Studies on the active components and antioxidant activities of the extracts of Mimosa pudica Linn. from southern China

Background: The total flavonoid (TF) and total phenolic (TP) contents of the ethanol extracts of the whole plant, stem, leaf, and seed of Mimosa pudica Linn belonging to the genus Mimosa (Family: Fabaceae alt. Leguminosae), which originates from the subtropical regions of southern China, were determined in this experiment. Materials and Methods: The antioxidant activity of the extracts and 5 flavonoid monomers of M. pudica Linn. were also evaluated by 2 assays, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing/antioxidant power (FRAP) assays. In addition, correlation analysis was also made in the present study. Results: The results showed that leaf extracts contained the highest amount of TF and TP, and the content was significantly higher than that found in other parts of the plant. Moreover, the sequence of antioxidant activity of the ethanol extracts was as follows: leaf > the whole plant > seed > stem; the sequence of the 5 flavonoid monomers was as follows: 5,7,3′,4′-tetrahydroxy-6-C-[β-D-apiose-(1→4)]-β-D-glycopyranosyl flavone (1) > isorientin (2) > orientin (3) > isovitexin (4) > vitexin (5) , and the antioxidant activity of compound 1 is equivalent to the synthetic antioxidant trolox or a bit stronger than trolox, and significant correlations were found among the active ingredient contents and the results of antioxidant activity. Conclusion: The present study suggested that M. pudica Linn. could be a potential rich source of natural antioxidants.