Inhibition of neuroinflammation by cinnamon and its main components

Uncontrolled activation of microglia contributes to neuroinflammation, which is highly involved in the development of neurodegenerative diseases. Although cinnamon has neuro-protective properties, its capacity to inhibit neuroinflammation has not been investigated and its active compounds remain unclear. Therefore, the composition of cinnamon extract was analysed by LC–MS and the ability of cinnamon and its main constituents to inhibit neuroinflammation was evaluated using a lipopolysaccharide (LPS)-activated BV2 microglia culture system. In total, 50 μg/mL cinnamon extract decreased significantly the production and expression of nitric oxide (NO), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in LPS-activated BV2 microglia. Blocking of nuclear factor-κB (NF-κB) activation was the most likely mechanism responsible for inhibition by cinnamon of neuroinflammation. Among the eight tested compounds, cinnamaldehyde had the greatest anti-neuroinflammatory capacity. Experimental results suggest that cinnamon may have a potential therapeutic effect against neurodegenerative diseases and its potent anti-neuroinflammatory capacity was primarily attributed to cinnamaldehyde.