Effects of Ozone on Injury after Gamma Knife Radiosurgery.

BACKGROUND: At present, gamma knife radiosurgery plays an important role in neurosurgical procedures. Gamma knife radiosurgery has been used to treat many types of brain tumors and as a functional intervention. However, gamma knife treatment has a devastating effect on the normal brain parenchyma surrounding the target point. It causes increased vascular permeability, vasodilation, and swelling in endothelial cells. Ozone has antioxidant, antiapoptotic, and anti-inflammatory effects in the body. Thus, we evaluated the radioprotective effects of ozone in rats undergoing gamma knife radiation. METHODS: In the present study, 24 Sprague-Dawley male rats weighing 250-300 g in 3 groups of 8 rats each were used. The rats were selected randomly. The control group did not receive any gamma knife radiation. The other 2 groups received 50 Gy of radiation, with 1 group given ozone treatment and the other group not given ozone treatment after gamma knife radiosurgery. At 12 weeks after gamma knife radiation, the rats were sacrificed with high-dose anesthetic agents and the tissues prepared for evaluation. The slides were evaluated for necrosis, vacuolization, glial proliferation, and vascular proliferation using hematoxylin-eosin staining. Vascular endothelial growth factor (VEGF) and extracellular matrix metalloproteinase inducer (also known as CD147) were evaluated using immunohistochemical staining. RESULTS: VEGF expression in glial tissue was significantly less in the group receiving ozone (χ2 = 15.00; df = 4; P = 0.005) compared with the group that had not received ozone and was similar to the expression in the control group. CONCLUSIONS: The lower expression of VEGF in the group receiving ozone might cause less edema in the surrounding tissue owing to less degradation of vascular permeability in the rat brain tissue.

The Histological Effects of Ozone Therapy on Sciatic Nerve Crush Injury in Rats.

OBJECTIVE: Peripheral nerve injury is a common, important problem that lacks a definitive, effective treatment. It can cause neurologic deficits ranging from paresthesia to paralysis. This study evaluated the effect of ozone therapy on sciatic nerve crush injury in rats. MATERIALS AND METHODS: Twenty-four male rats were divided into control sham surgery, sciatic nerve injury, and sciatic nerve injury with ozone groups (each n = 8). The sciatic nerve injury was inflicted via De Koning's crush-force method. The sciatic nerve injury group received medical air and the sciatic nerve injury ozone group received 0.7 mg/kg ozone. Sciatic nerve samples were obtained 4 weeks after injury. Vascular congestion, vacuolization, edema formation, S100 expression, and the thicknesses of the perineurium and endoneurium and diameter of the injured sciatic nerves were evaluated. RESULTS: The diameter of the sciatic nerve and thicknesses of the perineurium and epineurium were significantly greater in the sciatic nerve injury group (P < 0.05) and significantly less in the sciatic nerve injury with ozone group (P < 0.001). High S100 immunoreactivity was seen in the sciatic nerve injury group compared with the other 2 groups (P < 0.05). The distributions of vascular congestion and vacuolization were significantly less in the sciatic nerve injury with ozone group (P < 0.05). CONCLUSIONS: Ozone therapy improved sciatic nerve injury recovery without causing an increase in fibrotic tissue. Ozone reduced fibrosis, vascular congestion, vacuolization, and edema in rodents. Ozone treatment might be used to assist in sciatic nerve injury.

The Effect of Ozone Therapy on Experimental Vasospasm in the Rat Femoral Artery.

AIM: Oxidation products following subarachnoid hemorrhage (SAH) are among the causative substances of cerebral vasospasm and poor outcome. Ozone (O3) is a gas that contains three atoms of oxygen with a cyclic structure. It has been suggested that application of low-dose ozone has an antioxidant effect and provides resistance to oxidative stress. We investigated the effect of oxygen-ozone therapy on rat femoral artery vasospasm. MATERIAL AND METHODS: Twenty-four male Sprague-Dawley rats were randomly separated into vasospasm, vasospasm + ozone and control groups. The femoral artery vasospasm model was used. Rats in the vasospasm + ozone group were given 4 mL of ozone (20 µ/mL) daily for 7 days. Femoral arteries were examined by light microscopy for histological changes and morphometric analysis. Kruskal Wallis test and Mann Whitney U tests were used for the statistical analysis. The values of p < 0.01 and p < 0.05 were recognized as statistically significant. RESULTS: Ozone treatment reduced the morphometric changes as irregularity of the elastic lamina, disruption of the endothelial cells, vacuolization and hemorrhages that caused by vasospasm. The measurements of the wall thickness (p=0.003; p < 0.01) and lumen diameter (p=0.001; p < 0.01) showed statistically significant difference (p < 0.01) between the vasospasm and vasospasm+ozone groups. CONCLUSION: Ozone therapy may be useful in the treatment of post-hemorrhagic vasospasm.