Western Medicine Re-Discovers the Ancient Chinese Herb Ma Huang

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Western Medicine Re-Discovers the Ancient Chinese Herb Ma Huang

Overview

For over 5,000 years Chinese physicians have used the scrubby plant ma huang to treat asthma, a severe breathing condition. Ma huang is the Chinese name of the plant of the genus Ephedra, the source of the modern drug ephedrine. Introduction of the drug to scientific medicine arose from the work of Carl L. Schmidt (1893-1988) and his Chinese colleague Ko Kuei Chen (1899-?). Schmidt, a pharmacologist, became fascinated with ancient Chinese herbal medicine when he was assigned to teach at Peking University in 1922. With Chen's help, he investigated the plant, extracted the essence, and found that this extract, called ephedrine, could be useful in the treatment of asthma. In the 1920s Percy L. Julian (1899-1975) synthesized the drug.

Ephedrine gave hope to a generation of asthma sufferers, although a number of side effects began to be noted. In later years of the twentieth century ephedrine was used as a street drug for its amphetamine or upper-like qualities and in diet pills. The side effects caused many deaths, warranting the U.S. Food and Drug Administration (FDA) to issue a warning about the possible dangers of using ephedrine except under very strict supervision.

Background

In ancient medicine many ways—including magic and incantations—were used to treat people with a multitude of conditions. More active therapies included tonics to strengthen the person or "poisons" to drive off the evil spirits. Choice of the right herbal medicine depended on the symbolic use of a plant, which could be chosen for its shape or sound.

The Chinese have a long tradition of medicinal herbs. Ma huang, the plant from which ephedrine comes, is part of ancient history. The Chinese book of medicine Nei Jing, or Book of Medicine of the Yellow Emperor, written about the third century b.c., established the principle of yin and yang. The idea of yin and yang is based on balance—between the active and passive, hot and cold, male and female. Illnesses occur when these qualities are out of balance. The role of Chinese physicians was to restore this balance, and the use of herbs was only one of the ways adopted by Chinese physicians. Shen Nong Ben-caojung(Classes of Roots and Herbs of Shen Nong), a book that appeared in the third century a.d., mentioned ma huang.

Li Shih-chin (fl. 1500s), a physician of the Ming dynasty, gathered information on drugs in a giant encyclopedia of medicine called the Pents'ao kang-mu or "Great Pharmacopoia." These volumes described more than 2,000 drugs and gave directions for more than 8,000 prescriptions. Li included modern processes such as distillation. Ephedra and other plants, as well as mercury, iodine, and even information on smallpox inoculations were also discussed.

For over 5,000 years ma huang was used to treat asthma and hay fever. From the genus Ephedra, the Chinese species is E. sinica. The plant itself is a straggling gymnosperm or part of the evergreen family. It appears as a low or climbing desert shrub. North American kin include a small fir and a species called the Mormon tea bush.

The dried Ephedra stems look very much like the end of a broom. Users put a handful of crumbled stems in a glass or enamel pot with a quart of cold water. After boiling for 20 minutes, the tea is strained. The person is advised to drink 1-2 cups every 2-4 hours as needed. Chinese Ephedra is also found as tinctures and capsules.

In the 1800s concern over the quality of herbs and herbal preparations received attention. The new scientific knowledge from chemistry gave impetus to isolate "essences" from the plants, and among the new products developed was a group of plant constituents called alkaloids. Between 1817 and 1898 42 alkaloids, including morphine and quinine, were found. These preparations were presented as pills, infusions, tinctures, and extracts.

Folk medicine and treatments were popular in America in the 1800s, but toward the end of that century the production of medicines came into being. Small manufacturing companies emerged that later became household names like Parke-Davis, Burroughs-Wellcome, and Squibb. The new pharmaceutical houses became concerned with quality control and producing single doses in tablet form. The role of herbal extracts generally declined. However, some new herbals did appear in the 1920s.

Scientific medicine, as it was developing in the early twentieth century, basically denied and dismissed ancient herbal medicine as superstition. However, some researchers, studying ethnobotany, saw that certain herbs were effective painkillers, anesthetics, and narcotics. These drugs included salicylic acid (aspirin), ipecac, quinine, cocaine, digitalis, and later ephedrine.

