Modern Herbal Medicine

The World Health Organization (WHO) estimates that 80 percent of the population of some Asian and African countries presently use herbal medicine for some aspect of primary health care. Pharmaceuticals are prohibitively expensive for most of the world’s population, half of whom lived on less than $2 U.S. per day in 2002.

In comparison, herbal medicines can be grown from seed or gathered from nature for little or no cost. Many of the pharmaceuticals currently available to physicians have a long history of use as herbal remedies, including opium, aspirin, digitalis, and quinine. According to the World Health Organization, approximately 25% of modern drugs used in the United States have been derived from plants. At least 7,000 medical compounds in the modern pharmacopoeia are derived from plants. Among the 120 active compounds currently isolated from the higher plants and widely used in modern medicine today, 80% show a positive correlation between their modern therapeutic use and the traditional use of the plants from which they are derived.

Clinical tests

In 2015 the Australian Government’s Department of Health published the results of a review of alternative therapies that sought to determine if any were suitable for being covered by health insurance; Herbalism was one of 17 topics evaluated for which no clear evidence of effectiveness was found. In a 2010 survey of the most common 1000 plant-derived compounds, only 156 had clinical trials published. Preclinical studies (tissue-culture and animal studies) were reported for about one-half of the plant products, while 12% of the plants, although available in the Western market, had “no substantial studies” of their properties.

The bark of the cinchona tree contains quinine, which today is a widely prescribed treatment for malaria, especially in countries that cannot afford to purchase the more expensive anti-malarial drugs produced by the pharmaceutical industry. Strong evidence was found that 5 were toxic or allergenic, so that their use ought to be discouraged or forbidden. Nine plants had considerable evidence of therapeutic effect. According to Cancer Research UK, “there is currently no strong evidence from studies in people that herbal remedies can treat, prevent or cure cancer”. The U.S. National Center for Complementary and Integrative Health of the National Institutes of Health funds clinical trials of the effectiveness of herbal medicines and provides “fact sheets” summarizing the effectiveness and side effects of many plant-derived preparations.

2.2 Prevalence of use

The use of herbal remedies is more prevalent in patients with chronic diseases such as cancer, diabetes, asthma and end-stage renal disease. Multiple factors such as gender, age, ethnicity, education and social class are also shown to have association with prevalence of herbal remedies use.

A survey released in May 2004 by the National Center for Complementary and Integrative Health focused on who used complementary and alternative medicines (CAM), what was used, and why it was used. The survey was limited to adults, aged 18 years and over during 2002, living in the United States. According to this survey, herbal therapy, or use of natural products other than vitamins and minerals, was the most commonly used CAM therapy (18.9%) when all use of prayer was excluded.

Herbal remedies are very common in Europe. In Germany, herbal medications are dispensed by apothecaries (e.g., Apotheke). Prescription drugs are sold alongside essential oils, herbal extracts, or herbal teas. Herbal remedies are seen by some as a treatment to be preferred to pure medical compounds that have been industrially produced.

In India the herbal remedy is so popular that the government of India has created a separate department— AYUSH—under the Ministry of Health & Family Welfare. The National Medicinal Plants Board was also established in 2000 by the Indian government in order to deal with the herbal medical system.

2.3 Herbal preparations

There are many forms in which herbs can be administered, the most common of which is in the form of a liquid that is drunk by the patient—either an herbal tea or a (possibly diluted) plant extract. Whole herb consumption is also practiced either fresh, in dried form or as fresh juice.

Several methods of standardization may be determining the amount of herbs used. One is the ratio of raw materials to solvent. However different specimens of even the same plant species may vary in chemical content. For this reason, thin layer chromatography is sometimes used by growers to assess the content of their products before use. Another method is standardization on a signal chemical. Leaves of Eucalyptus olida being packed into a steam distillation unit to gather its essential oil.

2.4 Safety

Herbal teas, or tisanes, are the resultant liquid of extracting herbs into water, though they are made in a few different ways. Infusions are hot water extracts of herbs, such as chamomile or mint, through steeping. Decoctions are the long-term boiled extracts, usually of harder substances like roots or bark. Maceration is the old infusion of plants with high mucilage-content, such as sage, thyme, etc. To make macerates, plants are chopped and added to cold water. They are then left to stand for 7 to 12 hours (depending on herb used). For most macerates 10 hours is used. Tinctures are alcoholic extracts of herbs, which are generally stronger than herbal teas. Tinctures are usually obtained by combining 100% pure ethanol (or a mixture of 100% ethanol with water) with the herb. A completed tincture has an ethanol percentage of at least 25% (sometimes up to 90%). Herbal wine and elixirs are alcoholic extract of herbs, usually with an ethanol percentage of 12- 38%. Herbal wine is a maceration of herbs in wine, while an elixir is a maceration of herbs in spirits (e.g., vodka, grappa, etc.). Extracts include liquid extracts, dry extracts, and nebulisates. Liquid extracts are liquids with a lower ethanol percentage than tinctures. They are usually made by vacuum distilling tinctures. Dry extracts are extracts of plant material that are evaporated into a dry mass. They can then be further refined to a capsule or tablet. A nebulisate is a dry extract created by freezedrying.

