Abstract:

Objective  To investigate the signification and effect of emodin on expression of intercellular adhesion molecule-1(ICAM-1) in the corneas of acute keratitis-induced by lipopolysaccharide (LPS) in Wistar rats.  Methods Pseudomonas aeruginosa LPS-induced keratitis models were established in Wistar rats. Thirty minutes before LPS exposure, emodin and its vehicle were separately injected into sub-conjunctival tissues in Wistar rats. At 1, 3, 6, 12 and 24 hours after being challenged with LPS, signs of both groups were observed, and severity of rats′ ocular inflammation was examined with a slit lamp microscope. The aqueous humor of each group was extracted and examined with hematoxylin and eosin(HE)-stained, and expression of ICAM-1 mRAN was detected by reverse transcriptase-polymerase chain reaction(RT-PCR).  Results  Ocular behavior was improved in rats which had undergone subconjunctival injection with emodin before being challenged with LPS. Inflammatory cells of the cornea and aqueous humor were less in rats of the treatment group than those of the inflammation group. The corneal edema and collagen fibers which appeared in disarrangement were also improved after emodin treatment. Expression of ICAM1 mRNA of the treatment group was increased in each point after being challenged with LPS(P<0.01), which was significantly inhibited by pretreatment with emodin（ P <0.01）.　 Conclusion Emodin can decrease expression of ICAM-1mRNA induced by LPS in the corneas of rats, and protects against acute corneal injury and improves rats′ symptoms.

Key words: Emodin; Inflammation; Cornea; Rats, Wistar