Effect of ozone on vascular endothelial growth factor (VEGF) and related inflammatory cytokines in rats with diabetic retinopathy

The aim of this study was to investigate the effect of ozone on inflammatory cytokines in diabetic retinopathy (DR) rats. Male rats (40) weighing 300-360 g were included in this study. Thirty rats were randomly divided into the model and ozone groups after DR was induced by streptozotocin. Ten rats served as the blank group. After the diabetic models were established for one month, the rats in the ozone group were treated with 50 mg/kg ozone coloclysis for one month (three times a week). After the rats were anesthetized by intraperitoneal injection, blood samples from the abdominal aorta were collected, and the supernatant was obtained by centrifugation. Vascular endothelial growth factor (VEGF) and inflammatory cytokine content in the serum was detected by enzyme linked immunosorbent assay. The values of VEGF, intercellular cell adhesion molecule-1, interleukin-1 beta, tumor necrosis factor-alpha, and IL-6 were significantly different among the three groups (P < 0.05). The cytokine levels in the model group were higher than those in the blank group (P < 0.05). The level of each cytokine in the ozone group was higher than that in the blank group. Compared with the model group, the cytokine levels in the ozone group were significantly reduced (P < 0.05). Ozone had no effect on the blood glucose of diabetic rats. Treatment with ozone coloclysis may effectively reduce the secretion of VEGF and inflammatory cytokines in diabetic retinopathy rats.