Are plants used in modern medicine?

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A circa 1600 instructional illustration for trepanning
a skull. See more pictures of the brain.

The practice of medicine is an ancient one. A surgical procedure called trepanation shows just how long ago people began seeking to heal the ill and injured around them. Trepanation is the practice of opening the skull, usually to release pressure in the brain or free an individual from spirit possession or other metaphysical maladies. Evidence of this primitive form of cranial surgery dates back as far as the Neolithic period of 7000 to 2000 B.C. [source: Wellesley College].

Because trepanation seemed to be successful, the practice continued and spread. Archeologists studying Mesoamerican trepanation in Precolumbian Andean cultures found that patients had a survival rate of more than 70 percent [source: Tiesler Blos].

The use of drugs is just as old as surgery. At least as far back as the Kemites (ancient Egyptians), whose first pharaoh studied plants, and the Sumerians, who worshipped a goddess of medicine, humans were aware of medicinal plants. The era beginning 1500 B.C. saw an explosion of understanding of medicines, with cultures in China, Africa and India codifying their knowledge and documenting it for future generations [source: Heath].

These ancient practitioners identified what plants possessed various healing properties. In some cases, they attributed these properties to higher powers, but in large part, they accepted the medicinal powers of plants at face value -- the plants did what they did. As scientific inquiry developed, however, nothing could be taken at face value. The scientific method demands that the underlying processes of everything be understood.

Plants and Medicine

Once science had a grasp on the interactions between drugs and the body, it became possible to synthesize natural compounds through chemistry. Science and tradition diverged. In the first edition of the American Pharmacopoeia, published in 1820, 70 percent of drugs were plant-based. In the 1960 edition, 5.3 percent were of plant origin [source: Royal Society of Medicine].

As divergent as folk medicine and modern medicine have become, chemists have occasionally doubled back to the traditional roots of medicine in order to move forward. Read the next page to find out about the role of plants in modern medicine.

Ethnobotany: The Winning Combination of Drugs and Plants

Indigenous tribes can play a vital role in the creation of new drugs. The knowledge of medicinal plants these tribes possess is a starting point for modern science. Otherwise, researchers looking for naturally-occurring medicine would have the mundane and dangerous task of wandering the planet and randomly ingesting plants. Fortunately, anthropologists have discovered that there remains a vast amount of medicinal knowledge among indigenous tribes around the world that never made it into the annals of early Western pharmacology. As a result, a specialization of anthropology called ethnobotany developed. This is a hybridization of cultural anthropology and plant biology which leads practitioners deep into jungles and plains to uncover traditional medicinal knowledge in a process called natural products discovery [source: Service].

A traditional healer in India administers fish medicine to a patient in 2008.

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Without the aid of traditional healers like this man in India administering fish medicine to a patient in 2008, modern medicine would lack many of its most vital drugs.

An ethnobotanist learns about medicinal plants through a tribe: what kinds of healing properties the plant has, what conditions it's used to treat, what part of the plant is used and how it's prepared. He or she collects samples for analysis, and it's here that the process is transferred from the realm of anthropology to that of modern chemistry. It's the synthetic chemist's challenge to isolate the active ingredients in the plant. More importantly, chemists must figure out how to synthetically reproduce these natural ingredients.

The most basic level of deriving medicines from plants is extraction -- simply removing essential oils from the plant and concentrating them. This yields unreliable results, however, as concentrations aren't guaranteed. One bottle of medicine could be impotent, while another packs a dangerously powerful wallop. Synthetic chemists must take deriving medicine from plants to its highest level by producing compounds that mimic the molecular structure found in the plants. Without this necessary step, plant-derived medicines would have to be made from the plants directly, an expensive and often Herculean task.

This has been done successfully many times over in the history of synthetic chemistry. Quinine, used to treat malaria, is based on cinchona bark and digoxin, a treatment for heart conditions, comes from foxglove [source: Lee]. Morphine is another sterling example. This alkaloid found in poppy plants was isolated in the 19th century and synthesized in 1874 into diacetylmorphine, sold commercially by the Bayer Company from 1898 to 1910 under the trade name "Heroin" as a nonaddictive alternative to morphine [source: VCU]. While that product may have unleashed a scourge on humanity, synthesized morphine and its cousin codeine have eased the suffering of millions of patients since they were introduced into medicine.

Bayer's also responsible for another widespread medicine that traces its lineage back to plants: aspirin. In the 19th century, chemists isolated the natural compound salicin from willow bark. This bark has been used in traditional medicine at least as long as the time of Hippocrates, who prescribed it as a fever-reducer and anti-inflammatory [source: University of Maryland]. Salicin was synthesized into acetylsalicylic acid (aspirin).

Plants also play a role in modern chemistry beyond lending their molecular structure to synthesized drugs. Medicinal and nonmedicinal plants can provide chemists with enzymes and other structures that can act as catalysts in the production of synthetic compounds. Whole cells can be used as a "biological factory," producing ingredients needed in chemical synthesis and providing a stable environment for the chemical reactions needed to create them [source: Kutney].

It's clear that as removed as it is from the ancient lineage of traditional medicine, modern pharmacology owes a great deal to plants.

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