Your immune system is like an invisible shield that protects you from invading bacteria and viruses. The problem is that stress, a poor diet, environmental pollutants, and sleep deprivation can weaken it. Because of this, it’s more important than ever to support your immune system—especially during certain times of year.
Approximately 62 million Americans will get a cold each year, and put a $40 billion strain on the U.S. economy—because of lost work and school time. On top of that, the National Centers for Disease Control and Prevention (CDC) estimate that 10 to 20 percent of Americans will come down with the flu. Children are two to three times more likely than adults to get sick with the flu, and they frequently spread the virus to others.
Although most people recover from the illness, CDC estimates that in the United States more than 100,000 people are hospitalized and about 36,000 people die from the flu and its complications every year. But even more worrisome, scientists fear that a new flu virus will emerge in this century and cause a severe pandemic . . . and they are especially concerned about the deadly H5N1 flu strain, which is transmitted by birds and is becoming endemic in Asia.
In this special Health and Wellness report, we’ll tell you how to avoid respiratory infections and the flu. And if you do happen to get sick, you’ll learn how several herbal extracts can reduce the number of days that you are out of commission.
Maintaining a strong immune system
Immune health depends on eating right, getting enough sleep and exercise, and avoiding environmental toxins and stress. It’s almost impossible to avoid environmental toxins because of plastics, automobile emissions, and the overuse of insecticides and pesticides—just to name a few. Sugar and alcohol consumption inhibit proper immune function. And obesity has been linked to decreased immune function, as well.
Daily nutritional supplementation is your best bet for making sure your nutritional needs are met, as well as supporting your immune health.
About 60 years ago, researcher Weston Price, D.D.S., observed a high degree of immunity among native cultures as he traveled to places like Africa, New Zealand, and the Andes Mountains. The indigenous cultures were virtually free of tuberculosis, cancer, dental disease, and arthritis. Price also noticed that the two things these peoples had in common were a diet of whole, unprocessed foods and an active lifestyle.3
Scientific research has since confirmed Price’s observations. Proper immune function relies on good nutrition,4 physical activity,5 and emotional health.6
Daily nutritional supplementation is your best bet for making sure your nutritional needs are met, as well as supporting your immune health. And during cold and flu season, it’s important to take more aggressive measures.
Western medicine promotes vaccines, which contain dead or weakened bacteria, viruses or other materials such as inactive toxins, to stimulate the production of antibodies against a specific pathogen. But as we well know, these vaccines can upset the immune system’s balance and produce side effects—which can sometimes be uncomfortable and dangerous.
Fortunately, there are a number of safe herbs that enhance overall immunity by stimulating or strengthening the body’s own defense mechanisms, without adding stress to your system.
The truth behind flu vaccines
Vaccine sales are increasing and it seems the sky is the limit as to how high sales will go. Global revenues from the sale of vaccines, which was once primarily a commodity market, are expected to reach nearly $10 billion in 2008, up from $5.4 billion in 2001.
Recently, the U.S. government agreed to stockpile $100 million worth of a still-experimental vaccine against the deadly avian flu virus. But are flu vaccines safe . . . and do they work?
Here are some of the toxins that are typically used in vaccines7:
- Thimerosal (a mercury disinfectant/preservative) has been implicated as a possible cause of the rising epidemic of autism in American children. Although it has been eliminated from most vaccinations in the US, it is still included in the flu shot. And according to the World Health organization, it is still widely used in developing countries.
- Ethylene glycol (antifreeze)
- Phenol, also known as carbolic acid (this is used as a disinfectant, and/or dye)
- Formaldehyde, a known carcinogenic
- Aluminum, which is associated with seizures and is a carcinogenic in laboratory mice. (It is used as an additive to promote antibody response.) Although it has been linked to Alzheimer’s disease, there is no reason to believe it is a direct cause.
Vaccines are also grown and strained through animal or human tissues like monkey kidney tissue, chicken embryo, embryonic guinea pig cells, calf serum, and human diploid cells (the dissected organs of aborted human fetuses as in the case of rubella, hepatitis A, and chickenpox vaccines).
