ATLANTA—Using ginseng as an ingredient may benefit consumers in treating and preventing influenza and respiratory syncytial virus (RSV), a respiratory virus that infects the lungs and breathing passages, according to new research published in the journal Nutrients.

Ginseng, a well-known herbal medicine, has been reported to have anticancer, anti-inflammatory and immune modifying abilities. In addition, American ginseng is reported to have neurocognitive effects.  Study author Sang-Moo Kang and a team of researchers from Georgia State University's Institute for Biomedical Sciences found that red ginseng extract improves the survival of human lung epithelial cells infected with influenza virus. Also, treatment with red ginseng extract reduced the expression of genes that cause inflammation.

Seasonal influenza is a serious respiratory disease that causes annual epidemics in humans worldwide, resulting in about three to five million cases of severe illness and about 250,000 to 500,000 deaths, according to the World Health Organization. Influenza can spread quickly, and new, unexpected pandemic influenza viruses may emerge at any time and cross over to different species. The H1N1 influenza virus, a new strain known as swine flu that emerged in 2009, spread rapidly to more than 74 countries. There are also challenges with existing influenza vaccines, such as required annual updates and no protection against pandemic strains and bird flu.

In addition, there are no vaccines available for RSV, which affects millions and is the leading cause of inflammatory bronchiolitis pneumonia and viral death in infants and in some elderly adults.

After infection with influenza A virus, mice used in Kang's study that were orally administered ginseng over a long time showed multiple immune modifying effects, such as stimulated antiviral production of proteins important in immune response and fewer inflammatory cells in their bronchial walls. The study indicates the beneficial effects of red ginseng extract on preventing influenza A virus infections could result from immune modifying capabilities of ginseng.

In his upcoming publication in the International Journal of Molecular Medicine, Kang investigated whether Korean red ginseng extract has antiviral effects, or the ability to treat RSV infection. Kang found Korean red ginseng extract improved the survival of human lung epithelial cells against RSV infection and inhibited the virus from replicating, or multiplying, in the body. In addition, treatment with Korean red ginseng extract suppressed the expression of RSV-induced inflammatory genes and the formation of chemically reactive molecules containing oxygen, which play a role in virus-induced epithelial damage in RSV.

Also, mice that were orally administered Korean red ginseng extract had lower viral levels after infection with RSV. The results suggest that Korean red ginseng extract has antiviral activity against RSV infection.

Kang has further demonstrated ginseng's beneficial effects on influenza and RSV in previously published studies.

Incorporating ginseng into food presents challenges because it has a bitter taste, and food processing can eliminate its healthful benefits. However, a few years ago researchers in Spain formulated low-lactose functional milk that maintained beneficial levels of American ginseng after processing and was pleasing to consumers, according to a study published in the Journal of Dairy Science.