The potential antioxidant effect of N-acetylcysteine on X-ray ionizing radiation-induced pancreas islet cell toxicity.

PURPOSE: Previous research has highlighted the impact of X-ray irradiation-induced organ damage, on cancer patients after radiation therapy. The ionizing radiation-induced oxidative stress causes injury to the pancreatic islet cells of Langerhans. We used histopathological, immunohistochemical, and biochemical analyses to examine α- and ß-cells in the islets of Langerhans in rats undergoing whole-body x-ray ionizing radiation, a group of which was treated with NAC. MATERIAL AND METHODS: Twenty-four male rats were randomly divided into 3 groups, one control, and two experimental groups. Group I (Control) was administered only saline solution (0.09% NaCl) by oral gavage for 7 days. Group II (IR) was administrated whole body single dose 6 Gray ionizing radiation (IR) and saline solution (0.09% NaCl) by oral gavage for 7 days. Group III (IR + NAC) was administered 300 mg/kg NAC (N-acetylcysteine) by oral gavage for 7 days, 5 days before, and 2 days after 6 Gray IR application. RESULTS: In the X-ray irradiation group, we observed diffuse necrotic endocrine cells in the islets of Langerhans. In addition, we found that Caspase-3, malondialdehyde (MDA) levels increased, and insulin, glucagon, and glutathione (GSH) levels decreased in the IR group compared to the control group. In contrast, we observed a decrease in Caspase-3, and MDA levels in necrotic endocrine cells, and an increase in insulin, glucagon, and GSH levels in the IR + NAC group compared to the IR group. CONCLUSION: This study provides evidence for the beneficial effects of N-acetyl cysteine on islets of Langerhans cells with X-ray ionizing-radiation-induced damage in a rat model.

The protective effects of red ginseng and amifostine against renal damage caused by ionizing radiation.

This study aimed to elucidate the effects of amifostine (ethyol) (AM), a synthetic radioprotector, and red ginseng (RG), a natural radioprotective agent, against the toxic effect of ionizing radiation (IR) on kidney tissues through changes in biochemical and histopathological parameters in addition to contributions to the use of amifostine and RG in clinical studies. Five groups were established: Group I (control, receiving only saline by gavage), Group II (IR only), and Group III (IR+AM, 200 mg/kg intraperitoneally (i.p.). Group IV (IR + RG, 200 mg/kg orally once a day for 4 weeks), and Group V (IR+RG+AM, 200 mg/kg orally once/day for 4 weeks before IR and 200 mg/kg AM administered (i.p.) 30 min before IR). All groups, except for the control group, were subject to 6-Gy whole-body IR in a single fraction. 24 h after irradiation, all animals were sacrificed under anesthesia. IR enhanced MDA, 8-OHdG, and caspase-3 expression while decreasing renal tissue GSH levels (p < .05). Significant numbers of necrotic tubules together with diffuse vacuolization in proximal and distal tubule epithelial cells were also observed. The examination also revealed substantial brush boundary loss in proximal tubules as well as relatively unusual glomerular structures. While GSH levels significantly increased in the AM, RG, and AM+RG groups, a decrease in KHDS, MDA, 8-OHdG, and caspase-3 expression was observed, compared to the group subject to IR only (p < .05). Therefore, reactive oxygen species-scavenging antioxidants may represent a promising treatment for avoiding kidney damage in patients receiving radiation.

Are there predictors that can determine neoadjuvant treatment responses in rectal cancer?

BACKGROUND/AIMS: This study aimed to determine a predictive bioindicator that would detect the treatment response of patients diagnosed with rectal cancer and treated with neoadjuvant chemoradiotherapy (nCRT). MATERIALS AND METHODS: The data collected from 37 patients receiving nCRT were retrospectively evaluated. The p53 score and gene instability in MLH1 and MSH2, which are among the DNA mismatch repair (MMR) genes, were evaluated using immunohistochemical methods. The neutrophils-leukocytes ratio (NLR), carcinoembryonic antigen (CEA), and carbohydrate antigen (CA) 19-9 values were obtained as hematological parameters from computer records. The pathologic analysis of the therapy response after nCRT was classified according to the modified grading system by Ryan et al. Results: The changes in the NLR, CEA, and CA19-9 values before and after treatment were statistically significant (p<0.001 and p=0.005). A near significant effect of the decrease of the CEA value in the 5th week after treatment was detected on the pathological response score (p=0.075). The p53 mutation score in those patients with any residue was higher than the total response. Overall, 89.2% of the patients exhibited MMR positivity (stability), and 10.8% of the cases with MRM negativity (instability) had a macroscopic residue. Cases with pathological total response were MRM positive. CONCLUSION: Consequently, in most of the patients treated with nCRT, the treatment caused tumor and nodal remission. In the prediction of this therapy response, hematological and genetic parameters, such as NLR, P53, MLH1, and MSH2, play a predictive role.