Today, the American Academy of Pediatrics recommends 21 shots before age 2, the first—for hepatitis B—coming within hours of birth. Boyd Haley, a professor of chemistry at the University of Kentucky, contends that if a child in the 1990s got all of the shots, he or she would be exposed to mercury levels of more than 100 times those deemed safe by the EPA.
Drug resistance
According to a report published in the online version of the British journal The Lancet, (Sept. 22) worldwide resistance to drugs used to treat influenza has increased to 12 percent since the mid-1990s. Researchers from the Centers for Disease Control and Prevention (CDCP) in Atlanta screened 7,000 influenza A samples for gene mutations known to build drug resistance. They found that drug resistance increased from 0.4 percent in 1994-1995 to 12.3 percent in 2003-2004. They also found that 61 percent of resistant viruses isolated since 2003 were from people in Asia. Some Asian countries had drug resistance frequencies exceeding 70 percent.
The authors of the study express concern that rising rates of resistance will cause Amantadine and Rimantadine—the drugs typically used to prevent and treat influenza type A—to be ineffective in the event of an influenza pandemic. That, in turn, would make government stockpiles useless. The Lancet also warns that circulating human flu bugs are very quickly becoming resistant to two older-type flu drugs: Symmetrel and Flumadine. The findings “raise concerns” about the widespread use of these drugs, notes Rick Bright, PhD, research scientist at the CDC’s National Center for Infectious Diseases, and colleagues.8
Tom Jefferson, MD, and colleagues at Cochrane Vaccines Field in Alessandria, Italy, conducted a second study published in the same issue of The Lancet and concluded that flu vaccines are only mildly effective in the elderly, and at best, they help prevent onset of complications.
“In fact, the vaccine doesn’t work very well at all,” said study author Dr. Jefferson. “Vaccines are being used as an ideological weapon. What you see every year as the flu is caused by 200 or 300 different agents with a vaccine against two of them. That is simply nonsense.”9
Although drug manufacturers are working hard to produce a vaccine to ward off an avian flu pandemic, we can only guess as to whether the experimental new vaccines will work . . . and whether there will be enough of them.
Your best bet is to take control of your own health. Don’t leave it in the hands of the government and Big Pharma. Do everything you can NOW to strengthen your immune system with potent, yet gentle proven herbs that have a proven track record and scientific studies to back them up.
5 proven herbal extracts to get you through the winter without getting a cold or flu
- • Andrographis paniculata
- • Astragalus root
- • Olive Leaf extract
- • Elderberry extract
- • Echinacea
1) Andrographis
Andrographis paniculata is an herb used in traditional Chinese and Indian medicine to support healthy digestive, cardiovascular, and urinary systems. In Sweden, however, andrographis has been used for more than 10 years as a primary herb to combat flu and upper respiratory infections. And according to recent scientific studies, andrographis has demonstrated significant success in fighting the common cold, flu, upper respiratory infections, and even Streptococcus.
Active constituents
The most significant compounds in andrographis are diterpene lactones, known as andrographolides, which produce significant antimicrobial activity.10
Scientific studies
Several double-blind, placebo-controlled parallel group clinical trials investigated the effect of andrographis extract on uncomplicated upper-respiratory tract infections. In all of them there was significant improvement in the symptoms of subjects who took the herbal extract versus those who took a placebo.
