Free radical-scavenging and anti-amyloidogenic properties of chicoric acid

Abstract

Chicoric acid (CA) is a type of hydroxycinnamic acid that has been regarded as a functional ingredient given its health benefits for the treatment of Alzheimer’s disease (AD). In this study, free radical-scavenging capacities of CA were enhanced in a dose-dependent manner, after which the protective effects of CA against amyloid-beta (Aβ)-induced neurotoxicity in SH-SY5Y cells was investigated. CA suppressed Aβ25–35-induced increase in the production of reactive oxygen species. Stimulation with Aβ25–35 enhanced the protein expression of β-secretase and presenilin proteins, which were subsequently inhibited by CA. CA also affected the levels of low-density lipoprotein receptor-related protein-1 and receptor for advanced glycation endproducts, both of which are related to blood–brain barrier function. Furthermore, Aβ exposition downregulated insulin-degrading enzyme and neprilysin protein expressions, which were reversed by CA. Overall, the results suggest that CA may protect against Aβ-induced neurotoxicity via modulating Aβ generation and transportation.