Chapter 66 Ethnobotany

Plant-Derived Medical Therapy

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The history of ethnobotany begins before the advent of written records. In all ancient civilizations, plants served as important elements of food, shelter, dyes, ornamentation, religious rituals, and medicines. The term ethnobotany refers to an individual culture’s use of specific plants. Medicinal use of the plant kingdom has been termed herbalism, plant medicine, and natural-based medicine and is called phytomedicine in its current application. The word herb is broadly defined as a nonwoody plant that dies down to the ground after flowering. The most commonly used interpretation, however, is any plant used for medicinal therapy, nutritional value, food seasoning, or dyeing another substance.

The history of the discovery of the medicinal uses of plants by humans remains conjectural. Many scenarios probably occurred. Perhaps, in a prehistoric jungle of South America, a pool of water containing fallen plant material leached out some of the precious medicinal constituents of leaves, flowers, stems, and bark. Tannins, glycosides, sugars, and alkaloids from the bark were infused into the waters. Because of burning fever and severe dehydration, an extremely ill native drank from the pool, and his fever miraculously disappeared. The pond became known for its magical healing powers. If the water held bark from the cinchona tree, the native may have serendipitously discovered quinine.

Archaeologic evidence shows that prehistoric humans used plants extensively to treat physical ailments. Instinct and trial and error led to the realization that, for example, cinchona bark controlled intermittent fevers, animals fed ergotized grain aborted their fetuses, and the latex sap from the opium poppy could be eaten to alleviate pain. Innumerable medicinal plant traditions, some originating as far back as 2700 BC, still remain intact. Ethnobotanically, the use of plant-based medicines in a particular culture represented much more than an individual’s efforts to survive. Analyzing the methods and degrees of use of indigenous medicines reveals information about cultural philosophy, ingenuity, and sophistication. The Chinese developed an extensive and elaborate system for prescribing, classifying, and processing herbs that dates back to the third millennium BC. The formulas identified the specific effect of each herb and interactions with other herbs. Less tolerable herbs were blended with those that would counteract undesirable effects. Formulas were custom blended, taking into account a victim’s constitution and the stage of the disease. Some of the ancient knowledge from these writings is being used in contemporary herbal preparations commercially sold as “patent” (readily available in pill form) medicines.

Many native tribes of New Guinea, Indonesia, and the Amazon use single-herb formulations to treat nearly all medical conditions, as they did thousands of years ago. In the West, written records dating to the Sumerians accurately describe the medicinal uses of specific plants.¹¹⁰ In the same period of about 3000 years ago, the first Asian written record, the Ben Tsao Gan Mu, was compiled by the Chinese. It listed more than 360 medicinal plants and their classifications, uses, contraindications, and methods of action as perceived at that time. Roman and Greek herbal remedies were described in the writings of Hippocrates and later in those of Galen, providing a pattern for development of the Western medical tradition. Hippocrates was an advocate of using a few simple plant preparations, along with fresh air, rest, and proper diet, to help the body’s own “life force” eliminate problems. In contrast, Galen promoted use of direct intervention to correct the imbalances that cause disease, employing large dosages of complicated mixtures that included animal, plant, and mineral ingredients.¹²⁴

The earliest European compendium that listed the uses and properties of medicinal plants, De Materia Medica, was written by the Greek physician Dioscorides in the first century AD. He described about 600 plants, and his work remained the authoritative herbal medicinal resource into the 17th century.⁴²

Herbalism was practiced in many different ways during and after the Middle Ages. There were learned traditional herbalists and lay practitioners, as well as wandering herbalists, who professed pagan animism or Christian superstitions that often were more influential in healing than were the herbs’ properties. Little was added to the knowledge of herbalism during this period. After the Middle Ages and invention of the printing press in the 1400s, hundreds of herbal publications were compiled. Most early works were available only in Latin or Greek; it was not until the 15th through 17th centuries that the great age of herbalism was appreciated in English.¹¹⁰

Tides changed in European herbalism when a Swiss pharmacist-physician named Theophrastus Bombastus Von Hohenheim, better known as Paracelsus (1490 to 1541), introduced a new dimension. He advocated chemistry and chemical processing and used mineral salts, acids, and other preparations in medicinal therapies. This was a departure from the plant-based medicinal methods of the past. During the latter part of the 17th century, the predominance of plant medicines slowly eroded. In 1806, Freidrich Serturner, a small-town German pharmacist, became known for his efforts to isolate organic acids from plants in an attempt to find the active ingredient in opium. He discovered organic alkaloids, which became known as the first set of active plant constituents.¹⁶⁰ Because of their physiologic activity, the search for plant alkaloids continued into the 20th century.

Discoveries quickly followed. The bronchodilator and antitussive ephedrine, from the herb Ephedra sinica, was often used in Chinese medicinal formulas for bronchial asthma. The discovery of morphine led to the creation of all the narcotic analgesics. The bark of the cinchona tree was found to contain quinine in 1819, which led to the development of antimalarial drugs.