In one study (at the School of Medicine, University of Chile, Santiago) a group of 158 adult patients was divided in two. One group took the herbal extract and the other group took a placebo. The patients then self-evaluated their symptoms of headache, tiredness, sore throat, sleeplessness, nasal secretion, phlegm, and intensity of cough. By the second day, the group that took andrographis showed a significant decrease in the intensity of the symptoms of tiredness, sleeplessness, sore throat, and nasal secretion when compared to the placebo group. By the fourth day, the andrographis group exhibited a significant decrease in the intensity of all symptoms. The researchers concluded that andrographis had a high degree of effectiveness in reducing the prevalence and intensity of the symptoms in uncomplicated common cold beginning at day two of treatment. No adverse effects were observed or reported.11
Another study took place at the Erebuni Medical Centre, Yerevan, Armenia. Ninety-five patients took andrographis, and 90 took the placebo. After five days, the individuals who took the herbal extract showed great improvement in the symptoms of malaise, sore throat, nasal secretion and headache, while eye and cough symptoms didn’t differ much between the two groups. Temperature was also slightly lowered in the andrographis group. The researchers concluded that andrographis, in addition to having a positive effect on upper respiratory infections, also helps reduce the inflammatory symptoms of sinusitis.12
A meta-analysis (a statistical analysis that summarizes the results of many studies) of andrographis found that the data suggest that andrographis is superior to placebo in alleviating the subjective symptoms of uncomplicated upper respiratory tract infection. There is also preliminary evidence that andrographis produces a preventative effect.13
Researchers at the Department of Pharmacology, Chulalongkorn University, Bangkok, Thailand, found that andrographis inhibits the adherence of Streptococcus mutans to a surface.14
How safe is it?
Studies have found very few adverse reactions to andrographis, and many of them were rare and mild. Overall, andrographis has been found to be a safe and efficacious treatment for the relieving symptoms of uncomplicated upper respiratory.13
2) Astragalus root
Astragalus root is native to Mongolia and China, and has been used for thousands of years in China to ward off illness, strengthen the immune system, and chi—the building block of all spiritual and physical energy. While over 2,000 types of astragalus exist worldwide, the Chinese version has been extensively tested, both chemically and pharmacologically.15
Astragalus enhances immune function by increasing the activity of certain white blood cells, which increases the production of antibodies. It also increases the production of interferon (an anti-viral and anti-tumor agent naturally produced by the body) and stimulates natural killer cells.
In addition to boosting immunity, astragalus has antibacterial, adaptogenic, anti-inflammatory, and antiviral effects.
According to James Duke, Ph.D., a leading authority on healing herbs, astragalus increases production of the body’s own antiviral compounds alpha-and gamma-interferon, which generally protect against viral invasion.16
Astragalus also enhances T-cell production and stimulates macrophages,17 which in turn help other immune cells fight bacteria, viruses, parasites, fungi, toxins, and diseased cells.18
Active constituents
Astragalus contains numerous components, including polysaccharides, flavonoids, triterpene glycosides, amino acids, and trace minerals.19 It owes most of its immune-enhancing effects to polysaccharides, a group of complex sugars responsible for initiating the immune response. Polysaccharides work with other key components to then strengthen and build the immune system.
Scientific studies
In a small Chinese study, ten people whose heart muscles were infected with Coxsackie B virus—the cause of myocarditis or heart inflammation—received injections of astragalus extract for three to four months. The activity of their natural killer cells rose 11 to 45 percent. European studies suggest that many of the immune-stimulating compounds in astragalus are active when taken orally.20
Another Chinese study found that astragalus increased immune function in patients with congestive heart failure.21
A recent Japanese study tested the effect of astragalus (and two other root extracts) on laboratory animals and found that it stimulated immune response.22
How safe is it?
Astragalus is safe to take on a regular basis and does not appear to suppress the immune system with long-term use. It has no known side effects when used as recommended.23
3) Olive Leaf extract (Olea europaea L.)
The olive tree, a small evergreen native to Mediterranean regions, has been revered throughout history for its contribution to the culinary and healing arts. It has been used for thousands of years as a folk remedy for treating fevers, wounds, infection, and for skin rashes and boils.24 Now, scientific research has shown that the active ingredients in olive leaves do indeed have vast healing powers.
Olive leaf extract has been used effectively against viruses, retroviruses, bacterium, parasites, yeasts, protozoans, fungi, molds and other microbes and diseases in laboratory testing.
