Disparities of phytochemical constituents and antioxidant activities of some Indigofera species

The current study was intended to examine the difference in the phytochemical and antioxidant profile of nine Indigofera species. With this aim, the species were assessed for total phenolic content, flavonoid content, and antioxidant activity using ferric reducing antioxidant power (FRAP), DPPH free radical scavenging, ferrous ion chelating activity, phosphomolybdenum reducing power, deoxyribose degradation, β-carotene bleaching, nitric oxide scavenging, and superoxide radical scavenging assays. The content of total phenolics and flavonoids ranged from 1.33 to 22.5 mg TAE/g plant material and 0.47 to 5.02 mg QE/g plant material respectively in the various species, while the antioxidant activity as tested with different antioxidant test models varied with the species studied as well as with the solvents used for the extraction. Interestingly, all the tested extracts demonstrated considerable free radical scavenging activity, moreover, I. hirsuta, I. glandulosa, I. linnaei, I. hochstetteri, I. linifolia, and I. trita were found to be the most effective among the species studied. The results indicated the significant differences in phytochemical constituents and the antioxidant activity among the species. The Pearson correlation coefficient analysis exhibited a significant correlation of phenolics and flavonoids with the antioxidant activity.