From “atomic editing”, to “lasso antibiotics”, to mining the remotest forests and deepest oceans, the search for new drugs is endlessly fascinating. But even we have to admit, this is a new one on us: antiviral chewing gum. A new study unveils this marvel of mastication, which the authors say can significantly reduce viral loads for a number of common infections. All you have to do is chew.
“Controlling transmission of viruses continues to be major global challenge,” said first author Dr Henry Daniell of the University of Pennsylvania in a statement. Our recent experiences with COVID-19, the ever-evolving H5N1 bird flu situation, and even the rapid spread of measles during the current outbreaks in the US have shown us this beyond doubt.
A few years ago, at the height of the pandemic, Daniell and the team hit upon an innovative way of trying to limit SARS-CoV-2 transmission. They wanted to target the virus in saliva, going to the heart of where the virus replicates and can spread to others via sneezing, coughing, and speaking. To that end, they developed a chewing gum, now in clinical trials, containing plant-derived proteins that block the virus’s ability to interact with host cells.
Their latest study is an attempt to broaden this approach to more viruses.
“A broad-spectrum antiviral protein (FRIL) present in a natural food product (bean powder) to neutralize not only human flu viruses but also avian (bird) flu is a timely innovation to prevent their infection and transmission,” said Daniell.
The beans the scientists investigated, in a cracking example of nominative determinism, are called lablab beans (Lablab purpureus). Otherwise known as hyacinth beans, the high-protein pulses are included in some traditional recipes in parts of Sudan, but have largely fallen out of favor in their native Africa and are now considered an orphan crop.
As well as apparently being quite tasty, the beans are special for another reason: they naturally contain an antiviral protein called FRIL.
Daniell’s team, along with collaborators in Finland, tested gum made from lablab beans for its antiviral efficacy against two strains of influenza A (H1N1 and H3N2) and two herpes simplex viruses (HSV-1 and HSV-2). HSV infection is very common, there’s no vaccine for it, and HSV-1 in particular is usually spread orally, making antiviral chewing gum an exciting prospect.
Using a chewing simulator (literally a huge set of mock jaws) they demonstrated that chewing gums produced from 79 milligrams of lablab bean powder released FRIL into the pretend saliva in a reliable way.
A plaque reduction assay showed that just 40 milligrams of a 2-gram gum tablet was sufficient to reduce viral loads by more than 95 percent for flu. For HSV-1, 160 milligrams did the trick, and for HSV-2 just 74 milligrams was needed.
The gum was produced in accordance with regulatory guidelines – as if it were a real medical product – and stored at room temperature for nearly 800 days; it didn’t go bad, and it still contained active FRIL after all that time.
“These observations augur well for evaluating bean gum in human clinical studies to minimize virus infection/transmission,” said Daniell.
The team’s next target is bird flu, as others have shown that lablab bean powder may be effective against both the H5N1 and H7N9 strains. It’s certainly something to chew on.
The study is published in the journal Molecular Therapy.
