It appears that moms are right when they make us consume ginger for flu. A research indicates that ginger (Zingiber officinale Rosc), long believed to have the ability to ward off flu as our moms have been telling us, might have potential clinical applications as a preventive and therapeutic agents for flu virus infection.
The study was led by Dr. Hiroshi Ochiai at the Department of Human Science, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
In traditional Chinese medicine, ginger has been used as one of the principal herbs to treat a “cold” causing a functional decrease in the living body, or to improve blood stagnation and symptoms of acute respiratory infections such as the common cold and influenza.
The influenza virus enters our body through the upper respiratory tract and encounters pulmonary phagocytic cells including alveolar macrophages. In many cases, macrophages are the first barrier of the defense system responding rapidly and creating an environment for a subsequent immune response. As part of the defense system, macrophages produce various cytokines such as IL-1, IL-6, IL-8 and TNF-?.
In a previous report, TNF-? was identified as an anti-influenza cytokine and recent studies have indicated that this cytokine serves as the first line of defense against influenza virus infection in the body.
What are macrophages? Macrophages are cells within the tissues that originate from specific white blood cells called monocytes. Monocytes and macrophages are phagocytes, acting in both nonspecific defense (or innate immunity) as well as specific defense (or cell-mediated immunity) of vertebrate animals. Their role is to phagocytize (engulf and then digest) cellular debris and pathogens either as stationary or mobile cells, and to stimulate lymphocytes and other immune cells to respond to the pathogen.
What are cytokines? Cytokines are a group of proteins and peptides that are used in organisms as signaling compounds. These chemical signals are similar to hormones and neurotransmitters and are used to allow one cell to communicate with another. While hormones are released from specific organs into the blood and neurotransmitters are released by nerves, cytokines are released by many types of cells. They are particularly important in both innate and adaptive immune responses. Due to their central role in the immune system, cytokines are involved in a variety of immunological, inflammatory and infectious diseases.
What is tumour necrosis factor? Tumour necrosis factor is a protein produced by several of the body’s cell types, such as white blood cells, red blood cells, and other cells that line the blood vessels. It promotes the destruction of some types of cancer cells. In addition to tumour cell-killing activity, TNF-? has been noted for its role in the inflammatory response and the body’s resistance to pathogens. Moreover, the use of pure recombinant TNF-? has demonstrated that this cytokine can inhibit the replication of several viruses including the influenza virus.
Therefore, drugs that lead to TNF-? production in the alveolar macrophages might express an anti-influenza virus effect. In the present study, the inhibitory effect of ginger on the growth of influenza A/Aichi/2/68 (Aichi) virus was investigated in dog’s kidney cells. Direct addition of ginger extract to the infected cells did not have any inhibitory effect. However, ginger could exert its effect via macrophage activation leading to production of TNF-?.
When 100 microg/ml ginger extract was cultured with alveolar macrophages for 8 hours, there was an apparent reduction in viral production to 25% of the control. Finally, a 12-hour stimulation led to a reduction of 8.2% of the control. This was sufficient for an induction of the inhibitory effect. Stimulation longer than 12 hours demonstrated a plateau.
The researchers write that: “This study contributes to not only an explanation of the various biological activities of ZOR (ginger) but also to the promotion clinical applications of ZOR as a preventive and therapeutic agent for influenza virus infection.”