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The bark of the cinchona tree which is originally from South America had been the traditional cure of the Indians for malaria. European explorers brought it back home to cure hundreds of people. Now, there are many manufactured drugs that have replaced quinine—the chemical in cinchona which cures the disease.
Scientists have been studying medicinal plants for centuries in search of the active chemicals that make them useful. Once the active chemicals were discovered, the problem became one of producing them easily and cheaply. In many cases it was difficult to raise or gather the plants themselves and to remove the healing substances. In other cases scientists found that it took tons of plants to get enough of the active chemicals to meet medical needs. By learning the exact makeup of the chemicals, scientists hoped they could then build the chemicals form such simple parts as water, salts, oxygen, and carbon dioxide. This is, after all, what the plants themselves do. Chemists today can synthesize, or build, a great many drugs, but other healing drugs still come from the plants themselves. Thousands of plants have been used as medicines. Among these about 20 have played an important part in medical history. Here are the stories of some of them. Quinine Until well into the 1900’s, natural quinine was the only known remedy for the dreaded tropical disease malaria. Men, women, and children had suffered and died from this disease for centuries. A person with malaria would suddenly come down with a high fever and chills. Often he recovered, but a month or a year later the fever would mysteriously come back. If the sufferer did not die, he was likely to be troubled with the disease all his life. Men searched for plants to help cure this disease. But only the Indians on the eastern slopes of the Andes mountains seem to have been successful. They found a cure in the bark of a tree, now called cinchona, that grows in the forests of eastern Peru. Spanish priests learned of this remedy and took it back to Europe. By the 1800’s, knowledge of the drug from the cinchona bark was worldwide. But these trees grew only in very small areas of South America that were difficult to reach. Finally, in 1865, the Dutch gathered seeds from these trees in South America and planted them on the island of Java—then a Dutch colony. The cinchona grew there successfully. This meant that the Dutch could control the world’s supply of quinine. Meanwhile, two Frenchmen extracted a sticky gum from cinchona bark. This proved to be the curing chemical. The scientists named it quinine. Then German chemists produced a quinine-like chemical that they called atabrine, which acted like quinine in the treatment of malaria. Now there are many synthetic drugs to take the place of the natural chemical found in the bark of the cinchona tree.
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