Protective effects of citicoline-containing eye drops against UVB-Induced corneal oxidative damage in a rat model.

It has been reported that citicoline increases antioxidant activity in some tissues. However, the effect of citicoline on corneal wound-healing has not yet been demonstrated. The aim was to investigate the protective effects of citicoline on ultraviolet B (UVB) radiation-induced corneal oxidative damage in a rat model. Four groups (eight animals each) were investigated: controls; UVB only; UVB/citicoline; and citicoline only. Corneal oxidative damage was induced by exposure to UVB radiation at 560 µW/cm2 for five days in the UVB-exposed groups and 1% citicoline eye drops were applied (3xday) for eight days in the two citicoline groups. Corneal surface damage was evaluated by opacity and fluorescein staining. Corneal injury was assessed biochemically by measuring the concentrations of glutathione (GSH) and malondialdehyde (MDA) and the activity of corneal superoxide dismutase (SOD) and catalase. Matrix metalloproteinase (MMP) -2 and -9 and caspase-3 were evaluated by immunofluorescent staining and microscopic examination and by Western blot analysis. Corneal gene expression analysis was performed for vascular endothelial growth factor (VEGF), interleukin-1 beta (IL-1ß) and transforming growth factor-beta (TGF-ß). UVB radiation caused significant epithelial damage and evident opacity in the cornea, together with a local decrease in SOD, catalase and GSH activity. Corneal MDA concentrations increased with UVB exposure. The UVB/Citicoline group had significantly less corneal damage, greater SOD, catalase and GSH activity, and decreased MDA concentrations compared to the UVB only group (p < 0.05). Expression of TGF-ß, IL-1ß and VEGF was significantly lower in the citicoline/UVB group compared to the UVB group (p < 0.05). Interestingly, TGF-ß expression was lower in the citicoline only group compared with controls. Immunfluorescent staining and Western blot analysis showed increased MMP-2, -9 and caspase-3 in the UVB only group compared with the UVB/citicoline group. It was shown that citicoline treatment may be effective in suppressing oxidative stress and controlling inflammation in UVB corneal injury.

Mesenchymal stem cell application improves tendon healing via anti-apoptotic effect (Animal study).

OBJECTIVE: The aim of this study was to determine the effects of mesenchymal stem cell (MSC) application and the possible pathways of MSC's effects on tendon strength and healing after tendon repair. METHODS: The study included 40 Wistar albino rats. Mesenchymal stem cells were obtained from the femurs and tibias of 6 rats. Achilles tendons of the remaining 34 rats were cut and repaired with open surgical procedures. Rats were divided into 2 groups. Percutaneous MSCs were applied to the study group (n=17) and physiological serum only was applied to the control group (n=17) at the 4th week. Rats were sacrificed using the cervical dislocation method under ether anesthesia at the 12th week and samples were analyzed by histological and immunohistochemical methods. For biomechanical analysis, a traction force was applied at 10 mm/min and load to failure was recorded for each specimen in Newtons. RESULTS: Histologically, there was no significant difference between groups (p>0.05). In the immunohistochemical studies, MSCs were located more intensively at the repair zone. Apoptosis was minimally present in the study group and was clearly increased in the control group. Increase in tendon strength was significantly higher in the study group than in the control group at the 12th week (p<0.05). CONCLUSION: The application of MSCs to decrease re-ruptures has a positive effect on tendon strength, probably due to their anti-apoptotic effects. Mesenchymal stem cell application can be used percutaneously and is effective in clinical practice in the late stages of tendon healing.