The traditional herbal extract from rhubarb (Rheum spp.) has several active compounds. These compounds mediate many of the pharmacologic effects, such as its purgative action (from sennosides); antibacterial, antifungal, and antitumor activities (from anthraquinones); antiinflammatory and analgesic activities; and improvements of lipid metabolism (from stilbenes). Treatment of leukemias from an extract of Madagascar periwinkle (Catharanthus roseus), known as vincristine, has been highly effective.⁴³

Discoveries in the 19th and 20th centuries included atropine (from belladonna leaves, Atropa belladonna) in 1831, cocaine (from coca leaves, Erythroxylum coca) in 1860, ergotamine (from Claviceps purpurea) in 1918, and tubocurarine in 1935.¹²⁴

European settlers brought herbal knowledge and their medicinal methods to the Americas. Because of the abundance and wide use of plants on the new continents, they also learned much from the indigenous peoples. The colonists found that conditions afflicting them, such as malaria and scurvy, were treated effectively with herbs by the Native Americans.¹²⁶ In the 1700s, herbal medicine continued to have popular applications in lay circles, but it was also investigated by the new medical establishment. Although the creation of a small elite group of learned professionals was thought to violate the political and constitutional concepts of the early American democratic movement, the practice of medicine was carried over from England and Scotland during pre-Revolutionary days. Before a professional medical class was established, most illness in America was treated within the family or extended family network.

Many concepts were modified in the colonies between 1765, when the first medical school opened, and 1850, when more than 42 schools of medicine had been recognized. The inquiry into Digitalis purpurea (foxglove) by William Withering exemplified the change in perspective from anecdotal folk medicine to a critical examination for specific uses of botanicals from a biochemical point of view. During the early 1800s, the trend was to look at the efficacy of botanicals and their intrinsic value from a more scientific perspective.

Several developments delayed the appreciation of herbalism by physicians in the colonies. For instance, Samuel Thomson promoted a system of herbal medicine by proselytizing about his patented method of herbal prescribing, which used many Native American herbs. A central theme in his approach was advocacy of self-prescribing based on the philosophies and herbal prescriptions found in his book, New Guide to Health. The right to sell “family franchises” for use of the Thomsonian method of healing was the basis of a widespread lay movement between 1822 and Thomson’s death in 1843. Thomson adamantly believed that no professional medical class should exist and that democratic medicine was best practiced by laypersons within a Thomsonian “family unit.”⁴⁰ Although his methods were considered crude and unscientific, he had over 3 million faithful followers in 1839. Founded on ignorance, prejudice, and dogma, the Thomsonian school did little to help physicians accept European and American herbal medicines. European physicians in the Thomsonian movement wished to separate themselves from lay practitioners by creating requirements and standards for the practice of Thomsonian medicine. Thomson was adamantly against this, but a decade after his death, the Thomsonian physicians formed the Eclectic School of Medicine, which attempted to unite “professional physicians,” Thomsonianism, and traditional herbal medicine. Establishment of several Eclectic medical schools was a step toward validating herbal medicine, but it failed to bring herbalism into the mainstream medical establishment. The founding of the American Medical Association and the Flexner Report on medical education in 1910 thoroughly established the modern pharmaceutical industry in the medical education system.⁴⁰

Because of the availability of pure, active constituents from plant drugs and the synthetic drugs that began to appear on the market toward the end of the 19th century, the prescribing habits of physicians began to change. The sensibility and predictability of administering exact dosages were appealing. For example, the pure alkaloid of quinine, rather than a foul-tasting extract of cinchona bark containing variable percentages of quinine and other alkaloids with different physiologic properties, could be prescribed for malaria.

Many “crude drugs” were standardized for therapeutic activity. Digitalis, which still retains its status in the United States Pharmacopeia (USP), is one example. Of the 200 plant drugs officially listed in the USP in 1936, about 19% are still official today.¹⁶⁰ An estimated 25% of all prescriptions dispensed in community pharmacies between 1959 and 1980 contained ingredients extracted from higher plants. For a significant number of synthetic drugs, natural drug products continue to serve as either models or starting points for synthesis.

Evolution of Phytopharmaceuticals

The drive toward patenting and ownership in the pharmaceutical industry has been a strong incentive to research and develop plant-based products. Because a plant cannot be patented, however, little U.S. effort has gone into developing herbal medicines during the past century. The principal active constituents of botanicals are investigated for their biologic activity, but in many cases these are less effective than is the whole crude extract of an herb.¹²⁴

One problem in the development of the U.S. botanical pharmaceutical industry has been quality control. In addition, lack of standardization plagues plant-based products. Quality control and standardization of crude plant extracts for herbal medicines were virtually nonexistent until recently,¹²⁴ or we might be using more botanical medicines for common ailments. In Europe and Asia, where pharmaceutical firms have been producing standardized phytopharmaceuticals (plant-based standardized extracts) for decades, research and development have demonstrated that they make economic and medical sense. Europeans use phytopharmaceuticals as part of their mainstream medical practice. In hospitals, they are used primarily as adjuvant therapies. More than 70% of general practitioners in Germany prescribe phytopharmaceuticals, and the public health insurance system pays for most of these prescriptions. The total annual market for phytopharmaceuticals in Germany alone is $1.7 billion. Beginning in 1993, the licensing procedure for German physicians required a knowledge of phytotherapy.¹⁴²

Production and evaluation of botanical medicines have improved significantly in the past six decades. In crude plant evaluation, modern laboratory analysis can determine the percentage of active constituents, as well as solubility, specific gravity, melting point, optical rotation, and water content. Scientists detect resins, alkaloids, flavonoids, enzymes, essential oils, fats, carbohydrates, and protein content. They can precisely assay using liquid, high-pressure liquid, paper, and thin-layer chromatographies; spectrophotometry; atomic absorption; and magnetic resonance imaging. These methods improve the predictability and therapeutic effectiveness of standardized crude botanical medicines, which are then evaluated for their efficacy in animal studies to determine pharmacologic potency, activity, and toxicity. U.S. and European companies have set strict quality control guidelines to ensure optimal yields of pharmacoactive constituents, with acceptable levels of impurities, pesticides, residual solvents, and heavy metals, and acceptable bacterial counts.

