BACKGROUND/AIMS: The objective of this study was to elucidate the underlying antioxidant mechanism of aqueous extract of Piper betle (PB) in aging rats. The nuclear factor erythroid 2-related factor 2 (Nrf2)/ARE pathway involving phase II detoxifying and antioxidant enzymes plays an important role in the antioxidant system by reducing electrophiles and reactive oxygen species through induction of phase II enzymes and proteins. METHODS: Genes and proteins of phase II detoxifying antioxidant enzymes were analyzed by QuantiGenePlex 2.0 Assay and Western blot analysis. RESULTS: PB significantly induced genes and proteins of phase II and antioxidant enzymes, NAD(P)H quinone oxidoreductase 1, and catalase in aging mice (p < 0.05). The expression of these enzymes were stimulated via translocation of Nrf2 into the nucleus, indicating the involvement of ARE, a cis-acting motif located in the promoter region of nearly all phase II genes. CONCLUSIONS: PB was testified for the first time to induce cytoprotective genes through the Nrf2/ARE signaling pathway, thus unraveling the antioxidant mechanism of PB during the aging process.
BACKGROUND/AIMS: The objective of this study was to elucidate the underlying antioxidant mechanism of aqueous extract of Piper betle (PB) in aging rats. The nuclear factor erythroid 2-related factor 2 (Nrf2)/ARE pathway involving phase II detoxifying and antioxidant enzymes plays an important role in the antioxidant system by reducing electrophiles and reactive oxygen species through induction of phase II enzymes and proteins. METHODS: Genes and proteins of phase II detoxifying antioxidant enzymes were analyzed by QuantiGenePlex 2.0 Assay and Western blot analysis. RESULTS:PB significantly induced genes and proteins of phase II and antioxidant enzymes, NAD(P)H quinone oxidoreductase 1, and catalase in aging mice (p < 0.05). The expression of these enzymes were stimulated via translocation of Nrf2 into the nucleus, indicating the involvement of ARE, a cis-acting motif located in the promoter region of nearly all phase II genes. CONCLUSIONS:PB was testified for the first time to induce cytoprotective genes through the Nrf2/ARE signaling pathway, thus unraveling the antioxidant mechanism of PB during the aging process.