Topically applied water extract of propolis to suppress corneal neovascularization in rabbits

Purpose: Propolis, a natural honey bee hive product, has anti-inflammatory and antioxidative properties. We aimed to assess the possible contribution of topically applied propolis to the suppression of corneal neovascularizat ion (CNV). Methods: The effect of a water extract of propolis (WEP) 1% drop s (group 1) in comparison with dexamethasone 0.1% (group 2) and saline (gro up 3) on CNV was tested in rabbit corneas injured by silver nitrate cauteri zation. The extent of CNV was quantitated as the area of CNV and the percen t area of CNV for each cornea of the three groups (12 right eyes per group) in the first week of the treatment. The mean percent CNV was used for stat istical analysis. Results: The corneas treated with the topical WEP 1% had an almost equal percent CNV as compared with the corneas treated with topic al dexamethasone 0.1% and had less percent CNV than the control eyes. The q uantitative analysis in groups 1, 2 and 3 revealed that the mean percent CN V was 41.0 +/- 14.1, 39.4 +/- 11.0 and 56.9 +/- 18.4, respectively. The dif ferences between both groups 1 and 3 as well as groups 2 and 3 were statist ically significant (p = 0.02 and p = 0.01, respectively), whereas the diffe rence between groups 1 and 2 was not significant (p = 0.86). Conclusions Th e topical application of a WEP 1% has an inhibitory effect on CNV in the ra bbit's cornea. The inhibitory effect of propolis was shown to be comparable to that of topical dexamethasone 0.1%, a potent inhibitor of angiogenesis. We suggest that the effect of propolis may partially be due to its inhibit ory effect on the activity of both cyclo-oxygenase and lipo-oxygenase.