Comparison of the efficacy of various concentrations and combinations of serum, ethylenediaminetetraacetic acid, tetracycline, doxycycline, minocycline, and N-acetylcysteine for inhibition of collagenase activity in an in vitro corneal degradation model.
Abstract: OBJECTIVE To compare the efficacy of various concentrations and combinations of serum, EDTA, 3 tetracyclines, and N-acetylcysteine (NAC) for collagenase inhibition in an in vitro corneal degradation model. SAMPLE Grossly normal corneas from recently euthanized dogs and horses and fresh serum from healthy dogs and horses. PROCEDURES Serum was pooled by species for in vitro use. For each species, sections of cornea were dried, weighed, and incubated with clostridial collagenase (800 U/mL) in 5 mL of a 5mM calcium chloride-saline (0.9% NaCl) incubation solution and 500 μL of 1 of 19 treatments (homologous serum; 0.3%, 1.0%, or 2% EDTA; 0.1%, 0.5%, or 1.0% tetracycline, doxycycline, or minocycline; 0.5%, 1.0%, or 5.0% NAC; serum with 0.5% tetracycline; serum with 1.0% EDTA; or 1.0% EDTA with 0.5% tetracycline). Positive and negative control specimens were incubated with 5 mL of incubation solution with and without collagenase, respectively. Each control and treatment was replicated 4 times for each species. Following incubation, corneal specimens were dried and reweighed. The percentage corneal degradation was calculated and compared among treatments within each species. RESULTS Treatments with tetracyclines at concentrations ≥ 0.5%, with EDTA at concentrations ≥ 0.3%, and with NAC at concentrations ≥ 0.5% were more effective at preventing corneal degradation than serum in both species. The efficacy of each combination treatment was equal to or less than that of its components. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested EDTA, tetracyclines, and NAC may be beneficial for topical treatment of keratomalacia, but in vivo studies are required.
Publication Date: 2018-04-25 PubMed ID: 29688786DOI: 10.2460/ajvr.79.5.555Google Scholar: Lookup
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- Comparative Study
- Journal Article
Summary
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This research article investigates the effectiveness of different concentrations and combinations of serum, EDTA, three types of tetracyclines and N-acetylcysteine on inhibiting collagenase activity, which leads to corneal degradation. The aim is to explore potential treatment options for conditions such as keratomalacia, which causes corneal thinning and eventual rupture.
Study Design and Procedure
- The study used corneas from recently euthanized dogs and horses and fresh serum from these same animals.
- The researchers gathered serum by species and used it for the in vitro experiment.
- Different sections of the cornea were dried, weighed, and then exposed to clostridial collagenase (800 U/mL) in a calcium chloride-saline solution and one out of 19 treatments.
- These treatments involved varying concentrations and combinations of serum, EDTA, three tetracyclines (tetracycline, doxycycline, or minocycline), and NAC.
- There were also control specimens incubated with the solution, either with or without the collagenase enzyme, replicated four times for each species.
- After incubation, the corneal specimens were dried and weighed again, and the degree of corneal degradation was calculated and compared across the different treatments.
Analysis and Results
- Treatments that used tetracyclines at concentrations of 0.5% or more, EDTA at concentrations of 0.3% or more, and NAC at concentrations of 0.5% or more was found to be more successful at preventing corneal degradation than just serum alone.
- The data also highlighted that the efficiency of each combined treatment was equal to or lower than the effectiveness of its individual components.
Conclusion and Clinical Significance
- The study concluded that EDTA, tetracyclines, and NAC could be beneficial for topical treatment of keratomalacia, a condition that leads to corneal thinning and eventual rupture.
- However, in vivo studies are necessary to validate these findings and its clinical use in the treatment of corneal degradation.
Cite This Article
APA
Kimmitt BA, Moore GE, Stiles J.
(2018).
