Inhibition of microglial activation by elderberry extracts and its phenolic components.

Agnes Simonyi, Zihong Chen, Jinghua Jiang, Yijia Zong, Dennis Y Chuang, Zezong Gu, Chi-Hua Lu, Kevin L Fritsche, C Michael Greenlief, George E Rottinghaus, Andrew L Thomas, Dennis B Lubahn, Grace Y Sun

Index: Life Sci. 128 , 30-8, (2015)

Full Text: HTML

Abstract

Elderberry (Sambucus spp.) is one of the oldest medicinal plants noted for its cardiovascular, anti-inflammatory, and immune-stimulatory properties. In this study, we investigated the anti-inflammatory and anti-oxidant effects of the American elderberry (Sambucus nigra subsp. canadensis) pomace as well as some of the anthocyanins (cyanidin chloride and cyanidin 3-O-glucoside) and flavonols (quercetin and rutin) in bv-2 mouse microglial cells.The bv-2 cells were pretreated with elderberry pomace (extracted with ethanol or ethyl acetate) or its anthocyanins and flavonols and stimulated by either lipopolysaccharide (LPS) or interferon-γ (IFNγ). Reactive oxygen species (ROS) and nitric oxide (NO) production (indicating oxidative stress and inflammatory response) were measured using the ROS detection reagent DCF-DA and the Griess reaction, respectively.Analysis of total monomeric anthocyanin (as cyanidin 3-O-glucoside equivalents) indicated five-fold higher amount in the freeze-dried ethanol extract as compared to that of the oven-dried extract; anthocyanin was not detected in the ethyl acetate extracts. Elderberry ethanol extracts (freeze-dried or oven-dried) showed higher anti-oxidant activities and better ability to inhibit LPS or IFNγ-induced NO production as compared with the ethyl acetate extracts. The phenolic compounds strongly inhibited LPS or IFNγ-induced ROS production, but except for quercetin, they were relatively poor in inhibiting NO production.These results demonstrated differences in anti-oxidative and anti-inflammatory effects of elderberry extracts depending on solvents used. Results further identified quercetin as the most active component in suppressing oxidative stress and inflammatory responses on microglial cells.Copyright © 2015 Elsevier Inc. All rights reserved.