Licorice Licks Herpes Virus Infection

Appearing in the March 1 print edition of the Journal of Clinical Investigation, Ornella Flore and colleagues from New York University School of Medicine show, for the first time, that it is possible to interfere with herpesvirus latency by inhibiting the expression of Kaposi sarcoma–associated herpes virus (KSHV) latent genes. KSHV is the virus that is associated with Kaposi sarcoma, a disease characterized by tumors in tissues below the surface of the skin, often found in patients with immunodeficiencies like HIV and AIDS.

These investigators demonstrate that a compound found in licorice, glycyrrhizic acid (GA), can kill cells that are latently infected with KSHV. GA induces cell death by altering levels of proteins involved in latency like LANA and v-cyclin.

The possibility that GA-like compounds might be useful in treating clinical KSHV infections is of considerable interest. GA represents the first example of an anti-viral agent that specifically targets the expression of a herpesvirus gene required to maintain the virus in the latent state. The discovery of such drugs provides an opportunity for developing novel anti-herpesvirus agents to control, and perhaps eradicating latent viral infections.

In an accompanying commentary, Jeffrey Cohen states, "a compound present in licorice may seem like an unlikely candidate for the treatment of virus-associated cancers…derivates of GA might be used in the future for treating human diseases caused by latent virus infections."