A Systematic Strategy for Discovering a Therapeutic Drug for Alzheimer’s Disease and Its Target Molecule

Abstract

Natural medicines are attractive sources of leading compounds that can be used as interventions for neurodegenerative disorders. The complexity of their chemical components and undetermined bio-metabolism have greatly hindered both the use of natural medicines and the identification of their active constituents. Here, we report a systematic strategy for evaluating the bioactive candidates in natural medicines used for Alzheimer’s disease (AD). We found that Drynaria Rhizome could enhance memory function and ameliorate AD pathologies in 5XFAD mice. Biochemical analysis led to the identification of the bio-effective metabolites that are transferred to the brain, namely, naringenin and its glucuronides. To explore the mechanism of action, we combined the drug affinity responsive target stability with immunoprecipitation-liquid chromatography/mass spectrometry analysis, identifying the collapsin response mediator protein 2 protein as a target of naringenin. Our study indicates that biochemical analysis coupled with pharmacological methods can be used in the search for new targets for AD intervention.

Exploring the C‐Terminal Tail Dynamics: Structural and Molecular Perspectives into the Therapeutic Activities of Novel CRMP‐2 Inhibitors, Naringenin and Naringenin‐7‐O‐glucuronide, in the Treatment of Alzheimer's Disease

“…Apart from NAR, its 7-O-G derivative was reported to cross the BBB and exhibit possible CRMP-2 binding ability and anti-AD activities. [14] In other words, while NAR and NAR-7-O-G reportedly bind to CRMP-2, reduce phosphorylation and facilitate axonal growth, NAR-4-O-G did not show selective binding, despite being able to cross the BBB. These findings present an ample opportunity to comparatively investigate the structural implications of NAR and NAR-7-O-G binding to CRMP-2, coupled with the molecular basis of selectivity as common to both compounds ( Figure 1).…”

“…Although the possible binding activities of NAR and NAR-7-O-G have been previously demonstrated, [14] the mechanisms by which they reduce CRMP-2 phosphorylation with respect to the elimination of AD pathologies remain a subject of investigation till date. In our previous study, as a possible mechanism, we revealed the systemic perturbations of Tyr479, a target CRMP-2 phosphorylation site in the H19 helix, upon the binding of NAR.…”

“…Recently, there has been a paradigm shift towards the identification, characterization and use of natural compounds in disease treatment due to their low toxicity, diversity and broad-spectrum interactions. [14] According to previous studies, some antagonistic compounds have demonstrated the ability to bind and decrease CRMP-2 phosphorylation, either specifically or non-specifically. [14 -16] Most notable are certain phytochemical compounds found in Drynaria Rhizome (DR) extract, which enhanced memory function in mice models coupled with the improvement of cognition and learning.…”

“…In addition, their ability to move across the BBB presents them as attractive therapeutic molecules subject to further exploration. Moreover, previous Drug Affinity Responsive Target Stability (DARTS) studies identified CRMP-2 as a potential target for these compounds, [14,17] particularly NAR, which binds to CRMP-2 and induce conformational changes that alter its phosphorylative process. Apart from NAR, its 7-O-G derivative was reported to cross the BBB and exhibit possible CRMP-2 binding ability and anti-AD activities.…”

“…[21] In this study, molecular docking was employed as a tool to create a protein-ligand complex that is essential to investigate the interactions between NAR/NAR-7-O-G and CRMP-2, hence, representing the first step to determine the binding strength and affinity of both compounds with respect to their antagonistic functions as previously reported. [14] This technique also paves way for the use of other complementary approaches (such as MD simulations) to characterize the positioning and behavior/ activities of these compounds at the active site of CRMP-2.…”