New findings on the plant ginseng suggest that it may be a powerful tool in the fight against the flu, as well as respiratory syncytial virus (RSV), a viral infection of the lungs and breathing passages.

Recently published in Nutrients, and soon-to-be published in the International Journal of Molecular Medicine, Sang-Moo Kang of Georgia State University’s Institute for Biomedical Sciences sought to design and develop vaccines against viral diseases such as influenza virus and RSV. However, he partnered with university and research institutes in South Korea that wanted international collaborative projects to examine if ginseng can be used to improve health and protect against disease. A well-known herbal medicine, ginseng has been reported to have anticancer, anti-inflammatory and immune modifying abilities.

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 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.
 
In his study published in Nutrients, Dr. Kang investigated whether red ginseng extract had preventive effects on influenza A virus infection. He found that red ginseng extract improved 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.
 
After infection with influenza A virus, mice that were orally administered ginseng over a prolonged period 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 indicated 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, Dr. Kang investigated whether Korean red ginseng extract had antiviral effects, or the ability to treat RSV infection. Dr. 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.