Evaluation of Polyphenol Anthocyanin-Enriched Extracts of Blackberry, Black Raspberry, Blueberry, Cranberry, Red Raspberry, and Strawberry for Free Radical Scavenging, Reactive Carbonyl Species Trapping, Anti-Glycation, Anti-?-Amyloid Aggregation, and Microglial Neuroprotective Effects.

ABSTRACT: Glycation is associated with several neurodegenerative disorders, including Alzheimer's disease (AD), where it potentiates the aggregation and toxicity of proteins such as ?-amyloid (A?). Published studies support the anti-glycation and neuroprotective effects of several polyphenol-rich fruits, including berries, which are rich in anthocyanins. Herein, blackberry, black raspberry, blueberry, cranberry, red raspberry, and strawberry extracts were evaluated for: (1) total phenolic and anthocyanins contents, (2) free radical (DPPH) scavenging and reactive carbonyl species (methylglyoxal; MGO) trapping, (3) anti-glycation (using BSA-fructose and BSA-MGO models), (4) anti-A? aggregation (using thermal- and MGO-induced fibrillation models), and, (5) murine microglia (BV-2) neuroprotective properties. Berry crude extracts (CE) were fractionated to yield anthocyanins-free (ACF) and anthocyanins-enriched (ACE) extracts. The berry ACEs (at 100 ?g/mL) showed superior free radical scavenging, reactive carbonyl species trapping, and anti-glycation effects compared to their respective ACFs. The berry ACEs (at 100 ?g/mL) inhibited both thermal- and MGO-induced A? fibrillation. In addition, the berry ACEs (at 20 ?g/mL) reduced H?O?-induced reactive oxygen species production, and lipopolysaccharide-induced nitric oxide species in BV-2 microglia as well as decreased H?O?-induced cytotoxicity and caspase-3/7 activity in BV-2 microglia. The free radical scavenging, reactive carbonyl trapping, anti-glycation, anti-A? fibrillation, and microglial neuroprotective effects of these berry extracts warrant further in vivo studies to evaluate their potential neuroprotective effects against AD.

SUBMITTER: Ma H 

PROVIDER: S-EPMC5855683 | biostudies-other | 2018 Feb

REPOSITORIES: biostudies-other