Effects of ozone oxidative preconditioning on liver regeneration after partial hepatectomy in rats

Gultekin F.A. | Cakmak G.K. | Turkcu U.O. | Yurdakan G. | Demir F.E.O. | Comert M.

Article | 2013 | Journal of Investigative Surgery26 ( 5 ) , pp.242 - 252

Aim: Similar protective effect of ischemic and ozone oxidative preconditioning (OzoneOP) in hepatic ischemia-reperfusion (I/R) injury was demonstrated, providing evidences that both preconditioning settings shared similar biochemical mechanisms of protection. We investigated the effects of OzoneOP on liver regeneration after 70% partial hepatectomy (PHx) in rats. Methods: Rats were divided into three groups: PHx, I/R + PHx, and OzoneOP + I/R + PHx groups. Ozone (intraperitoneal, 1.2 mg/kg) was given to rats subjected to I/R and 70% hepatectomy daily five times before operation. At 24 hr and 48 hr after resection, samples were collec . . .ted for the measurement of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor alpha (TNF-?), and interleukin-6 (IL-6). Moreover, liver regeneration rate, proliferating cell nuclear antigen (PCNA) labeling index, mitotic index, and histopathological examination were evaluated. Results: OzoneOP reduced liver injury determined by liver histology and serum transaminases. There was a rise in serum TNF-? and IL-6 levels in the I/R + PHx group whereas OzoneOP significantly decreased the rise in the level of TNF-? but not IL-6 on the 24 hr and 48 hr of reperfusion. Moreover, liver regeneration in OzoneOP + PHx group, as assessed by the regenerated liver weight, mitotic, and PCNA-labeling index, was significantly improved when compared to I/R + PHx group. Conclusion: These results suggest that OzoneOP ameliorates the hepatic injury associated with I/R and has a stimulatory effect on liver cell regeneration that may make it valuable as a hepatoprotective modality. © 2013 Informa Healthcare USA, Inc Daha fazlası Daha az

Effects of ozone oxidative preconditioning on radiation-induced organ damage in rats

Gultekin F.A. | Bakkal, Bekir Hakan | Guven B. | Tasdoven I. | Bektas S. | Can M. | Comert M.

Article | 2013 | Journal of Radiation Research54 ( 1 ) , pp.36 - 44

Because radiation-induced cellular damage is attributed primarily to harmful effects of free radicals, molecules with direct free radical scavenging properties are particularly promising as radioprotectors. It has been demonstrated that controlled ozone administration may promote an adaptation to oxidative stress, preventing the damage induced by reactive oxygen species. Thus, we hypothesized that ozone would ameliorate oxidative damage caused by total body irradiation (TBI) with a single dose of 6 Gy in rat liver and ileum tissues. Rats were randomly divided into groups as follows: control group; saline-treated and irradiated (IR) . . .groups; and ozone oxidative preconditioning (OOP) and IR groups. Animals were exposed to TBI after a 5-day intraperitoneal pretreatment with either saline or ozone (1 mg/kg/day). They were decapitated at either 6 h or 72 h after TBI. Plasma, liver and ileum samples were obtained. Serum AST, ALT and TNF-? levels were elevated in the IR groups compared with the control group and were decreased after treatment with OOP. TBI resulted in a significant increase in the levels of MDA in the liver and ileal tissues and a decrease of SOD activities. The results demonstrated that the levels of MDA liver and ileal tissues in irradiated rats that were pretreated with ozone were significantly decreased, while SOD activities were significantly increased. OOP reversed all histopathological alterations induced by irradiation. In conclusion, data obtained from this study indicated that ozone could increase the endogenous antioxidant defense mechanism in rats and there by protect the animals from radiation-induced organ toxicity. © The Author 2012. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Therapeutic Radiology and Oncology Daha fazlası Daha az

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

Bakkal, Bekir Hakan | Gultekin F.A. | Guven B. | Turkcu U.O. | Bektas S. | Can M.

Article | 2013 | Brazilian Journal of Medical and Biological Research46 ( 9 ) , pp.789 - 796

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopat . . .hological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage Daha fazlası Daha az

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