Researchers also believe that the natural antioxidants found in olive leaves prevent cardiovascular disease by inhibiting the oxidation of low-density lipoprotein cholesterol (LDL) the “bad” cholesterol,25 which, in turn, retards the formation of atherosclerotic plaques. Olive leaf extract also plays a role in supporting normal blood pressure and in reducing the risks associated with stroke, by inhibiting the production of thromboxane—a factor in blood clotting.26 27
Active constituents
Olive leaf has a variety of active constituents including several types of flavonoids (apigenin, luteolin, chrysoeriol, hesperidin, rutin, quercetin, and kaempferol)26 and the most abundant active ingredient called oleuropein, (pronounced oh-lee-or-oh-pin) which has proved to be a powerful antioxidant and antimicrobial.28 29
Scientific studies
The components of olive leaf extract inactivated every cold and flu virus they were tested against. Oleuropein may also have antibacterial properties. When unheated olives are brined in order to preserve them, oleuropein is converted into another chemical called elenolic acid. Elenolic acid has shown antibacterial actions against Lactobacilli and Staphylococcus aureus and Bacillus subtilus in a test tube study.30
An in vitro study revealed that oleuropein and its derivative hydroxytyrosol act as natural antibiotics against a range of bacteria. Most impressively, these two components of olive leaf inhibited Staphylococcus aureus, the bacteria responsible for many hospital-acquired infections.31 32 Staphylococcus aureus is notorious for its ability to mutate against antibiotics.
In other studies, oleuropein was found to be effective against dozens of different viruses,33 Staphylococcus,34 Haemorrhagic septicaemia,35 and HIV-1 infection.36
How safe is it?
Olive leaf extract has been demonstrated to be safe and effective in animal experiments and by the hundreds of health practitioners around the country who have used it to treat their patients with remarkable results.
4) Elderberry extract
Elderberry extract has traditionally been used to ease cold and flu symptoms, sinus problems, fevers, and muscle pain. In the 1980s, virologist Madeline Mumcuoglu, Ph.D, researched how elderberry fights the flu. According to Mumcuoglu, flu viruses are covered by tiny protein spikes of hemagglutinin, which they use to attach to, and infect healthy human cells. Elderberry extract contains active substances that are able to prevent viral hemagglutinin, or the process of the invading cells using their spike-like projections to introduce its enzyme into healthy cell membranes. She further noted that the viral enzyme is also neutralized in the presence of elderberry extract.
Active constituents
Elderberry contains rutin and quercertin (flavonoids), vitamin C, and anthocyanins.
Scientific research
In 1993, a team of Israeli scientists studied the effect of elderberry on flu patients. During a flu epidemic at an Israeli Kibbutz, half of the flu patients were given elderberry syrup, the other half a placebo. Within two days, 90% of the group treated with elderberry extract had a complete recovery, whereas, it took 6 days for 91.7% of the control group to recover.37
In a double-blind, placebo-controlled, randomized study, scientists assessed the effect of elderberry extract on the healthy immune system—namely, its effect on cytokine production. (Cytokines are small secreted proteins which mediate and regulate immunity and inflammation.) The production of inflammatory cytokines was tested using blood-derived monocytes from 12 healthy human donors. Production of inflammatory cytokines was significantly increased, leading the researchers to conclude that elderberry extract might be beneficial to the immune system activation and in the inflammatory process in healthy individuals or in patients with various diseases. Elderberry extract could also have an immunoprotective or immunostimulatory effect when administered to cancer or AIDS patients, in conjunction with chemotherapeutic or other treatments.38
How safe is it?
Elderberry is very safe for adults and children. No adverse effects have been reported.
5) Echinacea
Echinacea purpurea is a perennial herb native to the midwestern and southeastern United States. Native Americans used it more than any other plant for treating illness and injury, including wounds, snakebites, burns, toothache, and joint pains. Although echinacea’s popularity waned with the advent of antibiotics, it became respected among herbal practitioners in Europe after the first scientific study in 1932. Today, echinacea is the best-selling herbal extract in America. In fact, according to Nutrition Business Journal, sales of echinacea products in 2004 totaled about $155 million.
