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.]
250-year-old pill formula proven good at fighting cold
CM NEWS - A popular herbal flu pill used widely among Chinese and Japanese has effective anti-inflammatory and analgesic functions, a study finds.
Liu Shen Wan (六神丸, “Six Spirits Pills“) is a famous traditional Chinese medicine for treatment of upper respiratory tract inflammation. The pills are made from a 250-year-old herbal formula and consist of 6 herbs (thus “Six Spirits Pills”). In a study done at the Department of Complex Prescription of TCM, China Pharmaceutical University in Nanjing, the anti-inflammatory and analgesic functions activities of Liu Shen Wan was evaluated.
It was observed that Liu Shen Wan exerted significant anti-inflammatory and analgesic activities in these models at doses of 30 and 90mg/kg crude drug in vivo.
At doses of 0.5-5mug/ml in vitro, Liu Shen Wan was able to prevent the immune system from over-reacting and hence becoming useless. This is done by targetting the “superantigens”, or super strong pathogens, that cause the infection.
The researchers say that Liu Shen Wan potently inhibited proliferation of human peripheral blood mononuclear cell (PBMC) stimulated by streptococcal pyrogenic exotoxin at doses of 0.5-5mug/ml in vitro.
What is PBMC? A Peripheral Blood Mononuclear Cell (PBMC) is a blood cell having a round nucleus, such as a lymphocyte or a monocyte. These blood cells are a critical component in the immune system to fight infection and adapt to intruders.
Streptococcal pyrogenic exotoxins are a superantigen which can cause a massive immune response by activating up to 20% of the body’s T-cells. Since one of the fundamental strengths of the adaptive immune system is its ability to target antigens with high specificity, superantigens produce an immune response that is effectively useless.
What are T cells? T cells belong to a group of white blood cells known as lymphocytes and play a central role in immunity">cell-mediated immunity. Antigen-specific T cells provides the immune system with “memory” against past infections.
What is streptococcal pyrogenic exotoxin? Streptococcus pyogenes (group A streptococcus) is a virulent organism that causes scarlet fever, rheumatic fever and streptococcal toxic shock syndrome (STSS). Streptococcal pyrogenic exotoxin A1 (SpeA1) is a superantigen commonly isolated from streptococcal strains infecting individuals with STSS.
Streptococcus pyogenes is one of the most frequent pathogens of humans. It is estimated that between 5-15% of normal individuals harbour the bacterium, usually in the respiratory tract, without signs of disease. Streptococcus pyogenes can casue infection when body defenses are compromised.
The researchers then separate Liu Shen Wan into fractions to test their individual functions. The pill was partitioned with chloroform, methanol, water and mineral fraction.
The results show that several fractions inhibited inflammation and pain in varying degrees. Among them, chloroform fraction exerted the most remarkable inhibitory effect on human PBMC proliferation.
Methanol and water fractions had more suppressive activities in vascular permeability, leukocyte migration.
These results suggest that Liu Shen Wan has significant anti-inflammatory and analgesic activities. The chloroform fraction is a key fraction of Liu Shen Wan to the overall anti-inflammatory and analgesic effects, while methanol and water fractions also partly contribute to anti-inflammatory activities of Liu Shen Wan.
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