Vol. 4 No. 2 November 30, 1983

During the academic year of 1982-3, Eric Sausjord worked with me as an Environmental Toxicology Intern. He chose to work on a project dealing with herbal remedies and this newsletter is the result of his extensive research. The October issue of the FDA Consumer contains an article titled "Herbs are often more toxic than magical". The FDA Consumer article offers information on herbal preparations that are potentially toxic and is suggested reading in addition to this newsletter which has
information on many herbs not covered in the FDA article.

Common Herbal Teas and The Basis of Their Medicinal Use

Herbal teas* are used by many people interested in "natural" substitutes for prepared drugs. Folk wisdom and hearsay commonly guide this practice, but often in an uninformed and limited manner. Throughout most of recorded history the study of plants has comprised the major portion of medicine. (A Mesopotamian pharmacy named some 250 plant drugs.) In 28 A.D. the Greek physician Dioscorides wrote De Materia Medica which included 600 medical plants and was the leading text on pharmacology until the Renaissance. The European Herbals drew considerably from both Dioscorides and local folk wisdoms, and have had wide public use since the Middle Ages. Chinese medicine continues to rely heavily on herbal treatments. The first United States Pharmacopeia (U.S.P.) was published in 1820 and established an officially approved body of drugs, which at that time were mostly plant preparations.

Drug treatment is, and will remain, indebted to this legacy of medicinal botany. While the majority of drugs are now synthetic, they are very often copies or variations of chemicals first isolated from plants. The plant kingdom continues to provide a source for new drugs. Researchers have found promising compounds for use in cancer therapy by screening thousands of plants. Many important drugs have been rediscovered by modern investigation of "primitive" folk and tribal remedies. Considering the paramount role plants have played in medicine, and the recent introductions of synthetic pharmacy, it is not surprising that many herbal remedies are popularly used. It should be noted that even though they are natural, medicinal herbs are drugs. Remember what Paracelsus said over 400 years ago: "All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy." The following points should be considered before attempting medication with herbs:

* As strictly defined, "herb" refers to plants without woody tissue. However, we will apply common usage and use "herb" and its forms to refer to any plant materials.

  1. Plant preparations are not purified. Along with the beneficial constituents there may be other undesireable and potentially toxic ones.
  2. It may be difficult to positively identify a plant. Common names are sometimes ambiguous. Closely related species may differ in the amount or kind of chemicals present and the amount of active ingredient may vary considerably depending on the stage of growth and other factors.
  3. The effect of herbal preparations (like all drugs) is dose- related. The amount of time and the method with which an herb is steeped will effect the strength of the infusion (tea). In addition, the beneficial components may become toxic if the dose is too high.
  4. Don't try to treat serious illness with these herbal remedies unless so instructed by a physician.

There are numerous inexpensive books available that discuss herbal use in great detail. These should be consulted for more information about types of preparations and recommended doses. Don't believe claims that state that any one plant can cure any and all diseases. There are no panaceas. Many of these herbal remedies work to help alleviate minor ailments, but don't expect miracles, and if they don't work, see your pharmacist for help in choosing other over-the-counter medications.

Most of the herbs listed in this publication can be purchased locally. Some of the plants contain potentially toxic chemicals, and some of them are even considered poisonous. With many drugs, it is the dose that makes the difference between therapeutic effect or toxic effect. Those herbs that have a potential to cause harm are marked with a warning sign (XXX).


(Barosma betulina)

Part Used: leaves

Constituents: A volatile oil with ketones, camphor, terpenes, and diosmin.

Popular use as tea: This herb has been widely used as a diuretic and urinary antiseptic. It is now used as a tea and for these same purposes.

Pharmacological basis: The oil is excreted through the urine which it disinfects and may discolor. Has been replaced in modern medicine by more effective treatments.

(Arctium lappa)

Part used: root

Constituents: 40% - 50% inulin, an essential oil, tannic acid.

Popular use as tea: A popular "blood purifier" and alterative.

Traditional in the West as well as in China.

Pharmacological basis: Tannins are astringent and have been used in treating inflamed throats, mouths and tonsils, and as a veterinary intestinal astringent. The astringent effect of tannins upon the alimentary tract while not necessarily therapeutic, may cause teas containing them to feel or taste like medicine. Insulin has been used to measure kidney function and may have a diuretic effect after intravenous injection. It is doubtful that inulin is absorbed from the gastrointestinal tract so inulin diuresis would not occur after drinking burdock root tea.