Active constituents
More than 500 scientific studies have been done to determine echinacea’s pharmacology and clinical applications. Researchers have discovered that the herb contains a diverse range of active components affecting different aspects of immune function. Echinacea’s polysaccharide and phytosterol constituents support the immune system by activating white blood cells (lymphocytes and macrophages).39 Echinacea also promotes nonspecific T-cell activation, a type of white blood cell important in providing resistance to mold like bacteria, yeast, fungi, parasites, and viruses (including herpes simplex, Epstein-Barr, and viruses that cause hepatitis). The T-cells then increase the production of interferon, an important part of the body’s response to viral infections.40
In addition, echinacea contains several components including the glycoside echinacoside and the polysaccharide echinacin, which have mild antibiotic and antifungal activity. Also, the polysaccharide constituents of echinacea roots have been shown to exhibit anti-inflammatory properties, which promote tissue repair41—which is why echinacea has a long history of use for the external treatment of wounds, burns, eczema, and other conditions.
Scientific studies
Several double-blind studies have confirmed the benefit of echinacea for treating colds and flu,42 43 44 45 and the vast amount of positive outcome clinical studies support the use of echinacea for preventing and treating cold and flu, preventing and treating upper respiratory infections, and increasing general immune system function.
What about the brouhaha over the study published in the July 28, 2005, issue of the New England Journal of Medicine? In case you didn’t read about it, it concluded that certain extracts of echinacea were statistically ineffective in lowering rates of infection or severity of symptoms of an induced cold virus in a group of 399 college students. And the media did a fantastic job of smearing echinacea as a reliable herb with powerful benefits.
It’s important to understand that the study was flawed. Although a majority of the scientific community acknowledges that the study was performed in a scientific manner by a reputable institute, Wayne Silverman, Chief Administrative Officer for the American Botanical Council, pointed out three main flaws of the study:
- First, the extracts used in the study were made in a university lab, and they were not comparable to any echinacea products currently sold.
Even in the published discussion of the study, researchers said, “Given the great variety of echinacea preparations, it will be difficult to provide conclusive evidence that echinacea has no role in the treatment of the common cold.”
- The second problem with the study was the dosage administered. Silverman said, “We believe that with more frequent and higher dosage, the results might have been different. The dosage used in the study was probably one-third of what it should have been,” he said.
The real problem is that all echinacea products are not equal. The right active constituents must be identified and standardized. Researchers make a huge mistake when they test an echinacea product without these qualifications.
- The third problem was that using a group of college students in a sequestered environment would not likely produce the same results as using subjects with weaker immune systems, such as the elderly.
“Unfortunately,” said Silverman, “the results [of this study] have been extrapolated to mean echinacea is not effective, period. This study should not be used as a reason to think echinacea is not effective at all.”46
Additionally, some health care professionals believe that coverage of the study was biased, since media sources positioned such a poorly designed study as front-page news.
The question that comes up, then, is why does the media ignore news pieces on well-designed studies such as the study that appeared in The Journal of Clinical Pharmacy and Therapeutics in 2004?
A randomized, double-blind, placebo-controlled study on standardized echinacea preparation [Echinilin], a commercially produced echinacea preparation, clinically proved that echinacea significantly reduced the severity and duration of the common cold. Two hundred eighty two subjects aged 18-65 years with a history of two or more colds in the previous year, but otherwise in good health, received either echinacea or placebo. They were instructed to start the echinacea or placebo at the onset of the first symptom related to a cold, consuming 10 doses the first day and four doses per day on subsequent days for 7 days. The severity of the symptoms and dosing were recorded daily, and a nurse examined the subjects on the mornings of days 3 and 8 of their cold. 47
One hundred twenty eight of the subjects got a common cold; 59 took echinacea and 69 took a placebo. The total daily symptom scores were found to be 23.1% lower in the echinacea group. Throughout the treatment period, the response rate to treatments was greater in the echinacea group. The researchers concluded that early intervention with a standardized formulation of echinacea resulted in reduced symptom severity in subjects with naturally acquired upper respiratory tract infection.47
How safe is it?
