Novel multi-target directed ligand-based strategies for reducing neuroinflammation in Alzheimer's disease

Alzheimer's disease (AD) is one of the most common causes of dementia. AD pathogenesis has been hypothesized to involve cholinergic deficits, amyloid-beta protein (Aβ) deposition, tau protein hyperphosphorylation, and chronic neuroinflammation. Many single-target drugs have gone through the various stages of pre-clinical and clinical development in an effort to cure AD; however, the current clinically approved drugs have only limited effects on the disease progression. With the accumulation of unsuccessful clinical trials using single-target drugs, multi-target directed ligand (MTDL) drug development is becoming more common. MTDLs incorporate two or more pharmacophores into a single drug molecule. This approach can alleviate side effects and lead to a better pharmacokinetic profile of the MTDL compared to two or more separate drugs representing respective single pharmacophores. This review discusses cathepsin B (CatB), dual specificity phosphatase 2 (DUSP2), and monoglycerol lipase (MAGL) as targets for MTDLs aimed at slowing down the neuroinflammatory component of neurodegenerative diseases. CatB, DUSP2 and MAGL inhibitors show promising preclinical anti-inflammatory effects in vivo and in vitro. Incorporating pharmacophores that inhibit these targets into MTDLs represents a promising avenue towards effective suppression of neuroinflammation associated with AD.