(Rhamnus purshiana)

Part used: bark

Constituents: Anthraquinones, tannins, resins.

Popular use as tea: As a laxative. Cascara Sagrada means "sacred bark" in Spanish. Native to the Northwest, it was used by the Indians and early settlers.

Pharmacological basis: The anthraquinones act by stimulating peristalsis. The active chemicals are excreted into the milk of nursing mothers and thus may exert a laxative effect in suckling infants. It is used in modern laxative preparations available at pharmacies.

(Anthemis nobilis)

Part used: flowers

Constituents: A complex oil with azulene and apigenin.

Popular use as tea: For insomnia, cramps, local pains, indigestion, nervous tension and more. Most popular as a bedtime tea.

Pharmacological basis: This herb is being actively researched and many constituents are known to have pharmacological effects on the stomach and intestine. Any beneficial effects would most likely be observed over a long period of time because a single cup of tea provides mall doses of the active chemicals. Chamomile has provoked allergic reactions in sensitized individuals.

(Coffea arabica, liberica)

Part used: beans

Constituents: 1% - 3% caffeine, .25% trigonelline, tannins, oils. Roasted coffee contains about 1% volatile acids.

Popular use: Coffee is one of the worlds most popular drinks and stimulants.

Pharmacological basis: Caffeine is a central nervous system stimulant, and a diuretic. Caffeine is found in many pain relieving formulas and in combination with other drugs is used for treating migraine. Over-use of coffee can lead to "caffeinism" which is characterized by nervousness, anxiety, and insomnia. Long term use of caffeine can also cause dependence which may result in similar symptoms when the drug is not ingested.

(Thea sinensis)

Part used: leaves

Constituents: 10% - 20% gallotannic acid, 1% - 4% caffeine, theophylline, theobromine, xanthine.

Popular use as tea: A very popular drink and stimulant.

Pharmacological basis: The caffeine is a stimulant, and the tannins are astringent. Tannins interfere with iron absorption, so heavy tea drinkers may need supplemental iron. Theophylline and theobromine are both methylated xanthines like caffeine and are also stimulants and diuretics.

(Symphytum officinale)

Part used: leaves

Constituents: .1% - .8% Allantoin, mucilage, pyrrolizidine alkaloids, tannin, aspargine, choline, inulin.

Popular use as tea: For intestinal problems, menstrual cramps, as a panacea.

Pharmacological basis: Allantoin is known to promote healing of epithelial tissues internally and externally. The mucilage could add a soothing effect. Deaths have occurred when people have mistaken foxglove for comphrey. Pyrrolizidine alkaloids are chemicals which have toxic effects on the liver. Although the amount of pyrrolizidine alkaloids in comphrey is small, and probably would not have any harmful effects if comphrey is used on an occasional basis, long or short term high dose use is discouraged until more is known of its potential to produce human toxicity.

(Ephedra sp.)

Part used: whole herb

Constituents: Chinese Ephedra, Ephedra major, contains up to 2% ephedrine, pseudoephedrine. American Ephedra, E. nevadensis, may or may not contain small amounts of these.

Popular use as tea: Used by early settlers to purify blood, and for syphilis (which it did not cure). The Chinese long recognized their Ephedra as a potent medicine.

Pharmacological basis: Ephedrines are stimulants of the central nervous system, and also effect the sympathetic nervous system which controls heart rate, blood pressure, and other internal organ functions. Ephedrine is important in the treatment of asthma, and pseudoephedrine is used as a nasal decongestant. It should not be used by persons with high blood pressure or cardiac (heart) problems. It can interact with medications and the interactions have the potential to cause serious problems.

(Hypericum perforatum)

Constituents: Hypericin, hyperine.

Popular use as tea: Long history since Dioscorides as sedative, antidepressant, diuretic.

Pharmacological basis: Small amounts of Hypericin appear to be tranquilizing. St. Johns wort grows wild in northwest where it is a livestock hazard due to its potential to cause direct photosensitization. It may have a similar toxic potential in humans.

