DPPH method was found to be used mostly for the in vitro antioxidant activity evaluation purpose while LPO (Lipid peroxidation) was found as mostly used in vivo antioxidant assay.
Antiradical activities of various antioxidants were determined using the free radical, 2.2-Diphenyl-l-pict3,1hydrazyl (DPPI-I°) in vitro. In its radical form, DPPI-I° has an absorption band at 515 nm which disappears upon reduction by an antiradical compound.