Antioxidant properties of apple juice and its protection against Cr(VI)-induced cellular injury.

Reactive oxygen species (ROS) have been shown to cause a broad spectrum of damage to the biological system. ROS-mediated reactions are believed to play a key role in Cr(VI)-induced carcinogenesis. Using electron spin resonance (ESR) spin trapping, the present study shows that apple juice efficiently scavenged hydroxyl radicals generated by Cr(VI) reduction catalyzed byglutathione reductase/NADPH. Apple juice reduced Cr(VI)-induced lipid peroxidation, DNA damage, cell apoptosis, and NF-kappaB activation in human lung epithelial A549 cells. The lipid peroxidation was measured by a colorimetric assay, DNA damage by single cell gel electrophoresis assay, induction of cell apoptosis by flow cytometry, and activation of NF-kappaB by luciferase assay. The results show that through its antioxidant properties, apple juice can protect Cr(VI)-induced cellular injury and may help reduce its carcinogenic potentiaL