Marine Natural Products, Multitarget Therapy and Repurposed Agents in Alzheimer's Disease

Alzheimer's disease (AD) is a multifactorial disease characterized by the presence of amyloid plaques, neurofibrillary tangles, and nerve cell death that affects, mainly, older people. After decades of investigation, the search for an efficacious treatment for AD remains and several strategies can be and are being employed in this journey. In this review, four of the most promising strategies, alongside with its most promising agents under investigation or development are highlighted. Marine natural products (MNP) are a source of unique chemical structures with useful biological activities for AD treatment. One of the most promising compounds, a marine-derived acidic oligosaccharide (GV-971) just passed phase III clinical trials with a unique mechanism of action. Combination therapy and multitargeted-directed ligand therapy (MTDL) are also two important strategies, with several examples in clinical trials, based on the belief that the best approach for AD is a therapy capable of modulating multiple target pathways. Drug repurposing, a strategy that requires a smaller investment and is less time consuming, is emerging as a strong contender with a variety of pharmacological agents resurfacing in an attempt to identify a therapeutic candidate capable of modifying the course of this disease.