Protective Effects of Aqueous Extract of <i>Mentha suaveolens</i> against Oxidative Stress-Induced Damages in Human Keratinocyte HaCaT Cells

Abstract

<i>Mentha suaveolens</i> is an aromatic herb that has a wide range of biological activities, including antimicrobial, antifungal, anti-inflammatory, and hepatoprotective properties. Although there are a few reports on the antioxidant property of <i>M. suaveolens</i>, its cytoprotective activity against oxidative stress has not been reported yet. The objective of this study was to determine the protective activity of <i>M. suaveolens</i> aqueous extract (MSAE) against hydrogen peroxide- (H₂O₂-) induced oxidative stress and apoptosis in human keratinocyte HaCaT cells. MSAE pretreatment decreased H₂O₂-induced cytotoxicity and suppressed H₂O₂-induced intracellular ROS generation. Furthermore, MSAE suppressed expression levels of H₂O₂-induced apoptotic genes such as cleaved caspase-3, caspase-9, and cleaved poly (ADP-ribose) polymerase (PARP). Pretreatment with MSAE induced expression of phase II enzyme such as HO-1 through translocation of NF-E2-related factor (Nrf2) upon H₂O₂ exposure. These results revealed that the cytoprotective effect of MSAE against oxidative stress-induced cell death was associated with activation of Nrf2-mediated phase II enzyme expression.