What do tea, beer, honey and marine sponges have in common?
They are all among the natural products Welsh scientists are targeting in the hunt for sources of new antimicrobials.
With increasing bacterial resistance to antibiotics, the need to find new agents to tackle dangerous pathogens – many of them in hospitals – is acute.
So, Cardiff University’s School of Pharmacy and Pharmaceutical Science has turned to some unlikely Welsh sources – including a few found in ancient remedies.
“Much of what we do is based on whizzy machines and science, but there’s a lot to learn from history,” said Prof Les Baillie.
“While some of these ancient remedies might well be hokum or snake oil, it’s likely that over thousands of years our ancestors hit on something that actually worked.”
And nothing could be more traditional than the time-honoured remedy of honey.
“Honey has been used for thousands of years to treat wounds and indeed is still used in our hospitals to treat patients with these intractable infections that are not responding to antibiotics,” Prof Baillie said.
So, the university enlisted the help of bees as prospectors in its pursuit of plant-derived anti-bacterial drugs and treatments.
After testing hundreds of samples sent from beekeepers across Wales, the team found a honey from Twywyn, in Gwynedd, with the same anti-bacterial potency of New Zealand’s famed Manuka.
The team, led by Dr Jenny Hawkins, identified the active compounds in the most powerful honeys to find out which flowers the bees had visited, using the National Botanical Garden of Wales’ DNA plant database.
And Prof Baillie believes this exploration of the domestic over more exotic climes could signal a new approach.
“Back in the day your prospector would head out on the Amazon in their canoe looking for exotic plants as cures for the next great ill,” he added.
“But wouldn’t it be fantastic if we just went out towards Welshpool or somewhere in the mountains and found the next cure for various conditions.”
In this spirit, Dr James Blaxland has gone no further than the local pub – or at least the brewery – to find his bacteria killers.
He is looking at the hops used in beer for compounds able to tackle a range of pathogens.
“Hops have been used for hundreds of years as a flavouring additive within beer. And they found in the early 18th Century that hops which were added to beer prevented it from spoiling so people started thinking that hops must be antibacterial,” he said.
“We have taken this forward in the last five years and we have screened more than 50 different hop samples from around the world against bacterium samples.”
Dr Blaxland is looking at derived compounds which could be effective at tackling hospital superbug MRSA and even the “massive problem” of bovine tuberculosis by using hops as a foodstuff for cows.
There is also the unlikely possibility hops could be part of the answer to global warming, with certain compounds preventing bacteria that causes cows to produce methane.
And with the university looking at a possible “super mead” to protect drinkers from myriad ills, what could be more popular?
Well, perhaps antimicrobial tea.
“It could surprise people to know that tea – the common drink they drink every day of their lives – also contains compounds called polyphenols that kill bacteria,” Prof Baillie explained.
Cardiff, in collaboration with Aberystwyth University, has looked at developing a tea to treat “super bug” clostridium difficile (C.diff) – the UK’s principle cause of hospital-acquired infection.
C.diff occurs when patients in hospital take antibiotics which get rid of the good bacteria in their stomach, allowing the infection to reproduce and cause disease.
Prof Baillie said C.diff is susceptible to certain polyphenols found in tea.
“Given that it’s a gut-borne disease and we drink tea, which goes to our guts, we were intrigued by the idea of, perhaps, making a ‘super tea’ that would be high enough in polyphennols that it would kill the C. diff.”
And in pursuit of the most benign brew the university teamed up with a tea company, analysing samples from the firm’s 37 plantations across the globe.
“We were able to show that tea from east Kenya was the most effective. This was green tea rather than the traditional black tea that we drink in this country,” Prof Baillie explained.
But perhaps the most alternative of antimicrobial sources under the team’s microscope are marine sponges found off the Swansea coast.
Sponges have a brief history of producing “novel pharmaceuticals”, with Caribbean species having provided the basis for cancer drug Cytarbine in the 1950s.
Dr Alex White said: “These organisms in temperate zones have adapted to harsher life. It means that they express some molecules which are there for competitive advantage.”
In this way, sponges have become adept at creating “potent molecules” which are affective at killing cells.
“It’s quite early days in our research but we have been able to find several potential anti-bacterial molecules and to test them against existing antimicrobial agents,” Dr White explained.