Licorice ingredient ferrets out herpes
Nathan Seppa
A compound in licorice homes in on lab-grown cells infected with a herpes virus and induces them to self-destruct, a new study finds. These results suggest that a drug based on the compound could seek and destroy herpes viruses hiding in people's bodies. Current antiherpes drugs attack the virus only when it's causing symptoms.
The virus in the new study is Kaposi's sarcoma-associated herpesvirus (KSHV), which causes skin and lymph cancers. The researchers suspect that the gene responsible for KSHV's capacity to hide out is latency-associated nuclear antigen (LANA).
Researchers at New York University ran lab tests on white blood cells, some of which were infected with the herpes virus. Exposing the infected cells to the licorice ingredient, glycyrrhizic acid, shuts down LANA. That starts a chain reaction of biochemical changes in the white blood cells, leading to their suicide and the virus' death. The uninfected cells showed no detrimental effects from glycyrrhizic acid, the researchers report in the March Journal of Clinical Investigation.
Despite these results, simply eating licorice is unlikely to purge a herpes virus from a person's system, says study coauthor Ornella Flore. Most of the glycyrrhizic acid in licorice is probably degraded in a person's stomach, she says.
To develop a treatment, Flore suggests, researchers could inject glycyrrhizic acid into animals previously infected with viruses and determine which viruses it can ferret out, how potent the drug is, and—if the results are promising—what dose would be needed in people.
********
References:
Curreli, F., A.E. Friedman-Kien, and O. Flore. 2005. Glycyrrhizic acid alters Kaposi sarcoma-associated herpesvirus latency, triggering p53-mediated apoptosis in transformed B lymphocytes. Journal of Clinical Investigation 115(March):642–652. Available at http://dx.doi.org/10.1172/JCI200523334.
Further Readings:
Arase, Y., et al. 1997. The long term efficacy of Glycyrrhizin in chronic hepatitis C patients. Cancer 79(April 15):1494–1500. Abstract available at http://dx.doi.org/10.1002/(SICI)1097-0142(19970415)79:8%3C1494::AID-CNCR8%3E3.0.CO;2-B.
Friborg, J., et al. 1999. p53 inhibition by the LANA protein of KSHV protects against cell death. Nature 402(Dec. 23):889–894. Abstract available at http://dx.doi.org/10.1038/47266.
Raloff, J. 2003. Sweet treatment for SARS. Science News Online (July 26). Available at http://www.sciencenews.org/articles/20030726/food.asp.
Sources:
Ornella Flore
New York University School of Medicine
Department of Microbiology
Room 238, 550 First Avenue
New York, NY 10016
From Science News, Volume 167, No. 18, April 30, 2005, p. 285.