Most of the studies of echinacea have shown it to be a safe herb with very limited side effects.
Zinc stops colds before they have a chance to take hold
In addition to the five herbs mentioned, the mineral zinc has proven to be extremely effective in shortening the duration of colds, and even halting them—sometimes before you reach for the tissue box.
Although a Case Western Reserve University School of Medicine review of articles published between 1980 to 2003 on the effectiveness of zinc in treating the common cold found that clinical tests have been inconsistent, the review concluded that zinc effectively and significantly shortened the duration of the common cold when it was given within 24 hours of the onset of symptoms. The review also found that the inconsistencies in the clinical studies were mainly due to poor study design and the contents of the zinc lozenges.48
In one study, 48 students, staff and employees at Wayne State University who had cold symptoms for 24 hours or less were given either a placebo or a zinc lozenge that contained 12.8 mg zinc acetate. Participants were given 50 lozenges and asked to dissolve one in their mouths every two to three hours while awake as long as they had cold symptoms. They didn’t take any other cold preparations, and all the participants returned to the clinic one day after their colds ended. At that time, their plasma was examined for an immune factor called pro-inflammatory cytokines which causes cold symptoms.
The zinc recipients suffered from their colds an average of 4.5 days, whereas the placebo group felt lousy for an average of 8.1 days. Most notably, the zinc recipients coughed for only three days compared to six days for the placebo patients. When they initially came in for treatment, those who ended up taking zinc supplements actually reported more severe cold symptoms, including fever, sneezing, and sore throat. However, by day four, their severity score was only half that of the placebo group.49
Zinc has proven to be extremely effective in shortening the duration of colds, and even halting them.
Lastly, anecdotal evidence often clarifies clinical evidence:
Many of us who use zinc lozenges or tinctures containing zinc have found that when we take it at the first sign of a cold—for instance, that scratchy feeling at the back of the throat, or a mild burning sensation in the lungs—we are able to “nip it in the bud,” and continue with our normal activity without succumbing to a bad case of the sniffles.
So pay attention to your body and start zinc as soon as you notice the very first symptoms of a cold.
Conclusion
The good news is that you now have the information you need to protect yourself and your family from getting sick this winter. Stock up on the immune-enhancing herbs, cut down on sugar consumption, get plenty of rest, and use common sense. If there’s a flu epidemic in your neck of the woods, go to the grocery store when there’s less likely to be a crowd. Don’t go to the movies. Instead, rent videos, etc.
And most importantly, wash your hands frequently!
References
- Nature (May 26, 2005).
- Associated Press, “Flu-Related Deaths Are Up Fourfold Since ’70s,” Wednesday, January 8, 2003; Page A03.
- Price W. Nutrition and Physical Degeneration. La Mesa (CA): Price-Pottenger Nutrition Foundation; 1945.
- Beisel W. Nutrition and immune function: overview J Nutr 1996:126:2611S-5S.
- Shephard RJ et al. Exercise, aging and immune function. Int J Sports Med 1995;16(1):1-6.
- Leserman J, et al. Severe stress, depressive symptoms, and changes in lymphocyte subsets in human immunodeficiency virus-infected men: a 2-year follow-up study. Arch Gen Psych 1997;54:279-85.
- Day, Chet. Why I Never Get Flu Shots. Chet Day’s Health and Beyond.
- Bright RA, Medina Mj, Xu X, Perez-Oronoz G, Wallis TR, Davis XM, Povinelli L, Cox NJ, Klimov AI. Incidence of adamantane resistance among influenza A (H3N2) viruses isolated worldwide from 1994 to 2005: a cause for concern.Lancet. 2005 Oct 1;366(9492):1175-81.
