A detailed study has been performed on the antioxidant activity of the acetone and methanol extracts of the stem bark of the plant, Shorea roxburghii. The total phenolic content and antioxidant activity of the extracts were determined by DPPH, radical scavenging, ferric ion reducing power, hydroxyl radical, ABTS(.) radical scavenging and hydrogen peroxide scavenging activities. Reducing efficiency of the S. roxburghii towards silver nanoparticles has been evaluated using surface plasmon resonance and transmission electron microscope. Spherical shapes of particles with 4-50 nm have been reported. Formation of silver nanoparticles ascertains the role of the water soluble phenolic compounds present in S. roxburghii. Both acetone and methanol extracts of S. roxburghii stem bark was found to be a potent antioxidant. This work provides a scientific support for the high antioxidant activity of this plant and thus it may find potential applications in the treatment of the diseases caused by free radical. The extract of this plant could be used as a green reducing agent for the synthesis of Ag nanoparticles.
Keywords: DPPH; Ferric reducing power; Hydrogen peroxide; Hydroxyl radical; Shorea roxburghii; Silver nanoparticles.