Effects of a Standardized Phenolic-Enriched Maple Syrup Extract on ?-Amyloid Aggregation, Neuroinflammation in Microglial and Neuronal Cells, and ?-Amyloid Induced Neurotoxicity in Caenorhabditis elegans.

ABSTRACT: Published data supports the neuroprotective effects of several phenolic-containing natural products, including certain fruit, berries, spices, nuts, green tea, and olive oil. However, limited data are available for phenolic-containing plant-derived natural sweeteners including maple syrup. Herein, we investigated the neuroprotective effects of a chemically standardized phenolic-enriched maple syrup extract (MSX) using a combination of biophysical, in vitro, and in vivo studies. Based on biophysical data (Thioflavin T assay, transmission electron microscopy, circular dichroism, dynamic light scattering, and zeta potential), MSX reduced amyloid ?1-42 peptide (A?1-42) fibrillation in a concentration-dependent manner (50-500 ?g/mL) with similar effects as the neuroprotective polyphenol, resveratrol, at its highest test concentration (63.5?% at 500 ?g/mL vs. 77.3?% at 50 ?g/mL, respectively). MSX (100 ?g/mL) decreased H2O2-induced oxidative stress (16.1?% decrease in ROS levels compared to control), and down-regulated the production of lipopolysaccharide (LPS)-stimulated inflammatory markers (22.1, 19.9, 74.8, and 87.6?% decrease in NOS, IL-6, PGE2, and TNF? levels, respectively, compared to control) in murine BV-2 microglial cells. Moreover, in a non-contact co-culture cell model, differentiated human SH-SY5Y neuronal cells were exposed to conditioned media from BV-2 cells treated with MSX (100 ?g/mL) and LPS or LPS alone. MSX-BV-2 media increased SH-SY5Y cell viability by 13.8?% compared to media collected from LPS-BV-2 treated cells. Also, MSX (10 ?g/mL) showed protective effects against A?1-42 induced neurotoxicity and paralysis in Caenorhabditis elegans in vivo. These data support the potential neuroprotective effects of MSX warranting further studies on this natural product.

SUBMITTER: Ma H 

PROVIDER: S-EPMC5819752 | biostudies-other | 2016 Nov

REPOSITORIES: biostudies-other