The effect of sulfur mustard and nitrogen mustard on corneal collagen degradation induced by the enzyme collagenase

Abstract

Objective: Sulfur mustard (SM) is an alkylating agent that can affect cornea and induce various complications. With regard to the role of the enzyme collagenase in dermatologic complications induced by SM and its role in other ocular disorders, we studied the effect of SM and nitrogen mustard (NM) on collagen degradation by collagenase.Materials and methods: This study included 7 groups of samples: The negative control group contained collagen without collagenase and toxins, the control group contained collagen and collagenase without any toxin, the positive control groups of NM and SM contained collagen and NM or SM without collagenase, the experimental groups of NM and SM contained collagen that was affected by NM or SM and collagenase, and the control group of collagenase contained only collagenase without containing collagen or receiving toxins. After incubation for 3.5 hours, the amount of hydroxyproline and the protein content of the samples were measured. Data were analyzed by analysis of variance (ANOVA).Results: The protein concentrations of the negative control group and the positive control groups of SM and NM were significantly lower than those for all other groups of the study. There was a significant difference in hydroxyproline concentration of control group and negative control group; however, there was no significant difference between experimental group of SM and the positive conrol group of SM. There was no significant difference between the negative control group and the positive control group of SM in the hydroxyproline concentration of sediment samples.Conclusion: According to the results of this study, SM can affect the corneal collagen in a way in which collagenase cannot degrade it. In addition, it can be hypothesized that ineffective activity of this enzyme can result in increasing concentration of collagenase, which can lead to the destruction of the normal collagen of the cornea. The main result of this study confirms the hypothesis that SM inhibits the effect of collagenase on corneal collagen.