Alfalfa

Description

Alfalfa (Medicago Sativa) Family: Legume (Leguminosesea)

Common Names:

• Buffalo herb
• Lucerne
• Purple medic

Habitat: North America, the Mediterranean region, western Asia; foothills and mountain areas.

Description: A perennial plant with a smooth, erect stem that grows 2 to 3 feet tall. It bears grayish-green pinnately trifoliate leaves, with egg-shaped leaflets; it looks much like a large clover. Its violet-purple flowers grow in racemes from June to August, producing spirally-coiled seed pods.

Medicinal Parts: Dried whole herb, including blossoms; gathered at the beginning of flowering seasons.

CHEMICAL COMPOSITION

* For definition of some of the above terms see the dictionary section of this book

FOLKLORE

Alfalfa has been extensively studied. Whole plant material contains many important substances, including several saponins, many sterols, flavonoids, coumarins, alkaloids, acids, vitamins, amino acids, sugars, proteins (25% by weight), minerals, trace elements, and other nutrients. Whole alfalfa also contains plenty of fiber with anticholesterolemic properties.

Alfalfa is one of the most nutritious foods known. Its calcium, chlorophyll, carotene, and vitamin K content make alfalfa an important nutritional supplement. Alfalfa root saponins can inhibit increases in blood cholesterol levels by 25% in experimental animals fed a high cholesterol diet. Offsetting this positive effect are findings that the root is hemolytic and may interfere with vitamin E metabolism.

The high concentration of vitamin K found in whole alfalfa has beneficial effect on several forms of hemolytic disease. Alfalfas also has antibacterial and antitumoral properties. In folk medicine, the herb has been used as an appetizer and tonic, and as a diuretic to relieve urinary and bowel problems.

Perhaps the most common modern use of alfalfas is in the treatment of symptomatic arthritis, but although numerous clinical and anecdotal reports are available, no scientific research has been done on it effectiveness.

METHOD OF ACTION

Alfalfa contains vitamin K, an antihemolytic agent.

Vitamin K is found in many green leafy plants, but is especially abundant in alfalfa. The herb has therefore been effectively used in treatment of vitamin K disorders in man. When the delivery of bile to the bowel is hindered, as in obstructive jaundice or biliary fistula, a bleeding disorder may arise. Other bleeding disorders may result from the use of artificial formulas to feed newborns, protracted antibiotic therapy, pancreatic insufficiency, chronic diarrhea and steatorrhea, and from the misuse of anticoagulants, aspirin, and anticonvulsant drugs

Alfalfa has antibiotic properties

The saponins in alfalfa have been shown to be antifungal. This activity is concentrated mainly in the medicagenic acid fraction. Alfalfa has shown some activity against tuberculosis bacteria, while aqueous and volatile extracts of alfalfa are antibacterial against gram negative bacteria.

Alfalfa has antitumor action

Basic proteins (histones) displaying antitumor activity without undesired side effects occur in alfalfa. These substances contain high levels of l-lysine, aspartic acid, and glutamic acid. Tumor stimulating fractions were also found, containing large amount of l-arginine. This basic relationship requires further study.

Other pharmacology of alfalfa

Tricin has been isolated from alfalfa and found to cause smooth muscle relaxation in guinea pig intestinal tissue, and to have some slight estrogenic property.

Alfalfa is highly nutritious

The nutrient content of alfalfa is one of the richest known, making it a useful livestock fodder and a highly recommended herb for the human diet as well.

Alfalfa root pharmacology

The hypocholesterolemic effect of alfalfa root saponins has been thoroughly established. Alfalfa root saponins can inhibit increases in blood cholesterol levels by 25% in experimental animals fed a high cholesterol diet.

Method of action

Alfalfa root saponins also have a hemolytic effect. It appears that this hemolytic effect is the result of a marked reduction in prothrombin factor concentration. In addition, they may interfere with the metabolism of vitamin E.

DRUG INTERACTIONS

Possible Interactions

Alfalfa's hypoprothrombonemic effect may be increased by the antiarrhythmic agent, quinidine. In addition, allopurinol has been tentatively shown to increase the half-life of anticoagulants.

Comments

Alfalfa is high in iron, which may cause it to interfere with the absorption of tetracyclines. This is especially true if large quantities of herb are ingested with two hours of taking tetracyclines.

Drug Interactions

It should also be noted that animal studies indicate that iron plus allopurinol may lead to increased hepatic iron concentration.

Alfalfa may, because of the presence of eugenol in the herb, inhibit certain liver microsomal hydroxylating systems. This produces toxic effects from drugs normally metabolized by those systems.

It should be noted that while the coumarin content of alfalfa is not high at normal usage levels, coumarins can affect the action of almost any drug.

The presence of tyramine and/or tryptophan in alfalfa could produce hypertension if monoamine oxidase inhibitors (MAOI's) are also being used. However, this is not a likely interaction.

General Herb Reference Collection: The following general reference books contain information about specific drug interactions as well as interactions between classes of drugs. This herb's possible interactions may be adduced by consulting the chapter on that class in the following volumes, since the herb resembles the class indicated.

Mowrey, D.B., Ph.D. Experimental Psychology, Brigham Young U. Director of Nebo Institute of Herbal Sciences. Director of Behavior Change Agent Training Institute. Director of Research, Nova Corp.

American Hospital Formulary Service. American Society of Hospital Pharmacists. Washington, D.C.

Goodman, L.S. & A. Gilman. 1975. The Pharmacological Basis of Therapeutics. Macmillan, New York.

Hansten, P.D. 1979. Drug Interactions, 4th ed. Lea & Febiger, Philadelphia.

List, P.H. & L. Hoerhammer. 1969-1976. Hagers Hanbuch der Pharmazeutischen Praxis, vols. 2-5. Springer-Verlag, Berlin.

Bressler, R., M.D. Bogdonoff & G.J. Subak-Sharpe. 1981. The Physicians Drug Manual. Doubleday & Co., Inc. Garden City, New York. 1213 pp.

Kastrup, E.K., ed. 1981. Drug Facts and Comparisons, 1982 edition. Facts and Comparisons Division, J.P. Lippincott Co., Philadelphia (St. Louis).

Marx, A.V. & Adler, E. "Ueber die blutzuckerherbasetzende wirkung von herba, urticae dioicae." Naunyn-Schmied. Arch. Parmakol., 112, 29-38, 56, 1926.

TOXICITY FACTORS

Generally regarded as safe by the FDA.

Contact dermatitis has occurred in hypersensitive individuals. Alfalfa root saponins are hemolytic and may also interfere with the metabolism of vitamin E; however, above-ground parts have just the opposite effects.

The toxic effects of alfalfa root saponins have been shown to be counteracted by cholesterol and beta sitosterol.