This study aimed to explore whether PARP-1 regulatory pathway mediated X irradiation induced cell cycle arrest and apoptosis or not. In this regard, colonic mucosal injury caused by whole-body X-irradiation induced apoptosis through PARP-1, caspase 3 and p53 regulatory pathway were evaluated in experimental rat models. Eighteen Wistar albino rats were divided into three groups. Two radiation groups received 8.3 Gy dose of whole-body X-irradiation as a single dose and the control group received physiological saline intraperitoneally. Radiation groups were sacrificed after 6 h and 4 days of irradiation. PARP-1 and caspase 3 expression in the nuclei of colonic crypt cells significantly increased 6 h after irradiation, and declined 4 days after irradiation. In conflict with other studies that reported p53 as not being expressed widely in colonic mucosa, in our study the expressions of p53 were elevated both in the cytoplasm and in the nucleus of the crypt cells, especially 6 h after irradiation. In the radiation groups, colonic mucosal injury score was significantly elevated compared with that of the control group. Our data demonstrated that PARP-1, caspase-3 and p53 expression increased in colonic mucosa 6 h after irradiation.

Purpose: In this study, we tested the effects of L-carnitine (LC) on radiation-induced ileal mucosal damage. Materials and methods: Thirty Wistar albino rats were divided into five groups. The control group received physiological saline intraperitoneally (i.p.). Radiation-1 and radiation-2 groups received whole-body X-irradiation of 8.3 Gy as a single dose. These groups were sacrificed at the 6th hour and 4th day after irradiation, respectively. The Radiation-1 + LC and the radiation-2 + LC groups received the same dose irradiation plus a daily dose of 200 mg/kg LC. LC was applied one day before and for four days after irradiation. Results: The levels of serum monocyte chemotactic protein-1 (MCP-1) and interferon gamma (IFN-γ) were significantly higher in the radiation groups when compared with the control. Treatment with LC decreased the serum MCP-1 and IFN-γ levels considerably. In the radiations groups, the Chiu score was significantly elevated compared with that of the control group. However, LC administered prior to the irradiation reduced the severity of mucosal damage. The number of apoptotic cells of the ileal crypt in the irradiated rats increased from the 6th hour after irradiation and then decreased at 4th day. Conclusions: Our data demonstrated that LC may be beneficial to radiation enteritis.

Context: Carbon tetrachloride (CCl4) is a chemical that is still widely used in industry and has been shown to cause structural defects in rat testicles through oxidative stress. Aims: In our study, the effect of curcumin on CCl4-mediated testicular damage was investigated. Methods: Twenty-four adult Wistar albino male rats weighing 300–350 g were divided into four groups: control group (olive oil was applied by gavage every consecutive day for 3 weeks); curcumin and CCl4 + curcumin groups (200 mg/kg curcumin dissolved in olive oil was given by gavage once a day, every consecutive day for 3 weeks); and CCl4 and CCl4 + curcumin groups (0.5 mL/kg CCl4 was dissolved in olive oil at a ratio of 1/1 and given by i.p. injection every other day for 3 weeks). Tissue samples were examined histopathologically, histomorphometrically, immunohistochemically and biochemically. Key results: CCl4 disrupted both testicular morphology and testosterone synthesis, whereas curcumin treatment resulted in an improvement in testicular morphology and biochemical parameters, as well as a decrease in caspase-3 and tumour necrosis factor-α expression. Conclusions: Curcumin has a protective effect on testicular tissue damage caused by CCl4 with its anti-inflammatory, antiapoptotic and antioxantioxidant properties. Implications: Curcumin can prevent testicular damage due to CCl4, an environmental pollutant.