Evaluation of the total phenolic content and primary antioxidant activity of various extracts of Amaranthus tricolor Linn

Abstract

The total phenolic contents and antioxidant potentials of aqueous dried leaf (AD), methanolic (MN & MS) and petroleum ether (PE) extracts of Amaranthus tricolor were evaluated. The free radical scavenging activity, ferric reducing ability and total antioxidant capacity of the extracts were tested using three different in vitro antioxidant systems (2,2-Diphenyl-1-Picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP) and Phosphomolybdenum assays). The AD extracts exhibited the highest total phenolic contents, while PE extracts exhibited the least. AD and PE extracts exhibited significant antioxidant activities but MN and MS extracts showed lowest activities. However the total antioxidant capacity as depicted by phosphomolybdenum assay was higher in MN than in PE extracts. A strong correlation between the DPPH and FRAP values was observed (R2=0.8390). The antioxidant assays also showed significant correlations with the total phenolic contents.