Brazilian red propolis extract enhances expression of antioxidant enzyme genes<i>in vitro</i>and<i>in vivo</i>

Abstract

Brazilian red propolis reportedly has reactive oxygen species (ROS) scavenging effects <i>in vitro</i>, but the cellular mechanisms remain unclear. In the present study, the effects of an ethanol extract of Brazilian red propolis (EERP) on the Nrf2-ARE intracellular antioxidant pathway were examined <i>in vitro</i> and <i>in vivo</i>. EERP and its constituents transactivated the reporter gene through the ARE sequence and enhanced the expression of Nrf2-regulated genes in HEK293 cells. It also increased Nrf2 protein in the nucleus, which was partially inhibited by kinase inhibitors. Furthermore, EERP suppressed ROS generation and cytotoxicity induced by <i>tert</i>-butyl hydroperoxide. <i>In vivo</i>, orally administered EERP increased the expression of Nrf2-regulated genes in mice liver. These results suggest that EERP is a potential resource for preventing oxidative stress-related diseases as an Nrf2 inducer.