A scientific presentation at the 2014 International Liver Congress provided research on a compound called SBEL1 that inhibits Hepatitis C virus, (HCV), activity in cells at diverse points in the life cycle of the virus. Estimates place the number of people living with chronic HCV at 150-200 million people. Hepatitis C is a liver disease caused by the hepatitis C virus: the virus can cause both acute and chronic hepatitis infection, ranging in severity from a mild illness lasting a few weeks to a serious, lifelong illness.
The hepatitis C virus is a bloodborne virus and the most common modes of infection are through unsafe injection practices; inadequate sterilization of medical equipment in some health-care settings; and unscreened blood and blood products. People infected with hepatitis C are at risk of developing severe liver damage including liver cancer and cirrhosis.
HCV invades cells in the body by binding to specific receptors on the cell, enabling the virus to enter it. Once inside, HCV hijacks functions of the cell known as transcription, translation and replication, which enables HCV to make copies of its viral genome and proteins, allowing the virus to spread to other sites of the body.2 When HCV enters the host cell, it releases viral (+)RNA that is transcribed by viral RNA replicase into viral (-)RNA, which can be used as a template for viral genome replication to produce more (+) RNA or for viral protein synthesis. Once the viral RNA is transcribed, HCV initiates a process known as IRES-mediated translation, which allows the viral RNA to be translated into proteins by bypassing certain protein translation checkpoints that would normally be required by the host cell to start protein translation. Viral RNA is the genetic material that gives HCV its particular characteristics. This process enables the virus to take advantage of the host cell’s protein translation machinery for its own purposes
The compound that impacts on HCV originates from Chinese Herbal medicine, from a herb found in regions of Taiwan and Southern China. and the inhibition of the virus is estimated at approximately 90%. The study that demonstrated HCV inhibition consisted of pre-treatment of human liver cells in vitro with SBEL1 prior to HCV infection and determined that SBEL1 pre-treated cells contained 23 percent less HCV protein than the control, suggesting that SBEL1 blocks virus entry. The liver cells transfected with an HCV internal ribosome entry site (IRES)-driven luciferase reporter that were treated with SBEL1 reduced reporter activity by 50% compared to control. This suggests that that SBEL1 inhibits IRES-mediated translation, a critical process for viral protein production. The HCV ribonucleic acid (RNA) levels were significantly reduced by 78 percent in HCV infected cells treated with SBEL1 compared to the control group. This demonstrates that SBEL1 may also affect the viral RNA replication process.
Professor Peck-Radosavljevic, the Secretary-General of the European Association for the Study of the Liver and Associate Professor of Medicine, University of Vienna, Austria, said: “SBEL1 has demonstrated significant inhibition of HCV at multiple stages of the viral lifecycle, which is an exciting discovery because it allows us to gain a deeper understanding of the virus and its interactions with other compounds. Ultimately this adds to our library of knowledge that may bring us closer to improving future treatment outcomes.”
C.W Lin et al. Multiple Effects Of Chinese Herbal Medicine SBEL1 On Hepatitis C Virus Life Cycle. Abstract presented at the International Liver Congress™ 2014
Scheel, T.K.H. and Charles M Rice, C.M. Understanding the hepatitis C virus life cycle paves the way for highly effective therapies. Nature Medicine, 2013; 19: 837-849
Komar, A.A. and Hatzoglou. Cellular IRES-mediated translation. Cell cycle, 2011; 10 (2): 229-240
European Comission. Horizon 2020. Breaking the Hepatitis C lifecycle. February 2014.] Centers for Disease Control and Prevention. Hepatitis C FAQs for the Public. 2014.
European Association for the Study of the Liver. “New Chinese herbal medicine has significant potential in treating hepatitis C, study suggests.”