Uso do ozônio no modelo de retinopatia diabética em zebrafish (Danio rerio)

Abstract

Diabetic retinopathy (DR) is an ocular complication in diabetic patients that requires studies to understand it and develop treatments. Such studies can be performed using animal models such as Danio rerio (zebrafish), and different compounds can be investigated to control the pathophysiological mechanisms, such as ozone (O3). The objective of this study is to evaluate the effects of O3 in the hyperglycemic model of DR in zebrafish. 570 adult zebrafish were used in two experimental trials to evaluate the effects of O3 on retinal and gill tissue under normal conditions (trial 1) and on retinal tissue in animals induced for the disease (trial 2), at concentrations of 52 and 72 μg/ml once and twice a day, every 48 hours for 15 days. The redox potential (ORP) of water, morphometry, oxidative effect, glycemia and glycated proteins of the animals were also evaluated. In test 1, O3 did not trigger morphometric changes in retinal and gill tissue (p> 0.05) in healthy animals. However, a significant increase (p < 0.05) in reactive oxygen species (ROS) and superoxide dismutase (SOD) was observed, indicating the development of acute and controlled oxidative stress, without deleterious effects. In the second test, it was observed through the significant increase (p < 0.05) in ROS, SOD and catalase (CAT) that the zebrafish also develop a picture of oxidative stress. Furthermore, when treated with O3, it was observed that there were better morphometric results and results regarding oxidative stress, with no significant differences compared to the negative control group (CN) that remained only in water (p > 0.05) and even with significantly lower EROs, SOD and CAT values than animals in the positive control group (CP) that were only induced for the disease (p < 0.05), with the exception of the group tested with the dosage of 72 μg/ml twice a day (T4), indicating that this dosage in sick animals exceeds the threshold of beneficial effects and causes toxic effects. Based on these findings, it is concluded that the O3 protocols used are safe in terms of their applicability in water and gill health, in addition to not causing changes in healthy retinal tissue. Furthermore, when used in sick animals, it provided better control of the neurodegeneration and oxidative stress. Therefore, it is possible to indicate the carrying out of new studies in the species with this compound to better understand these results and their possible mechanisms of occurrence.