Vinegars are prepared in the same way as tinctures, except using a solution of acetic acid as the solvent. Syrups are extracts of herbs made with syrup or honey. Sixty-five parts of sugar are mixed with thirty-five parts of water and herb. The whole is then boiled and macerated for three weeks.

The exact composition of an herbal product is influenced     by the method of extraction. A tea will be rich in polar components because water is a polar solvent. Oil on the other hand is a non-polar solvent and it will absorb non-polar compounds. Alcohol lies somewhere in between.

A herb shop in the souk of Marrakesh, Morocco Many herbs are applied topically to the skin in a variety of forms. Essential oil extracts can be applied to the skin, usually diluted in a carrier oil. Many essential oils can burn the skin or are simply too high dose used straight; diluting them in olive oil or another food grade oil such as almond oil can allow these to be used safely as a topical. Salves, oils, balms, creams and lotions are other forms of topical delivery mechanisms. Most topical applications are oil extractions of herbs. Taking a food grade oil and soaking herbs in it for anywhere from weeks to months allows certain phytochemicals to be extracted into the oil. This oil can then be made into salves, creams, lotions, or simply used as an oil for topical application.

Many massage oils, antibacterial salves, and wound healing compounds are made this way. One can also make a poultice or compress using the whole herb or the appropriate part of the plant, which is usually crushed or dried and re-hydrated with a small amount of water and then applied directly in a bandage, cloth, or just as is. Inhalation, as in aromatherapy, can be used as a mood changing treatment to fight a sinus infection or cough, or to cleanse the skin on a deeper level (steam rather than direct inhalation here)

2.4 Safety

Datura stramonium is a highly effective treatment for asthma symptoms when smoked, because it contains atropine, which acts as an antispasmodic in the lungs. However, datura is also an extremely powerful hallucinogen and overdoses of the tropane alkaloids in it can result in hospitalization or death. For partial list of herbs with known adverse effects, see List of herbs with known adverse effects.

A number of herbs are thought to be likely to cause adverse effects. Furthermore, “adulteration, inappropriate formulation, or lack of understanding of plant and drug interactions have led to adverse reactions that are sometimes life threatening or lethal. " Proper doubleblind clinical trials are needed to determine the safety and efficacy of each plant before they can be recommended for medical use.  Although many consumers believe that herbal medicines are safe because they are “natural”, herbal medicines and synthetic drugs may interact, causing toxicity to the patient. Herbal remedies can also be dangerously contaminated, and herbal medicines without established efficacy, may unknowingly be used to replace medicines that do have corroborated efficacy.

Standardization of purity and dosage is not mandated in the United States, but even products made to the same specification may differ as a result of biochemical variations within a species of plant. Plants have chemical defense mechanisms against predators that can have adverse or lethal effects on humans. Examples of highly toxic herbs include poison hemlock and nightshade. They are not marketed to the public as herbs, because the risks are well known, partly due to a long and colorful history in Europe, associated with “sorcery”, “magic” and intrigue. Although not frequent, adverse reactions have been reported for herbs in widespread use. On occasion serious untoward outcomes have been linked to herb consumption. A case of major potassium depletion has been attributed to chronic licorice ingestion., and consequently professional herbalists avoid the use of licorice where they recognize that this may be a risk.

Black cohosh has been implicated in a case of liver failure. Few studies are available on the safety of herbs for pregnant women, and one study found that use of complementary and alternative medicines are associated with a 30% lower ongoing pregnancy and live birth rate during fertility treatment. Examples of herbal treatments with likely cause-effect relationships with adverse events include aconite, which is often a legally restricted herb, ayurvedic remedies, broom, chaparral, Chinese herb mixtures, comfrey, herbs containing certain flavonoids, germander, guar gum, liquorice root, and pennyroyal. Examples of herbs where a high degree of confidence of a risk long term adverse effects can be asserted include ginseng, which is unpopular among herbalists for this reason, the endangered herb goldenseal, milk thistle, senna, against which herbalists generally advise and rarely use, aloe vera juice, buckthorn bark and berry, cascara sagrada bark, saw palmetto, valerian, kava, which is banned in the European Union, St. John’s wort, Khat, Betel nut, the restricted herb Ephedra, and Guarana.

