Abstract

The purpose of this study was to investigate the protective effects of purple waxy corn extract (Zea may L.) on aflatoxin B1-induced cytotoxicity, oxidative stress and micronuclei in HepG2 cells. Purple waxy corn extract contained phenolics (187.15-341.65 µg gallic acid/mg), flavonoids (0.55-21.35 µg quercetin/mg) and anthocyanins (43.70-220.43 mg cyanidin-3-glucoside/l). Antioxidant activities of the extracts were measured using oxygen radical absorbance capacity (1410.70-2214.49 µM trolox/mg) and ferric reducing/antioxidant power (292.38-612.38 µM trolox/mg) assays. There were significant correlations between phenolic, flavonoid and anthocyanin content and antioxidant activities (R= 0.740-0.778) of purple waxy corn extract. Studies in HepG2 cells found that 0.5 and 1 mg/ml purple waxy corn extract increased cell viability in AFB1-treated HepG2 cells. Purple waxy corn extract reduced intracellular ROS production, increased GSH content and antioxidant enzyme GR, GPx and GST activities and micronucleus in aflatoxin B1-treated HepG2 cells. Therefore, purple waxy corn extract reduced aflatoxin B1 toxicity through induction of antioxidant activities and, thus, inhibited oxidative stress-induced DNA damage caused by aflatoxin B1.