A second antimalarial treatment is currently being seriously considered and evaluated for its effectiveness against COVID-19. The treatment is made from the plant Artemisia annua, which most people know as Sweet absinthe. Other names for this plant include Annual Sage and Sweet Annie.
Research over the past decades has revealed multiple health benefits of this medicinal plant, which has a history of centuries of use in folk medicine. In 2015, Chinese scientist Tu Youyou received a partial Nobel Prize in physiology or medicine for his discovery of artemisinin and dihydroartemisinin,1 both have potent malaria fighting properties.
As reported by the University of Kentucky,2 “Artesunate, a popular antimalarial drug, was developed from these compounds and is still used today as a first-line treatment for the disease.
Artemisinin – A viable cure for COVID-19?
Interestingly, in addition to having a long history of use as a highly effective pest control, it also has anti-cancer properties. In addition, artemisia annua has antiviral activity which may be useful against SARS-CoV-2.
In an April 8, 2020, Mateon Therapeutics press release reported3 “Artemisinin is very effective in inhibiting the ability of the virus responsible for COVID-19 (SARS-CoV-2) to multiply while having an excellent safety index.”
After testing the plant’s antiviral effects in the lab for a few years, researchers at the University of Kentucky are also exploring its use for treating COVID-19,4 as do researchers in Denmark and Germany.5 According to the University of Kentucky:6
“Surprisingly, the results showed that the leaves of the plant, when extracted with absolute ethanol or distilled water, provided more antiviral activity than the drug itself – meaning that coffee or tea mixed with Artemisia annua may be more effective than taking the medicine.
Based on these results, the researchers decided to test artemisinin in patients diagnosed with COVID-19. Some of the first human studies, intended to study both the extract mixed in coffee and tea, as well as artesunate, were implemented by UK HealthCare.
Researchers at the University of Kentucky founded a company called ArtemiFlow to develop and manufacture the drug, in conjunction with the Kentucky Tobacco Research & Development Center.seven A sister company, ArtemiLife, markets Artemisia tea and coffee to raise research funds.
The mechanism of action remains unknown
As for its mechanism of action, such details remain to be discovered. C&EN explains:8
“To fight malaria, artemisinin exploits the parasite’s taste for hemoglobin in the blood of its host. When the parasite digests hemoglobin, it releases the heme iron-porphyrin complex of the protein.
Because this heme is toxic to the parasite, the body normally converts the complex to a more benign crystalline form. “But artemisinin corrupts this heme detoxification pathway,” says Paul O’Neill, a medicinal chemist at the University of Liverpool.
If artemisinin has any effect against SARS-CoV-2, however, it probably relies on a completely different mechanism than it uses against the malaria parasite, Harvard. [malaria researcher Dyann F.] Said Wirth.
In vitro study reports positive results
An in vitro study9,ten examining the effectiveness of artemisinin-based treatments for SARS-CoV-2, published on the bioRxiv pre-release server on October 5, 2020, reports promising results.
The study was a collaboration between researchers from Germany, Denmark and Hong Kong, led by Kerry Gilmore, Ph.D., of the Max Planck Institute for Colloids and Interfaces in Potsdam, Germany.
Three extracts of artemisinin, as well as pure synthetic artemisinin, artesunate and artemether were evaluated. During the initial screening for antiviral activity, a German strain SARS-CoV-2 obtained in Munich was used.
Later, during the concentration-response phase of the trial, they used a Danish strain of SARS-CoV-2 from Copenhagen. These two strains would be “more closely linked to the majority of strains of SARS-CoV-2 circulating in the world than the Wuhan strain”.11,12
In summary, they found that pretreatment and treatment with extracts of artemisinin, synthetic artemisinin, and drug artesunate were able to inhibit SARS-CoV-2 infection of Vero E6 cells and Huh7.5 human hepatoma cells. Having said that, artesunate was the most effective in terms of treatment and, from a clinical point of view, it might be the only one to benefit.13,14
World Health Organization warns against its use
While the world is eager to add another remedy to their Treatment of covid-19 list, the World Health Organization has spoken out against artemisinin-based products. In an article from May 27, 2020, C&EN reported:15
“One of the most prominent advocates for using the herbal remedy for the novel coronavirus is Madagascar President Andry Rajoelina, who touts Covid-Organics, a tonic containing A. annua that the Madagascan Institute of applied research has developed …
But health officials are deeply concerned with the promotion and use of these herbal remedies for three main reasons. First, there is no evidence that extracts from A. Annua can prevent or cure COVID-19 …
Second, the preparations of A. Annua such as teas, tonics or herbal capsules also contain a cocktail of bioactive compounds in addition to artemisinin which can have side effects such as dizziness, hearing problems, and vomiting.
Third, and perhaps most concerning of all, the widespread use of herbal extracts from A. Annua could strengthen drug-resistant strains of malaria parasites like Plasmodium falciparum.16
For people living in areas where malaria is endemic, exposure to subtherapeutic doses of artemisinin in A. annua may be enough to kill some of the parasites in their body, but not all. Eliminating weak parasites leaves more room for drug-resistant siblings to proliferate, making ACTs vital [artemisinin-based combination therapies] ineffective.”
According to Pascal Ringwald, who heads the drug resistance and response unit of the WHO’s Global Malaria Program, artemisinin resistance is a significant problem in Southeast Asia, where Artemisia easily grows. and is commonly used.17
That said, this risk is bound to be low for Americans and residents of many other Western countries where malaria is extremely rare. According to C&EN,18 “Scientists interviewed by C&EN agree that although this use is contrary to WHO recommendations, it is not likely to accelerate resistance because there are so few cases of malaria in the USA”