Antioxidant Potential and its Correlation with the Contents of Phenolic Compounds and Flavonoids of Methanolic Extracts from Different Medicinal Plants

Abstract

In this study, methanolic extracts of ten species of medicinal plants collected at Gurupi, Tocantins state, Brazil, were subjected to assays of neutralization of ABTS and DPPH radicals, ferric reducing antioxidant power (FRAP), and reducing power to investigate their antioxidant potential. The results revealed that the plants that were investigated exhibited strong antioxidant activities. The species Buchenavia tetraphylla, Buchenavia tomentosa, and Lippia sidoides displayed the highest activities, as well as the largest contents of phenolic compounds and flavonoids. Using Pearson's correlation coefficient, we could observe correlations between the contents of phenolic compounds and the antioxidant activities in all the assays. On the other hand, we could not observe satisfactory correlations between the flavonoid contents and these activities, which suggest that the phenolic compounds provide the main contributions to the antioxidant potential displayed by the medicinal plant extracts that were studied.