Specific cultivation and harvesting techniques affect the therapeutic value of a given herb, which is related to the amount of active constituents in a specific medicinal plant. Methods of packaging, storage, and transport can dramatically affect the stability of active compounds. Both extracts and concentrates are obtained by adding appropriate solvents to raw herbs, which draws out the active constituents. The most common method is infusion, which is analogous to a tea bag being steeped in hot water to make tea; in this case, water is the solvent. When the water is slowly evaporated, the concentrate contains the active constituents.

Pure ethanol is a solvent that is often used effectively to concentrate active herbal constituents. Immersing a high-quality bulk or raw herb in pure ethanol for hours or days, depending on the herb and the part used, and then pressing the solids out, yields an herbal tincture. The alcoholic tincture is diluted with water to yield a 20% alcohol tincture. In another method, a 20% alcohol mixture is the solvent. Fluid extracts can be made by vacuum-distilling some of the alcohol off; this avoids elevating the temperature, which may affect some of the active constituents. Another concentration process, solid extraction, yields a solid or semisolid product that can then be powdered or granulated for administration.

Once an extract is produced, qualitative and quantitative analyses can be performed to assist in standardization. The percentage of known active constituents is assayed, to obtain predictable clinical results.

An herbal infusion is generally a better source of active compounds than is an air-dried or a sun-dried powdered herb (Figure 66-1), but its action may not be as strong as those of concentrates such as tinctures, solid extracts, and fluid extracts. Potency of an extract can be defined by (1) percentage of active constituents or (2) concentration. Herbalists express concentration as an equivalency: a four-to-one extract is equivalent to or derived from four parts of the crude herb to yield one part extract. This is usually written as “4 : 1 solid extract.” Longer shelf life, greater effectiveness, and higher concentration of active constituents make a more standardized (thus better) product than the raw powdered herb; however, efficacy is difficult to compare.

FIGURE 66-1 A, Calendula officinalis. B, Calendula drying and dried in a jar. C, Calendula flower bud.

(A and B courtesy Cascade Anderson Geller; C courtesy Jill Stansbury.)

An example of a product that is standardized by the percentage concentration of pharmacoactive glycosides is Ginkgo biloba extract, marketed in Europe under the trade names Tanakan, Rokan, and Tebonin. It is typically standardized as 24% flavonoid glycoside. G. biloba extract has been shown to prevent metabolic and neuronal disturbances of cerebral ischemia and hypoxia in experimental models.^93,¹⁰⁵

Quality control is addressed for many herbal products when the known clinical effectiveness can be attributed to a specific active constituent. Improved analytic methods and use of high-quality herbs (i.e., high in active constituents) helps ensure standardization. In Europe, the dosage is expressed in milligrams of active constituents, a system that favors consistency. The main difference between the infusion or extraction method and chemical isolation or synthesis is that the extracts still contain all the synergistic cofactors that enhance the function of the active ingredient. This important aspect of herbal medicine is lost once the active constituent is removed from the whole plant.

Herbal Preparations for Clinical and Wilderness Use

Botanical preparations can be readily and accurately prescribed for travelers and wilderness enthusiasts who need medical help. Throughout the ages, botanicals have been useful adjunctive therapeutic agents. Knowing which preparations from the natural pharmacopeia can be used and how to use them engenders a sense of integration with the natural environment. Indigenous peoples who depend on the botanical world hold a vast amount of untapped knowledge. Wilderness enthusiasts should help preserve this understanding of the natural world and do what they can to save natural habitats. Further investigation into the plant kingdom for useful medicinal agents will aid in these efforts.

Herbal medicines can be prepared by decoction or infusion of bulk or raw herbs, or by making an extract, a concentrate, or a tincture.

Infusions are prepared like a standard tea. The soft parts of plants—flowers, stems, and leaves—are placed in a warmed pot. Boiling water is poured over the herb, and the pot is covered to prevent beneficial essential oils from evaporating. The mixture infuses for about 10 minutes and then is strained. The supernatant can be used immediately or refrigerated in an airtight container for as long as 2 days. A standard adult dose of an herbal preparation is 28.3 g (1 oz) of dried herb in 473.2 mL (1 pint) of water, or 1 tablespoon per cup. The amount is doubled if the herb is fresh.

Generally, it is best to take infusions hot by the cupful, 3 times daily for a chronic problem and up to every hour or two during an acute illness. To make infusions palatable, many herbalists add licorice, aniseed, or honey. The hard or woody parts of plants, such as bark, seeds, roots, rhizomes, and nuts, have tough cell walls that must be broken down by longer heating before they impart their constituents to water. The herbs can be first broken into small pieces by chopping, crushing, or hammering.

