LAUSR

The effect on the intracellular reactive oxygen species (ROS) generation, and the antioxidant and cytotoxicity properties of rice bran polysaccharides (RBP) and RBP-metal complexes RBP-Fe(III), RBP-Cu, RBP-Zn and RBP-Ca, were evaluated using atomic absorption spectroscopy (AAS), scavenging activity assays, cell viability assay and fluorescence microscopy. The RBP-metal complexes were prepared using the hydrothermal method. The RBP-Fe(III) complexes were found to be potent scavengers for superoxide (O2-) free radicals. The RBP alone and RBP-Ca complex showed high scavenging activity for 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. In addition, the RBP-Fe(III) complex also showed good biocompatibility and lowered the intracellular ROS levels, while RBP alone, RBP-Zn and RBP-Ca complexes were observed to increase the intracellular ROS level. Our findings suggest that among the tested RBP-metal complexes, RBP-Fe(III) complex is a strong candidate as an antioxidant therapeutic.