Differential Effects of Whole Red Raspberry Polyphenols and Their Gut Metabolite Urolithin A on Neuroinflammation in BV-2 Microglia

Authors

Ashley Mulcahy Toney, University of Nebraska - LincolnFollow
Mahaa Albusharif, University of Nebraska - LincolnFollow
Duncan Works, University of Nebraska-LincolnFollow
Luke Polenz, University of Nebraska - LincolnFollow
Stacie Schlange, University of Nebraska-LincolnFollow
Virginia Chaidez, University of Nebraska - LincolnFollow
Amanda E. Ramer-Tait, University of Nebraska - LincolnFollow
Soonkyu Chung, University of Nebraska-Lincoln & University of Massachusetts AmherstFollow

Date of this Version

2021

Citation

Toney, A.M.; Albusharif, M.; Works, D.; Polenz, L.; Schlange, S.; Chaidez, V.; Ramer-Tait, A.E.; Chung, S. Differential Effects of Whole Red Raspberry Polyphenols and Their Gut Metabolite Urolithin A on Neuroinflammation in BV-2 Microglia. Int. J. Environ. Res. Public Health 2021, 18, 68. https://dx.doi.org/10.3390/ ijerph18010068

Comments

2020 by the authors.

Abstract

Whole red raspberry polyphenols (RRW), including ellagic acid, and their gut-derived metabolite, urolithin A (UroA), attenuate inflammation and confer health benefits. Although results from recent studies indicate that polyphenols and UroA also provide neuroprotective effects, these compounds differ in their bioavailability and may, therefore, have unique effects on limiting neuroinflammation. Accordingly, we aimed to compare the neuroprotective effects of RRW and UroA on BV-2 microglia under both 3 h and 12 and 24 h inflammatory conditions. In inflammation induced by lipopolysaccharide (LPS) and ATP stimulation after 3 h, RRW and UroA suppressed pro- inflammatory cytokine gene expression and regulated the JNK/c-Jun signaling pathway. UroA also reduced inducible nitric oxide synthase gene expression and promoted M2 microglial polarization. During inflammatory conditions induced by either 12 or 24 h stimulation with LPS, UroA—but not RRW—dampened pro-inflammatory cytokine gene expression and suppressed JNK/c-Jun signaling. Taken together, these results demonstrate that RRW and its gut-derived metabolite UroA differentially regulate neuroprotective responses in microglia during 3 h versus 12 and 24 h inflammatory conditions.