Ancient Chinese medicine for malaria could potentially aid in treatment of tuberculosis

In continuation of my update on Artemisinin

A centuries-old herbal medicine, discovered by Chinese scientists and used to effectively treat malaria, has been found to potentially aid in the treatment of tuberculosis and may slow the evolution of drug resistance.

In a promising study led by Robert Abramovitch, a Michigan State University microbiologist and TB expert, the ancient remedy artemisinin stopped the ability of TB-causing bacteria, known as Mycobacterium tuberculosis, to become dormant. This stage of the disease often makes the use of antibiotics ineffective.

The study is published in the journal Nature Chemical Biology.

"When TB bacteria are dormant, they become highly tolerant to antibiotics," Abramovitch said, an assistant professor in the College of Veterinary Medicine. "Blocking dormancy makes the TB bacteria more sensitive to these drugs and could shorten treatment times."

One-third of the world's population is infected with TB and the disease killed 1.8 million people in 2015, according to the Centers for Disease Control and Prevention.

Mycobacterium tuberculosis, or Mtb, needs oxygen to thrive in the body. The immune system starves this bacterium of oxygen to control the infection. Abramovitch and his team found that artemisinin attacks a molecule called heme, which is found in the Mtb oxygen sensor. By disrupting this sensor and essentially turning it off, the artemisinin stopped the disease's ability to sense how much oxygen it was getting.

"When the Mtb is starved of oxygen, it goes into a dormant state, which protects it from the stress of low-oxygen environments," Abramovitch said. "If Mtb can't sense low oxygen, then it can't become dormant and will die."

Abramovitch indicated that dormant TB can remain inactive for decades in the body. But if the immune system weakens at some point, it can wake back up and spread. Whether it wakes up or stays 'asleep' though, he said TB can take up to six months to treat and is one of the main reasons the disease is so difficult to control.

"Patients often don't stick to the treatment regimen because of the length of time it takes to cure the disease," he said. "Incomplete therapy plays an important role in the evolution and spread of multi-drug resistant TB strains."

He said the research could be key to shortening the course of therapy because it can clear out the dormant, hard-to-kill bacteria. This could lead to improving patient outcomes and slowing the evolution of drug-resistant TB.

After screening 540,000 different compounds, Abramovitch also found five other possible chemical inhibitors that target the Mtb oxygen sensor in various ways and could be effective in treatment as well.

"Two billion people worldwide are infected with Mtb," Abramovitch said. "TB is a global problem that requires new tools to slow its spread and overcome drug resistance. This new method of targeting dormant bacteria is exciting because it shows us a new way to kill it."

Ref : http://www.nature.com/nchembio/journal/vaop/ncurrent/full/nchembio.2259.html

Potent parasite-killing mechanism of anti-malarial drug uncovered: New understanding of how artemisinin works could facilitate development of new drugs and therapeutic strategies against malaria -- ScienceDaily

In continuation of my update on artemisinin

A team of researchers has uncovered the mystery behind the potent parasite-killing effect of artemisinin, a drug that is considered to be the last line of defense against malaria. Given the emergence of artemisinin resistance, these findings could potentially lead to the design of new treatments against drug-resistant parasites.

Assistant Professor Lin Qingsong, who is from the Department of Biological Sciences under the NUS Faculty of Science and is one of the scientists who led the study, explained, "Many people may not realise that more human lives are lost to the tiny mosquito, more specifically malaria parasites, each year as compared to ferocious animals such as lions and sharks. After infection, malaria parasites, known for their blood-eating nature, can propagate inside the human body rapidly and consume up to 80 per cent of red blood cells in a short period of time, leading to a series of deadly symptoms."

About 3.2 billion people -- almost half of the world's population -- are considered to be at risk of malaria by the World Health Organization. As of September 2015, there were an estimated 214 million cases of malaria and 438,000 malaria-linked deaths this year alone.

Artemisinin and its derivatives are currently the most potent class of anti-malarial drugs. In recognition of its importance against malaria, the discovery of artemisinin won Chinese scientist Ms Tu Youyou the 2015 Nobel Prize in Physiology or Medicine earlier in October this year. While there have been extensive studies on artemisinin, the mechanism of the drug is not well understood.

Asst Prof Lin, together with Dr Wang Jigang, who was formerly with the NUS Department of Biological Sciences and now with the Singapore-MIT Alliance for Research & Technology, Associate Professor Kevin Tan from the Department of Microbiology and Immunology at the NUS Yong Loo Lin School of Medicine and their research team, discovered over 120 protein targets of artemisinin, and the mechanism that activates its deadly killing effect. The findings of the study are published in the journal Nature Communications on 23 December 2015.

Potent parasite-killing mechanism of anti-malarial drug uncovered: New understanding of how artemisinin works could facilitate development of new drugs and therapeutic strategies against malaria

Anti-malaria drug synthesised with the help of oxygen and light

In continuation of my update, artemisinin... The most effective anti-malaria drug can now be produced inexpensively and in large quantities. This means that it will be possible to provide medication for the 225 million malaria patients in developing countries at an affordable price. Researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam and the Freie Universität Berlin have developed a very simple process for the synthesis of artemisinin, the active ingredient that pharmaceutical companies could only obtain from plants up to now. The chemists use a waste product from current artemisinin production as their starting substance. This substance can also be produced biotechnologically in yeast, which the scientists convert into the active ingredient using a simple yet very ingenious method..... Look at http://www.mpg.de/4984709/artemisinin_malaria