Image_3_Anti-inflammatory Effects of Curcumin in Microglial Cells.JPEG

<p>Lipoteichoic acid (LTA) induces neuroinflammatory molecules, contributing to the pathogenesis of neurodegenerative diseases. Therefore, suppression of neuroinflammatory molecules could be developed as a therapeutic method. Although previous data supports an immune-modulating effect of curcumin, the underlying signaling pathways are largely unidentified. Here, we investigated curcumin’s anti-neuroinflammatory properties in LTA-stimulated BV-2 microglial cells. Inflammatory cytokine tumor necrosis factor-α [TNF-α, prostaglandin E2 (PGE2), and Nitric Oxide (NO] secretion in LTA-induced microglial cells were inhibited by curcumin. Curcumin also inhibited LTA-induced inducible NO synthases (iNOS) and cyclooxygenase-2 (COX-2) expression. Subsequently, our mechanistic studies revealed that curcumin inhibited LTA-induced phosphorylation of mitogen-activated protein kinase (MAPK) including ERK, p38, Akt and translocation of NF-κB. Furthermore, curcumin induced hemeoxygenase (HO)-1HO-1 and nuclear factor erythroid 2-related factor 2 (Nrf-2) expression in microglial cells. Inhibition of HO-1 reversed the inhibition effect of HO-1 on inflammatory mediators release in LTA-stimulated microglial cells. Taken together, our results suggest that curcumin could be a potential therapeutic agent for the treatment of neurodegenerative disorders via suppressing neuroinflammatory responses.</p

Additional file 1: Figure S1. of The mechanism of (+) taxifolin’s protective antioxidant effect for •OH-treated bone marrow-derived mesenchymal stem cells

The CCK-8 assay for normal bmMSCs exposed to (+) taxifolin. Figure S2. Dose–response curves for (+) taxifolin •OH-scavenging assay based on DNA. Figure S3. Dose–response curves for (+) taxifolin in PTIO• radical-scavenging assay and its IC50 values at various pH values. Figure S4. Dose–response curves for (+) taxifolin in the ABTS+• radical-scavenging assay. Figure S5. Dose–response curves for (+) taxifolin in the Cu2+-reducing assay. Figure S6. Dose–response curves for (+) taxifolin in the FRAP assay. Figure S7. Dose–response curves for (+) taxifolin in the DPPH•-radical-scavenging assay. Figure S8. The UV-visible spectra for the 4’-O-methyltaxifolin–Fe2+ complex. Figure S9. The UV absorption bands of flavonoid. Figure S10. The UV-Vis spectra and solution colors for (+) taxifolin–Fe2+ and catechol–Fe2+. Figure S11. The UV-Vis spectra for (+) taxifolin–Fe2+ and dihydromyricetin–Fe2+. Table S1. The IC50 values listed in different units. (DOCX 789 kb