Planta Med 2013; 79 - PN41
DOI: 10.1055/s-0033-1352384

Inhibition of human cytomegalovirus IE gene expression by the extract of Glycyrrhiza uralensis

R Pusztai 1, J Hohmann 2, G Gang 3, J Molnár 1
  • 1University of Szeged, Department of Medical Microbiology and Immunbiology, Szeged, 6720, Hungary
  • 2University of Szeged, Institute of Pharmacognosy, Szeged, 6720, Hungary
  • 3The Hospital of Traditional Chinese Medicine of Inner Mongolia, Hohhot, 010021, China

The human cytomegalovirus (CMV) preferentially infects tumor tissues, and the accumulated CMV immediate early (IE) antigen may lead to tumor promotion and progression. The development of strategies to inhibit the expression and/or function of human IE antigen is an important goal to prevent and treat certain forms of cancer associated with human CMV.

Recent pathological investigations demonstrated that HCMV can be found in Epstein-Barr virus-negative Hodgkin's disease, colorectal cancer, malignant glioma and prostate cancer cells. HCMV infection fails to transform susceptible normal human cells, but it modulates the malignant properties of cancer cells through its ability to interfere with a variety of cellular signal transduction processes.

In the present study the CHCl3 extract of Glycyrrhiza uralensis roots (chinese licorice) was studied on the expression of HCMV IE antigen expression in A549 (human lung adenocarcinoma) cells by immunofluorescence analysis. G. uralensis has been used since ancient times, and is one of the most popular medicinal plant in the world. Licorice contains several classes of secondary metabolites; with these compounds numerous human health benefits have been associated.

In the present study the early phase of human CMV replication was used as a model of the early steps of malignant transformation in a modified in vitro system for measuring the antipromotion effects. Before this, the ID50 value of the extract was determined (49 µg/mL) on A549 cell line. The inhibition of IE antigen expression of CMV-infected cells in the presence of non-toxic doses of the CHCl3 extract was evaluated. DMSO was used as positive control. It was observed that the extract caused a dose-dependent inhibition of IE antigen expression (growth inhibition dose ID1= 76.3% and ID10= 11% of control).

This study was supported by the European Union and co-funded by the European Social Fund (TÁMOP-4.2.2.A-11/1/KONV-2012 – 0035), and Szeged Foundation for Cancer Research.