Development of a cell-based antioxidant activity assay using-dietary fatty acid as oxidative stressor

The existing cellular antioxidant activity (CAA) assays always use chemical stressors [e.g. 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)] to initiate oxidative stress (OS), which is not accordance with the pathology of OS-related diseases. In contrast to previous cell models, an oleic acid (OA)-induced OS model of the HepG2 cells was developed in the current work. The antioxidant activities (AAs) of the 16 flavonoid standards in the CAA(OA) assay were significantly different from the results of the CAA(AAPH) and peroxyl radical-scavenging assays (PRSA). The AAs of these flavonoids in the PRSA were significantly associated with those of the CAA(AAPH) assay (r = 0.848, P < 0.01). On the other hand, isoflavones and epicatechin could significantly attenuate the OS in the CAA(OA) assay. However, the three flavonoids had no quantifiable M in CAA(AAPH) and PRSA. The aforementioned results suggest that the CAA(OA) assay can probably better reflect the AAs of samples in biological systems. (C) 2013 Elsevier Ltd. All rights reserved.