Green Tea Component May Help Prevent HCV Re-infection after Liver Transplant

An anti-oxidant compound in green tea may inhibit entry of hepatitis C virus (HCV) into liver cells, which could potentially prevent re-infection of the new liver after transplantation, according to a study described in the December 2011 issue of Hepatology.

Over years or decades, chronic hepatitis C can progress to advanced liver disease including cirrhosis or liver cancer, which in the most severe cases may necessitate a liver transplant. Unfortunately, HCV almost always re-infects the new liver graft soon thereafter. People with advanced liver disease do not respond well to current interferon-based hepatitis C therapy and may be unable to tolerate its side effects.

Sandra Ciesek fromHannover Medical School in Germany and colleagues identified and tested epigallocatechin-3-gallate (EGCG), a compound known as a catechin (a type of polyphenol), isolated from green tea.

EGCG and various derivatives -- including epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC) -- have been previously shown to have antiviral and antioncogenic (anti-cancer) properties in laboratory studies, the authors noted as background. Here, they looked at the effect of EGCG on HCV replication in vitro.

Results

• EGCG was found to have no effect on HCV RNA replication, virus assembly, or release of progeny virions (viral particles).
• However, it did potently inhibit HCV entry into hepatoma laboratory cell lines and primary human hepatocytes (liver cells collected from patients).
• The entry inhibitor effect was observed with different HCV genotypes.
• The compound blocked both infection by free-floating virions and cell-to-cell spread of HCV.
• Although pre-treating cells with EGCG before HCV exposure did not reduce infection, adding it at the same time as HCV exposure strongly reduced infectivity.
• EGCG did not alter expression of any known HCV receptors, nor the overall number or density of virions.
• EGCG inhibited HCV attachment to the cell, disrupting the initial step of viral entry.

Based on these findings, the study authors concluded, "The green tea molecule, EGCG, potently inhibits HCV entry and could be part of an antiviral strategy aimed at the prevention of HCV re-infection after liver transplantation."

Although the researchers and a related media release focused on preventing HCV infection post-transplant, EGCG it may also inhibit infection of new liver cells in people with chronic hepatitis C. Prior studies have shown that EGCG has a similar inhibitory effect on HIV cell entry.

Investigator affiliations: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany; Division of Experimental Virology, TWINCORE, Center for Experimental and Clinical Infection Research; Medical School Hannover (MHH) and the Helmholtz Center for Infection Research (HZI), Hannover, Germany; Departments of Biochemistry and Medical Microbiology and Immunology and Li Ka Shing Insitute of Virology, University of Alberta, Edmonton, Alberta, Canada; Institute of Medical Microbiology, University Hospital Essen, Essen, Germany; Center for Vaccinology, Ghent University and Hospital, Ghent, Belgium.

12/13/11

Reference

S Ciesek, T von Hahn, CC Colpitts, et al. Steinmann. The Green Tea Polyphenol Epigallocatechin-3-Gallate (EGCG) Inhibits Hepatitis C Virus (HCV) Entry." Hepatology 54(6):1947-1955. December 2011.

Other Source

Wiley Blackwell. Green tea flavonoid may prevent reinfection with hepatitis C virus following liver transplantation. Press release. December 1, 2011.