In the present study, the antioxidant activity of successive solvent extracts of Indigofera astragalina was evaluated by different in vitro antioxidant assay models. The prepared solvent extracts were screened for the antioxidant and radical scavenging activity on ABTS radical cation, DPPH free radical, hydrogen peroxide, superoxide radical and hydroxyl radical. Among the prepared extracts, ethanol and ethyl acetate extracts showed prominent activity against the tested models. Aqueous extract showed moderate activity in all the models next to ethyl acetate. Hexane extracts fails to exhibit the antioxidant and radical scavenging activity in all the tested models.
Chloroform extract did not produce significant activity. The antioxidant and free radical scavenging activities of the extracts were compared with standard antioxidants like ascorbic acid and rutin. Preliminary phytochemical screening revealed that ethanol and ethyl acetate extracts are rich in flavonoids, polyphenols, tannins and saponins. The radical scavenging and antioxidant activity of the extracts may be due to the presence of these kinds of phytochemicals in the extract. Therefore, the plant could be considered as a very good antioxidant source with therapeutic potential.
Key Words: Indigofera astragalina, antioxidant, radical scavenging, flavonoids, phenols, phytochemicals.