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


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Biochemistry, University of Missouri, Columbia, MO, USA; Interdisciplinary Neuroscience Program, University of Missouri, Columbia, MO, USA; Center for Translational Neuroscience, University of Missouri, Columbia, MO, USA.
Agnes
A
Simonyi
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Biochemistry, University of Missouri, Columbia, MO, USA.
Zihong
Z
Chen
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Biochemistry, University of Missouri, Columbia, MO, USA.
Jinghua
J
Jiang
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Interdisciplinary Neuroscience Program, University of Missouri, Columbia, MO, USA; Center for Translational Neuroscience, University of Missouri, Columbia, MO, USA.
Yijia
Y
Zong
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Interdisciplinary Neuroscience Program, University of Missouri, Columbia, MO, USA; Center for Translational Neuroscience, University of Missouri, Columbia, MO, USA.
Dennis Y
DY
Chuang
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Interdisciplinary Neuroscience Program, University of Missouri, Columbia, MO, USA; Center for Translational Neuroscience, University of Missouri, Columbia, MO, USA; Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, MO, USA.
Zezong
Z
Gu
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Animal Sciences, University of Missouri, Columbia, MO, USA.
Chi-Hua
CH
Lu
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Animal Sciences, University of Missouri, Columbia, MO, USA.
Kevin L
KL
Fritsche
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Chemistry, University of Missouri, Columbia, MO, USA.
C Michael
CM
Greenlief
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Veterinary Medical Diagnostic Laboratory, University of Missouri, Columbia, MO, USA.
George E
GE
Rottinghaus
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; University of Missouri Southwest Research Center, Mt. Vernon, MO, USA.
Andrew L
AL
Thomas
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Biochemistry, University of Missouri, Columbia, MO, USA; Department of Animal Sciences, University of Missouri, Columbia, MO, USA.
Dennis B
DB
Lubahn
MU Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA; Department of Biochemistry, University of Missouri, Columbia, MO, USA; Interdisciplinary Neuroscience Program, University of Missouri, Columbia, MO, USA; Center for Translational Neuroscience, University of Missouri, Columbia, MO, USA; Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, MO, USA. Electronic address: sung@missouri.edu.
Grace Y
GY
Sun
D000818:Animals; D000872:Anthocyanins / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D017628:Microglia / Q000187:drug effects* / Q000276:immunology; D009569:Nitric Oxide / Q000096:biosynthesis; D010636:Phenols / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D011794:Quercetin / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D027923:Sambucus / Q000737:chemistry*
D000872:Anthocyanins; D008070:Lipopolysaccharides; D010636:Phenols; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D011794:Quercetin
Elderberry; Lipopolysaccharide; Microglia; Nitric oxide; Quercetin; Reactive oxygen species