- T Jefferson, D Rivetti, A Rivetti, M Rudin, C Di Pietrantonj, V Demicheli. Efficacy and effectiveness of influenza vaccines in elderly people: a systematic review.Lancet. 2005 Oct 1;366(9492):1165-74.
- Singha, PK, Roy S., Antimicrobial activity of Andrographis paniculata. Fitoterapia. 2003 Dec;74(7-8):692-4.
- Caceres DD, Hancke JL, Burgos RA, Sandberg F, Wikman GK. Use of visual analogue scale measurements (VAS) to asses the effectiveness of standardized Andrographis paniculata extract SHA-10 in reducing the symptoms of common cold. A randomized double blind-placebo study. Phytomedicine. 1999 Oct;6(4):217-23.
- Gabrielian ES, Shukarian AK, Goukasova GI, Chandanian GL, Panossian AG, Wikman G, Wagner H. A double blind, placebo-controlled study of Andrographis paniculata fixed combination Kan Jang in the treatment of acute upper respiratory tract infections including sinusitis. Phytomedicine. 2002 Oct;9(7):589-97.
- Coon JT, Ernst E. Andrographis paniculata in the Treatment of Upper Respiratory Tract Infections: A Systematic Review of Safety and Efficacy. Planta Med. 2004;70:293-8.
- Limsong J, Benjavongkulchai E, Kuvatanasuchati J. Inhibitory effect of some herbal extracts on adherence of Streptococcus mutans. J Ethnopharmacol. 2004 Jun;92(2-3):281-9.
- Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 50-3.
- Duke, James A., Ph.D. The Green Pharmacy. Emmaus, PA: Rodale Press, 1997, p. 544.
- Yoshida Y, et al. Immunomodulating activity of Chinese medicinal herbs. Intl JImmunopharmacol 1997:19(7):359.
- Lau B, et al. Chinese medicinal herbs inhibit growth of murine renal cell carcinoma. Cancer Biotherapy 1994;9(2):153.
- Shu HY. Oriental Materia Medica: A Concise Guide.
- Liu ZG, Xiong ZM, Yu XY. [Effect of astragalus injection on immune function in patients with congestive heart failure] [Article in Chinese] Zhongguo Zhong Xi Yi Jie He Za Zhi. 2003 May;23(5):351-3.
- Makino T, Sasaki SY, Ito Y, Kano Y. Pharmacological properties of traditional medicine (XXX): effects of Gyokuheifusan ([Symbol: see text]) on murine antigen-specific antibody production. Biol Pharm Bull. 2005 Jan;28(1):110-3.
- The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Mark Blumenthal ed. American Botanical Council. Austin, Texas. 1998.
- Foster S. 101 Medicinal Herbs. Loveland, CO: Interweave Press, 1998, 148-9.
- Steinberg, d. et.al., 1989; Gey, F. et.al., 1991.
- Hansen, K., Adsersen, A., Christensen, S.B., Jensen, S.R., Nyman, U. and Smitt, U.W. (1996) Isolation of an angiotensin converting enzyme (ACE) Inhibitor from olea europaea and olea lancea. Phytomedicine 2:319-325.
- Petroni, A., Blasevic, M., Salami, M., Papii, N., Montedoro, G.F. and Galli, C. (1995). Inhibition of platelet aggregation and eicosanoid production by phenolic components of olive oil. Thrombosis Research 78: 151-160.
- Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris, France: Technique & Documentation-Lavoisier, 1995, 487-9.
- Visioli, F., G. Bellomo and C. Galli (1998). “Free radical-scavenging properties of olive oil polyphenols.” Biochem Biophys Res Commun 247(1): 60-4.
- Bisignano, G., A. Tomaino, R. Lo Cascio, G. Crisafi, N. Uccella and A. Saija (1999). “On the in-vitro antimicrobial activity of oleuropein and hydroxytyrosol.” J Pharm Pharmacol 51(8): 971-4.
- Renis, H. (1969). In vitro antiviral activity of calcium elenolate. Antimicrobial agents and chemotherapy 9: 167-172.
