RESUMO
Alzheimer's disease (AD) is a devastating neurodegenerative condition provoking the loss of cognitive and memory performances. Despite huge efforts to develop effective AD therapies, there is still no cure for this neurological condition. Here, we review the main biological properties of Phycocyanobilin (PCB), accounting for its potential uses against AD. PCB, given individually or released in vivo from C-Phycocyanin (C-PC), acts as a bioactive-molecule-mediating antioxidant, is anti-inflammatory and has immunomodulatory activities. PCB/C-PC are able to scavenge reactive oxygen and nitrogen species, to counteract lipid peroxidation and to inhibit enzymes such as NADPH oxidase and COX-2. In animal models of multiple sclerosis and ischemic stroke, these compounds induce remyelination as demonstrated by electron microscopy and the expression of genes such as Mal up-regulation of and Lingo-1 down-regulation. These treatments also reduce pro-inflammatory cytokines levels and induce immune suppressive genes. PCB/C-PC protects isolated rat brain mitochondria and inactivate microglia, astrocytes and neuronal apoptosis mediators. Such processes are all involved in the pathogenic cascade of AD, and thus PCB may effectively mitigate the injury in this condition. Furthermore, PCB can be administered safely by oral or parenteral routes and therefore, could be commercially offered as a nutraceutical supplement or as a pharmaceutical drug.