Fucoidan reduces oxidative stress by regulating the gene expression of HO‑1 and SOD‑1 through the Nrf2/ERK signaling pathway in HaCaT cells.

Fucoidan, a sulfated polysaccharide, is found in edible brown algae. In the present study, the molecular mechanisms of fucoidan against mild oxidative stress in human keratinocytes were investigated. The current study indicated that fucoidan significantly augmented the antioxidants heme oxygenase‑1 (HO‑1) and superoxide dismutase‑1 (SOD‑1) via the upregulation of nuclear factor erythroid 2‑related factor 2 (Nrf2) and markedly reduced the cytoplasmic stability of kelch‑like ECH‑associated protein 1. The upregulation of HO‑1 and SOD‑1 detected in the fucoidan‑treated cells may be responsible for the increased resistance to mild oxidative stress, indicating that fucoidan may augment the activities of antioxidant enzymes via stimulating Nrf2. This is the first report, to the best of our knowledge, to demonstrate that fucoidan attenuates oxidative stress by regulating the gene expression of SOD‑1 and HO‑1 via the Nrf2/extracellular signal‑regulated kinase signaling pathway.