Nobel Prize in Medicine for the developers of methods of curing diseases caused by parasites including malaria and river blindness

A drug against malaria and a drug against river blindness isolated from plants and bacteria respectively

The Nobel Prize Committee at the Karolinska Institute, which selects the winners of the Nobel Prize for Physiology and Medicine, has decided to award the prize for 2015 to three researchers. Half of the prize will be jointly awarded to William Campbell and Satoshi Ōmura for discovering an innovative drug against infections caused by parasitic roundworms, and the other half will be awarded to Youyou Tu for developing an innovative drug against malaria, a disease caused by parasites and which has been affecting humanity for thousands of years , and is still one of the most common serious diseases in the world. In particular, diseases transmitted by parasites affect the poorest populations and are a barrier to improving public health and quality of life.

"This year's prize winners developed drugs that caused a revolution in the treatment of some of the most serious parasitic diseases. William Campbell and Satoshi Omura discovered a new drug, Avermectin, a derivative of which was able to reduce the rate of infection in river blindness and Lymphatic Filariasis, also known as the elephant man's disease. It also shows effectiveness against the spread of several other parasitic diseases. Yuyu Tu, a member of the Chinese Academy of Traditional Chinese Medicine, discovered Artemisinin, a drug that significantly reduces the mortality rate of malaria patients."

"These two discoveries provide humanity with powerful new means to fight these debilitating diseases that affect hundreds of millions of people every year. The consequences of medicines in terms of improving human health and reducing suffering are endless." The members of the award committee write.

Parasites cause serious diseases

"We live in a biologically complex world, inhabited not only by humans and other large animals, but also by a multitude of other creatures, some of which are harmful or even fatal to us.

A variety of parasites cause diseases. An important group of these parasites are the parasitic worms (helminths), which are estimated to have affected about a third of the world's population and in particular are common in the sub-Saharan region of Africa, South Asia and Central and South America. River blindness and lymphatic filariasis are two diseases caused by parasitic worms. From the name it can be understood that river blindness eventually leads to blindness, due to chronic corneal inflammations. Lymphatic Filariasis leads, among other things, to elephantiasis or filariasis (or by its popular name the elephant man's disease), affects one hundred million people. This parasite causes chronic swelling of organs in the body and leads to symptoms that cause disability. (See Figure 1).

Malaria has accompanied mankind for a long time, perhaps since the dawn of mankind. It is a disease transmitted by mosquitoes, and which is caused by single-celled parasites that invade the red blood cells and cause fever and, in severe cases, brain damage and even death. Over 3.4 billion people from the population of the weakest and most vulnerable countries are at risk of contracting malaria and every year the epidemic claims 450 thousand victims, mainly among children.

From bacteria and plants to an innovative anti-parasitic drug

After decades of little progress in developing viable treatments against curable diseases, the discovery of this year's laureates changes the situation. Satoshi Omura, a Japanese microbiologist and expert in the isolation of natural products, focused on a group of bacteria - Streptomyces, which live in the soil and from which they produce many drugs with an antibiotic effect, including streptomycin, which was discovered by Zalman Waxman, winner of the Nobel Prize in 1952. Equipped with the ability to develop unique methods for large-scale cultivation And in characterizing these bacteria, Omura isolated new strains of Staphylococcus from soil samples and was able to grow them in the laboratory. From the thousands of different cultures, he chose about 50 of the most promising, to analyze their activity against harmful micro-organisms.

William Campbell, an expert in the biology of parasites in the USA, studied the effectiveness of the bacteria isolated by Omura. Campbell showed that a component of one of the cultures was found to be effective against parasites in domestic and farm animals. The bioactive agent is isolated and called Avermectin. Campbell improved it by chemical means to create a more effective ingredient known as Ivermectin. Later Iberamycin was tested on humans who had parasitic diseases and it killed the parasite larvae (microfilaria). The joint contribution of Omura and Campbell led to the discovery of a new class of drugs that are particularly effective against parasitic diseases.

Malaria is often treated with chloroquine or quinine, but successfully with pus. By the end of the XNUMXs, efforts to eradicate malaria had failed and the epidemic was raging. At the same time, Yuyu Tu in China turned to traditional herbal medicine to deal with the challenge of developing innovative drugs for malaria.

The award committee continued with its reasoning: "After scanning many herbal remedies on animals suffering from malaria, it discovered that a derivative of one of the plants known as Artemisia annua (one of the wormwood species) emerged as a promising candidate. However, the results were not consistent. Thus Tu searched ancient literature and discovered clues that would lead her to search for the best active ingredient, which was later called artemisinin. This substance has been shown to be effective against the malaria parasite, both in infected animals and humans. Artemisinins are an example of a new class of drugs that rapidly eliminate malaria parasites at an early stage of their development, which explains the unprecedented potential in the treatment of patients with severe malaria."

Abramstine, artemisinin and public health

"The discovery of avermectin and artemisinin significantly changed the treatment of parasitic diseases. Today one of the derivatives of Abramstine - Ivermectin (Ivermectin) is used in parts of the world that suffer from parasitic diseases. Iberamycin is particularly effective against a variety of parasites, has few side effects, and is freely available worldwide."

"The importance of Ibermastine for improving the health and quality of life of millions of people suffering from river blindness and elephantiasis, mainly in the poor areas of the world, is enormous. The treatments are so successful that these diseases are on the verge of extinction - a heroic act in human history. Over 200 million people contract malaria every year. Artemisinin, as part of a drug combination, reduces mortality from malaria by more than 20% in general, and by more than 30% in children. In Africa alone, this means that the lives of over 100 people are saved every year.

"The discoveries of avermectin and artemisinin caused a revolution in the treatment of patients suffering from severe parasitic diseases. Campbell, Omura and Tu revolutionized the treatment of parasitic diseases. The global impact of their discoveries and their benefit to humanity is enormous." The members of the award committee conclude.

Editor's Notes

1. In this article an effort has been made to check every name and data, if a mistake has been made I would appreciate it if you would comment on it.
2. Many medicines are derived from plants, some of them from well-known medicinal plants, however, when a medicine is consumed in its herbal form, the concentration of the substance is not constant, and the active substance in it may work more effectively together with other substances in the final medicine. There is no award given to the Society of the Chinese Academy of Medicine. Simon Singh and Edzard Ernst, the authors of the book "Cure or Temptation" also discovered that some of the medicinal plants are the only alternative medicines in contrast to, for example, homeopathy, where even this little is not