How to boost your immune system with herbs – Astragalus
Eight Herbs for the Immune System
Common Names: Astragalus (English) • huang-qi (Chinese)
Species Used: This is a huge genus of some three thousand species, prevalent throughout the world. The primary species used is Astragalus membranaceus, a.k.a. A. membranaceus var.mongholicus, a.k.a. A. mongholicus. Sigh … now that the number of species in this genus has been, almost, settled, the number of variants is in question. (Yes, this one isAstragalus membranaceus, but it looks funny. I found it in Mongolia; therefore …)
There is not much information on whether any of the other species in the genus can be used similarly.
Note: Astragalus propinquusis, in some circles, a synonym forA. membranaceus. However, a number of sources now insist (cue shocked expression) thatthis is the correct name for the plant. And of course, Astragalus mongholicus is just a rose by any other name.
The plant is a perennial with a long fibrous rootstock. The root, which is the part used for medicine, is often found thinly sliced and dried (a traditional preparation in Chinese medicine) and most closely resembles a yellow (medical) tongue depressor. Bulk quantities of the powdered or coarsely ground organic root are commonly available through herbal suppliers to Western botanic practitioners.
Properties of Astragalus
Enhances function in lungs, spleen, and GI tract
Immune enhancer, modulator, stimulant, and restorative
Astragalus is an immune potentiator and modulator. Increases interferon-gamma and interleukin-2 levels. Enhances CD4+ counts and balances the CD4:CD8 ratio. Astragalus is specific for immune atrophy and enhances function in the spleen and thymus.
Herb stores everywhere and the Internet.
Preparation and Dosage
Many astragalus formulations are standardized, though I’m not sure that the literature really supports standardization with this herb.
The root is usually standardized for either 0.4 percent or 0.5 percent 4′-hydroxy-3′-methoxyisoflavone 7-sug, but the reasons are not entirely clear for doing so. No literature exists that I can find that lays out why in fact this particular constituent was singled out and not the astragalosides. (Astragaloside IV, for instance, is one of the primary active ingredients of the plant in heart disease. It increases exercise tolerance and reduces chest distress and dyspnea and optimizes left ventricular function.) The methoxyisoflavone constituent for which the plant is standardized is an anabolic-type compound that enhances strength and muscle formation and may have some protective actions in upper respiratory infections and on digestive function. Data on its functions are somewhat unclear and hard to come by; I have been unable to locate any clinical or laboratory studies on the constituent—though they must exist somewhere. Their rarity stimulates speculation.
The whole root contains constituents that are essential for carditis and enhanced immune function. And, indeed, the majority of the Chinese studies—clinical and laboratory—were with the whole herb.
The herb may be taken as tea, powder, capsules, or tincture or in food.
Use 2–3 ounces of herb per pot of tea; drink throughout the day.
1:5, 60 percent alcohol, 30–60 drops up to 4x daily
In chronic conditions: Take up to 3 tablespoons per day.
In acute conditions: Take up to 6 tablespoons per day.
Astragalus has been used for centuries as an additive to meal preparation. The sliced root is placed in soups and removed before eating or a strong infusion of the root is made and used to cook rice and as a stock for soups.
Side Effects and Contraindications
No toxicity has ever been shown from the regular, daily use of the herb nor from the use of large doses. The Chinese report consistent use for millennia in the treatment of colds and flu and suppressed immune function without side effects.
Astragalus is contraindicated, however, in late-stage Lyme disease because it can exacerbate autoimmune responses in that particular disease.
Synergistic actions: Use of the herb with interferon and acyclovir may increase their effects. The herb has been used in clinical trials with interferon in the treatment of hepatitis B; outcomes were better than with interferon alone. It has also shown synergistic effects when used with interferon in the treatment of cervical erosion; antiviral activity is enhanced.
Drug inhibition: Use of the herb with cyclophosphamide may decrease the effectiveness of the drug. Not for use in people with transplanted organs.
Synergistic with echinacea and licorice in the stimulation of immune function.
Habitat and Appearance
Of the more than three thousand species of astragalus in the world, 16 grow in the United States. The leaf structure looks like a typical member of the pea family. It is a short-lived, sprawling perennial and grows up to 4 feet in size.
The medicinal astragalus is native to northeast China though it has been planted a great many other places, including the United States. Wild populations are still rare in the West though it is under wide cultivation as a medicinal in the United States and escape to the wild is imminent.
