Tamiflu alert
The Standard - Worried patients pushing doctors to prescribe the anti-flu drug Tamiflu could be leaving themselves more open to the deadly H5N1 bird flu virus. Read more
Echinacea halves risk of catching cold, study concludes
CBC - Echinacea (紫錐花), a herb widely used to fight the sniffles, helps reduce the risk of getting the common cold and shortens its duration, a new review suggests.
In the July issue of the medical journal The Lancet Infectious Diseases, researchers analyzed the results of 14 published trials on echinacea, or purple coneflower. The beneficial effect was seen after combining results from 1,600 participants.
Echinacea refers to flowers, roots and stems of nine related plants that are native to North America. Extracts are thought to boost the body’s immune system.
Taking the supplements seemed to reduce the risk of developing a cold by 58% and shortened duration of a cold by an average of 1.4 days, the team reported.
“An analysis of the current evidence in the literature suggests that echinacea has a benefit in decreasing the incidence and duration of the common cold,” the review concluded.
In one study, taking echinacea along with vitamin C reduced cold incidence by 86 per cent, compared to 65% for the herb alone.
Previous studies looking at the anti-cold effects of echinacea have shown opposite results. In 2005, a review published in the New England Journal of Medicine on more than 400 people concluded the herb was useless for cold symptoms.
The latest review was led by Craig Coleman, a pharmacist at the University of Connecticut.
The plant has three major ingredients, called alkamides, chicoric acid and polysaccharides, but it remains unclear how the herb may stimulate the immune system against cold viruses, Coleman and his colleageus said.
More than 800 products containing echinacea are available, the researchers found. Supplements may contain different parts, or combine echinacea with other herbs that have not been tested.
The study’s authors cautioned that clinical trials are needed before doctors can recommend echinacea to prevent or treat the common cold.
Health Canada requires all natural health products be licensed before sale, and to be labelled with an eight-digit product licence number that shows the product has been reviewed and approved by the department for safety and efficacy.
Use of echinacea is contraindicated during pregnancy and breastfeeding, the department said. People with HIV/AIDS, tuberculosis, multiple sclerosis and autoimmune disorders are advised to consult a health-care professional before using it.
Some earlier small studies were poorly controlled and sponsored by industry, Wallace Sampson, editor of the Scientific Review of Alternative Medicine and an emeritus clinical professor of medicine at Stanford University, said in a commentary accompanying the 2005 review.
A spokesperson for the supplements industry said echinacea may be more effective when its three active components are combined in a specific ratio.
The World Health Organization recognized echinacea as a cold treatment in 1999.
chinese medicineGinger does ward off flu: study
CM NEWS - It appears that moms are right when they make us consume ginger in time of 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 ofthe principal herbs to treat a “cold” causing a functional decrease in the livingbody, or to improve blood stagnation and symptoms of acute respiratory infections suchas 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-α.
In a previous report, TNF-α 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-α has been noted for its role in the inflammatory response and the body’s resistance to pathogens. Moreover, the use of pure recombinant TNF-α has demonstrated that this cytokine can inhibit the replication of several viruses including the influenza virus.
Therefore, drugs that lead to TNF-α 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-α.
When 100 μg/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.”
[The American Journal of Chinese Medicine. 2006;34(1):157-69.]
My community
