Biology / Nobel Prize / Tiago Palmisano

Ancient Medicine and the Fight Against Malaria

By: Tiago Palmisano. Edited by: Bryce Harlan

Malaria is one of the most well known parasitic diseases in the modern world. Much of its fame (or infamy, to be precise) is driven by the incredible access to medical knowledge that comes with the age of smartphones. World Malaria Day was established in 2007, and the disease has even managed to inspire a British-American TV film, Mary and Martha. Yet, a more probable reason why malaria is so well known is the miserable fact that for centuries it has been one of the most prolific killers known to man. According to the World Malaria Report 2013 released by the WHO (World Health Organization), there were approximately 207 million reported cases of malaria in 2012, of which over 600,000 were fatal.

The disease is primarily associated with mosquitoes, but these insects are only the vehicles of transmission. Malaria is caused by any of five species of the single-celled parasite known as Plasmodium, which most often enter a human’s bloodstream via the bite of a female mosquito. The parasitic organisms invade and destroy liver cells and red blood cells. Infections typically occur in sub-Saharan Africa and other equatorial regions. Malaria has been a part of human society since antiquity – references to the disease can be traced back to ancient Greek and Chinese writings. But despite its history, the biggest step to fighting malaria didn’t occur until about forty years ago.

Shown above is the Artemesia annea plant, also known as sweet wormwood, from which artemisinin is derived. An extract of the drug is shown in the top left corner.  Image Credit: http://image.made-in-china.com/

Shown above is the Artemesia annea plant, also known as sweet wormwood, from which artemisinin is derived. An extract of the drug is shown in the top left corner.
Image Credit: http://image.made-in-china.com/

In the late 1960s, the prevalence of malaria provoked China to initiate a national research project to develop new treatments for the disease. DDT and Chloroquine, chemicals developed by scientists, were the treatments of choice at the time and were both losing their effectiveness due to increased resistance. One team working on this Chinese national project was led by Youyou Tu. Forgoing the idea of synthesizing a new drug, Youyou and her team investigated ancient Chinese herbal recipes and eventually honed in on a plant known as Artemesia annea, or sweet wormwood. Youyou isolated a compound from the plant, artemisinin (qinghaosu in Chinese), which she discovered had remarkable anti-malaria effects.

In order to find an effective means of obtaining artemisinin from the plant, the team once again enlisted the help of ancient writings. Inspired by The Handbook of Prescriptions for Emergency Treatments (a Chinese medical text from 340 BC), Youyou experimented with a cold extraction process that ultimately allowed her to successfully isolate the drug on October 4th, 1972. In subsequent experiments, artemisinin proved to be extremely effective against strains of malaria in mice and monkeys. Youyou writes about this “breakthrough in the discovery of artemisinin” in her 2011 commentary published in Nature Medicine.

In the years that followed, artemisinin became the go-to drug for the treatment of malaria. Youyou Tu was awarded part of the 2015 Nobel Prize in Medicine for her work. Indeed, the contribution of artemisinin has managed to alleviate significant amounts of suffering worldwide. Between 2000 and 2013, the malaria treatment method centered on artemisinin resulted in a decrease in the international mortality rate by forty-seven percent. Despite progress, the parasitic disease continues to be a major issue in modern society, demonstrated by the hundreds of thousands of fatal cases in 2012. An important lesson from Youyou’s research is the potential of looking towards antiquity for medical inspiration. Even in the wave of modern pharmaceutical technology, the answers to some of our most pressing physiological problems may reside in a look towards the past.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s