Traditionally, a decoction was prepared in an earthen crock reserved especially for making herbal preparations. In the past, herbalists believed that some quality of the medicine was affected by the type of vessel or container in which the brew was prepared. Contemporary practitioners generally recommend the use of stainless steel, ceramic, or enamel and specifically discourage the use of aluminum or other alloyed metal pots. The herb is placed in an appropriate container and covered with cold water. The mixture is brought to a boil, covered, and simmered for 10 to 45 minutes, depending on the type and part of the herb being used. A decoction can be strained, flavored, or sweetened like an infusion, and it is consumed while hot.

Modern practitioners use the most efficient and predictable forms of specific herbal medicines. Concentrates in capsule form are most effective and easiest to administer. The standard herbal concentrate found in the marketplace is in a ratio of 4 : 1. Ease of administration and dosing and the predictable clinical effects have made this the industry standard. Herbal tinctures are extracted into a specific percentage of alcohol and can be mixed easily to make formulas tailored to personal circumstances. Formula prescribing is an art, and a combination may be many times more effective than a single herb. Classic formulas for common ailments have been cataloged since the first herbal compendiums were recorded centuries ago. In this chapter, however, the focus is on single herbs and their specific uses, identification, and preparation.

Homeopathic Use of Botanicals

Medical pioneer Samuel Hahnemann developed a radically different system of medicine nearly 200 years ago. Homeopathy is derived from the Greek words homoios, which means “similar,” and pathos, which means “disease” or “suffering.” The law of similars states that a substance that causes a set of symptoms in pharmacologic dosages can be used as a cure for similar symptoms (even if the etiologic agent is different) if that substance is given in a homeopathic dilution. Most homeopathic remedies are prepared from plant, mineral, and animal products. In homeopathic medicine, there is a perfectly matched simillimum (the most effective medicine) if the predominant symptoms of a disease or illness match the symptoms produced when the substance is taken in large dosages by a healthy individual. For example, the herb A. belladonna, which contains atropine, is poisonous. In excessive dosages, the herb causes death; in moderate dosages, it creates hot, feverish states; and in tiny (homeopathic) dosages, it can effectively treat certain types of fevers, viral syndromes, and inflammatory states.

A homeopathic dilution is created by taking a prepared tincture (mother tincture) of a botanical or an extract from nonplant sources and diluting it in a sequential or serial method. The difference in a homeopathic dilution is in its methodology. A homeopathic medicine must be succussed (shaken or agitated) mechanically or manually a prescribed number of times between the serial dilutions to be effective. The succussion method originally discovered by Hahnemann is said to “dynamize” the medicine. The succussion method is purported to affect the water molecules, creating a “memory” that the water molecules store in a lattice formation. This is similar to the storage of information on a magnetic disk or tape, except the signature resonance pattern is created from the interaction of the original tincture within the water’s lattice structure. The dilution can range from a 1× potency, which is a decimal dilution of a given ingredient (one part mother tincture per nine parts solute), to a 1 cup (one part mother tincture to 99 parts solute), to an extremely dilute 200c (one part mother tincture per 99 parts solute, serially diluted 200 times). A high-potency dilution (serially diluted more than 30 times in the × potencies and more than 12 times in c potencies) would be taken much less frequently than a low-potency dilution.

To make a 30× homeopathic preparation of Arnica montana, one drop of the plant tincture is added to nine drops of pure water, and the mixture is succussed 50 to 100 times. Next, one drop from that solution would be added to nine drops of pure water and again succussed 50 to 100 times. This is repeated 30 times to yield the desired 30× homeopathic remedy. The number refers to the number of succussions and the letter to the ratio of the mother tincture to pure water.

The mechanisms by which homeopathy works have yet to be elucidated, even though it has been practiced effectively for several hundred years. In 1900, an estimated 15% of U.S. physicians were prescribing homeopathic remedies.¹¹⁴ Recent studies have shown effective results in clinical trials using homeopathic medicines.^31,^88,¹⁰⁰ Mechanisms of action for many common pharmaceuticals also remain unknown. Many theories in medicine are still based largely on empirical observations rather than on theoretical understanding.

One herbal folk remedy for bruises, sprains, strains, and rheumatism in European and Native American medicine is topical application of the plant A. montana (leopard’s bane). Consistent with the homeopathic principle, toxic quantities of the whole-plant extract of arnica produce the same set of symptoms that it is intended to cure when administered internally in a homeopathic dosage or when the tincture or oil is applied topically to the affected area.

Arnica is contained in herbal and homeopathic dosages in numerous ointments, salves, and poultices for the treatment of trauma resulting from localized sprains, strains, or contusions. Controlled studies in Germany have shown that effective products for sprains from athletic activity use an ointment that contains homeopathic arnica.¹⁷¹

Topical Application

The earliest method of plant administration was topical application. Although many plants contain generalized moisture-enhancing properties, some were found to be particularly effective in ameliorating specific acute conditions when applied topically. Two methods are used to apply remedies to the skin. The endermatic method applies medicine on the skin without friction, as when applying a compress to the dermis and epidermis after an abrasion or laceration. The epidermatic method uses friction and is most effective with botanical oils, liniments, ointments, and medicated warm and cold friction rubs, primarily for subdermal contusions and trauma, to effect circulatory changes.⁵⁴

Topical application of medicinal plants is useful for many conditions, including abrasions, lacerations, burns, insect bites, infections, rashes, and dermatoses. Other applications include contusions, varicosities, joint pain, inflammation, and musculotendinous aches, strains, and sprains.

