Protective Effects of Cashew (Anacardium Occidentale) Leaf Extract Against Hydrogen Peroxide-Induced Oxidative Stress in Intestinal Caco-2 Cells

Abstract

Oxidative stress with the overproduction of free radicals results in several chronic disorders of the gastrointestinal tract. The cashew (Anacardium occidentale) leaves contain high levels of various antioxidants, anti-inflammatory agents and exhibit anticytotoxic properties. This study was aimed to investigate the protective effects of cashew leaf extract against hydrogen peroxide (H₂O₂) induced oxidative stress in Caco-2 cells. Cells were treated with H₂O₂ with and without various concentration of cashew leaf extract (CLE) or quercetin that was used as positive control. Cell viability was assessed by the MTT assay. Intracellular reactive oxygen species (ROS) was evaluated using 2′,7′-dichlorofluorescein (DCF) fluorescence. Mitochondrial membrane potential (MMP) was monitored using rhodamine123 (Rh123) and caspase-3 activity was measured using a fluorometric assay kit. The results showed that exposure of Caco-2 cells to H₂O₂ increased ROS generation, disrupted MMP, activated caspase-3 activity and decreased cell viability that partly resulted from apoptosis. Treatment with CLE or quercetin significantly reduced the level of ROS, improved MMP, inhibited caspase-3 activation and increased cell viability compared to H₂O₂ treatment alone. The greater suppressing H₂O₂-induced ROS generation were observed with CLE treatment compared to quercetin at the same concentrations. These results demonstrated the protective activities of CLE against H₂O₂ induced oxidative stress in intestinal Caco-2 cells.