The antioxidant activity of O. gratissimum was analyzed by in vitro antioxidant assays such as DPPH, iron chelating, ABTS, nitric oxide and hydroxyl radical scavenging which showed a potent free radical scavenging activity with IC50 values of 470 ± 28.6, 330 ± 17.4, 133 ± 7.2, 83 ± 4.4, 260 ± 12.7 μg/mL. OGE was checked for its macromolecules such as DNA, protein and lipidperoxidation damage protective activities.