Topical herbal remedies are applied with a poultice, a compress, a fomentation, or an ointment. Probably the most common, the poultice is used to apply a remedy to a skin area with moist heat. A poultice is prepared by bruising or crushing the medicinal parts of the plant to a pulpy mass, and then applying this to the affected area and covering it all with a moist heat source. If dried plants are used (or fresh plants if necessary), the materials are moistened by mixing with a hot, soft, adhesive substance such as moist flour or corn meal. A good way to apply a poultice is to spread the paste or pulp on a hot, wet cloth, which is wrapped around the affected area to help retain moisture and heat. The cloth is moistened with hot water as necessary. With irritant plants, such as those used in a mustard plaster, the paste is kept between two pieces of cloth to prevent direct contact with the skin. After the poultice is removed, the area is washed well with water to remove any residue. A poultice can be used to soothe, to irritate, or to draw impurities from the affected area, depending on which plants are applied.

A fomentation is a hot cloth soaked with an herbal infusion or decoction. Fomentations are generally less active than are poultices. A cold compress is used for conditions that require an antiinflammatory cure. A cold, infusion- or decoction-soaked cloth is applied to an area and then removed when the body’s circulation has warmed the cloth to body temperature. The botanicals’ active constituents determine what actions the external applications will impart. For example, a poultice with an astringent herb such as Hamamelis (witch hazel) has an entirely different effect from one made with a strong vasodilator and rubefacient, such as capsicum (cayenne pepper).

Ointments are another method of topical administration. Most ointments are made in a base of petroleum jelly, stable vegetable oils, beeswax, or a combination of these. The extract from the desired botanical is suspended within the base to create a stable solid product. Topical botanical products have the same function as do topical pharmaceutical ointments and are used to treat lacerations, abrasions, infections, and insect bites. Other uses for botanical topicals include hemostatic, antiinflammatory, antihistamine, rubefacient, analgesic, emollient, and circulatory stimulant actions. Herbal poultices, compresses, and ointments deliver their active compounds transdermally, as do pharmaceutical topical agents.

The first uses of most medicinal plants were probably topical. In contemporary herbology, many of these plants are also used internally. Whole plants containing more than one ingredient with biologic activity generally invoke synergistic action of several components to produce the therapeutic action. Thus most botanicals have multiple applications for therapeutic purposes. Herbalists and homeopaths treat trauma of the skin, muscles, tendons, ligaments, and joint tissue with a topical agent in ointment or poultice form and give the same medicine internally in minute (homeopathic) dosages to enhance the activity, as with concurrent use of arnica ointment and homeopathic arnica.

The major precaution in medical botany is to identify toxicity. Some of the most effective topical agents can be toxic if ingested. Most of these plants found in the wild could not be taken in sufficient dosages to be fatal before causing gastrointestinal (GI) upset. A tincture, herbal concentrate, or powdered version of the plant, however, could have deadly potential.

Use of Herbal Medicine in the Wilderness

Travelers in the wilderness can choose preprocessed herbal preparations or naturally available plants in the immediate vicinity. A surprisingly large number of minor medical conditions encountered in an outdoor setting can be treated with plants in that location. North American recreational areas are home to medicinal plants that have been used by Native Americans for centuries. Recreationists in desert, alpine, and river environments can find medicinal plants in abundance. Nearly all plants encountered during an alpine trek in North America have some medicinal property, as do many in tropical and subtropical regions.

Considerations for using herbal products in the wilderness are availability, ease of application, incidence of side effects, toxicity, spectrum of applicability, affordability, and effectiveness.

Availability and Application

If a condition can be improved by application of a local botanical growing in the immediate vicinity, the pharmacy is immediately available. Plants may be in season, plentiful, and easily harvested. Finding the appropriate plants can be challenging, however, depending on the location, the season, the traveler’s familiarity with botanicals, and the type of medical condition. During mild seasons and at elevations conducive to plant growth in the continental United States, the chances of finding common plants are good. Otherwise, standardized commercial preparations of these herbs can be carried. These are packaged for long storage life, sanitary and convenient application, and standardization of active ingredients.

Hundreds of plants can be applied topically for a variety of conditions. Most of the readily available plants, even if properly identified, require some form of processing for the active constituents to be used fully. Furthermore, expertise in the field requires years of training by a knowledgeable botanist and herbalist. It also requires knowledge of plants’ seasonal variations, ecologic niches, and precise identifications. However, a person who is neither a botanist nor a herbalist can gain a basic understanding of a few plant medicines that have a wide spectrum of applicability and a broad range of geographic distribution.

Side Effects and Toxicity

The American Association of Poison Control Centers annually reports plant ingestion as a significant category of accidental poisoning. In 1997, 5.6% of U.S. poisonings came from plants and mushrooms. Of the substances that were involved in pediatric poisonings, plants were responsible for 7.4% of exposures.

