Quercetin and Sesamin Protect Dopaminergic Cells from MPP⁺-Induced Neuroinflammation in a Microglial (N9)-Neuronal (PC12) Coculture System

Figure 6

Neuronal PC12 cells were cocultured with MPP⁺-activated N9 cells pretreated or not with quercetin or sesamin for 24 h. DNA fragmentation in neuronal cells was detected with a monoclonal antibody to single-stranded DNA (ssDNA). Ctrl: non-activated microglial cells were placed on neuronal PC12 cells; no neuronal death was detected. MPP⁺: MPP⁺-activated microglial cells were placed on neuronal PC12 cells; a significant increase of neuronal cell death was apparent, indicating that cytokines produced by microglial cells induce neuronal death. Pretreatment of N9 cells with quercetin or sesamin prior to MPP⁺ clearly reduced neuronal PC12 cell death. Pretreatment of non-MPP⁺-activated N9 cells with quercetin or sesamin did not produce any cellular death. 𝑛=3. ***𝑃<0.01 compared to the controls (Ctrl), ^◊◊𝑃<0.01 compared to quercetin, ^◊◊◊𝑃<0.001 compared to sesamin, as determined by 1-way ANOVA, followed by Tukey’s multiple comparison test.