Alisma, a member of the plant family Alismataceae, is a herb commonly used in traditional Chinese medicine (TCM). The medicinal part of the plant is the dried root of Alisma plantago-aquatica. Alisma is also called mad-dog weed, water plantain, American water plantain, or northern water plantain. It belongs to a different species from the edible plantain or cooking banana of the Caribbean or the plantain that produces psyllium seed. The Chinese name for alisma is ze xie.
Alisma is a perennial plant that grows aggressively in shallow water and boggy spots in parts of Europe, North America, and northern China. Its leaves take different shapes depending on whether the leaves grow above or in the water. The plant rarely reaches a height of more than 30 in (0.9 m). There are several subspecies of Alisma plantago found throughout the world, but their medicinal uses are the same.
Alisma has been used for centuries in China. It is also used today in North America and Europe. In the categories used by traditional Chinese medicine, which classifies herbs according to energy level (hot, warm, cool, or cold) as well as taste, alisma is said to have a cold nature and a sweet, bland taste. It is used primarily to treat conditions of damp heat associated with the kidney, bladder, and urinary tract.
Alisma is a diuretic and is used to rid the body of excess water. It has mild and safe tonic qualities that especially affect the kidney and bladder. It is often combined with other herbs in general tonic formulas. It is used to treat kidney stones, pelvic infections, nephritis, and other urinary tract infections, as well as yellowish discharges from the vagina. Alisma is also believed to have an antibacterial action that helps control infection. In China, alisma is also used to help rid the body of phlegm, to reduce feelings of abdominal bloating, and to treat diabetes. The herb is also widely used in Japan.
Outside of China, alisma leaves are sometimes used medicinally. They can be applied externally to bruises and swellings, or taken internally to treat kidney and urinary tract inflammations. The roots are also used for kidney and urinary tract disorders, as well as to lower blood pressure and to treat severe diarrhea. A minor homeopathic remedy can also be made from the root.
Modern scientific research shows that alisma does act as a mild diuretic. In several studies done in Japan, alisma extracts were shown to reduce artificially induced swelling in the paws of rats. Studies using human subjects have not been done, but test tube and animal studies do seem to indicate that there is a scientific basis for some of the traditional uses of alisma. There is also some indication that alisma does have a mild antibacterial effect, but again, evidence in humans is anecdotal and by observation rather than by controlled trials.
Alisma roots are harvested before the plant blooms and is dried for future use. Fresh root is toxic. Heating or drying deactivates the poisonous compounds in the root. If the leaves are used, they must be boiled for a long time before using. Fresh leaves are also poisonous.
Alisma is an ingredient in many common Chinese preparations to improve kidney balance and general health. These include rehmannia eight and rehmannia six combination, lycium chrysanthemum and rehmannia combination, rehmannia and schizandra, rehmannia and cornus, rehmannia and magnetitum formula, immortal long life pill, gentiana, and hoeln five. An extract of alisma root is commercially available. Some herbalists indicate that a large dose is necessary for alisma to be completely effective when treating infections, or that it should be combined with other anti-infective herbs.
Fresh alisma roots and leaves are poisonous. Dried roots or cooked leaves are safe, even in fairly large doses. However, the kidney infections that alisma is used to treat can be serious. Anyone who suspects that they have a kidney infection should see a medical practitioner.
Some Chinese herbalists indicate that long-term use of alisma can irritate the intestines.
In China and Japan, alisma is often taken together with antibiotics for kidney infections without any negative interactions. Since alisma is primarily an Asian herb, there is no body of information on how it might interact with most Western pharmaceuticals.
Molony, David. Complete Guide to Chinese Herbal Medicine. New York: Berkeley Books, 1998.
PDR for Herbal Medicines. Montvale, New Jersey: Medical Economics Company, 1999.
Teegaurden, Ron. The Ancient Wisdom of the Chinese Tonic Herbs. New York: Warner Books, 1998.
American Association of Oriental Medicine (AAOM). 433 Front Street, Catasauqua, PA 18032. (610) 266-2433.