Therapeutic intervention with chicken egg white ovomacroglobulin and a new quinolone on experimental Pseudomonas keratitis.

⊎ Background: Chicken egg white ovomacroglobulin (ovoM) is a potent protease inhibitor with broad-spectrum activity against various proteases. The combined effects of ovoM and the new quinolone, ofloxacin (OFLX) on experimental Pseudomonas aeruginosa keratitis were investigated. ⊎ Methods: The in vitro inhibitory effects of ovoM on protease activity in culture fluid of clinically isolated P. aeruginosa and on activity of human neutrophil elastase and cathepsin G were assayed using azo-casein as substrate. Albino rabbits received intrastromal injection of the isolated Pseudomonas strain (1 × 10 colony-forming units). At 16 h after inoculation, three treatment groups -0.1% ovoM alone, 0.3% OFLX alone, and a combination of both -and a non-treatment control group were tested. ⊎ Results: Protease activity in the culture solution and human neutrophil elastase was inhibited by ovoM, whereas cathepsin G was not inhibited effectively. In vivo additive therapeutic effects of ovoM and OFLX were observed at 96 h ( P < 0.05 compared with OFLX alone). ⊎ Conclusion: The results indicate that inhibition of proteolytic activity with ovoM is useful in preventing stromal degradation in P. aeruginosa keratitis. [ABSTRACT FROM AUTHOR]