Effects of Mining-impacted Polished Rice on the Glutathione Peroxide and Glutathione S-transferase Activities, and Oxidative Stress-induced Apoptosis Signal Regulating Kinase 1, p38 Mitogen-activated Protein Kinase Isomer, and Jun N-terminal Kinase in Human Keratinocytes Cell

In toxic elements (TEs)-contaminated polished rice, human keratinocytes cell viability was significantly inhibited to a maximum of 30%. Glutathione peroxide (GPx) and glutathione S-transferase (GST) activities, and gene activation of apoptosis signal regulating kinase 1 (ASK1) were significantly induced at 72 h. Strong activation in p38α-, weak activation in p38δ-, and no expression in p38 β,γ-mitogen-activated protein kinase (MAPK), and jun N-terminal kinase (JNK) were observed at 24 and 72 h. At protein level, the ASK1 and p38 MAPK activities were found to be strongly stimulated at 72 h, whereas phosphorylated ASK1 and p38 MAPK proteins were not detected in contaminated polished rice. Both JNK and phosphorylated JNK were not activated at 24 and 72 h. These results demonstrate that mine-impacted polished rice induced HaCaT cell toxicity associated with oxidative stress.