Anti-inflammatory effects of quercetin in lipopolysaccharide-activated cortical astrocytes

Dysregulated neuroinflammation is a hallmark of multiple neurodegenerative diseases, characterized by increased pro-inflammatory cytokines, and reduced anti-inflammatory cytokines, and is mediated by resident astrocytes. Previous studies have demonstrated the neuroprotective effects of quercetin hydrate, a plant flavonoid, however, limited studies exist showing the targets of quercetin in astrocytes. Here, we demonstrate the anti-inflammatory effects of quercetin hydrate at the gene expression level and the involvement of signalling pathway molecules. The rat primary cortical astrocytes were preincubated with different concentrations of quercetin (25–200 μM) followed by lipopolysaccharide (LPS) stimulation. Semi-quantitative PCR analysis showed the therapeutic potential of quercetin by decreasing the gene expression of pro-inflammatory cytokines (IL-1β, IL-6), and Cyclooxygenase-2, and increasing Hemeoxygenase-1 in LPS-stimulated astrocytes. By Immunoblotting analysis, we document the modulatory effects of quercetin on phospho p38 and phospho ERK1/2 in LPS-stimulated astrocytes. The study indicates the anti-inflammatory effects of quercetin against inflammatory responses in astrocytes.