Side effects or toxic reactions from botanicals are rare. Among the botanicals covered in this chapter, toxicity is not a major consideration, although anything can be toxic when used excessively or indiscriminately. Many toxic plants produce GI distress, vomiting, or diarrhea before any severe neurologic or cardiorespiratory derangement. Often, toxic side effects are caused by one substance in a plant. When isolated, minute amounts of an alkaloid may be potentially dangerous, but when ingested in a form modified by other constituents, the altered drug effect allows tolerance of larger amounts of the toxic substance or substances.

As is true for any medication, medicinal plants should be applied appropriately, and dosages for internal use should not exceed recommendations. Pregnancy and nursing may be contraindications. Dosages for almost any herb can be found in numerous references.¹²⁴ Felter⁵⁴ stated that “as a rule, doses usually administered are far in excess of necessity and it is better to err on the side of insufficient dosage and trust to nature, than to overdose to the present or future harm or danger of the patient.” In general, for the self-harvested herbs presented in this chapter, the dry, crushed, herbal adult dosage should be 1 teaspoon per cup or 8 oz of water; when the fresh herb is used, the amount should be twice that. Although no absolute law exists for administering medicines to children, Cowling’s rule takes the child’s age at the next birthday and divides by 24 to determine what fraction of the adult dosage should be given.⁵⁴

Spectrum of Applicability

Most herbal medicines that have been cataloged and used historically are specifically indicated for one condition, although additional therapeutic effects have been noted over time. All the botanicals covered here have multiple uses. Comfrey (Symphytum officinale) may be used as a topical antiinflammatory agent; it also has constituents that are effective for GI conditions when taken internally.¹¹⁰ Aloe vera gel is an excellent topical agent for abrasions and burns; taken internally, the latex portion serves as an effective laxative.¹¹⁰ Calendula officinalis has antimicrobial properties that make it an effective topical dressing for mild infectious conditions, whereas internally it has antipyretic effects.¹¹⁰

Affordability

If the herbalist collects plants and processes them personally, the cost is minimal. The purchase price of botanicals depends on the rarity and origin. Some exotic and rare botanicals from Asia and the Amazon rainforest demand a high price on the world market. Panax ginseng has long been regarded by Asian peoples as a prized herbal tonic and can cost hundreds of dollars per root, depending on the size, origin, and age. Panax quinquefolius, or American ginseng, can cost as much as $52 per pound and was valued at $62 million as a cash crop in 1992.¹⁸ Many exotic herbal and animal-derived medicines from China have prices as high as those of precious metals.

Most of the herbs produced in the continental United States and used for common ailments average 20¢ to 30¢ per dose (equivalent to 1 teaspoon of herbal tincture). Prices are not yet standardized. Quality control for production and supply and demand seem to dictate the cost of the mass-marketed herbal products. The best way to obtain a standardized product with a good quality-to-price ratio is to acquire the product from a botanical company that has been in business for at least 10 years and sells only to licensed health care practitioners.

North American Plant Medicines

Ephedra (Ephedra species)

Description and Habitat

Common names for ephedra include Brigham Young weed, desert herb, Mormon tea, squaw tea, and teamsters’ tea.

Ephedra spp. are shrubs with erect, straw-like branches found in desert or arid regions throughout the world and in the southwestern deserts of the United States. The Chinese ephedra called Ma Huang, E. sinica, is found throughout Asia; Ephedra distacha is found throughout Europe; Ephedra trifurca or Ephedra viridis (desert tea) (Figure 66-2), Ephedra nevadensis (Mormon tea), and Ephedra americana (American ephedra) (Figure 66-3, online) are found in North America; and Ephedra gerardiana (Pakistani ephedra) is found in Pakistan and India. The 0.6- to 2.1-m (2- to 7-foot) shrubs grow on dry, rocky, or sandy soils. The broom-like shrub has many jointed green stems with two or three small scale-like leaves that grow at the joint of stems and branches (Figure 66-4, online).

FIGURE 66-2 Ephedra viridis.

(Courtesy Cascade Anderson Geller.)

FIGURE 66-3 Ephedra americana.

(Courtesy Jill Stansbury.)

FIGURE 66-4 Ephedra.

(Courtesy Jill Stansbury.)

Ephedrine promotes weight loss.¹²⁴ Appetite suppression plays a role, but increased metabolic rate of adipose tissue is the main mechanism.⁸ The weight reduction effects can be enhanced by up to 60% with the addition of methylxanthine.⁴⁹

In response to accumulating evidence of adverse affects related to Ephedra, the FDA banned the sale of Ephedra-containing supplements on the retail market.

In the wilderness, specifically the desert, the raw herb Mormon tea from E. nevadensis or E. viridis can be useful for hay fever, mild asthma, bronchitis, or upper respiratory infection (URI). These species contain minimal amounts of ephedrine and principally contain pseudoephedrine; thus they can be used without some of the unpleasant side effects of the Asian species. They can also be used for mild fevers associated with influenza or URI.

The shrubs are typically found growing on dry, rocky, or sandy slopes. The leaves can be picked fresh or sun dried for 6 to 8 hours and can be prepared as a steeped tea or an infusion. Generally, the dose should be the equivalent volume of 1 teaspoon of dried, crushed stems per 8 oz of water, steeped for 10 minutes. The patient should not exceed a dosage of this amount given 6 times per day. Once harvested, the leaves can be kept for an indefinite period for later use if stored in an airtight container.

