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Neem tree bark extract may provide a useful starting point for new COVID-19 treatments. Nuk2013/Shutterstock
  • Researchers in Colorado and India are researching the bark of the neem tree as a way to treat COVID-19.
  • They learned that an extract from the tree bark, Azadirachta indica, may have antiviral benefits and help reduce symptoms in people with a SARS-CoV-2 infection.
  • The scientists believe Azadirachta indica may act as a pan-antiviral, capable of treating future emerging variants of SARS-CoV-2.

As the COVID-19 pandemic presses on, researchers continue looking for ways to prevent infection of the virus and treat the disease.

Scientists at the University of Colorado and the Indian Institutes of Science Education and Research believe that Azadirachta indica, more commonly called neem tree, may be instrumental in the future of the pandemic. The tree is native to India, and practitioners use it within Eastern-based Ayurvedic medicine.

A preclinical study, which appears in the journal Virology, examines how the extract from the bark of Azadirachta indica affects human lung cells and mice with a SARS-CoV-2 infection.

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According to the authors, neem tree bark (NTB) is “antibacterial, anti-inflammatory, anticancer, anti-allergic, anti-parasitic, and antifungal.” As such, they wanted to learn if NTB extract could aid in preventing SARS-CoV-2 infection and its replication.

“The goal of this research is to develop a neem-based medication that can reduce the risk of serious illness when someone [has an infection] with coronaviruses,” says study co-author Dr. Maria Nagel, research professor in the Department of Neurology and Ophthalmology at the University of Colorado School of Medicine.

In different experiments, the researchers tested NTB extract on human lung cells and mice with SARS-CoV-2.

After testing the NTB extract on human lung cells, they found it “restricted the pathological effects of multiple coronaviruses.”

In the testing with the mice, they found that the NTB extract inhibited inflammation in the lungs. This is an important finding, considering the damage COVID-19 does to the lungs.

Additionally, NTB extract prevented the virus from replicating as much. It also stopped the virus from causing “inflammation of the brain, spinal cord, and liver.”

While these results seem promising, more research is necessary before health experts can use NTB as a virus preventive or therapy.

“The next step in our research is to identify the specific components in neem bark extract that are antiviral. Because these components bind to various regions of SARS-CoV-2, we believe that it will be effective on emerging variants with spike mutations,” says Dr. Nagel.

“We will then determine the formulation of dosage for an antiviral drug to treat coronavirus infections.”

Dr. Amichai Perlman spoke with Medical News Today on the study findings. Dr. Perlman is a pharma domain expert at K Health, a digital care company based in New York.

“I think this is an interesting and promising study,” commented Dr. Perlman. “It suggests that specific compounds in the extract from the bark of the neem tree are active against the coronavirus and may be useful in treating and preventing COVID-19.”

“However, it is a ‘preclinical’ study, based on lab testing on cells and animals,” Dr. Perlman continued. “So it requires further research to conclusively establish its efficacy and safety in humans.”

The authors acknowledge that this study had some limitations since the predominant findings with the NTB extract were in mice.

“Mechanistic studies of SARS-CoV-2 pathogenesis are difficult in patients,” write the authors. “[And] experimental animal models of [human coronaviruses] are limited in mimicking human disease.”

Prof. Winston Morgan, Director of Impact & Innovation at the Medicines Research Group at the University of East London, also spoke with MNT on the study. He agreed that the mice study had limitations, commenting that it is “interesting, but very preliminary.”

“The study focuses on efficacy (reduced viral particle replication and organ damage) rather than [the] safety of the extract, so for example, we do not know what the impact is of the extract on the mice beyond 6 days.”

– Prof. Morgan

He went on to say that the extract could cause long-term issues.

“Unlike vaccinations, which require limited dosing, the problem with all antiviral drugs is that the plasma concentration has to be maintained at high levels over a long period of time to provide protection […] Long-term dosing is likely to cause short- and definitely long-term toxicity problems.”

“This study should be seen as a starting point rather than the solution,” said Prof. Morgan.

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