CHANGES IN ANTIOXIDANT SYSTEM ACTIVITY FOLLOWING CHEMICAL ALKALI CORNEAL BURNS TREATED WITH MESENCHYMAL STEM CELLS

Abstract

Introduction. The action of the damaging factor itself and the activation of the redox system against a background of suppressed antioxidant defense represent a universal mechanism of eye tissue damage in alkali burns. Therefore, the implementation of methods to activate antioxidant defense will help to activate protective mechanisms and sanogenesis in this pathology. The Aim of the study. To determine the dynamics of changes in free radical activity and the status of antioxidant enzyme systems in rabbits with experimental alkaline corneal burns following the application of Corne-Regel and mesenchymal stem cells. Materials and Methods. The experiment conducted on three groups of rabbits: Group I (control) – 10 intact animals; Group II – animals in which a chemical corneal burn was induced (10 rabbits) and no intervention performed; Group III – 10 animals in which the burn process treated using stem cell applications in the “Corneregel” preparation. Burn injury was induced by applying a 5-mm-diameter filter paper moistened with a 1 N NaOH solution to the cornea. Tissue samples collected on days 1, 7, 14, and 21, based on the burn process staging in the corneal tissue. Indicators of free radical oxidation and antioxidant systems were determined using standard methods. A suspension of placental stem cells in Corneregel was prepared using a standard method and applied to the burn wound under a contact lens. Results. Alkali burns of the cornea activate the redox system, leading to the accumulation of reactive oxygen species, which further damage ocular tissues, negatively affect plasma and subcellular membranes, and inhibit ocular tissue regeneration. The dynamics of changes in antioxidant defense parameters occur in phases and do not coincide with periods of free radical oxidation activation, which exacerbates destruction and impairs corneal regeneration. Applications of corneal burn wounds with stem cells in Corneregel significantly increased the activity of antioxidant defense systems, leading to a significant increase in their activity as early as within the first 7 days (by 10% for SOD and GSH and by 43–48% – K and CP) compared to untreated animals. Importantly, antioxidant activity gradually increased during treatment and reached the level observed in intact animals by days 21–28 of observation. Conclusion. Chemical burns of the corneal epithelium with alkali in experimental animals lead to a significant increase in the production of reactive oxygen species at all stages of burn disease. The activation of antioxidant defense does not coincide with periods of ROS activation. It causes a sluggish course of the disease and the development of destructive changes in the burned eye tissues. The method of applying Corneregel and stem cells to the burn wound demonstrated its promise and sufficiently high efficacy due to a significant increase in the activity of enzymatic and non-enzymatic antioxidant defense systems.