Artemisinin

[9] Combination therapies, featuring artemisinin or its derivatives alongside some other antimalarial drug, constitute the contemporary standard-of-care treatment regimen for malaria.

[10] The World Health Organization (WHO) recommends artemisinin or one of its derivatives ― typically in combination with a longer-lasting partner drug ― as frontline therapy for all cases of malaria.

[19] The side effects from the artemisinin class of medications are similar to the symptoms of malaria: nausea, vomiting, loss of appetite, and dizziness.

[19][20] One case of significant liver inflammation has been reported in association with prolonged use of a relatively high-dose of artemisinin for an unclear reason (the patient did not have malaria).

[28] A synthetic compound with a similar trioxolane structure (a ring containing three oxygen atoms) named RBx-11160[29] showed promise in in vitro testing.

As the drug molecules come in contact with the haem (associated with the hemoglobin of the red blood cells), the iron(II) oxide breaks the endoperoxide ring.

[36] In contrast, clinical practice shows that unlike other antimalarials, artemisinin is active during all life cycle stages of the parasite.

[37] Clinical evidence for artemisinin drug resistance in southeast Asia was first reported in 2008,[38] and was subsequently confirmed by a detailed study from western Cambodia.

[44] In 2011, the WHO stated that resistance to the most effective antimalarial drug, artemisinin, could unravel national Indian malaria control programs, which have achieved significant progress in the last decade.

WHO advocates the rational use of antimalarial drugs and acknowledges the crucial role of community health workers in reducing malaria in the region.

The WHO is pressuring manufacturers to stop making the uncompounded drug available to the medical community at large, aware of the catastrophe that would result if the malaria parasite developed resistance to artemisinins.

[52] Key steps of the Schmid–Hofheinz approach included an initial Ohrloff stereoselective hydroboration/oxidation to establish the "off-ring" methyl stereocenter on the propene side chain; two sequential lithium-reagent mediated alkylations that introduced all needed carbon atoms and that were, together highly diastereoselective; and further reduction, oxidation, and desilylation steps performed on this mono-carbocyclic intermediate, including a final singlet oxygen-utilizing photooxygenation and ene reaction, which, after acidic workup closed the three remaining oxacyclic rings of the desired product, artemisinin, in a single step.

In 2006, a team from UC Berkeley reported they had engineered Saccharomyces cerevisiae yeast to produce a small amount of the precursor artemisinic acid.

In this effort of synthetic biology, a modified mevalonate pathway was used, and the yeast cells were engineered to express the enzyme amorphadiene synthase and a cytochrome P450 monooxygenase (CYP71AV1), both from Artemisia annua.

The final successful technology is based on inventions licensed from UC Berkeley and the National Research Council (NRC) Plant Biotechnology Institute of Canada.

[citation needed] In 2010, a team from Wageningen University and Research reported they had engineered a close relative of tobacco, Nicotiana benthamiana, that can also produce the precursor, artemisinic acid.

In addition to clinical research performed in China and southeast Asia, Artequick was used in large-scale malaria eradication efforts in the Comoros.

[68] Artesunate injection for severe malaria treatment is made by the Guilin Pharmaceutical factory in China where production has received WHO prequalification.

[66] Using seed supplied by Action for Natural Medicine (ANAMED), the World Agroforestry Centre (ICRAF) has developed a hybrid, dubbed A3, which can grow to a height of 3 meters and produce 20 times more artemisinin than wild varieties.

In northwestern Mozambique, ICRAF is working together with a medical organization, Médecins Sans Frontières, ANAMED and the Ministry of Agriculture and Rural Development to train farmers on how to grow the shrub from cuttings, and to harvest and dry the leaves to make artemisia tea.

The partnership to create a new pharmaceutical manufacturing process was led by PATH's Drug Development program (through an affiliation with OneWorld Health), with funding from the Bill & Melinda Gates Foundation and based on a modified biosynthetic process for artemisinic acid, initially designed by Jay Keasling at UC Berkeley and optimized by Amyris.

1.7 million doses of Sanofi's ASAQ, a fixed-dose artemisinin-based combination therapy will be shipped to half a dozen African countries over the next few months.

In 1596, Li Shizhen recommended tea made from qinghao specifically to treat malaria symptoms in his Compendium of Materia Medica.

Tu says she was influenced by a traditional Chinese herbal medicine source The Handbook of Prescriptions for Emergency Treatments written in 340 CE by Ge Hong saying that this herb should be steeped in cold water.

[78][86] On October 5, 2015, she was awarded half of the 2015 Nobel Prize in Physiology or Medicine for discovering artemisinin, "a drug that has significantly reduced the mortality rates for patients suffering from malaria".

[2] The other half of the prize was awarded jointly to William C. Campbell and Satoshi Ōmura for discovering avermectin, "the derivatives of which have radically lowered the incidence of river blindness and lymphatic filariasis, as well as showing efficacy against an expanding number of other parasitic diseases".

[2] The WHO notes four additional ACTs that are in preliminary clinical trials or regionally used for which there is no evidence to recommend widespread use: artesunate/pyronaridine, arterolane-piperaquine, artemisinin-piperaquine base, and artemisinin/naphthoquine.

[87] A serendipitous discovery was made in China in the early 1980s while searching for novel anthelmintics for schistosomiasis that artemisinin was effective against schistosomes,[88][89] the human blood flukes, which are the second-most prevalent parasitic infections, after malaria.

[90] Artemisinins were later found to possess a broad spectrum of activity against a wide range of trematodes, including Schistosoma japonicum, S. mansoni, S. haematobium, Clonorchis sinensis, Fasciola hepatica, and Opisthorchis viverrini.

One derivative, SM934, was approved in 2015 by the Chinese National Medical Products Administration for a clinical trial as a drug for systemic lupus erythematosus.

Biosynthesis of Artemisinin
Figure 1. Biosynthesis of Artemisinin
Artemisia annua