Effect of caffeic acid phenethyl ester on corneal neovascularization in rats.

PURPOSE: Caffeic acid phenethyl ester (CAPE), a biologically active component of propolis from honeybee hives, has potent antiinflammatory and antioxidant properties. We aimed to evaluate the ability of topically applied CAPE in comparison with known steroidal (dexamethasone sodium phosphate) and nonsteroidal (indomethacin) topical agents to reduce corneal neovascularization (CNV) induced by silver nitrate cauterization in rats. METHODS: Following silver nitrate cauterization on both eyes, male rats were randomly assigned to the study and control groups, each consisting of ten rats. The inhibitory effects of the test drugs against a placebo (isotonic saline) on CNV were tested and compared to each other using a previously described method in which extent of neovascularization and burn stimulus intensity were scored by a masked examiner. Briefly, burn stimulus intensity was scored from 0 to +3 according to the height of blister from corneal surface, and extent of neovascularization was recorded from 0 to +6 according to the distance from limbus to the end point of CNV toward the central corneal burn. Results. The mean burn stimulus score were not different among the groups (P = 0.807). Percent inhibition of CNV compared to the placebo control and its significance were 31.5 %, P = 0.011 for indomethacin; 56 %, P < 0.001 for dexamethasone; and 52 %, P < 0.001 for CAPE. Dexamethasone was significantly (P < 0.05) more effective than indomethacin in inhibition of neovascular growth. CAPE was found to be superior (P < 0.05) to indomethacin and almost as effective as (P > 0.05) dexamethasone in reducing CNV. Conclusion. Topically applied CAPE was demonstrated to have an inhibitory effect, comparable to that of topical dexamethasone, on CNV in this rat model. Antiinflammatory and antioxidant properties of CAPE may contribute to its suppression on CNV.

Caffeic acid phenethyl ester prevents intestinal reperfusion injury in rats.

BACKGROUND/PURPOSE: Ischemia-reperfusion injury is encountered frequently in conditions that diminish intestinal blood flow. Caffeic acid phenethyl ester (CAPE), which is a specific component of the honeybee hive product propolis, exhibits potential antioxidant properties. This experimental study was designed to determine the effect of CAPE on ischemia-reperfusion injury in rat intestine. METHODS: Fifty rats were divided into 5 groups; sham (SH), saline ischemia (SI), saline reperfusion (SR), CAPE ischemia (CI), and CAPE reperfusion (CR). Either CAPE, 10 micromol/kg, or saline was administered intraperitoneally 30 minutes before ischemia. Intestinal ischemia for 30 minutes and reperfusion for 60 minutes were applied. Ileum specimens were obtained to determine the tissue levels of malondialdehyde, superoxide dismutase, catalase, and histological changes. RESULTS: Malondialdehyde levels in the CR group did not increase after reperfusion when compared with the CI group. However, statistically significant differences were observed between the SR and SI groups. Additional mucosal injury in the CR group when compared with the CI group was not observed. Whereas, there was a statistically significant increase in mucosal injury in the SR group. Reperfusion did not cause further injuries through both biochemical and histological parameters in the CR group. CONCLUSIONS: Results of this study showed that prophylactic administration of CAPE in ischemic condition prevents reperfusion injuries by eliminating oxygen radicals and inhibiting polymorphonuclear leukocyte infiltration. CAPE may be useful in combating the diseases of oxidative stress.

Caffeic acid phenethyl ester to inhibit posterior capsule opacification in rabbits.

PURPOSE: To assess whether caffeic acid phenethyl ester (CAPE) prevents posterior capsule opacification (PCO) by suppressing the transformation of the lens epithelial cells. SETTING: Departments of Ophthalmology, Chemistry, and Pathology, Turgut Ozal Medical Center, University of Inonu, Malatya, Turkey. METHODS: Twenty pigmented island rabbits having phacoemulsification in their right eyes were randomized into two groups. In group 1, 10 micrograms/ml of CAPE was added to the anterior chamber irrigating solution and a 1% solution of CAPE was injected subconjunctivally for 3 weeks postoperatively. The irrigating solution in Group 2 (control) did not include CAPE. The development of PCO was assessed weekly and its density was graded by slitlamp biomicroscopy. Histologic analysis was performed 3 months after surgery. RESULTS: Group 1 had clear capsules or minor PCO. Group 2 developed more severe PCO or complete opacification. The difference between the two groups was statistically significant (P = .04). CONCLUSION: These preliminary results indicate that CAPE is effective in suppressing PCO in pigmented rabbits and may be beneficial in clinical use in humans because it has no documented harmful effects on normal cells.