Toxicity

According to Duke,⁴⁸ an infusion of ephedra produced a “prompt and extensive contraction of uterine muscle when applied to smooth muscle strips of virgin guinea pig uteri.” Ephedra may also elevate blood pressure. Frequent use may result in nervousness and restlessness. It should be used with caution if the patient has hypertension, heart disease, thyrotoxism, diabetes, or benign prostatic hypertrophy. Ephedra should not be used with antihypertensive or antidepressant medications.

Goldenseal (Hydrastis canadensis)

Description and Habitat

Hydrastis (Figure 66-5) has a perennial root or rhizome that is tortuous, knotty, and creeping. The internal color is bright yellow, with numerous long fibers. The stem is erect, simple, herbaceous, and rounded, from 15 to 30 cm (5.9 to 11.8 inches) in height, becoming purplish and bearing two unequal terminal leaves. The leaves are alternately palmate with three to five lobes, hairy, dark green, and cordate at the base. The flowers, which are evident in early spring, are solitary, terminal, small, and white or rose colored.

FIGURE 66-5 Goldenseal (Hydrastis canadensis).

The plant is a native of eastern North America and cultivated in Oregon and Washington. The parts used are the dried rhizome and roots.

Pharmacology

The alkaloids derived from Hydrastis are hydrastine (1.5% to 4%), berberine (0.5% to 6%), berberastine (2% to 3%), canadine, hydrastinine, and related compounds. Other constituents include meconin, chlorogenic acid, phytosterins, and resins.¹²⁴

Native American and European Medicinal Uses and Folklore

Native Americans used Hydrastis extensively as an herbal medicine and clothing dye. The Cherokee Indians used the roots as a wash for local inflammations, as a decoction for general debility and dyspepsia, and to improve appetite. The Iroquois Indians used a decoction of the root for whooping cough, diarrhea, liver trouble, fever, sour stomach, flatulence, pneumonia, and heart trouble.¹¹⁹

Early European uses date back to 1793: in Collections for an Essay Towards a Materia Medica of the United States, Benjamin Smith Barton noted that Hydrastis was useful as an eyewash for conjunctival inflammation and as a bitter tonic. In the pharmacy of the 19th century (1830), goldenseal was listed among the official remedies in the first revision of the New York edition of the USP. It was listed in the USP until 1926 and recognized in the National Formulary until 1955.⁷⁵

Modern Clinical and Wilderness Applications

Goldenseal is among the top sellers in the American herbal medicine market. It is used as an antiseptic, hemostatic, diuretic, laxative, tonic, and antiinflammatory for inflammation of the mucous membranes. It has also been recommended for hemorrhoids, nasal congestion, sore mouth and gums, conjunctivitis, external wounds, sores, acne, and ringworm.¹⁰⁷

Modern research into the active ingredients berberine and hydrastine has shown why some of the folk applications are effective. The most widely studied component is berberine. This isoquinoline alkaloid has demonstrated antibiotic, immunostimulatory, anticonvulsant, sedative, febrifugal, hypotensive, uterotonic, choleretic, and carminative (promoting the elimination of intestinal gas) activities.¹²⁴ Berberine has broad-spectrum antibiotic activity. The antimicrobial activity has been demonstrated on protozoa, fungi, and bacteria, both in vitro and in vivo. Antimicrobial action has been noted against Staphylococcus, Streptococcus, Chlamydia, Corynebacterium diphtheriae, Escherichia coli, Salmonella typhi, Vibrio cholerae, Pseudomonas, Shigella dysenteriae, Entamoeba histolytica, Trichomonas vaginalis, Neisseria gonorrhoeae, Neisseria meningitidis, Treponema pallidum, Giardia lamblia, Leishmania donovani, and Candida albicans.¹²⁴ Berberine inhibits adherence of bacteria to host cells.¹⁵¹

Active ingredients in the crude botanical may be responsible for the wide-spectrum effectiveness of Hydrastis. The antifungal properties, for example, prevent the overgrowth of Candida that frequently occurs with use of other antibiotic therapies.

Other studies have shown the immunostimulatory activity of berberine-containing plants. Berberine increases blood flow through the spleen; improved circulation may augment the immune function of this lymphoid organ.¹³⁷ Berberine also activates macrophages.⁹⁹ Historically, berberine-containing plants have been used as febrifuges, and in rat studies they have an antipyretic effect three times as potent as that of aspirin.¹²⁴

Plants such as goldenseal are very effective in treating acute GI infections. In several clinical studies, berberine has successfully treated acute diarrhea caused by E. coli, S. dysenteriae, Salmonella, Klebsiella, Giardia, and V. cholerae.* Berberine-containing plants, in addition to having antimicrobial properties, influence the enterotoxins produced by offending pathogens.^25,^152,¹⁵³

GI illness is a major concern of travelers to areas with questionable sanitation. Both waterborne and food-borne bacterial and protozoal infections are concerns for persons in wilderness and Third World environments. Some experts recommend using a berberine-containing botanical source prophylactically at least 1 week before a visit to questionable areas and for 1 week after return.¹²⁴

Various eye complaints involving the conjunctivae and surrounding mucous membranes have been effectively treated with forms of berberine extract. Recent studies point to the effectiveness of berberine in treating infection caused by Chlamydia trachomatis. Clinical trials found that a 2% berberine solution compared favorably with sulfacetamide. Although the symptoms resolved more slowly with the berberine extract, the rate of relapse was much lower in the berberine-treated group.^10,¹²⁰