Cultivation and Collection
Astragalus is started from seeds in the early spring indoors. The seed coat needs to be scored with something like sandpaper prior to planting. Growers (e.g., Elixir Farm in Missouri) have found that it prefers a sunny location with, as the Elixir Farm website notes, “deep, sandy, well-drained, somewhat alkaline soil. It does not like mulch or deep cultivation. The crowns of the emerging plants are very sensitive to compost and respond well after they have gained some momentum in the spring.” Not surprisingly, given the plant’s medicinal actions, it is highly resistant to insect damage, crown rot, mildew, and drought.
The plant grows larger and more woody each year, with the roots harvested beginning the fall of the third year or spring of the fourth. Spring and fall harvests occur in China.
Astragalosides 1-7, astraisoflavan, astramembranagenin, astrapterocarpan, beta-sitosterol, betaine, formononetin, GABA, isoastragaloside 1, 2, and 4, isoliquiritigenin, linoleic acid, linolenic acid, soyasaponin I, kumatakenin, choline, glucuronic acid, 4′-hydroxy-3′-methoxyisoflavone 7-sug, a couple of dihydroxy-7, 4-dimethyl-isoflavones, 3′-hydroxyformonontin, calcium, folic acid, choline, copper, iron, magnesium, manganese, potassium, sodium, zinc.
Traditional Uses of Astragalus
Astragalus, first mentioned in the two-thousand-year-old Chinese text Shen Nong Cao Jing, is one of the 50 fundamental herbs in Chinese medicine and is considered to be one of the superior tonic herbs. The plant has developed into one of the primary immune herbs used worldwide over the past four decades.
Five species of astragalus are used in the materia medica of India, none of them this species. They are minor herbs, used primarily as emollients.
TRADITIONAL CHINESE MEDICINE
Astragalus has been a major herb in Chinese medicine for between two thousand and four thousand years. Its traditional uses are for spleen deficiency with lack of appetite, fatigue, and diarrhea. It is specific for disease conditions accompanied by weakness and sweating, stabilizes and protects the vital energy (qi), and is used for wasting diseases, numbness of the limbs, and paralysis. Other uses are: for tonifying the lungs, for shortness of breath, for frequent colds and flus; as a diuretic and for reduction of edema; for tonifying the blood and for blood loss, especially postpartum; for diabetes; for promoting the discharge of pus, for chronic ulcerations, including of the stomach, and sores that have not drained or healed well.
WESTERN BOTANIC PRACTICE
The herb was not used in Western botanic practice until the tremendous East/West herbal blending that began during the 1960s. It is now one of the primary immune tonic herbs in the Western pharmacopeia.
A considerable amount of scientific testing has occurred with astragalus, including clinical trials and both in vivo and in vitro studies. Medline lists 799 citations for studies with astragalus and this does not include the many Chinese studies that have never been indexed for Medline. Two U.S. patents have been granted for the use of astragalus for immunostimulation. What follows is merely a sampling.
Most of the clinical studies and trials regarding immunostimulation have been focused on the use of astragalus in the treatment of cancer and/or as an adjunct to chemotherapy to help stimulate chemo-depressed immune function. A number of other studies have examined its immune effects with a range of different conditions.
The herb has been used with children suffering tetralogy of Fallot after a radical operation to correct the condition. Tetralogy of Fallot is a complex of four heart abnormalities that occur together, generally at birth. Surgery is used to correct it. Astragalus was found to decrease abnormal levels of IgG, Igm, C3, C4, CD8+, and CD19+ while increasing levels of CD4+ and CD56+. The ratios of CD4:CD8, CD3:HLA-DR, and CD3:CD16 normalized between the second and third week of use. IL-6 and TNF-alpha both began decreasing in the first week and by week 4 were in the normal range.
When astragalus was used in the treatment of herpes simplex keratitis, levels of Th1, including IL-2 and IFN-gamma, increased and Th2 levels, including IL-4 ad IL-10, decreased, showing that the herb modulated Th1 and Th2 levels. This same kind of effect has been found in the treatment of numerous cancers. For example, in a study of 37 lung cancer patients astragalus was found to reverse the Th2 status normally present in that condition. Th1 cytokines (IFN-gamma and IL-2) and its transcript factor (T-bet) were enhanced and Th2 cytokines were decreased.