There is also concern with respect to the numerous wellestablished interactions of herbs and drugs. In consultation with a physician, usage of herbal remedies should be clarified, as some herbal remedies have the potential to cause adverse drug interactions when used in combination with various prescription and over-the-counter pharmaceuticals, just as a patient should inform a herbalist of their consumption of orthodox prescription and other medication. For example, dangerously low blood pressure may result from the combination of an herbal remedy that lowers blood pressure together with prescription medicine that has the same effect. Some herbs may amplify the effects of anticoagulants. Certain herbs as well as common fruit interfere with cytochrome P450, an enzyme critical to much drug metabolism.

2.4.1 Labeling accuracy

A 2013 study published in the journal BMC Medicine found that one-third of herbal supplements sampled contained no trace of the herb listed on the label. The study found products adulterated with filler including allergens such as soy, wheat, and black walnut. One bottle labeled as St. John’s Wort was found to actually contain Alexandrian senna, a laxative.

Researchers at the University of Adelaide found in 2014 that almost 20 per cent of herbal remedies surveyed were not registered with the Therapeutic Goods Administration, despite this being a condition for their sale. They also found that nearly 60 per cent of products surveyed had ingredients that did not match what was on the label. Out of 121 products, only 15 had ingredients that matched their TGA listing and packaging. In 2015 the New York Attorney General issued cease and desist letters to four major U.S. retailers (GNC, Target, Walgreens, and Walmart) who are accused of selling herbal supplements that were mislabeled and potentially dangerous. 24 products were tested by DNA barcoding as part of the investigation, all but five contained DNA that did not match the products’ labels. The investigation was prompted by the 2013 BMC study.

2.5 Practitioners of herbalism

1.    A person whose life is dedicated to the economic or medicinal uses of plants.

2.    One skilled in the harvesting and collection of medicinal plants (see wildcrafter).

3.    Traditional Chinese herbalist: one who is trained or skilled in the dispensing of herbal prescriptions; traditional Chinese herb doctor. Similarly, traditional Ayurvedic herbalist: one who is trained or skilled in the dispensing of herbal prescriptions in the Ayurvedic tradition.

4.    One trained or skilled in the therapeutic use of medicinal plants.

5.    One who is skilled in the preparation/manufacture of dried and/or liquid herbal products who possesses a pharmacognostic, formulary and/or clinical understanding of the products being prepared/manufactured. Herbalists must learn many skills, including the wildcrafting or cultivation of herbs, diagnosis and treatment of conditions or dispensing herbal medication, and preparations of herbal medications. Education of herbalists varies considerably in different areas of the world. Lay herbalists and traditional indigenous medicine people generally rely upon apprenticeship and recognition from their communities in lieu of formal schooling. In some countries formalized training and minimum education standards exist, although these are not necessarily uniform within or between countries. For example, in Australia the currently self-regulated status of the profession (as of April 2008) results in different associations setting different educational standards, and subsequently recognising an educational institution or course of training. The National Herbalists Association of Australia is generally recognised as having the most rigorous professional standard within Australia. In the United Kingdom, the training of medical herbalists is done by state funded Universities. For example, Bachelor of Science degrees in herbal medicine are offered at Universities such as University of East London, Middlesex University, University of Central Lancashire, University of Westminster, University of Lincoln and Napier University in Edinburgh at the present.

2.6 Government regulations

The World Health Organization (WHO), the specialized agency of the United Nations (UN) that is concerned with international public health, published Quality control methods for medicinal plant materials in 1998 in order to support WHO Member States in establishing quality standards and specifications for herbal materials, within the overall context of quality assurance and control of herbal medicines.

In the European Union (EU), herbal medicines are now regulated under the European Directive on Traditional Herbal Medicinal Products. In the United States, herbal remedies are regulated dietary supplements by the Food and Drug Administration under current good manufacturing practice (cGMP) policy for dietary supplements. Manufacturers of products falling into this category are not required to prove the safety or efficacy of their product so long as they don't make 'medical' claims or imply being other than for 'dietary supplement' use, though the FDA may withdraw a product from sale should it prove harmful. The National Nutritional Foods Association, the industry’s largest trade association, has run a program since 2002, examining the products and factory conditions of member companies, giving them the right to display the GMP (Good Manufacturing Practices) seal of approval on their products. Some herbs, such as cannabis and coca, are outright banned in most countries though coca is legal in most of the South American countries where it is grown. The Cannabis plant is used as an herbal medicine, and as such is legal in some parts of the world. Since 2004, the sales of ephedra as a dietary supplement is prohibited in the United States by the Food and Drug Administration.,  and subject to Schedule III restrictions in the United Kingdom.