Title:Flavonoids in Neurodegeneration: Limitations and Strategies to Cross CNS Barriers
Volume: 23
Issue: 36
Author(s): Paula Branquinho Andrade, Clara Grosso, Patrícia Valentao and Joao Bernardo
Affiliation:
Keywords:
Flavonoids, brain-delivery, blood-brain-barrier, permeability, transporters, nano-carriers, neurodegeneration.
Abstract: The central nervous system (CNS) is a mythical target for drug delivery. There is
an ongoing debate over the brain accessibility of flavonoids, a group of plant-derived secondary
metabolites widely known by their multifarious bioactivities achieved by distinct
mechanisms. Recently, their applicability in the management of neurologic and psychiatric
disorders, such as Alzheimer’s and Parkinson’s diseases, and major depression, has received
particular attention. To reach their target, flavonoids must cross over the ultimate obstacle -
the blood-brain barrier - at pharmacologically effective concentrations. This review addresses
the low brain-bioavailability issue, based on in vitro and in vivo evidences. Besides
the lipophilic character of the flavonoids, their permeability will depend upon the role of
membrane transporters, especially those from the ABC superfamily. The enzymatic elements,
namely β-glucuro-nidase, can induce a transient deconjugation process and affect
permeability, as well. Novel drug delivery systems are successful strategies to overcome the
low bioavailability issue, and redirect the native forms to CNS-targets. This work bridges a
solid opinion over this hot topic of medicinal chemistry and natural products research.