Delineation of gamma irradiation (60Co) induced oxidative stress by decrypting antioxidants and biochemical responses of microalga, Chlorella sp.

Abstract

The use of different radiation technologies are becoming more popular in health care (radiotherapy) and food processing. On the other hand, gamma (γ) radiation is a potential ionizing radiation that can generate huge amount of free radicals and Reactive Oxygen Species (ROS) cause a potential damage to important macromolecules in the cell. Therefore, information on biochemical components significantly need attention for their potential usefulness in counteracting gamma radiation-induced oxidative damage. Chlorella is an unicellular microalga enrich with high protein contents and other potential nutritional supplements. However, the information about the change of active biochemical attributes by the effects of gamma radiation on Chlorella is scanty. Hence, this is highly significant to assess the impacts of gamma radiation on microalga Chlorella sp. (BUACC06). The main objectives of this study is to unlock the information of the change of phytochemicals and antioxidants content in response to γ-irradiation on Chlorella sp. (BUACC06). This strain was treated with acute doses of γ-irradiation (0.01 kGy, 0.05 kGy, 0.075 kGy of 60 Co). The effect of higher dose γ-irradiation resulted in a decline in growth, total phenolic, total flavonoid, antioxidant activity, free radical scavenging and alternation of pigmentation; these could be due to the accumulation of radiation-induced ROS in the cell. Further, protein content and antioxidant enzyme activities were increased as increasing of dose and the effective dose was 0.075 kGy. It was concluded that the administration of Chlorella sp. showed radio resistance response to low dose of gamma radiation by synthesize more proteins, carotenoids, and active antioxidant compounds as radio-protective phytochemicals. This gamma radiation could be used as novel effective method to activate biosynthesis of certain bioactive compounds in algal cells to establish improved varieties of microalgae.