ingredients, S-allyl-L-cysteine (SAC) in restricting several pathological cascades related to the synaptic degeneration and neuroinflammatory pathways associated with AD. Thus, based on the reported positive preliminary results reviewed herein, further research is required to develop the full potential of AGE and/or SAC into an effective preventative strategy for AD.