Cinnamein Inhibits the Induction of Nitric Oxide and Proinflammatory Cytokines in Macrophages, Microglia and Astrocytes.

Chronic inflammation driven by proinflammatory cytokines (TNFα, IL-1β, IL-6, etc.), and nitric oxide (NO) plays an important role in the pathogenesis of several autoimmune, inflammatory as well as neurodegenerative disorders like rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, etc. Therefore, identification of nontoxic anti-inflammatory drugs may be beneficial for these autoimmune, inflammatory and neurodegenerative disorders. Cinnamein, an ester derivative of cinnamic acid and benzyl alcohol, is used as a flavoring agent and for its antifungal and antibacterial properties. This study underlines the importance of cinnamein in inhibiting the induction of proinflammatory molecules in RAW 264.7 macrophages and primary mouse microglia and astrocytes. Stimulation of RAW 264.7 macrophages with lipopolysaccharide (LPS) and interferon γ (IFNγ) led to marked production of NO. However, cinnamein pretreatment significantly inhibited LPS- and IFNγ-induced production of NO in RAW 264.7 macrophages. Cinnamein also reduced the mRNA expression of inducible nitric oxide synthase (iNOS) and TNFα in RAW cells. Accordingly, LPS and viral double-stranded RNA mimic polyinosinic: polycytidylic acid (polyIC) stimulated the production of TNFα, IL-1β and IL-6 in primary mouse microglia, which was inhibited by cinnamein pretreatment. Similarly, cinnamein also inhibited polyIC-induced production of TNFα and IL-6 in primary mouse astrocytes. These results suggest that cinnamein may be used to control inflammation in different autoimmune, inflammatory and neurodegenerative disorders.