Antiviral Res. Glycyrrhizin inhibits Influenza A virus uptake into the cell.

[Giuseppe]

Antiviral Res. 2009 May 2. [Epub ahead of print]

Glycyrrhizin inhibits Influenza A virus uptake into the cell.

Wolkerstorfer A, Kurz H, Bachhofner N, Szolar O. - Onepharm Research & Development GmbH, Veterin?rplatz 1, 1210 Vienna, Austria.


We investigated the mechanism by which glycyrrhizin (GL), the main active component of licorice roots, protects cells from infection with influenza A virus (IAV).
We found that GL treatment leads to a clear reduction in the number of IAV-infected human lung cells as well as a reduction in the CCID50 titer by 90 %.
The antiviral effect, however, was limited to one or two virus replication cycles.
Analysis of different GL treatment protocols suggested that the antiviral effect of GL was limited to an early step in the virus replication cycle.
A direct inhibitory action of GL on IAV particles could be excluded and GL did not interact with the virus receptor either.
The antiviral effect of GL was abolished by treatment 1 hr after virus infection, whereas pre-treatment and treatment during and after virus adsorption led to a reduction in the cytopathic effect, reduced viral RNA within the cells and in the cell supernatants, and reduced viral hemagglutination titers.
Detailed virus uptake analyses unambiguously demonstrated reduced virus uptake in various GL-treated cells.
These observations lead to the conclusion, that the antiviral activity of GL is mediated by an interaction with the cell membrane which most likely results in reduced endocytotic activity and hence reduced virus uptake inside the cells.
These insights might help in the design of structurally related compounds leading to potent anti-influenza therapeutics.

PMID: 19416738 [PubMed - as supplied by publisher]
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[Shannon Bennett]

Re: Antiviral Res. Glycyrrhizin inhibits Influenza A virus uptake into the cell.

We looked at licorice roots in our earlier research here at FT. There is some good data out there on it's ability to reduce viral lode. There are however many who cannot take this because of side-effects. If someone does choose to investigate the possible use of licorice please double check whether or not using this would be inadvisable.

The following is snipped from THE LIST FOR HERBS AND ALTERNATIVES FOR FLU

All of the following are herbs. Please check to see that none are contra-indicated before taking.
<NOBR>Echinacea Childrens dosage: Adjust by weight. Typically, </NOBR>
<NOBR>dosage is 1/2 the adult dosage over the age of 7 and 1/4 under the age of 7.
Use alcohol-free preparations for children.
Adult: 1 to 2 grams dried root or herb, as tea
2 to 3 mL of standardized tincture extract
200 mg of powdered extract containing 4&#37; phenolics
Tincture (1:5): 1 to 3 mL (20 to 90 drops)
</NOBR><NOBR>Licorice root:
Crushed Licorice Root: 5 to 15 grams (about 1-1/2 to 5 teaspoonfuls)
Licorice Extract: 0.5 to 1 gram for sinus and throat inflammations; 1.5 to 3 grams for ulcers
Licorice Tea: 1 cup after each meal
</NOBR>

[FrenchieGirl]

Re: Antiviral Res. Glycyrrhizin inhibits Influenza A virus uptake into the cell.

Shannon

As you say, one wants to check carefully on secondary effects. Liquorice root is one I have used for the purpose of raising blood pressure. In susceptible people, one cup of 3x4 inches pieces of the root in an overnight water steep is enough to do so significantly, and the effect, depending on the person, may remain for a fortnight. Therefore, people afflicted with idiopathic high blood pressure (hypertension) should be careful with it.

If liquorice root were to be used nevertheless to combat the flu, in those cases where one would estimate that the disadvantages of using it were smaller than the gains from it, and in case blood pressure went too high, I would probably have on hand some dried leaves of Hawthorn (Crataegus Oxyacantha) to make into a tea. One cup, three times a day, to calm the heart. As an aside, Hawthorn reduces emotional stress that is sometimes responsible for extra systoles (extra heart beats) and is generally considered very safe.

Disclaimer. This post is for information. Do not start taking any herbs, or other listed compounds before checking with your doctor and also doing a quick search to see if any medicines you are taking will interact adversely with any. This is especially true for pregnant or nursing women, the very young and those with chronic medical conditions.

[Shannon Bennett]

Re: Antiviral Res. Glycyrrhizin inhibits Influenza A virus uptake into the cell.

FrenchieGirl, you are absolutely right. Just because something is an easily found herb does not mean it is safe for use by everyone. Before anyone takes anything they should check for drug interactions as well as for negative side-effects.