Rhizoma coptidis and berberine-induced activation of murine microglia N9 cells

Aims of the studyTo investigate the effect of water extract of Rhizoma coptidis (WEC) and berberine on the activation of murine microglia N9 cells and corresponding mechanism related to mitochondria.Materials and methodsPhagocytic activity of murine microglia N9 cells was measured by neutral red staining method after the cells were treated with various concentrations of WEC and alkaloids for 24 h. Flow cytometric analysis was performed to determine the level of intracellular ROS, Ca2+, and mitochondrial transmembrane potential (Δψ) after 87 μg/ml of WEC and 12.4 μg/ml of berberine treatment. Global changes of gene expression in WEC- and berberine-treated N9 cells were measured using cDNA microarray.ResultsWEC and berberine, but not palmatine and jatrorrhizine, enhanced phagocytic activity of murine N9 cells in a dose-dependent manner. Both of WEC and berberine stimulated free radical generation, enhanced mitochondrial Δψ and induced gene expression of Ndufab1, Cox6a2 and Atp5a1. However, a more significant phagocytic effect was observed for WEC. WEC, but not berberine, increased intracellular Ca2+ concentration. The gene expression of Atp5c1 was selectively up-regulated by WEC, while three genes of Uqcrq, Cox8b, and Atp5g2 were induced by berberine.ConclusionsWEC and berberine activated murine microglia N9 cells by the regulation of mitochondrial function and mitochondria-related signal molecules. The action of WEC is stronger than that of berberine, indicating that the effect of WEC is ascribed partially, but not totally, to berberine.

Murine microglia N9 cells were activated by both the water extract of Rhizoma coptidis (WEC) and berberine by the regulation of mitochondrial Δψ, free radicals, as well as three genes of Ndufab1, Cox6a2 and Atp5a1. However, WEC induced this activation more remarkably than berberine, which ascribed to its specific modulation of Atp5c1 gene expression and Ca2+ influx.Figure optionsDownload as PowerPoint slide