Comparison of the efficacy of various concentrations and combinations of serum, ethylenediaminetetraacetic acid, tetracycline, doxycycline, minocycline, and N-acetylcysteine for inhibition of collagenase activity in an in vitro corneal degradation model.
Am J Vet Res, 79(5), 555-561.
https://doi.org/10.2460/ajvr.79.5.555 Publication
Researcher Affiliations
MeSH Terms
- Acetylcysteine / administration & dosage
- Animals
- Anti-Bacterial Agents / administration & dosage
- Collagenases / chemistry
- Cornea / drug effects
- Corneal Diseases / prevention & control
- Disease Models, Animal
- Dogs
- Doxycycline / administration & dosage
- Edetic Acid / administration & dosage
- Horses
- Matrix Metalloproteinase Inhibitors / administration & dosage
- Minocycline / administration & dosage
- Serum / chemistry
- Tetracycline / administration & dosage
Citations
This article has been cited 10 times.- Piso DYT, Barreto MYP, Bonilla MDPS, Rincón AC, Páez OLA, Rengifo CA, de Andrade AL. Effects of platelet-rich plasma on corneal re-epithelization and metalloproteinase expression in the cornea of sheep with experimentally-induced infectious keratoconjunctivitis. Vet World 2023 Apr;16(4):799-810.
- Walter H, Verspohl J, Meißner J, Oltmanns H, Geks AK, Busse C. In Vitro Antimicrobial Activity of N-Acetylcysteine against Pathogens Most Commonly Associated with Infectious Keratitis in Dogs and Cats. Antibiotics (Basel) 2023 Mar 11;12(3).
- Diehm YF, Kotsougiani-Fischer D, Porst E, Haug V, Siegwart LC, Overhoff D, Kneser U, Fischer S. Oral doxycycline prevents skin-associated adverse effects induced by injectable collagenase in a rodent model of capsular contracture around silicone implants. PLoS One 2022;17(7):e0270112.
- Moore AL, desJardins-Park HE, Duoto BA, Mascharak S, Murphy MP, Irizarry DM, Foster DS, Jones RE, Barnes LA, Marshall CD, Ransom RC, Wernig G, Longaker MT. Doxycycline Reduces Scar Thickness and Improves Collagen Architecture. Ann Surg 2020 Jul;272(1):183-193.
- Heun F, Meißner J, Schieder AK, Ohnesorge B, Busse C. Pantoea agglomerans in Equine Ulcerative Keratitis: Prevalence and Comparative Efficacy of Four Topical Antiseptics. Vet Ophthalmol 2026 Jan;29(1):e70044.
- Wolff HT, Piroth AC, Oltmanns H, Meißner J, Verspohl J, Volk HA, Busse C. Commercially available antiseptics show high in vitro efficacy against pathogens most commonly associated with canine and feline infectious keratitis. Front Vet Sci 2025;12:1552230.
- Busse C, Raab A, Kreienbrock L, Volk HA. Insights from an online survey: Veterinary surgeons' antibiotic practices in ophthalmic surgery in Germany. Vet Ophthalmol 2025 Sep;28(5):820-829.
- Kubai MA, Roy MM, Stinman CC, Kenne DE, Allbaugh RA, Sebbag L. Topical blood products modulate the effects of ophthalmic antibiotics against common bacterial pathogens in dogs with infectious keratitis. Front Vet Sci 2024;11:1417842.
- Caretti L, Pillon G, Verzola G, Monterosso C, Formisano M. A Prospective Randomized Study Comparing 27-Gauge Vitrectomy to 23-Gauge Vitrectomy for Epiretinal Membranes and Full-Thickness Macular Holes. J Curr Ophthalmol 2023 Jul-Sep;35(3):259-266.
- Thomasy SM, Leonard BC, Greiner MA, Skeie JM, Raghunathan VK. Squishy matters - Corneal mechanobiology in health and disease. Prog Retin Eye Res 2024 Mar;99:101234.
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