Dr. John Riddle, a professor of history, actually started off with an education in medicine, eventually earning an MD. He became interested in history through studying traditional medicinal plants–plants he said were just laughed at and dismissed when people wrote papers on their pharmaceutical uses.
These plants first caught his eye when a close friend of his was diagnosed with lymphoma cancer.
“I looked up to see what he was taking… I found out those two chemical compounds for chemotherapy where from a plant–a Vinca plant — periwinkle is the English word,” Riddle said.
Surprised that such a common plant was being used as a medicine, he then looked to ancient Greco-Roman medical authorities and found they prescribed the same plant, and even the same dosage.
“They said a side effect was to make hair fall out,” Riddle said. That stands true today.
At that point in time there were nine known chemotherapy agents, and seven of those came from plants that had been used throughout history. So why, Riddle further investigated, if they had been used in ancient times have they escaped the notice of modern science?
“In the 13th century, surgeons maintained that giving drugs… was not as effective as surgery,” Riddle said.
Humanity had lost most of its knowledge of medicinal plants in the Dark Ages and has been rediscovering it since — how periwinkle is used in chemotherapy was not rediscovered until the 1950’s. Riddle now looks to ancient texts to see what other useful remedies we could have forgotten, and measures the usefulness of ancient drugs against their modern counterparts.
“After all, we get our religion from the ancients; we get much of our philosophy — why would they be so stupid regarding medical science? These were intelligent people,” Riddle said.
Of course, some accuse these remedies of being solely placebos, but Riddle points out that all the laxatives used modernly were also used in ancient times.
“Now a laxative is not apt to be a placebo. You know whether it works or it doesn’t work,” Riddle said.
Other examples of rediscovered medicines include aspirin – the acid it contains originally came from willow bark, though we now synthesize it artificially. Cherry juice was also a cure for colds, which is why so many of our cold medicines are cherry flavored. Pistachio nuts are broken down and used to treat stomach ulcers.
Many contraceptives also had ancient equivalents – Riddle is the discoverer of records of a plant called silphium , which grew in Cyrene and was such a good contraceptive it was put onto coins of the region. It was also unfortunately so effective that it was harvested into extinction.
Some people are still using these plants, according to Riddle, even here in North Carolina. A tablespoon of Queen Anne’s lace taken with water prevents implantation of zygotes (fertilized mammilian eggs) to the uterus, and is therefore often used as a ‘plan b’ by people in the Appalachian Mountains.
“It’s in the fields all around here and it actually does work,” Riddle said, but he doesn’t recommend it.
However, he does think that superstitions and old wives’ tales should be further investigated so that we might use the compounds in the plants to create medicines.
“There’s usually wisdom to what people do,” Riddle said.
The kind of research Riddle suggests, taking long-established medicinal plants and modifying them, is what De-Yu Xie , a professor in plant biology, does. He recently published a paper on his research combating malaria.
Traditionally in China, the plant Artemisia annua , or wormwood, was used to bring down high fevers to stop people from getting chills.
“That plant has been used for more than two thousand years in China,” Xie said.
Xie first encountered wormwood when he caught malaria in middle school, and the plant was used to save his life.
“Because of this medicine I was saved,” Xie said. “At that time we didn’t have any tablets — it was just crude extractions.”
He therefore began to research the plant for his master’s degree after a research team in China had isolated a compound within its leaves called artemisinin . This compound is highly effective against malaria, a valuable trait seeing as a large percentage of malaria has become resistant to our prior go-to drug, quinine. Moreover, the plant is abundant all throughout China and parts of the United States.
“They’ll grow anywhere – on the side of the road. They don’t need many nutrients,” Xie said.
Xie wanted this compound to be cheap enough to viably use, so he genetically modified wormwood plants so that they could be harvested efficiently. His plants are self-pollinating, flower quickly, and have a high concentration of artemisinin .
“Variation can lead to low production of artemisinin–a low yield–which increases the price of the compound and medicine,” said Xie .
Most of malaria occurs in tropical regions where the people are relatively poor, said Xie , and so the cheaper the medicine the more effectively it will be used. If the medicine is too expensive, people generally only take a little bit of it — causing the disease to adapt and evolve instead of killing it. The medicine made from wormwood is cheap enough if would ameliorate this problem.
Evoca is one of the companies that produces these medicines from plants by extracting and modifying compounds. David Danehower , previously a professor of crop science, has been working at Evoca for about a month now.
The company is most well known for their work in Taxol , a medicine made from extracts of the Pacific Coast Yew tree, and the leading breast cancer drug in the world. They use chromatography to separate out individual components of the tree.
“So it’s a combination of extracting the plant and then doing further purification to get to the compounds that you want,” Danehower said. “Most of what they do is known chemicals… they are just simply trying to produce that compound.”
Few manage to recognize the ubiquity of flora that surrounds us, but Xie reminded that these plants could be our next vaccines.
“Twenty five percent of medicines come directly from plants,” Xie said.
