Inhibitory Effect of High Dose of X-ray on Plasmodium berghei in Cell Culture
L. M. Spencer 1, A. Foinquinos 1, J. Davila 2, L. Sajo-Bohus 1*, M. De Santis 1, E. Salcedo 2
1 Universidad Simon Bolivar, Valle de Sartenejas, Baruta, Caracas 1080A - Venezuela
2 Servicio de Radioterapia La Trinidad. Centro Medico Docente la Trinidad, Baruta. Caracas – Venezuela
High doses of X-ray has been employed succefuly to reduce bioactivity in cell culture; here we present a study of the radiation effect on Plasmodium berghei. Malaria, one of the most important infections disease problems in the world, is caused by protozoan parasites of the genus Plasmodium. This disease is responsible for hundreds of the millions of clinical cases and more than one million deaths per year for that, malaria is a priority and the WHO estimates that half of the world population is at risk. Therefore it would be useful to study how the absorbed ration dose inactivated the parasite (Plasmodium berghei) in rodent model (BALB / c mice), by applying X-ray irradiation. The dose was increased from 10 at to 100 Gy in parasitized red blood cells (RBC) with merozoite stage using in vitro short cultures. Also the reduction of the bioactivity was determined by intra-peritoneal inoculations of irradiated parasites. The parasitaemia was assessed daily on smears made from tail blood and stained with Giemsa’s reagent. Besides, the effect of irradiation was evaluated using immunological test as indirect immunofluorescence assay (IFA). The results of this study showed that the most effective radiation for inactivation of parasites is above 50 Gy. The immunofluorescence pattern showed a different distribution of the fluorescence pattern on parasites for higher irradiatin time. Results show direct correlation between the effect of irradiated parasites and parasitaemia in the group of mice infected with RBC above the mentioned dose. Our results indicated that the threshold to inactivate the parasites is between 30 to 50 Gy.