[Effects of emodin on expression of cytokines induced by lipopolysaccharide in corneal fibroblasts].
OBJECTIVE
To investigate the effects of emodin on expression of cytokines induced by lipopolysaccharide (LPS) in cultured human corneal fibroblasts in vitro.


METHODS
Primary human corneal fibroblasts of passages 4 were used in this research. Cells were treated with 10 microg/L LPS for 1, 2, 4, or 8 hours, which were pretreated with or without emodin for 30 minutes before LPS challenge. The degeneration of inhibitor of kappaB-alpha (I kappaB-alpha) and the effect of emodin on it were analyzed by Western blot analysis with a specific antibody. The cellular abundance of the mRNA of interleukin (IL)-6 and IL-8 from corneal fibroblasts under different conditions was determined by reverse transcriptase polymerase chain reaction (RT-PCR).


RESULTS
Compared with cells without LPS treatment, I kappaB-alpha level significantly decreased in every time point after LPS challenge (P < 0.01). Emodin inhibited the LPS-induced degeneration of I kappaB-alpha by corneal fibroblasts in a dose-dependent manner (P < 0.05). Compared with cells without LPS treatment, the expressions of IL-6 and IL-8 mRNA significantly increased in every time point after LPS challenge (P < 0.01). At the same time, the expressions of the mRNA of IL-6 and IL-8 induced by LPS in corneal fibroblasts were also inhibited by emodin in a dose-dependent manner (P < 0.05).


CONCLUSIONS
Emodin can inhibit the expressions of IL-6 and IL-8 mRNA induced by LPS in corneal fibroblasts, which maybe via inhibiting the degeneration of I kappaB-alpha and suppressing the activation of nuclear factor-kappaB.
Chen
Guo-Ling
GL
Department of Anatomy, School of Medicine, Shandong University, Ji'nan 250012, China. cgl7198@163.com
Zhang
Han
H
Liu
Yan-Li
YL
Sun
Hong-Yi
HY
Wei
Lu-Wan
LW
Liu
Zhi-Yu
ZY
D002478:Cells, Cultured; D003315:Cornea / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D004336:Drug Antagonism; D004642:Emodin / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000633:toxicity*; D016328:NF-kappa B / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics
D015850:Interleukin-6; D016209:Interleukin-8; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger; D004642:Emodin