Inhibitory effect of 1,8-cineol (eucalyptol) on Egr-1 expression in lipopolysaccharide-stimulated THP-1 cells.
OBJECTIVE
To study the effects of 1,8-cineol (eucalyptol) on the expression of early growth response factor-1 (Egr-1) and NF-kappaB in the human monocyte THP-1 cell line stimulated by lipopolysaccharide (LPS).


METHODS
The THP-1 cells were incubated with serial doses of 1,8-cineol (1, 10, and 100 mg/L, 30 min) before being stimulated with LPS (1 mg/L, 30 min). The localization of Egr-1 in the THP-1 cells was detected by immunofluorescence and a laser scanning confocal microscope. The expression of Egr-1 in the nuclei and whole cell, and NF-kappaB in the nuclei, were measured by Western blot analysis.


RESULTS
When stimulated by LPS, the FITC-labeled Egr-1 was detected mainly in the nuclei. Moreover, the expression of Egr-1 in the whole cell increased markedly compared with the control cells. 1,8-Cineol pretreatment decreased the expression of Egr-1 in both the nuclei and whole cell of the LPS-stimulated THP-1 cells, and this effect was concentration-dependent, but there was no reaction on the expression of NF-kappaB in the nuclei protein in the LPS-stimulated THP-1 cells.


CONCLUSIONS
In a concentration-dependent manner, 1,8-Cineol reduces LPS-induced Egr-1 expression in nuclei and in whole cell of THP-1 cells, but shows no effect on NF-kappaB expression.
Zhou
Jian-Ya
JY
Department of Respiratory Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China. zydrw@hotmail.com
Wang
Xue-Fen
XF
Tang
Fa-Di
FD
Zhou
Jian-Ying
JY
Lu
Guo-Hua
GH
Wang
Yan
Y
Bian
Ru-Lian
RL
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003511:Cyclohexanols / Q000494:pharmacology*; D004277:DNA, Single-Stranded; D051766:Early Growth Response Protein 1 / Q000235:genetics / Q000378:metabolism*; D000077591:Eucalyptol; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology*; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D039821:Monoterpenes / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism
D000890:Anti-Infective Agents; D003511:Cyclohexanols; C400152:DNA enzyme ED5; D004277:DNA, Single-Stranded; D051766:Early Growth Response Protein 1; D008070:Lipopolysaccharides; D039821:Monoterpenes; D016328:NF-kappa B; D000077591:Eucalyptol