Regulation of Inflammatory Repertoires and NF-κB Signal Transduction by DDB, an Active Compound from Schizandra Chinensis Baillon

Background: Chronic inflammation in the brain has known to be associated with the development of a various neurological diseases including dementia. In general, the characteristic of neuro-inflammation is the activated microglia over the brain where the pathogenesis occurs. Pro-inflammatory repertoires, interleukin-1 (IL-1) and nitric oxide (NO), are the main causes of neuro-degenerative disease, particularly in Alzheimer's disease (AD) which is caused by neuronal destruction. Those pro-inflammatory repertoires may lead the brain to chronic inflammatory status, and thus we hypothesized that chronic inflammation would be inhibited when pro-inflammatory repertoires are to be well controlled by inactivating the signal transduction associated with inflammation. Methods: In the present study, we examined whether biphenyl dimethyl dicarboxylate (DDB), an active compound from Schizandra chinensis Baillon, inhibits the NO production by a direct method using Griess reagent and by RT-PCR in the gene expression of inducible nitric oxide synthase (iNOS) and IL-1. Western blots were also used for the analysis of NF- and I. Results: In the study, we found that DDB effectively inhibited IL-1 as well as NO production in BV-2 microglial cell, and the translocation of NF- was comparably inhibited in the presence of DDB comparing those to the positive control, lipopolysaccharide. Conclusion: The data suggested that the DDB from Schizandra chinensis Baillon may play an effective role in inhibiting the pro-inflammatory repertoires which may cause neurodegeneration and the results imply that the compound suppresses a cue signal of the microglial activation which can induce the brain pathogenesis such as Alzheimer's disease.