Ginseng has a world of uses -- it is popularly used as an aphrodisiac, a cure for sexual dysfunction, a memory aid, and its immune system boosting properties help treat a number of medical conditions, including colds and headaches. A new study provides proof of the plant's versatility as it is also apparently helpful in the prevention and treatment of flu.

In the study published in Nutrients in January and in the upcoming issue of the International Journal of Molecular Medicine, researchers headed by Sang-Moo Kang from the Institute for Biomedical Sciences at Georgia State University in Atlanta, studied the effects of red ginseng extract (RGE) on influenza. They first infected mice with the influenza A virus, which causes flu, and then orally dosed them with ginseng extract over a long time.

Flu is a viral illness that is easily spread from person to person. It infects the throat, lungs and nose and is characterized by fever and aching. Symptoms associated with the disease such as headache, sore throat and runny nose, muscle and joint pain and cough can range from mild to severe. Although seasonal, the disease can cause epidemics and even death. The World Health Organization says that the flu is responsible for about 250,000 to half a million deaths worldwide per year.

Kang and her colleagues discovered that the mice treated with red ginseng extract showed improved immune effects. Those mice, for instance, had fewer inflammatory cells in the bronchial walls and had stimulated antiviral production of proteins that play a crucial role in immune response, suggesting that ginseng's beneficial effects on flu can be attributed to its ability to modify immune functions.

"RGE might have the potential beneficial effects on preventing influenza A virus infections via its multiple immunomodulatory functions," the researchers wrote. They also reported that RGE improved the survival of human lung epithelial cells that were infected with the influenza virus.

The researchers also studied the effects of RGE on respiratory syncytial virus (RSV), a virus that infects the lungs, and found that it can stop the virus from multiplying. To date, no vaccine is yet available for RSV, which commonly causes pneumonia and bronchiolitis in children less than 1 year old. Up to 125,000 children under 1 year old are hospitalized each year because of RSV infection.