Cranberries may help fight the herpes virus, according to Taiwanese researchers.

A plant compound, called proanthocyanidin A-1 (search), which was isolated by Taiwanese researchers, is found in a berry that goes by several names, including mountain cranberry, alpine cranberry, and lingonberry. The chemical is a tannin-like antioxidant that occurs widely in plants and already has several uses.

Its fruit is featured in products including juices, sauces, candies, jellies, and liqueurs. The plant's leaves are harvested as an ingredient in stomach medicines, and its flowers are dried and prepared as herbal remedies for lung problems, say the researchers.

Chun-Ching Lin and colleagues from Taiwan's Kaohsiung Medical University recently tested the herpes virus fighting potential of the berry and sought to evaluate the way the antioxidant compound worked to fight herpes simplex type 2 (HSV-2) infection.

Herpes simplex-2 (search) is one of the most common viral infections in humans. It causes genital sores or ulcers, as well as inflammation of the brain and infection of newborns and people with weakened immune systems.

Rates of herpes simplex virus infection have been continuously rising all over the world.

The scientists' lab tests showed that proanthocyanidin A-1 helped combat herpes simplex-2.

The proanthocyanidins appear to be powerful chemicals, with health effects that include battling bacteria, viruses, carcinogens, inflammation, and allergies, write Lin and colleagues in the Journal of the Science of Food and Agriculture.

The plant compound didn't make herpes simplex-2 any less infectious. Instead, it interfered with the virus when it tried to latch onto and penetrate cells — a necessary step for infection by the herpes virus. The compound did not exhibit any harmful effects on cells at doses necessary to block entrance of the virus into the cells.

Based on their findings, the researchers recommend further studies of proanthocyanidin A-1. They say that the compound has many actions that may guard against infection from the herpes virus and thus merits further investigation.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Cheng, H. Journal of the Science of Food and Agriculture. News release, The Society of Chemical Industry. Chemistry & Industry, Oct. 18, 2004.