Ma huang was introduced to modern medicine by a University of Pennsylvania researcher named Carl Frederick Schmidt. Schmidt graduated with an M.D. from the University of Pennsylvania in 1918 and joined the faculty at Penn in 1920. He became interested in the emerging field of pharmacology as it applied to clinical medicine and dentistry. In 1922 his life and outlook changed when he went to teach at Peking Union Medical College in China. His China experience was a powerful eye opener. He had always assumed that the scientific medicine of the West had all the answers and that Chinese folk medicine was little more than old-time myth.

He became enthralled with how effective certain Chinese medicinal herbs were and was impressed with a Chinese colleague, Ko Kuei Chen, who pointed out the uses of many of these ancient herb remedies. When Western medicine had been imported to China by missionary doctors and others, the Chinese physicians combined the best of both worlds. They practiced Western medicine but also used the herbal remedies when necessary or advantageous.

The investigations of Schmidt and Chen led them to look at many plants, including the herb ma huang from the Ephedra plant. Returning to Penn in 1924, the two continued their collaboration—isolating the medicine from plants and investigating the effects on patients who suffered from bronchial asthma. The research was done in the late 1920s and published in Ephedrine and Related Substances in 1930.

Another step in the development of the use of ephedrine was made by Percy L. Julian (1899-1975). Julian first synthesized both ephedrine and nicotine. An African-American chemist, he sought to isolate simple compounds in natural products, understand how the body used them, and then create the synthetic compound.

Impact

Chemically, ephedrine is an alkaloid closely related to epinephrine or adrenaline. The two compounds have similar effects on the body. Ephedrine stimulates the central nervous system. In sufficient doses, it acts to constrict small blood vessels, elevates the blood pressure, and accelerates the heart rate. Ephedrine relaxes the bronchioles, the small branches of the bronchial tubes, and dilates the pupils of the eyes. Ephedrine has numerous applications in medicine. The primary treatment is for asthma, but physicians have also used it to treat low blood pressure and as an antidote to poisons that depress the central nervous system. Eye physicians may use it to dilate the pupils, but it seems to work only on light-colored eyes. The drug does have some undesirable side effects of restlessness, palpitations, and insomnia.

Schmidt continued his influence and interest in herbal research and ultimately became head of the Department of Pharmacology at Penn from 1936-59. In 1948 he was appointed to the Board of Directors of the American Bureau for Medical Aid to China. He went on to hold the office of Secretary of the International College of Pharmacologists (1954) and research director of the Aviation Medical Acceleration Laboratory in the Navy Aid Development Center.

Asthma has been a condition of age-old concern for children as well as adults. A sudden constriction of the bronchial tubes results in wheezing when one breathes out and difficulty breathing air in. Such an attack is called an "episode." The condition is often very mysterious and difficult to treat. The actual attack is caused by a tightening of the muscles that regulate the size of the bronchial tubes. Nerves normally control these muscles, but the reasons why the nerve ceases to function properly are not clear. Asthma may be an allergic reaction. Emotional stress may trigger an attack, as may exercise or respiratory infection. A case that appears with no obvious cause is called "intrinsic." Striking without warning, an intrinsic episode may require emergency treatment, without which the patient may die. Toward the end of the twentieth century, incidence of asthma in the United States was increasing, perhaps due to increased air pollution and other environmental problems.

In the last decades of the twentieth century, some herbals re-emerged. The argument that plant products were safer and more pleasant than synthetics became popular. Ephedrine received a great deal of attention as a type of street drug with "upper"-like properties, similar to amphetamine. It was also put into diet drugs. In 1997 the U.S. Food and Drug Administration (FDA) proposed strong safety measures for ephedrine as a weight-loss source. The FDA warned that ephedrine alkaloids are amphetamine-like compounds with powerful stimulant-like effects on the nervous system and heart. However, under the supervision of a physician and responsible use, ephedrine is very useful and effective for the treatment of asthma.

EVELYN B. KELLY