Reduction of Radiation-Induced Changes in Biophysical Properties of Erythrocytes

The increase in uses of nuclear technologies in power production, medical and industrial applications enhanced the probability of accidental radiation exposure to occupational workers, patients and public, thereafter increasing hazardous health effects. In comparison with planned radiation exposure during diagnosis and therapy, the management of accidental radiation exposure is relatively complicated due to uncertainties in dose, duration, organs involved in radiation exposure. Although radiation accidents are not common, human error, failure to follow safety precautions and inadequate control and regulation of radiation sources have led to deaths and significant exposures among workers and members of the public. Treatment of the victim in this case needs information and measurements that may take time in order to determine the suitable therapeutic strategy for its case. However, after the event of the radiation accident, it will be important to provide an agent that would mitigate the effects of exposure to ionizing radiation and can promote or increase the efficiency of the treatment. Ideally this agent would be long-lasting, be easily administered (preferably orally) and possesses low toxicity. Development of agents for prophylaxis, mitigation and treatment of radiation injury is an important task for radiological studies. The aim of the present work is to study the prophylactic and mitigation effect of poly-MVA (a dietary supplement of Palladiumlipoic acid nano-complex) against acute whole body gamma irradiation through measurements of biophysical changes in blood erythrocytes of rats. Adult male rats were exposed to 6 Gy single dose from Cs- 137 source. The animals received daily oral administration of 2ml/Kg body weight of poly-MVA with three different time intervals. The prophylactic effect was examined by two modes of administration: first mode was uptake of poly-MVA for two weeks before irradiation then the administration was stopped and the second animal group received continuous administration for two weeks before and two other weeks after irradiation (total time of administration 28 days). While the mitigation effect of poly-MVA was evaluated by its daily administration immediately after irradiation for two weeks. Measurements had been carried out include determination of cellular antioxidant enzymes (Glutathione (GSH), catalase and superoxide dismutase) and lipid peroxidation in liver homogenate. The rheological properties of blood, electrical properties, osmotic fragility and scanning electron microscope photography of erythrocytes were also performed. The electrical properties of erythrocytes suspension were measured in the frequency range 40 kHz to 5 MHz using LCR meter HIOKI 3531. The erythrocyte normal hemolysis, mean corpuscular hemoglobin concentration, mean corpuscular volume, hemoglobin concentration and hematocrit were also measured. The results showed that exposure to radiation resulted in a significant decrease in cellular antioxidant enzymes (GSH, Catalase and SOD) and decrease in the AC conductivity, relative permittivity, area under the loss curve, membrane effective capacitance, blood Bingham viscosity, yield stress and aggregation index. Furthermore it induced slightly increase in average osmotic fragility of erythrocytes accompanied by decrease in osmotic dispersion and remarkable modification of erythrocytes morphology. It also caused significant increase (75%) in the lipid peroxidation 1 day after exposure to radiation. The later change persisted until the 14th day recorded after irradiation. Oral uptake of poly-MVA showed markedly elevation in the concentration of antioxidant enzymes (GSH, Catalase and SOD), while it produced a significant decrease in blood Bingham viscosity and yield stress with a non significant change in aggregation index, accompanied by a significant increase in average osmotic hemolysis and osmotic dispersion which continued increasing with time of poly-MVA administration. The administration of poly-MVA after irradiation alleviated the radiation-induced damage as appeared from the non-significant change in the measured parameters compared to control. It also showed improvement in the observed parameters. The group which received continuous administration, before and after irradiation, showed better results compared to the group which received administration before irradiation only. The present work gives insight on the radio-protective role of poly-MVA and recommends that it can be used as prophylactic as well as mitigator agent on planned and accidental radiation exposure.