A standardized form of H. canadensis is beneficial for generalized digestive disorders (acute dysentery, gastritis) and for infective, congestive, and inflammatory states (sinusitis, pharyngitis, stomatitis) of mucous membranes. A typical dosage depends on the source and method of the extract. For the previous conditions, the following dosages, 3 times a day, are recommended: dried root or as infusion, 2 to 4 g; tincture (1 : 5), 6 to 12 mL (1.5 to 3 teaspoons); or solid extract (4 : 1 or 10% alkaloid content), 250 to 500 mg. Hydrastis can also be used as a wash or rinse for conjunctivitis, sinusitis, and pharyngitis. Eye drops, nasal lavage, and gargle are applied in a 5% preparation of a 1 : 5 tincture, or 1 to 2 teaspoons of powdered herb in 8 oz of water to create an infusion for application to inflamed mucous membranes. This can be repeated 3 times a day.

Toxicity

Berberine and berberine-containing plants are generally nontoxic. In recommended dosages, berberine-containing plants have not been shown to be toxic in clinical trials. The median lethal dose (LD₅₀) of berberine sulfate in mice is approximately 25 mg/kg, and in dogs, intravenous (IV) dosages up to 45 mg/kg do not produce lethal or gross toxic effects.¹³⁷ Hydrastis should not be used during pregnancy, and long-term ingestion may interfere with the metabolism of B vitamins.

Arnica (Arnica montana)

Pharmacology

The flower is used both internally and externally for medicinal effects. The rootstock is used to make commercial preparations for tinctures and oils that are applied topically. The active constituents of the plant drug are flavonoids, volatile oils, and plant pigments (carotenoids).¹⁶⁶ Specific constituents include arnicine, formic acid, thymohydroquinone, lobelamine, and lobeline (piperidine alkaloid).³¹

Native American and European Medicinal Uses and Folklore

The Catawba Indians administered the tea of arnica roots to treat back pain. In Europe, the flower heads have been used since the 16th century as an application for bruises and strains.¹⁶⁴ European arnica was included in the USP from the early 1800s until 1960 and was recognized for its effects on the healing of bruises and sprains.

Specific instructions given in the American Dispensory in 1922 listed arnica as effective for “muscular soreness and pain from strain or overexertion; advanced stage of disease, with marked enfeeblement, weak circulation, and impaired spinal innervation; … tensive backache, as if bruised or strained; [and] … headache with tensive, bruised feeling and pain on movement.”⁵⁴ Arnica in concentrated tincture form has been a popular but not necessarily safe medicine to treat inflammatory swellings and to relieve the soreness of myalgia and the effects of bruises and contusions. Dosages above the therapeutic range cause vagal inhibition when ingested and may cause toxicity if the concentrated tincture is applied topically. Therefore the most common use has been fomentation of the flowers for topical applications in the treatment of strains and sprains.

Modern Clinical and Wilderness Applications

Contemporary use of A. montana is generally limited to topical commercially prepared ointments and salves, in conjunction with internal homeopathic (low-dose) use for the same indications. Although its alkaloid (arnicine) and volatile oil (thymohydroquinone) are both relatively toxic, the actions of these constituents are extremely useful in resolving contusions and soft tissue injury. Most ointments are found to contain a 1× homeopathic dilution of arnica tincture, which is about 4% by volume. Oral dosage is given in homeopathic potencies of 6× to 200c, depending on the severity of the condition.

For application in the wilderness, most naturopathic first-aid kits include both the ointment and the oral homeopathic forms of arnica. For direct use of the plant in treating minor sprains and strains, 2 teaspoons of the dried flower tops can be steeped in 1 cup of water for 10 minutes, and the infusion applied in a cold compress to the affected area. This should be repeated each 2 hours in addition to standard first-aid procedures. The infusion lasts a day if refrigerated and a few hours if not; therefore it is best to use a fresh infusion whenever possible. In addition, if available, the oral homeopathic preparation (30× to 200c) should be taken 3 times daily until the swelling is reduced significantly. A topical ointment can be applied every 2 to 3 hours for this condition in place of the compress.

According to Weiss,¹⁶⁵ arnica is safe and effective for topical contusions and for stimulating granulation and epithelialization. A tablespoon of tincture is added to 500 mL of water, and the gauze compress is then placed on the wound. This stimulates local circulation and acts on the peripheral vasculature. After granulation has occurred, ointments may be applied.

Toxicity

Arnica tincture or infusion can be toxic if the concentration is too high. Undiluted tincture should not be used internally or in compress form over an open wound. Vagus nerve inhibition is the primary toxic effect; GI irritation is also noted. Toxic reactions include gastric burning; nausea; vomiting; headache; decreased temperature; dyspnea; cardiovascular collapse; convulsions; motor, sensory, and vagal paralysis; and death.³¹

Garlic (Allium sativum)

Description and Habitat

Garlic is a member of the lily family. It is a perennial plant cultivated worldwide (Figure 66-9). The garlic bulb is composed of individual cloves enclosed in a white skin. The medicinal herb is found in the bulb and is used either fresh or dehydrated. Garlic oil, which also has medicinal value, is obtained by steamed distillation of the crushed fresh bulbs.¹⁰⁷