Scientists have made a 'wonder drug' out of bananas that can kill off a wide range of viruses – including hepatitis C, flu and AIDS.
It is hoped the new medicine will become a vital ‘broad spectrum anti-viral’ that could protect humanity from some of the most vicious diseases.
The key ingredient is a protein found in bananas called banana lectin, or ‘BanLec’.
It was first discovered five years ago – and considered as a potential AIDS treatment.
But it caused nasty side effects that scientists have now overcome.
Now, scientists have created a new version of BanLec which can fight viruses in mice – but does not cause unwanted irritation and inflammation.
BanLec works by clinging to sugar molecules found on the surface of some of the world’s deadliest viruses.
Once the drug has locked on to the virus, it is rendered harmless – and can easily be disposed of by the body’s immune system.
In tests on mice, the new form of BanLec, called H84T, stopped them getting the flu - without the increased inflammation earlier versions had caused.
The new variation also worked in the laboratory – on tissue and blood samples against AIDS, hepatitis C and influenza.
The researchers believe the drug may even work on Ebola, as all of these viruses are covered in similar sugar molecules that BanLec clings to.
However they warn eating regular bananas will not have the same beneficial effect, as the ingredient is a modified version of the chemical found in the fruit.
Dr David Markovitz, professor of internal medicine at the University of Michigan and co-author of the paper, published in the journal Cell, said: ‘What we've done is exciting because there is potential for BanLec to develop into a broad spectrum anti-viral agent - something that is not clinically available to physicians and patients right now.’
However several years of research still lie ahead before BanLec can be tested in humans.
Despite this, Dr Markovitz and his co-author, Dr Hashim Al-Hashimi, professor of biochemistry at Duke University, hope the team's work can help address the lack of antiviral drugs that work well against many viruses - or against viruses that change rapidly, such as influenza.
The new form of BanLec, called H84T, stopped animals from getting flu. It also worked in the lab on tissue and blood samples against AIDS, hepatitis C and influenza
‘Better flu treatments are desperately needed,' said Dr Markovitz.
‘Tamiflu is only modestly effective, especially in critically ill patients, and influenza can develop resistance to it.
‘But we also hope that BanLec could become useful in situations such as emergency pandemic response, and military settings, where the precise cause of an infection is unknown but a viral cause is suspected.’
British scientists today hailed the development.
Professor Wendy Barclay, chair in influenza virology at Imperial College, London, called it a ‘a new strategy for combatting a wide range of viruses’ and ‘beautiful science’.
Dr Ben Neuman, a virologist at the University of Reading, said: ‘In this new study, the researchers changed the banana lectin just enough to stop the side effects, while keeping its virus-blocking properties intact.
And Jonathan Ball, professor of molecular virology at the University of Nottingham, added: ‘Each new virus outbreak is a timely reminder of our need for antivirals that can work against a range of viruses.
'Lectins have that potential as they are able to bind to the sugars that are present on the surface of a range of viruses including HIV, influenza and Ebola, many of which have caused or have the potential to cause severe epidemics or even pandemics.’
The key question now, he stressed, was whether the drug will work in humans.
'There are lots of hurdles that still need to be overcome before antiviral lectins find their way into clinic,' he said.
'For one thing, there’s a risk the immune system will recognise this as foreign and mount an immune response to it, potentially rendering it ineffective.
'But even so, given recent events, generating antivirals that can work against a range of viruses is well worth pursuing.’