Magnolia Bark Chemical: Honokiol's Triumph Against SARS-CoV-2 and Future Coronaviruses

A chemical called honokiol found in the bark of various species of magnolia trees suppresses replication of the SARS-CoV-2 virus in several types of cells. The findings were reported in Microbiology Spectrum, a journal of the American Society for Microbiology (1^✔ ✔Trusted Source
Honokiol Inhibits SARS-CoV-2 Replication in Cell Culture at a Post-Entry Step

Go to source). The researchers discovered that Honokiol suppresses SARS-CoV-2 replication in various cell types, resulting in a 1,000-fold decrease in infectious SARS-CoV-2 particle generation in treated cells.

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Efficacy of a Broad-Spectrum Chemical Against Human Coronaviruses

Other extremely deadly human coronaviruses, such as MERS- and SARS-CoV, were similarly suppressed by the chemical. "This suggests that it has a broad spectrum of activity and would likely inhibit novel coronaviruses that may emerge in the future," said Martijn J. van Hemert, Ph.D., Associate Professor, Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands. The absence of vaccinations and therapies early in the pandemic, as well as the urge to be prepared for the next emerging coronavirus, drove the research. Van Hemert noted that his group, along with others from around the world, responded to COVID-19 by evaluating a wide range of chemicals for antiviral properties.

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Honokiol as a Promising Drug Candidate Against Emerging Coronaviruses

“If honokiol can be developed into a drug, possibly in combination with other compounds, stockpiling it would help us to increase our preparedness for the emergence of the next coronavirus,” said van Hemert. “Broad-spectrum drugs could then be used to treat early patients and prevent spread, or they could be used prophylactically among healthcare workers, and in high-risk groups, such as among nursing home residents.”

Honokiol also has anti-inflammatory effects, according to van Hemert. This, he believes, could be useful in cases when individuals wait until a relatively late stage of the disease to seek medical care, which is common, by which time the body's natural inflammatory reactions to the infection are generating symptoms. "At that point, inhibiting virus replication may no longer be useful," van Hemert explained, "but honokiol's anti-inflammatory response may mitigate the illness."

Honokiol blocks a later stage of the viral replication cycle, once the virus has entered the cell. The researchers believe that honokiol accomplishes this by activating systems in the host cell that prevent viral multiplication. It did so with the original SARS-CoV-2 versions as well as with

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Honokiol's Promising Role Against SARS-CoV-2 and Other Coronaviruses

At this early stage in the research, “Our study merely provides the basis for further research into potential therapeutic applications,” said van Hemert. “It is important to mention that it is too early to claim that honokiol might be used in SARS-CoV-2 patients. This requires much more research and—if successful—properly conducted clinical trials.”

During the early phases of the pandemic, Van Hemert learnt about honokiol from Emory School of Medicine's Jack Arbiser, M.D., Ph.D. Arbiser had been exploring honokiol's anticancer qualities, and he told van Hemert that the compound's actions on the host cell could be useful for COVID-19 sufferers as well.

The majority of the studies were carried out by Clarisse Salgado-Benvindo, a Ph.D. student in van Hemert's lab, utilizing cultured cells infected with SARS-CoV-2 or the extremely deadly coronaviruses SARS-CoV and MERS-CoV. Experimenters worked within a BSL-3 lab, a very high containment lab, using protective suits and full-face masks to avoid infection.

Reference:

1. Honokiol Inhibits SARS-CoV-2 Replication in Cell Culture at a Post-Entry Step - (https://journals.asm.org/doi/10.1128/spectrum.03273-22)

Source-Medindia