American Asian
(Panax quinquefolium) (Panax ginseng)

Part used: root

Constituents: A complex mixture of glycosides, mostly triterpenoid saponins.

Popular use as tea: Ginseng is popular in China as an alterative, aphrodisiac, etc. Has gained a reputation as a panacea in the West.

Pharmacological basis: Western studies support some therapeutic effects, but it is not officially used. It is a stimulant and prolonged use may lead to hypertension (high blood pressure), chronic insomnia, diarrhea, and nervousness.

(Glycyrrhiza glabre)

Part used: root

Constituents: 5% - 20% Glycyrrhizin, a glycoside 50 times as sweet as sugar and safe for diabetics. Contains other glycosides and coumarins as well.

Popular use as tea: For coughs and colds and as a general tonic; to treat gastric ulcers. Popular in Ancient Egypt, China. Used as a flavor to mask unpleasant taste of other herbs.

Pharmacological basis: Used in modern cough remedies. Glycyrrhiza is demulcent (soothing), and expectorant (helps loosen phlegm). It has proven anti-peptic ulcer activity which has been attributed to the glycosides liquiritoside and isoliquiritoside. It is also mildly antiflammatory. Licorice extract is used as a pharmaceutical flavor vehicle and in candy.

(Lobelia inflata)

Part used: whole herb

Constituents: .2% - .4% Lobeline, other alkaloids.

Popular use as tea: It is used as an aid to help quit smoking or other uses of tobacco. It has been used for nervous tension, as an emetic, and to treat asthma.

Pharmacological basis: Lobeline is the major active ingredient and it has exactly the same effects as nicotine. It is a non-specific nervous system stimulant which causes increased alertness, increased heart rate, blood pressure, and peristalsis (movement of the intestines). It can be toxic at very high doses, but is less potent than tobacco.

(Mentha piperata)

Part used: leaves

Constituents: .5% Essential oil which contains 50% - 75% menthol, tannins.

Popular use as tea: It is used as a carminative to reduce flatulence, abdominal cramps, and nausea; and for relief from colds and nervous tension.

Pharmacological basis: Most essential oils have a carminative effect that helps alleviate flatulence by promoting eructation (belching). Menthol can provide symptomatic relief from colds.

(Passiflora incarnata)

Part used: flower

Constituents: Passiflorine, harmine, and other alkaloids.

Popular use as tea: It is used for insomnia, nervous tension and as an antispasmodic.

Pharmacological basis: The alkaloids are active on the central nervous system. Harmine is a stimulant and passiflorine a sedative.

(Salvia officinalis)

Part used: whole herb

Constituents: 2% Sage oil of which 30% is thujone. Tannins, cineol, camphor.

Popular use as tea: It is used for nervous excitement, hysteria and as a digestive aid. It is also used to inhibit perspiration and as a gargle for sore throats.

Pharmacological basis: The oil is bactericidal and astringent. A sedative action has not been demonstrated. More than a few drops of the oil can be toxic due to the high thujone content. Thujone is a nervous system stimulant that may cause convulsions at high doses. The antimicrobial effect of many essential oils may have contributed to the popularity of spices of food, as they can help in food preservation.

(Sassafras officinalis)

Part used: root bark

Constituents: Root bark has 6% - 9% oil of which 80% is safrole.

Popular use as tea: It is used as a spring tonic - alterative; for arthritis and as a diuretic. Sassafras is one of the traditional root beer flavorings. It was once very popular (and ineffective) for treating syphillis.

Pharmacological basis: The unique and aromatic flavor of Sassafras probably encouraged people to believe it was a panacea. Long-term feeding of safrole has been shown to induce tumors in rats and therefor

(Cassia argostidola)

Part used: leaves and pods

Constituents: About 3% anthraquinones (sennosides).

Popular use as tea: As a laxative.

Pharmacological basis: See Cascara Sagrada. Senna is also found in drugstore preparations.

(Betula lenta)

Part used: bark

Constituents: Oil from bark contains 98% methylsalicylate.

Popular use as tea: For insomnia and as an analgesic. As a tonic.

Pharmacological basis: The liver rapidly hydrolyzes methylsalicylate to salicylic acid which is the active form of aspirin. This might explain the analgesic effect.

