The people and plants shaping modern medicine

Few discoveries better exemplify the power of traditional botanical knowledge than Chinese scientist Youyou Tu's work on antimalarial medicines.

As part of China's ambitious Project 523, Tu led research that incorporated modern Western and traditional Chinese medical approaches in the search for new chemical compounds to fight malaria.

Tu’s research focused on Artemisia annua, a wormwood similar to the plant pictured here.

They include the many different kinds of sagebrush, as well as the plants that give us tarragon and absinthe. All are well known for their strong aromas and bitter taste.

The common mugwort shown here is a species of Artemisia, which is found in Britain.

It was among plants illustrated by Elizabeth Blackwell, the mid-eighteenth century Scottish author and illustrator of A Curious Herbal.

Blackwell’s work was not only highly influential, it was one of the small number of herbals written by women.

The author records the mugwort as easing women’s menstrual pain as well as being "good to strengthen the Head & Nerves, & help hysteric Fits or Vapours.”

In the context of Youyou Tu’s discovery two hundred years later, Blackwell’s comments on Artemisia demonstrate ubiquitous use of these plants in folk remedies.

This illustration of a Chinese species of Artemisia, Chinese mugwort, is from a series of almost 200 paintings made in the early 1770s by John Bradby Blake, a trader working for the British East India Company, and the Chinese artist, Mauk-Sow-U.

Both Blake and Blackwell emphasize the medicinal properties of wormwood in their 18th-century works, but the use of Artemisia in Chinese traditional medicine has much longer history.

It was a much older work - a medical volume by 7th-century Chinese scholar Ge Hong - that helped Youyou Tu and colleagues develop a new approach to fighting malaria.

Of the hundreds of traditional Chinese herbal remedies that Tu and team examined in the search for potential anti-malarials Artemisia annua offered the most promising results.

Frustratingly, though, trial after trial failed to produce the required level of anti-malarial activity.

It was then that Youyou Tu remembered the ancient recommendation from Ge Hong that soaking (instead of drying) wormwood leaves was key to activating their medicinal effect.

This simple change was crucial in the ultimate discovery of artemisinin, which offers new approaches to treating malaria, and led Tu to receive the first Nobel Prize awarded to a Chinese woman.

Tu’s success shows the value of integrating modern approaches and ancient knowledge. But the unexpected nature of many key breakthroughs also shows the need for an open mind.

The work of Canadian scientists Robert Noble and Charles Beer provide another example...

In their search for new compounds to treat diabetes, Noble and Beer were studying the Madagascar periwinkle - a traditional remedy.

But they found no new leads that could be beneficial for diabetes.

However, they did uncover an interesting property of the plant.

It produced a compound that halted white blood cell production - a discovery with profound implications for cancer treatment.

In partnership with the US pharma company Eli Lilly, which had already been developing drugs derived from the periwinkle, Noble and Beer’s findings led to the anticancer drugs vinblastine and vincristine.

Both drugs are now used widely around the world, particularly to treat childhood leukemia.

The grandson of slaves, Percy Julian was one of the few African-Americans to receive a degree from DePauw University.

After his MS at Harvard and a PhD in Vienna, he went on to become one of the most influential chemists of the 20th century.

But his life was plagued by racial discrimination.

At DePauw, the Trustees refused him a permanent job because of his race. Another job fell through because a Wisconsin town would not allow African Americans on its premises after dark.

When Julian and his family moved to the then predominantly white Chicago suburb of Oak Park, their home was fire-bombed.

Back at DePauw University, he synthesized a chemical derivative of the calabar bean.

The project was make-or-break: If successful, he’d be established as a leader in chemistry. But it went against the approaches of his eminent contemporaries, presenting a risk to his career.

It was a success, and the drug he synthesized from the calabar bean is still used to treat glaucoma.

But he continued to face discrimination, and employers backed out of offers when they saw his skin color.

Finally, in 1936, pharmaceutical company Glidden offered Julian a position as head of a new Chicago research lab focused on the study of soybeans.

There, he made successive key, commercially successful discoveries.

He found a new way to make the human hormones progesterone, estrogen and testosterone from compounds isolated from soybean oil.

As with many drug discoveries, serendipity was key.

When water leaked into a tank of valuable soybean oil - an expensive accident - Julian recognized that crystals formed in the mixture could have interesting properties.

He later showed that they were an excellent precursor in the manufacture of steroids. Previously, steroids could only be made in small quantities from animal sources. It was a costly process.

His discovery gave rise to inexpensive steroids to ease pregnancy and prevent miscarriages.

And this opened the door to new contraceptive pills, uterine cancer treatments and hormone replacement therapy - great leaps in medical progress.