title: TSG (2,3,4' ,5-tetrahydroxystilbene 2-O-β-D-glucoside) suppresses induction of pro-inflammatory factors by attenuating the binding activity of nuclear factor-κB in microglia.
abstract: BACKGROUND
  Induction of pro-inflammatory factors is one of the characteristics of microglia activation and can be regulated by numerous active components of Chinese traditional herbs. Suppression of pro-inflammatory factors is beneficial to alleviate microglia-mediated cell injury. The present study aims to investigate the effect and possible mechanism of 2,3,4',5-tetrahydroxystilbene 2-O-β-D-glucoside (TSG) on LPS-mediated induction of pro-inflammatory factors in microglia.
  
  
  METHODS
  Western blot, ELISA, and Hoechst 33258 were used to measure the protein expression, TNF-α/IL-6 content, and apoptotic nuclei, respectively. The mRNA level was measured by real time-PCR. Nitric oxide (NO) content, lactate dehydrogenase (LDH) content, and NF-κB binding activity were assayed by commercial kits.
  
  
  RESULTS
  TSG reduced iNOS protein expression as well as TNF-α, IL-6, and NO content in LPS-stimulated BV-2 cells. TSG attenuated the increase in apoptotic nuclei, caspase-3 cleavage, and LDH content induced by BV-2 cell-derived conditioned medium in primary hippocampal neurons. Mechanistic studies showed that TSG reduced the mRNA level of iNOS, TNF-α, and IL-6. TSG failed to suppress IκB-α degradation, NF-κB phosphorylation and nuclear translocation, and ERK1/2, JNK, and p38 phosphorylation. TSG, however, markedly reduced the binding of NF-κB to its DNA element. Chromatin immunoprecipitation (ChIP) assays confirmed that TSG reduced NF-κB binding to the iNOS promoter. These findings were ascertained in primary microglia where the LPS-induced increase in iNOS expression, NO content, apoptotic nuclei, and NF-κB binding to its DNA element were diminished by TSG.
  
  
  CONCLUSIONS
  These studies demonstrate that TSG attenuates LPS-mediated induction of pro-inflammatory factors in microglia through reducing the binding activity of NF-κB. This might help us to further understand the pharmacological role of TSG in inflammatory response in the central nervous system.
authors.forename: Chao
authors.initials: C
authors.lastname: Huang
authors.forename: Yuzhe
authors.initials: Y
authors.lastname: Wang
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Yao
authors.forename: Xiangfan
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Pharmacology, School of Medicine, Nantong University, 19 Qixiu Road, Nantong 226001, Jiangsu, China. asicampa@aliyun.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D004797:Enzyme-Linked Immunosorbent Assay; D005960:Glucosides / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D013267:Stilbenes / Q000494:pharmacology*
chemical_list: D005960:Glucosides; D016328:NF-kappa B; D013267:Stilbenes; C093026:2,3,5,4'-tetrahydroxystilbene 2-O-glucopyranoside