Comparison of DPPH and ABTS assays for determining antioxidant potential of water and methanol extracts of Spirulina platensis

Present research was to evaluate and compare the antiradical and antioxidant activities of extracts from Spirulina platensis. In the present study, three extracts (Water, absolute methanol and 50% methanol in water) were analyzed for the total phenolic compounds, phycobiliprotein content: Antiradical and antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging methods at 100 and 200 μg/mL. Results revealed that, absolute methanol extract recorded the highest number of antiradical units 1 mg extract followed in descending order by that of water while the lowest number was that of aqueous methanol (against DPPH and ABTS radical methods) and these correlated with chemical constituents of extract from phenolic and phycobiliprotein compounds. It is elucidated that selection of the cyanobacterium (Spirulina platensis) very important for consumer’s health, as it is considered as potential sources of dietary antioxidants.