The daily uptake of food, supplemented with antioxidants, shows several health benefits and is advised to be taken reg-ularly in order to lead a healthy life as well as to avoid many diseases. However, a few natural antioxidants are also generated in the human body, but the imbalance between natural antioxidants and free radicals creates many health hazards. Hence, synthetic antioxidants can be used as health promoters to prevent the oxidative stress caused by reactive oxygen species. But the adverse effects of synthetic antioxidants call for a new natural source of antioxidants. In this regard, microalgae have been proven to be a potential source of natural antioxidants. Therefore, an attempt has been made to study the comparative antioxidant activity of Chlorella sp. JD-2016, Oscillatoria sp. (MK636802) and Desertifilum dzianense (MK634687) isolated from Chilika Lake. Antioxidant activity of the crude extracts from the aforementioned species was conducted by quantifying the total antioxidant activity, DPPH assay, total phenol and total flavonoid content. All the pigments except carotenoids were high in the chloroform extract of Desertifilum dzianense, while carotenoid was found to be higher in Oscillatoria sp. The reverse results were observed in the methanol extract of the algal isolates. Total anti-oxidant activity was significantly higher in the methanolic extract of the three algae in comparison to the chloroform extract. Maximum DPPH radical scavenging activity was observed in both chloroform and methanol extracts of Deser-tifilum dzianense. Phenol content was found to be higher in the methanol extract of Oscillatoria sp. However, the methanol extract of Chlorella sp. depicts the highest amount of flavonoid content in comparison to other species.

Antioxidants, Free Radicals, Micro-algae, Pigments, ROS