- Bisignano G, Tomaino A, Lo Cascio R, Crisafi G, Uccella N, Saija A. On the In-Vitro Antimicrobial Activity of Oleuropein and Hydroxytyrosol. J. Pharm. Pharmacol. 1999; 51: 971-74.
- Nychas GJE, Tassou SC, Board RG. Phenolic extract from olives: inhibition of Staphylococcus aureus. Letters in Applied Microbiology. 1990; 10: 217-220.
- Esti, M., L. Cinquanta and E. La Notte (1998). “Phenolic Compounds in Different Olive Varieties.” J Agric Food Chem 46(1): 32-35.
- Zanichelli D, Baker TA, Clifford MN, Adams MR. Inhibition of Staphylococcus aureus by oleuropein is mediated by hydrogen peroxide. J Food Prot. 2005 Jul;68(7):1492-6.
- Micol V, Caturla N, Perez-Fons L, Mas V, Perez L, Estepa A. The olive leaf extract exhibits antiviral activity against viral haemorrhagic septicaemia rhabdovirus (VHSV). Antiviral Res. 2005 Jun;66(2-3):129-36. Epub 2005 Apr 18.
- Lee-Huang S. Anti-HIV activity of olive leaf extract and modulation of host cell gene expression by HIV-1 infection and olive leaf extract treatment. Biochem Biophys Res Commun. 2003 Aug 8;307(4):1029-37.
- Zakay-Rones Z, Varsano N, Zlotnik M, Manor O, Regev L, Schlesinger M, Mumcuoglu M. Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra L.) during an outbreak of influenza B Panama. J Altern Complement Med. 1995 Winter;1(4):361-9.
- Barak V, Halperin T, Kalickman I. The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. Eur Cytokine Netw. 2001 Apr-Jun;12(2):290-6.
- See DM, Broumand N, Sahl L, Tilles JG. In vitro effects of echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiency syndrome patients. Immunpharmacol 1997;35:229-35.
- Melchart D, Linde K, Worku F, et al. Immunomodulation with Echinacea-a systematic review of controlled clinical trials. Phytomedicine 1994;1:245-54.
- Tubaro A, Tragni E, Del Negro P, Galli CL, et al. Anti-inflammatory activity of a polysaccharide fraction of Echinacea angustifolia J Pharm Pharmacol 1987 Jul;39(7):567-9.
- Dorn M, Knick E, Lewith G. Placebo-controlled, double-blind study of Echinacea pallida redix in upper respiratory tract infections. Comp Ther Med 1997;5:40-2.
- Hoheisel O, Sandberg M, Bertram S, et al. Echinacea shortens the course of the common cold: a double-blind, placebo-controlled clinical trial. Eur J Clin Res 1997;9:261-8.
- Braunig B, Dorn M, Knick E. Echinacea purpurea root for strengthening the immune response to flu-like infections. Zeitschrift Phytotherapie 1992;13:7-13.
- Brikenborn RM, Shah DV, Degenring FH. Echinaforce® and other Echinacea fresh plant preparations in the treatment of the common cold. A randomized, placebo-controlled, double-blind clinical trial. Phytomedicine 1999;6:1-5.
- Oliver, Hillary. “Study no death knell for echinacea.” Natural Foods Merchandiser, 9/1/2005.
- V. Goel, R. Lovlin, R. Barton, M. R. Lyon, R. Bauer, T. D. G. Lee , T. K. Basu Efficacy of a standardized echinacea preparation (EchinilinTM) for the treatment of the common cold: a randomized, double-blind, placebo-controlled trial. Journal of Clinical Pharmacy and Therapeutics 2004 Feb;29(1):75-83.
- Hulisz D. Efficacy of zinc against common cold viruses: an overview. J Am PharmAssoc,2004 Sep-Oct;44(5):594-603.
- Prasad AS, Fitzgerald JT, Bao B, Beck FW, Chandrasekar PH. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 2000 Aug 15;133(4):245-52.