Researchers evaluate artemisinin for the management of COVID-19

In a recent study published in Moleculesresearchers assessed the effectiveness of artemisinin-based antimalarials in the management of coronavirus disease 2019 (COVID-19).

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have played a vital role in the fight against the transmission of COVID-19. Although there have been several cases of COVID-19 infections, vaccinated patients have a remarkably lower risk of being hospitalized due to complications from SARS-CoV-2. However, there is still an urgent need for therapeutic options to treat people infected with SARS-CoV-2.

Impact of Mugwort excerpts on COVID-19

In the present study, researchers summarized the significance of the antiviral activity exhibited by artemisinins and two mugwort species, namely A. afra and A. annua, against COVID-19.

In April 2020, the Malagasy Institute for Applied Research (IMRA) developed a herbal tea based on mugwort for COVID-19 treatment. This herbal tea contained 62% A. annua as well as a mixture of Malagasy medicinal plants which were used as bronchial thinners and antiseptics. However, the widespread and unregulated use of such a remedy has raised concerns that malaria parasites may develop resistance to artemisinin. This could further lead to a reduction in the efficacy of accessible drugs and the potential development of resistance of P. falciparum to artemisinin-based combination therapies (ACTs).

A study also noted that the ethanol extract of leaves of A. annua exhibited antiviral activity, which increased significantly when the extract was mixed with coffee. These extracts were first added to VeroE6 cells either 1.5 hours before infection (pretreatment (pt)) or one hour after infection (treatment

Moreover, the cell viability tests of the extract of A. annua showed median cytotoxic concentrations (CC₅₀) of 1044 µg/mL for the ethanol extract, 632 µg/mL for the ethanol extract of coffee), and 2721 µg/mL for the aqueous extract. Overall, the use of the leaves of A. annua can be used as a potentially therapeutic and inexpensive method for the treatment of COVID-19.

Another study tested the hot water extract derived from the leaves of A. annua against SARS-CoV-2 variants B1.1.7 and B1.351. The study observed IC₅₀ values ​​corresponding to less than 12 µM of artemisinin. Moreover, the antiviral activity of the extracts declined inversely with respect to the artemisinin content. The team noted that A. annua contained compounds that inhibited inflammation as well as fibrosis formation, which would have affected COVID-19 patients.

The team also reported that treatment with aqueous and ethanolic extracts of A. annua, artemisinin, artemether, and artesunate inhibited SARS-CoV-2 infection of human hepatoma cells Huh7.5, VeroE6 cells, as well as human lung cancer A549-angiotensin- converting enzyme cells 2 (ACE-2). Hot water extracts of A. annua were also found to be active against SARS-CoV-2 Alpha, Beta, Gamma, Delta, and Kappa variants. Additionally, cultivars of A. annua with the lowest concentrations of artemisinin were the most effective against Gamma, Delta and Kappa variants, thus indicating the efficacy of the extracts against the virus.

Artemisinin in the management of COVID-19

Evaluation of in vitro The efficacy of artemisinin-based therapy against SARS-CoV-2 revealed that artesunate treatment had the strongest anti-SARS-CoV-2 activity, followed by artemether, extracts of HAS. annua and artemisinin. The study also showed that artesunate attacked SARS-CoV-2 at the post-entry level.

A. annua has also been reported to stimulate adaptive immunity via the generation of CD4 and CD8 lymphocytes which are responsible for producing antibodies to target SARS-CoV-2 as well as down-regulating the production of cytokines. Artemisinin and its derivatives also regulated several immune cells such as monocytes, macrophages, T cellsand dendritic cells to prevent the release of pro-inflammatory cytokines and the cytokine storm epidemic.

Artemisinin-based combination therapies (ACT) for COVID-19

One study observed that artesunate-mefloquine exhibited high anti-SARS-CoV-2 activity with approximately 72.1 ± 18.3% inhibition. Additionally, other ACTs such as artesunate-amodiaquine, artesunate-pyronaridine, artemether-lumefantrine, and dihydroartemisinin-piperaquine also inhibited SARS-CoV-2 by 27.1-34.1%. This indicated that ACT drugs could be used effectively for the treatment of COVID-19.

Artesunate has also been shown to inhibit the production of interleukin-1B (IL-1B), IL-6 and IL-8. Since elevated IL-6 levels in COVID-19 patients have been attributed to cytokine release syndrome, controlling IL-6 levels could potentially reduce the severity of COVID-19.

Overall, the study found that A. annua, artemisinin and its derivatives such as artemether and artesunate could potentially inhibit SARS-CoV-2. Researchers believe that Mugwort-virus-based treatment options could be used to boost immunity and improve tolerance against viral infections such as COVID-19.