Glycyrrhizin May Be Useful in Treating HHV-6

A Chinese study suggests that glycyrrhizin may be
helpful in the treatment of HHV-6.

Information about glycyrrhizin itself can be found
here:
http://www.siu.edu/~ebl/leaflets/glycyrrhizin.htm

The study of its effect on HHV-6:
http://www.tcm120.com/tcm/sars/sarsyj/6-27/sarsyj0627_2.htm

The Abstract:
It has been demonstrated that glycyrrhizin inhibits
the growth of different viruses in vitro, among which
are some herpesviruses, of which HHV-6 and HHV-7 are
the most recently discovered. HHV-6 is the etiol.
agent of exanthem subitum, but it may be responsible
for more severe pathologies. HHV-7 has been isolated
from healthy subjects, patients with chronic fatigue
syndrome and children with febrile illness but it has
not been casually assocd. with any pathol. The aim of
our study was therefore to test the activity of
glycyrrhizin and of 18a-and 18b-glycyrrhetinic acids
against HHV-6 and HHV-7. The antiviral activity of
non-toxic concns. of each drug was assayed on
lymphocytes infected with HHV-6 or HHV-7, the growth
of the virus being monitored by immunofluorescence
assay. Results show that glycyrrhizin at 1.2 mM
caused a 2.5-fold redn. of HHV-6 immunofluorescence
pos. cells. A 10-fold redn. was obtained using
glycyrrhizin at 3.6 mM, but at this concn. it also had
a few cytotoxic effects. 18a- And 18b-glycyrrhetinic
acids seem to have a stimulating effect on HHV-6
growth, with a two-fold increase in pos. cells. The
three drugs did not show any activity on HHV-7 growth.