Sargassum horneri ethanol extract containing polyphenols attenuates PM-induced oxidative stress via ROS scavenging and transition metal chelation

Abstract

Particulate matter (PM) generate oxidative stress and damage to exposed cells. In this study, we investigated the antioxidant mechanisms of Sargassum horneri ethanol extract (SHE) against PM in lung epithelial cell, MLE-12 cells. We discovered that transition metals in PM adhered to the surfaces of MLE-12 cells, triggering intracellular ROS generation and lipid peroxidation. The PM-induced oxidative stress in turn reduced the antioxidant enzymes activities. This disturbance in redox balance further produced oxidative DNA damage and eventually led to apoptotic cell death as expected. However, we uncovered that SHE containing polyphenols chelated the transition metals (Si, Mg, Al, Ti, and Fe) on the surfaces of MLE-12 cells. In addition, SHE not only attenuated the intracellular ROS and lipid peroxidation but also regulated antioxidant enzymes to suppress the PM-induce oxidative DNA damage and apoptotic cell death. These results suggest that SHE containing polyphenols contribute to the alleviation of the PM-induced oxidative stress and apoptotic cell death via ROS scavenging and transition metals chelating.