A clinical study with 63 people suffering serious abdominal traumatic injury found that the addition of astragalus to the treatment regimen significantly increased cellular immunity.
In clinical trials with a number of different cancers and congestive heart conditions, astragalus has been found to increase CD4+ levels, reduce CD8+ levels, and significantly increase the CD4:CD8 ratio. The plant has been found to have a broad immunostimulatory effect. Use of the herb with cancer patients undergoing chemotherapy found that white blood cell counts improved significantly (normalizing). The herb has been found to be specifically useful in preventing or reversing immunosuppression from any source: age-related, bacterial, viral, or chemical. It enhances phagocytosis and increases superoxide dismutase production from macrophages.
There have been numerous clinical trials with the herb for treating heart disease. The herb has been found specific for inhibiting Coxsackie B infections, both as an antiviral and as a heart protector. It will reverse damage to the heart in a number of conditions. With respect to Lyme carditis probably the most important are its impacts on left ventricular function, angina, and shortness of breath. While it is not completely protective for atrioventricular (AV) block, it does improve electrophysiological parameters and ameliorates AV block to some extent.
In a trial of astragalus for 2 weeks with 19 people with congestive heart failure, 15 people experienced alleviation of symptoms of chest distress and dyspnea, and their exercise tolerance increased substantially. Radionuclide ventriculography showed that left ventricular modeling and ejection function improved, and heart rate slowed from 88.21 to 54.66 beats/minute.
In another trial, 43 people suffering from myocardial infarction were tested with astragalus. Left ventricular function strengthened. Superoxide dismutase activity or red blood cell levels increased, and lipid peroxidation of plasma was reduced.
In a study with 366 cardiac patients astragalus was found to be effective when compared to lidocaine and mexiletine (which were not found effective). With astragalus the duration of ventricular late potentials shortened significantly.
In the treatment of 92 patients suffering ischemic heart disease, astragalus was more successful than nifedipine. Patients were “markedly relieved” from angina pectoris. EKG test results improved 82.6 percent.
Astragalus has been found to possess anti-inflammatory activity by inhibiting the NF-kB pathway and blocking the effect of interleukin-1 beta in leukotriene C production in human amnions. The constituent astragaloside IV inhibits increases in microvascular permeability induced by histamine. The whole-herb decoction has been found to reduce capillary hyperpermeability.
Astragalus has been found to improve anisodine-induced impairment of memory acquisition and alcohol-elicited deficit of memory retrieval. After use of the herb the number of errors was reduced. The plant has been found to exert potent antioxidant effects on the brain, helping to prevent senility.
Astragalus has been found effective in alleviating fatigue in heart patients and in athletes. In one trial, 12 athletes were randomly separated into two groups, and six were given astragalus. Astragalus was found to positively influence anaerobic threshold, enhance recovery from fatigue, and increase fatigue threshold.
A double-blind, randomized, controlled trial with 36 adults with chronic fatigue found that a mixture of astragalus and Salviae Radix significantly decreased fatigue scores.
A number of trials have found the herb effective in the clinical treatment of hepatitis B and liver disease. Liver function is improved, the liver is protected from damage, and regeneration is stimulated.
Robyn Landis and K. P. S. Khalsa share a tasty recipe for an immune-enhancing astragalus broth in their book, Herbal Defense (Warner Books, 1997).
3 cups water or vegetable broth
1 ounce astragalus (five “tongue depressor” lengths of the sliced root)
1 bulb (5 to 10 cloves) fresh garlic, sliced or whole Salt and pepper to taste
Combine the water, astragalus, and garlic and simmer for several hours, until the garlic is soft. Season with salt and pepper to taste. Consume all the broth if you feel an infection coming on, or take a cup or two several times during the week to prevent infection. Consume the garlic separately, leave in the broth, or use as a spread on toast.
1½ ounces sliced astragalus root
4 cups water, plus more as needed
2 cups (uncooked) brown rice
Add the astragalus to the water, bring to boil, and simmer, covered, for 2 hours. Remove from the heat and let stand overnight. Remove the astragalus, and add enough water to bring the broth volume back up to 4 cups. Add the rice, bring to a boil, then reduce the heat and simmer, covered, until the rice is done, approximately 1 hour. Use this rice as you would any rice, as a base for meals throughout the week.