Evaluation of the effect of Spirulina against Gamma irradiation induced oxidative stress and tissue injury in rats

Many antioxidants have been investigated as hepato-protectors against ionizing radiation induced injury since they reduce the oxidative effect of the reactive oxygen species on normal cells. Spirulina is a potent scavenger of a variety of free radicals. The aim of this study was to investigate the radio-protective effect of Spirulina algae against oxidative stress and tissue injury caused by gamma radiation. Rats were irradiated at two doses of 2 and 4Gy from cesium-137 source. Ten days prior to irradiation, animals received Spirulina daily (300mg/kg body weight i.p.). In the irradiated animal group, the oxidative stress markers malondialdehyde (MDA) was significantly increased in the liver, while a marked decrease in hepatic contents of DNA, and glutathione (GSH).The level of cholesterol, triglyceride (TG), low density lipoprotein (LDL), as well as activitiy of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT), were significantly increased in sera of the irradiated rats. This was coupled with a decreased serum level of high-density lipoprotein (HDL) and total serum protein by irradiation. The administration of Spirulina alone daily for 10 days caused a significant decrease in MDA and produced significant elevation of liver GSH. Moreover, a significant decrease occurred in cholesterol, and TG level with no change in serum LDL or HDL levels in serum. Treatment of rats with Spirulina for 10 days before acute irradiation significantly abolished radiation induced elevation in liver MDA level and significantly maintained hepatic GSH content and CAT activity close to the control values. Pre-irradiation treatment of rats with Spirulina showed a significantly higher hepatic DNA content compared to that of irradiated rats. The level of cholesterol, TG, HDL, LDL as well as the activity of AST, ALT, and GGT in serum was significantly ameliorated when Spirulina was injected before irradiation. In conclusion, the increase in oxidative stress markers and the concomitant change in antioxidant levels indicate the role of oxidative stress in radiation-induced tissue damage. It was concluded that administration of Spirulina algae possess a radio protective capacity against ionizing-radiation induced oxidative stress and organ injury.