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

Mentha suaveolens 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 M. suaveolens, its cytoprotective activity against oxidative stress has not been reported yet. The objective of this study was to determine the protective activity of M. suaveolens aqueous extract (MSAE) against hydrogen peroxide- (H(2)O(2)-) induced oxidative stress and apoptosis in human keratinocyte HaCaT cells. MSAE pretreatment decreased H(2)O(2)-induced cytotoxicity and suppressed H(2)O(2)-induced intracellular ROS generation. Furthermore, MSAE suppressed expression levels of H(2)O(2)-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 H(2)O(2) 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.