{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T12:58:46Z","timestamp":1780318726066,"version":"3.54.1"},"reference-count":25,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2025,4,3]],"date-time":"2025-04-03T00:00:00Z","timestamp":1743638400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Japan Agency for Medical Research and Development (AMED)"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Marine Drugs"],"abstract":"<jats:p>The liver is an active metabolic site that generates high levels of reactive oxygen species (ROS). Oxidative stress has been implicated in the chronicity of hepatitis and hepatitis B virus (HBV) infection. This study aimed to determine the involvement of oxidative stress in HBV-infected cells and the efficacy of natural Nrf2 activators. The intracellular HBV pregenomic RNA copy number relative to total RNA was measured by RT-PCR, and various protein expressions associated with oxidative stress were analyzed by a Western blot analysis. The results showed that the Nrf2, HO-1, Akt, and Bcl-xL proteins were decreased by the continuous infection, indicating that HBV-positive cells were exposed to oxidative stress. The present study evaluated the anti-HBV infection effects of the Nrf2 activator fucoxanthin (Fx), a marine carotenoid from edible biological resources, including the comparative natural Nrf2 activator pteryxin (Ptx). These Nrf2 activators suppressed the HBV pregenomic RNA production in the HBV-infected cells, thus increasing the expression of the proteins of Nrf2 and HO-1. In the persistently infected cells transfected with the HBV genome, the Bcl-xL and Keap1 proteins, which contribute to suppressing the HBx protein involved in the HBV replication, were overexpressed. In particular, the activity of these protein expressions was marked at low concentrations of Fx. This suggests that natural Nrf2 activators may play a significant role in the HBV infection and could be a valuable source for further development through the functional utilization of food resources.<\/jats:p>","DOI":"10.3390\/md23040155","type":"journal-article","created":{"date-parts":[[2025,4,3]],"date-time":"2025-04-03T04:33:43Z","timestamp":1743654823000},"page":"155","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Effect of Nrf2 Activators in Hepatitis B Virus-Infected Cells Under Oxidative Stress"],"prefix":"10.3390","volume":"23","author":[{"given":"Junsei","family":"Taira","sequence":"first","affiliation":[{"name":"Department of Bioresources Technology, National Institute of Technology, Okinawa College, Okinawa 905-2192, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takuya","family":"Kubo","sequence":"additional","affiliation":[{"name":"Department of Bioresources Technology, National Institute of Technology, Okinawa College, Okinawa 905-2192, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiroya","family":"Nagano","sequence":"additional","affiliation":[{"name":"Department of Bioresources Technology, National Institute of Technology, Okinawa College, Okinawa 905-2192, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryuji","family":"Tsuda","sequence":"additional","affiliation":[{"name":"Department of Bioresources Technology, National Institute of Technology, Okinawa College, Okinawa 905-2192, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takayuki","family":"Ogi","sequence":"additional","affiliation":[{"name":"Department of Environment and Natural Resources, Okinawa Industrial Technology Center, Okinawa 904-2234, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1816-6482","authenticated-orcid":false,"given":"Kenji","family":"Nakashima","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tetsuro","family":"Suzuki","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,3]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2022). Hepatitis B, World Health Organization. Available online: https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/hepatitis-b."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"418035","DOI":"10.1038\/nrdp.2018.35","article-title":"Hepatitis B virus infection","volume":"4","author":"Yuen","year":"2018","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"12061","DOI":"10.1128\/JVI.00740-07","article-title":"Hepatitis B virus replication is associated with an HBx-dependent mitochondrion-regulated increase in cytosolic calcium levels","volume":"81","author":"McClain","year":"2007","journal-title":"J. Virol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1016\/j.virol.2008.07.037","article-title":"Identification of functionally important amino acid residues in the mitochondria targeting sequence of hepatitis B virus X protein","volume":"381","author":"Li","year":"2008","journal-title":"Virology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1111\/jvh.12831","article-title":"A direct role for hepatitis B virus X protein in inducing mitochondrial membrane permeabilization","volume":"25","author":"Lee","year":"2018","journal-title":"J. Viral Hepat."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"15460","DOI":"10.1074\/jbc.M309280200","article-title":"Human hepatitis B virus-X protein alters mitochondrial function and physiology in human liver cells","volume":"279","author":"Lee","year":"2004","journal-title":"J. Biol. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.canlet.2012.12.004","article-title":"C-terminal region of HBx is crucial for mitochondrial DNA damage","volume":"331","author":"Jung","year":"2013","journal-title":"Cancer Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1304","DOI":"10.1016\/j.freeradbiomed.2009.07.035","article-title":"Nrf2:INrf2 (Keap1) signaling in oxidative stress","volume":"47","author":"Kaspar","year":"2009","journal-title":"Free Radic. Biol. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"41074","DOI":"10.1074\/jbc.M110.145862","article-title":"Hepatitis B virus induces expression of antioxidant response element-regulated genes by activation of Nrf2","volume":"285","author":"Schaedler","year":"2010","journal-title":"J. Biol. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Bender, D., and Hildt, E. (2019). Effect of hepatitis viruses on the Nrf2\/Keap1-signaling pathway and its impact on viral replication and pathogenesis. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20184659"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e1980","DOI":"10.1038\/cddis.2015.322","article-title":"Hepatitis B virus stimulates G6PD expression through HBx-mediated Nrf2 activation","volume":"6","author":"Liu","year":"2015","journal-title":"Cell Death Dis."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1186\/s12964-023-01351-6","article-title":"A state-of-the-art review on the NRF2 in Hepatitis virus-associated liver cancer","volume":"21","author":"Kalantari","year":"2023","journal-title":"Cell Commun. Signal."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e0128723","DOI":"10.1128\/jvi.01287-23","article-title":"Oxidative stress sensor Keap1 recognizes HBx protein to activate the Nrf2\/ARE signaling pathway, thereby inhibiting hepatitis B virus replication","volume":"97","author":"Ariffianto","year":"2023","journal-title":"J. Virol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Taira, J., Sonamoto, M., and Uehara, M. (2017). Dual biological functions of a cytoprotective effect and apoptosis induction by bioavailable marine carotenoid fucoxanthinol through modulation of the Nrf2 activation in RAW264.7 macrophage cells. Mar. Drugs, 15.","DOI":"10.3390\/md15100305"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Taira, J., Miyazato, H., and Ueda, K. (2018). Marine peroxy sesquiterpenoids induce apoptosis by modulation of Nrf2-ARE signaling in HCT116 colon cancer cells. Mar. Drugs, 16.","DOI":"10.3390\/md16100347"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Taira, J., and Ogi, T. (2019). Induction of Antioxidant protein HO-1 through Nrf2-ARE signaling due to pteryxin in Peucedanum japonicum Thunb in RAW264.7 macrophage cells. Antioxidants, 8.","DOI":"10.3390\/antiox8120621"},{"key":"ref_17","first-page":"1747","article-title":"Anti-inflammatory effect of fucoxanthinol as bioavailable marine carotenoid on LPS stimulated RAW264.7 macrophages through iNOS suppression and nitrogen radical scavenging","volume":"3","author":"Taira","year":"2015","journal-title":"World J. Pharm. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Taira, J., Tsuda, R., Miyagi-Shiohira, C., Noguchi, H., and Ogi, T. (2023). Cytoprotective effect of pteryxin on insulinoma MIN6 cells due to antioxidant enzymes expression via Nrf2\/ARE activation. Antioxidants, 12.","DOI":"10.3390\/antiox12030693"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1016\/j.ejphar.2010.09.032","article-title":"Fucoxanthin inhibits the inflammatory response by suppressing the activation of NF-kB and MAPKs in lipopolysaccharide-induced RAW 264.7 macrophages","volume":"649","author":"Kim","year":"2010","journal-title":"Eur. J. Pharmacol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.bbagen.2004.08.012","article-title":"Fucoxanthin induces apoptosis and enhances the antiproliferative effect of the PPARgamma ligand, troglitazone, on colon cancer cells","volume":"1675","author":"Hosokawa","year":"2004","journal-title":"Biochim. Biophys. Acta."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.canlet.2005.05.014","article-title":"Hepatitis B virus X protein induces apoptosis in hepatoma cells through inhibiting Bcl-xL expression","volume":"236","author":"Miao","year":"2006","journal-title":"Cancer Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3192","DOI":"10.1038\/s41467-019-11173-1","article-title":"Structural and functional analyses of hepatitis B virus X protein BH3-like domain and Bcl-xL interaction","volume":"10","author":"Zhang","year":"2019","journal-title":"Nat. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"808","DOI":"10.1016\/j.bbrc.2013.12.052","article-title":"Evaluation and identification of hepatitis B virus entry inhibitors using HepG2 cells overexpressing a membrane transporter NTCP","volume":"443","author":"Iwamoto","year":"2014","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1016\/j.bbrc.2014.08.029","article-title":"Formation of covalently closed circular DNA in Hep38.7-Tet cells, a tetracycline inducible hepatitis B virus expression cell line","volume":"452","author":"Ogura","year":"2014","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Ito, N., Nakashima, K., Sun, S., Ito, M., and Suzuki, T. (2019). Cell type diversity in hepatitis B virus RNA splicing and its regulation. Front. Microbiol., 10.","DOI":"10.3389\/fmicb.2019.00207"}],"container-title":["Marine Drugs"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-3397\/23\/4\/155\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:09:13Z","timestamp":1760029753000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-3397\/23\/4\/155"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,3]]},"references-count":25,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["md23040155"],"URL":"https:\/\/doi.org\/10.3390\/md23040155","relation":{},"ISSN":["1660-3397"],"issn-type":[{"value":"1660-3397","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,3]]}}}