Reactive oxygen metabolites and anti-oxidative defenses in aspirin-induced gastric damage in rats: Gastroprotection by Vitamin E

OBJECTIVE: It has been proposed that neutrophil infiltration and oxygen radicals may be the important prime events that lead to mucosal injury induced by aspirin. Vitamin E acts as a potent antioxidant, and is capable of scavenging free radicals. The aim of this study was to evaluate the oxygen metabolites and anti-oxidative defenses in acute gastric damage induced by aspirin and to find the effects of Vitamin E. METHODS: Ninety-six Wistar rats were divided into four groups of 24 rats each as follows: (1) the control group; (2) the ASA group that received 300mg/kg of ASA; (3) the Vitamin E plus ASA group and (4) the Vitamin E group that received Vitamin E (75 units) alone. At 3, 6, 9 and 24h after the drug administration, six rats were randomly selected from each group and gastric mucosal injury, prostaglandin E2, and the activities of myeloperoxidase, xanthine-oxidase, superoxide dismutase, glutathione peroxidase as well as glutathione level were measured and compared between the groups. RESULTS: Oral administration of ASA caused acute gastric erosions and an increase in myeloperoxidase activity. It also decreased prostaglandin E2, superoxide dismutase activity, glutathione peroxidase activity and glutathione level. Concomitant administration of Vitamin E and ASA restored all the changes toward the control levels. CONCLUSION: Free radicals and suppression of anti-oxidizing enzymes play important roles in gastric damage induced by aspirin. Increased myeloperoxidase activity suggests that activated neutrophils may be a major source of free radicals. Vitamin E protects against ASA-induced damage due to its anti-oxidizing activity.     

Action fluency identifies different sex,age, global cognition,executive function and brain activation profile in non-demented patients with Parkinson’s disease

Journal of Neurology - Patients with Parkinson’s disease (PD) have difficulties processing action words, which could be related to early cognitive decline. The action fluency test can be used...     

Gold nanoparticles in combination with megavoltage radiation energy increased radiosensitization and apoptosis in colon cancer HT-29 cells

Purpose: Gold nanoparticles (GNP) act as a radiosensitizer in radiation therapy. However, recent studies have shown contradictory evidence in terms of radiosensitization in the presence of GNP combined with X-ray megavoltage energy (MV) on different cell types. In this study, the effect of GNP on radiosensitization enhancement of HT-29 human colorectal cancer cells at MV X-ray energy was evaluated.

Materials and methods: The cytotoxicity and radiosensitization of GNP were evaluated in HT-29 human colorectal cancer cells by MTS-assay and multiple MTS-assay, respectively. Cellular uptake was assayed using graphite furnace atomic absorption spectrometry (GFAAS). Apoptosis and cell cycle progression were determined by an Annexin V-FITC/propidium iodide (PI) kit and PI/RNase solution with flow cytometry, respectively.

Results: Results showed that the cell viability of the HT-29 cells was not influenced by exposure to different concentrations of GNP (10–100 μM). GNP alone did not affect the cell cycle progression and apoptosis. In contrast, GNP, in combination with radiation (9?MV), induced more apoptosis. The interaction of GNP with MV energy resulted in a significant radiosensitization enhancement compared with irradiation alone.

Conclusion: It was concluded that GNP may work as bio-inert material on HT-29 cancer cells and their enhancement of radiosensitization may be due to increase in the absorbed irradiation dose.