Antioxidant activity and the estimation of total phenolic and flavonoid contents of the root extract of Amaranthus spinosus

Abstract

Amaranthus spinosus (204.84g) roots were extracted successively with petroleum ether (80-100 and methanol by Soxhlet process. All the extracts were subjected to Total phenolic content, Total flavonoid content and antioxidant activity using DPPH assay and Ferric Reducing Antioxidant Power assay (FRAP). Ethyl acetate extract showed the highest antioxidant activity with 61.47 ± 4.8 % inhibitions at a higher concentration. The three solvents; Methanol, ethyl acetate and Pet-ether extracts showed moderate activity when compared with the standard. The total phenol content was 48.01 ± 2.0, 135.22 ± 3.7 and 46.01± 1.3 mg g -1 in the methanol, ethyl acetate and pet-ether extracts respectively. In all, ethyl acetate extract generally, exhibited the highest values of antioxidants. The potency of radical scavenging effect of A. spinosus extract was about 2 times less than the synthetic antioxidant Ascorbic acid. The greater amount of phenolic compounds leads to more potent radical scavenging effect as shown by A. spinosus extract