We confirmed the protective effects of Acer palmatum Thumb. leaf extract against the degeneration of rat retinal ganglion cells after
ischemia/reperfusion (I/R) induced by midbrain cerebral artery occlusion (MCAO) in
a previous study. Referring to the results of that, in this study, we determined the
effects of two kinds of
A. palmatum Thumb. leaf extract (KIOM-2015E, hot water extract KIOM-2015EW and 25% ethanol extract
KIOM-2015EE) in a benzalkonium chloride (BAC)-induced dry eye mouse model. Dry eye
was induced by 0.2% BAC for 2 weeks, followed by treatment three times (eye drop)
or once (oral administration) daily with KIOM-2015E for 2 weeks. Treatment with both
KIOM-2015EE and KIOM-2015EW resulted in a marked increase in tear volume production
for the 4 days of treatment. The Lissamine Green staining score, TUNEL- positive cells
and inflammatory index were significantly decreased after 2 weeks. Topical KIOM-2015EE
administration exhibited greater improvement in decreasing the ocular surface staining
scores, inflammation, dead cells and increasing tear production in a dose-dependent
manner compared with the other groups. Furthermore, KIOM-2015E significantly reduced
the phosphorylation of NF-κB, which was activated in the BAC-treated cornea. Topical
administration was much more effective than oral administration for KIOM-2015E and
KIOM-2015EE was more effective than KIOM-2015EW. Application of KIOM-2015E resulted
in clinical improvement, including inhibiting the inflammatory response and alleviating
signs of dry eye. Taken together, these results indicate that KIOM-2015E has potential
as a therapeutic agent for the clinical treatment of dry eye.
