Identification of Antiviral Agents Targeting Hepatitis B Virus Promoter from Extracts of Indonesian Marine Organisms by a Novel Cell-Based Screening Assay
Atsuya Yamashita,
Yuusuke Fujimoto,
Mayumi Tamaki,
Andi Setiawan,
Tomohisa Tanaka,
Kaori Okuyama-Dobashi,
Hirotake Kasai,
Koichi Watashi,
Takaji Wakita,
Masaaki Toyama,
Masanori Baba,
Nicole J. de Voogd,
Shinya Maekawa,
Nobuyuki Enomoto,
Junichi Tanaka,
Kohji Moriishi
Affiliations
Atsuya Yamashita
Department of Microbiology, Division of Medical Sciences, Graduate School of Interdisciplinary Research, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
Yuusuke Fujimoto
Department of Microbiology, Division of Medical Sciences, Graduate School of Interdisciplinary Research, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
Mayumi Tamaki
Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
Andi Setiawan
Department of Chemistry, Faculty of Science, Lampung University, Jl. Sumantri Brodjonegoro No. 1, Bandar Lampung 35145, Indonesia
Tomohisa Tanaka
Department of Microbiology, Division of Medical Sciences, Graduate School of Interdisciplinary Research, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
Kaori Okuyama-Dobashi
Department of Microbiology, Division of Medical Sciences, Graduate School of Interdisciplinary Research, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
Hirotake Kasai
Department of Microbiology, Division of Medical Sciences, Graduate School of Interdisciplinary Research, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
Koichi Watashi
Department of Virology II, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
Takaji Wakita
Department of Virology II, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
Masaaki Toyama
Division of Antiviral Chemotherapy Center for Chronic Viral Disease, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan
Masanori Baba
Division of Antiviral Chemotherapy Center for Chronic Viral Disease, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan
Nicole J. de Voogd
Naturalis, National Museum of Natural History, P.O. Box 9517, Leiden 2300 RA, The Netherlands
Shinya Maekawa
The First Department of Internal Medicine, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
Nobuyuki Enomoto
The First Department of Internal Medicine, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
Junichi Tanaka
Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
Kohji Moriishi
Department of Microbiology, Division of Medical Sciences, Graduate School of Interdisciplinary Research, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
The current treatments of chronic hepatitis B (CHB) face a limited choice of vaccine, antibody and antiviral agents. The development of additional antiviral agents is still needed for improvement of CHB therapy. In this study, we established a screening system in order to identify compounds inhibiting the core promoter activity of hepatitis B virus (HBV). We prepared 80 extracts of marine organisms from the coral reefs of Indonesia and screened them by using this system. Eventually, two extracts showed high inhibitory activity (>95%) and low cytotoxicity (66% to 77%). Solvent fractionation, column chromatography and NMR analysis revealed that 3,5-dibromo-2-(2,4-dibromophenoxy)-phenol (compound 1) and 3,4,5-tribromo-2-(2,4-dibromophenoxy)-phenol (compound 2), which are classified as polybrominated diphenyl ethers (PBDEs), were identified as anti-HBV agents in the extracts. Compounds 1 and 2 inhibited HBV core promoter activity as well as HBV production from HepG2.2.15.7 cells in a dose-dependent manner. The EC50 values of compounds 1 and 2 were 0.23 and 0.80 µM, respectively, while selectivity indexes of compound 1 and 2 were 18.2 and 12.8, respectively. These results suggest that our cell-based HBV core promoter assay system is useful to determine anti-HBV compounds, and that two PBDE compounds are expected to be candidates of lead compounds for the development of anti-HBV drugs.
