Molecule extracted from birch could block HIV, Ebola and dengue fever: Quebec research

Two molecules found in various plants, including one extracted from birch, could prevent viruses as formidable as HIV, Ebola, and dengue fever from infecting the body, according to research conducted in Quebec.

Researchers say this could one day lead to the development of broad-spectrum antiviral prophylactic treatments that would be administered to populations at risk of infection.

“These molecules attach to a receptor on immune system cells and block the HIV entry pathway, but it’s a pathway that’s also used by the Ebola virus, SARS-CoV-2, and the dengue virus,” said professor Charles Gauthier of the Institut national de la recherche scientifique (INRS). “It’s truly a primary receptor.”

Gauthier and his colleagues focused on betulinic acid, found in birch bark and the Chaga mushroom, and echinocystic acid, found in sunflowers and other plants.

The scientists used a unique methodology to modify these molecules by adding a sugar, Lewis X, resulting in new chimeric compounds that had never before been described in the scientific literature: “saponins.”

These compounds have several advantages over the original molecules, including being much more soluble in water; dissolving relatively easily in biological media; and being safe for human cells.

“Our results suggest that these saponins hold promise for preventing the early stages of HIV-1 infection while being relatively non-toxic in vivo,” the authors write.

Another interesting property of saponins lies in their ability to spontaneously form structures called “micelles” or to integrate into structures — liposomes — that transport substances throughout the body. This could allow future research to further improve their effectiveness against HIV, particularly by facilitating their targeting to cells affected by the virus.

Furthermore, the researchers add, since saponins interfere with a pathway that several infectious agents, not just HIV, use to infiltrate human cells, they are “currently studying the inhibitory activity of saponins (…) against other pathogens,” such as Ebola hemorrhagic fever, dengue fever, and even SARS-CoV-2.

The antiviral properties of betulinic acid have long been known, but its use has been limited by the fact that the molecule is essentially impossible to dissolve in water, making its medical administration difficult.

The work of Gauthier and his colleagues could help overcome this obstacle. And since betulinic acid is found in large quantities in birch bark, it’s a new use for the common forestry industry residue.

“We don’t know what to do with this bark,” said Gauthier, who is also a member of the INRS-UQAC Joint Research Unit in Sustainable Health. “We make panels from it, we burn them… So, we could use bark residues, isolate these molecules, add the Lewis sugar (…) and generate these molecules that could prevent the emergence of the AIDS virus.”

This work may only be the tip of the iceberg, added Gauthier, since there is reason to believe that adding Lewis sugar X to other molecules found in nature could lead to the development of even more products with interesting properties, such as vaccine adjuvants.

All of this highlights the unimaginable richness of the nature that surrounds us and proves that it still holds surprises with revolutionary potential, Gauthier speculates.

“For example, we’re working on fruits (from the Quebec forest) that have never been studied,” said Gauthier. “We’re studying them and we’re coming across molecules that could revolutionize antibiotic treatments (…) but that’s for a future publication.”

The findings of this current work were published in the scientific journal “Chemistry – A European Journal” and will soon be presented at a scientific conference in Poland.

–This report by La Presse Canadienne was translated by CityNews