Changes in biologic markers of oxidative stress and plasma endotoxin levels in gynecologic cancer patients treated with pelvic radiotherapy: a pilot study

Gliclazide protects ionizing radiation-induced intestinal injury in mice by inhibiting oxidative stress and caspase-3

Gliclazide (GLZ), an oral antihyperglycemic medication, has additional beneficial effects, such as anti-inflammatory and antioxidant properties, besides lowering blood glucose levels. In this study, the radio-protective effect of GLZ was evaluated against ionizing radiation (IR)-induced intestinal injury in mice. Eight groups of mice were randomized as follows: control, GLZ (5, 10, and 25 mg/kg), IR (6 Gy), and IR + GLZ (at 5, 10, and 25 mg/kg). GLZ was administered to the mice for eight consecutive days, after which they were exposed to X-rays at a single dose of 6 Gy. After irradiation, biochemical parameters, immunohistochemical, and histological examinations were conducted on the ileum of the mice. IR exposure increased the levels of malondialdehyde and protein carbonyl, while glutathione levels, as oxidative stress biomarkers, decreased. Apoptosis in ileum tissues was also assessed. Furthermore, histopathological changes were observed in the irradiated mice. GLZ treatment significantly mitigated these changes. The administration of GLZ resulted in a marked decrease in caspase-3 immunoreactivity in the ileum of irradiated mice. This preclinical study exhibited that GLZ has a radioprotective effect against intestinal injury by inhibiting oxidative stress and apoptosis.

Sera total oxidant/antioxidant status in lung cancer patients

We investigated oxidative stress parameters in the sera of patients with lung cancer and healthy individuals to evaluate their correlations with lung cancer.Ninety-four lung cancer patients and 64 healthy controls were enrolled after obtaining informed consent. Their sera oxidative stress parameters were measured.Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were significantly different between patients and healthy groups (all P < .001). TAS gradually decreased and TOS and OSI gradually increased from stage I to III, but it did not reach statistical significance (all P > .05). TAS and OSI were significantly different between the nonsmoking and smoking groups, radiotherapy and without radiotherapy groups, chemotherapy and without chemotherapy groups (P < .05), but not TOS (P > .05). In a receiver operating characteristic curve analysis comparing patients with lung cancer with healthy controls, the Youden indices of TOS, TAS, and OSI were 0.541, 0.532, and 1, respectively.The oxidative stress may be correlation with lung cancer staging. Smoking, surgery, radiotherapy, and chemotherapy showed correlation with parts oxidative stress parameters.

Targeting antioxidant enzymes as a radiosensitizing strategy

Radiotherapy represents a major anti-cancer modality and effectively kills cancer cells through generation of reactive oxygen species (ROS). However, cancer cells are commonly characterized by increased activity of ROS-scavenging enzymes in adaptation to intrinsic oxidative stress, leading to radioresistance. Abrogation of this defense network by pharmacological ROS insults therefore is shown to improve radioresponse in preclinical models; some of them are then tested in clinical trials. In this review, we address (1) the importance of ROS in radioresponse, (2) the main systems regulating redox homeostasis with a special focus on their prognostic effect and predictive role in radiotherapy, and (3) the potential radiosensitizers acting through inhibition of antioxidant enzymes.