NEW YORK—The sheer volume of herbal medicines now available can be daunting, and the choice is complicated by the fact that specific standardized extracts are sometimes marketed under a number of different of brand names.
"'Which products to choose? Which companies can we trust?' I get that question all the time," said Mark Blumenthal, founder and executive director of the American Botanical Council, and one of the nation's leading experts on botanical medicine. "A good place to start is with the products that have been most researched."
Much of the best botanical research has been done in Europe, particularly in Germany. But the herbal agents used in European trials—typically proprietary standardized single plant extracts—are often marketed under different names in the US. Speaking at Columbia University's annual Botanical Medicine in Modern Clinical Practice course, Mr. Blumenthal outlined the most well-researched European products, and their US trade names.
"The data in the German Commission E monographs, and other studies used to guide labeling and policy in Europe are done on a relatively small number of standardized products," said Mr. Blumenthal, principal author of the first English translation of the seminal Commission E text.
"I'm not here to recommend or endorse these, or to say that ones not on the list are not as good," he said, adding that use of standardized single-ingredient extracts is only one way, albeit a convenient one, of practicing herbal medicine. The emphasis on single ingredient extracts should not be construed as a denigration of the use of fresh, whole-herb tinctures or multiple plant combinations, as is common in traditional Chinese medicine.
The products listed below are simply those with the most clinical documentation, and they provide a convenient way to become familiar with common botanicals.
Black Cohosh (Cimifuga racemosa): There are roughly 30 good clinical studies supporting use of this popular herb for menopausal symptoms. Most were done with Remifemin®, an extract standardized to 1% deoxyactine. The extract is made by Schaper & Brummer, and marketed in the US as Remifemin, by Enzymatic Therapies/PhytoPharmica. The dose range in the Commission E studies is 40–80 mg/day. "You don't need much," said Mr. Blumenthal.
Chaste Tree (Vitex agnus-castus): This increasingly popular herb for symptoms of premenstrual syndrome (PMS), has also been widely studied by German investigators. The subject of most of the studies is Agnolyt®, made by Madaus AG, and marketed in this country as Femaprin®, by Nature's Way. The dose range in the German studies is 30–40 mg/day.
Echinacea (Echinacea purpurea): Arguably the most widely used herb for colds, flu and upper respiratory infections, echinacea extract has been extensively studied in Europe. There are 242 positive published trials supporting Echinacin®, a concentrate of the expressed plant juice made by Madaus AG, and marketed here as Echinaguard® by Nature's Way.
Garlic (Allium sativum): As a medicine, garlic has substantial scientific support as a way of reducing cholesterol and improving peripheral circulation. The Commission E studies used a product called Kwai®, which is marketed here and abroad by Lichtwer Pharma. There are also several supportive studies from Japanese investigators using Kyolic®, manufactured by the US-based Wakunaga corporation.
Ginkgo (Ginkgo biloba): This popular herb is approved by Commission E as an agent for increasing cerebral circulation, improving intermittent claudication, and as a treatment for vertigo and tinnitus of vascular origin. Two products have received the most study, with 119 supportive trials between them: Schwabe's Tebonin®, and Lichtwer's Kaveri®. Tebonin® is the key ingredient in three US products: GinkGold® by Nature's Way, Ginkgoba® by Pharmaton, and the Quanterra® ginkgo product by Warner-Lambert. Kaveri is also available in the US, marketed by Lichtwer, the product's manufacturer.
|Hawthorn (Crataegus spp.), popular with European cardiologists, has inotropic effects. © 2001 stevenfoster.com. |
Hawthorn (Crataegus spp.): Though not as popular in the US as in Europe, this herb has very definite cardiovascular inotropic effects, owing to its ability to inhibit myocardial ATPase, and has been shown to increase cardiac output. Mr. Blumenthal noted that some European cardiologists combine Hawthorn with digitalis. "This is probably not an herb patients should use for self-medication, but be aware that some people are doing it, none the less."
The European studies supporting Hawthorn as a cardiac tonic have been done on two products: Schwabe's Crataegutt®, marketed in the US as HeartCare® by Nature's Way, and Lichtwer's Faros®, not yet available in the US.
|Horse chestnut seed (Aesculus hippocastanum) improves chronic venous insufficiency. © 2001 stevenfoster.com. |
Horse Chestnut Seed (Aesculus hippocastanum): Dermatologists have been quick to pick up on horse chestnut seed extract for treatment of chronic venous insufficiency and to prevent varicose ulcers. There are 13 published placebo controlled trials to support its use. Most involved Venostasin®, a standardized extract made by Klinge Pharma, and marketed here as Venastat® by the Pharmaton company.
Milk Thistle (Silybum marianum): Milk thistle extract, or silymarin, is gaining in popularity among patients with hepatitis C, owing to its potential antioxidant and hepatoprotective effects. While there is no evidence that it is antiviral, it has garnered the interest of the National Institutes of Diabetes, Digestive and Kidney Disease, which has planned a trial of silymarin as an adjunct to conventional drug treatment. The most well-researched product in Europe is Legalon®, made by Madaus, and sold here as Thisylin® by Nature's Way.
Saw Palmetto (Serenoa repens): There are a handful of well-researched forms of this popular herb for benign prostatic hypertrophy. The most widely available is Prostagutt®, made by Schwabe, and sold here as ProstActive® by Nature's Way, and in Warner Lambert's Quanterra® line.
St. John's Wort (Hypericum perforatum): The popular "natural antidepressant" is available in many forms, but three seem to predominate in trials cited by Commission E: Jarsin®, a 0.3% hypericin extract made by Lichtwer, and sold in the US under the brand name Kira®; LI160, jointly manufactured by Lichtwer and Schwabe and marketed by Warner-Lambert in its Quanterra® St. John's Wort product; and Neuroplant®, a 5% hyperforin extract, sold here as Perika® by Nature's Way, and Movana® by Pharmaton.