(Thymus vulgaris)

Part used: whole herb

Constituents: 2% volatile oil, of which 25% is thymol. Other phenols.

Popular use as tea: For coughs, colds, hysteria, indigestion, and more.

Pharmacological basis: The oil in Thyme is a power germicide. Steam from the boiling herb can be inhaled. Thymol is used in medicine as a topical anti-fungal agent.

(Arctostaphylos uva-ursi)

Part used: leaves

Constituents: A volatile oil containing 7% - 8% arbutin. Ericolin, urson, tannins, gallic and other acids. Popular use as tea: As a urinary disinfectant for genito-urinary afflictions. For excessive menstruation, for gonorrhea. Found in "dieting blends".

Pharmacological basis: The oil is excreted in the urine which it disinfects and may discolor. It is also diuretic and astringent which may explain its use as a dieting agent. It is not effective for treatment of venereal disease.

(Valariana officinalis)

Part used: leaves

Constituents: 1% volatile oil containing the alkaloids chatinine and valerine. Valeric and other acids.

Popular use as tea: Long history of use as an antispasmodic (for alleviating muscle cramps) and for nervous tension.

Pharmacological basis: The alkaloids have a sedative action and may have some effects that alleviate stress related heart "palpitations".

(Prunus serotina)

Part used: bark

Constituents: contains the glucoside Prunasin which yields HCN (hydrocyanic acid) on hydrolysis.

Popular use as tea: This fragrant bark is popular in teas and is sometimes used to mask the flavors of other herbs.

Pharmacological basis: Is used as a pharmaceutical flavor. Because of the cyanide in the leaves and bark, this tree is a hazard to livestock particularly when leaves are wilted and hydrolysis has taken place.

(Ilex paraquarensis)

Part used: leaves

Constituents: Caffeine

Popular use as tea: As a stimulant. Is the main ingredient in "Morning Thunder"R tea and other "wake up" blends of tea.

Pharmacological basis: Caffeine is a stimulant. This tea can be brewed to contain more caffeine than coffee.

(Gaultheria procumbens)

Constituents: Oil is 99% methyl salicylate from leaves. "Mountain Tea" in the Rockies.

Popular use as tea: Used for migraine, sciatica (inflammation of the major nerve of the leg which results in severe pain), lumbago (lower back pain), and as an antiseptic.

Pharmacological basis: Methyl salicylate may hydrolyze to salicylic acid (Aspirin) and methyl alcohol, which would explain this properity. The essential oil can be very toxic to children.



The need to better understand the implications of managing agricultural wastewater is a concern of many agencies and public interest groups. Concern focuses on the effects of agricultural drain and wastewater (trace elements, salts, and chemicals) on water quality, the aquatic ecosystem and associated fish and wildlife resources. This concern has been intensified by recent finding by Fish and Wildlife Service researchers of dead embryos and deformed young of aquatic birds nesting on the Kesterson evaporation ponds of the Bureau of Reclamation located near Gustine in Merced County. Workshop discussions will stress recent studies and data from monitoring water quality; aquatic ecosystems research; wildlife research; state-of-the-art analysis of water, plant and animal tissue for chemicals and trace elements; and potential groundwater contamination by salts and applied chemicals. The concerns and needs of natural resource management and regulatory agencies will be outlined along with potential studies which address these concerns. Representatives of the following agencies are participating in the program: the Fish and Wildlife Service (USDI), the National Marine Fisheries Service, the U.S. Geological Survey, the Bureau of Reclamation, the Soil Conservation Service, the California Departments of Water Resources and Fish and Game, and the State Water Resources Control Board. Other participants in the program are from several departments of the University of California including Cooperative Extension; Environmental Toxicology; Land, Air and Water Resources; Wildlife and Fisheries Biology; and Avian Sciences of U.C. Davis, and the Division of Biological Control, U.C. Berkeley.

Topics in the Workshop include the following:

The registration fee is $25 and does not include meals. Participants should plan to bring sack lunches or dine nearby at the Student Union. University of California students may attend for $10. To preregister for this workshop call University Extension at 916-752-0880. The section number for UC students is 833E34 and for others the section number is 833E33. I hope to see you there.

Arthur L. Craigmill
Extension Toxicologist
U.C. Davis