The therapeutic effect of DA-6034 on ocular inflammation via suppression of MMP-9 and inflammatory cytokines and activation of the MAPK signaling pathway in an experimental dry eye model.
OBJECTIVE
To investigate the effect of DA-6034, 7-carboxymethyloxy-3',4',5-trimethoxy flavone, in experimentally-induced inflammatory dry eye in rabbit. In addition, to elucidate the mechanism of DA-6034, we evaluated the mitogen-activated protein kinase (MAPK) signaling pathway and transcriptional factor-kappa B (NF-kB) in corneal epithelial cells.


METHODS
Rabbit lacrimal glands were injected with the T-cell mitogen concanavalin A (Con A). DA-6034 was then administered topically four times a day for six days starting 24 hr after Con A injection. Tear volume, tear function, MMP-9 and inflammatory cytokine levels in the lacrimal glands, and histological evaluation were subsequently assessed. In in vitro study, phosphorylated MAPKs (c-Jun NH2-terminal kinase (JNK) and p38 MAPK) and NF-kB were detected by enzyme-linked immunosorbent assay (ELISA) using human corneal epithelial cells.


RESULTS
A single injection of Con A into the lacrimal glands induced a pronounced inflammatory response, caused elevated levels of MMP-9 and cytokines IL-8 and TGF-beta(1), and induced a decrease in tear volume and shortening of tear breakup time (TBUT). In this inflammation model of dry eye, DA-6034 clearly showed therapeutic efficacy by restoring tear function and inhibiting inflammatory responses after topical ocular application. Furthermore, DA-6034 attenuated the phosphorylation of JNK and p38 MAPK and inhibited NF-kB activation in a concentration-dependent manner in corneal epithelial cells.


CONCLUSIONS
These results suggest that DA-6034 has the therapeutic effect in rabbit lacrimal gland inflammation model of dry eye and might be a potential treatment option for acute dry eye syndrome.
Research Institutes, Dong-A Pharmaceutical Company, Yongin, Kyunggi, South Korea.
Mi Jeong
MJ
Seo
Ju Mi
JM
Kim
Min Jung
MJ
Lee
Yong Sung
YS
Sohn
Kyung Koo
KK
Kang
Moohi
M
Yoo
D000287:Administration, Topical; D000818:Animals; D015153:Blotting, Western; D018929:Cell Culture Techniques; D016207:Cytokines / Q000378:metabolism*; D003607:Dacryocystitis / Q000188:drug therapy* / Q000201:enzymology; D004195:Disease Models, Animal; D015352:Dry Eye Syndromes / Q000188:drug therapy* / Q000201:enzymology; D004789:Enzyme Activation; D004797:Enzyme-Linked Immunosorbent Assay; D019573:Epithelium, Corneal / Q000378:metabolism; D005419:Flavonoids / Q000627:therapeutic use*; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D011817:Rabbits; D013666:Tears / Q000737:chemistry
D016207:Cytokines; D005419:Flavonoids; D016328:NF-kappa B; D020928:Mitogen-Activated Protein Kinases; D020780:Matrix Metalloproteinase 9; C121889:recoflavone