Triphlorethol-A induces heme oxygenase-1 via activation of ERK and NF-E2 related factor 2 transcription factor.

Triphlorethol-A, phlorotannin found in Ecklonia cava, induced heme oxygenase-1 (HO-1) expression at mRNA and protein levels, leading to increased HO-1 activity. Transcription factor NF-E2 related factor 2 (Nrf2) regulates antioxidant response element (ARE) of phase 2 detoxifying and antioxidant enzymes. Triphlorethol-A increased nuclear translocation, ARE binding, and transcriptional activity of Nrf2. Triphlorethol-A exhibited activation of ERK and U0126, inhibitor of ERK kinase, suppressed triphlorethol-A induced activation of Nrf2, finally decreased HO-1 protein level. Taken together, these data suggest that triphlorethol-A augments cellular antioxidant defense capacity through induction of HO-1 via ERK-Nrf2-ARE signaling pathway, thereby protecting cells from oxidative stress.