Tormentilla (Potentilla erecta)
A wildflower once used to treat wounds and sore throats has shown great potential in fighting dangerous superbugs.
Long before we had modern antibiotics, people often turned to traditional plant medicines to treat infections.
A tormentila root (Potentilla erecta)a small yellow wildflower that grows in Europe, has been used for centuries in traditional medicine on the Old Continent. Was used to treat wounds, sore throats, diarrhea and gum disease.
These traditional uses suggest that tormentila could contain compounds powerful enough to kill microbes.
This is what a group of British researchers sought to discover, in a recent study at Microbiology Society.
Research has shown that tormentil has antimicrobial activity and can be powerful enough to combat resistant microbes to modern antibiotics.
As researchers warn in an article in , antimicrobial resistance is a growing global threat. This occurs when bacteria evolve to survive medications used to treat common infections. This makes some infections very difficult and sometimes impossible to treat. Antimicrobial resistance may be pushing us back to a time when Once-treatable infections could once again become deadly.
Researchers are therefore always on the lookout for new antimicrobial compounds. Plants are a promising source, having evolved over millennia to produce a wide range of bioactive chemicals to defend against microbes.
The new study investigated whether several plants from Irish peatland areas contain compounds that could help combat multidrug-resistant bacteria.
To do this, extracts were prepared from more than 70 different species of plants collected from peat bogs throughout Ireland. They were then tested against clinically relevant bacterial pathogens in the laboratory – including bacteria that cause severe pneumonia and urinary tract infections.
Antimicrobial susceptibility tests were used to verify whether the extracts inhibited bacterial growth. This involved exposing the bacteria to various plant extracts to see which extract inhibited the growth of the bacteria.
These extracts were then tested on biofilms to determine whether the plant compounds could prevent bacteria from forming biofilms. Biofilms are bacterial communities surrounded by a viscous layer of carbohydrates that protect them from antibiotics, disinfectants and the immune system.
Excitingly, initial screening showed that tormentil extracts were antimicrobial and limited the formation of biofilms. This suggested that these extracts contained compounds with antimicrobial activity, which may explain their historical use in treating infections.
It was also explored whether these plant extracts could work in combination with existing antibiotics, as some plant compounds do not directly kill bacteria but can make antibiotics more effective.
Like this, low levels of the antibiotic colistin were combined – antibiotic that is only used as a last resort against serious infections due to its potential toxicity for patients – with tormentil extract.
The low dose of antibiotic was not enough to kill the bacteria when used alone. But when combined with tormentil extract, the plant compound increased the effectiveness of the antibiotic.
Our team then carried out an analysis to identify the compounds present in tormentil extracts. Plants in the genus Potentilla are known to contain naturally occurring compounds such as ellagic acid ea agrimoninwhich have antioxidant and anti-inflammatory properties.
Afterwards, the compounds ellagic acid and agrimoniin that were present in the peat bog tormentila. It was shown that these specific compounds could inhibit bacterial growth. This indicates that may be responsible for the antimicrobial activity of tormentil.
Subsequently, it was found that These compounds acted to capture iron – an essential nutrient for bacterial growth. This effectively starved the bacterial cells, preventing them from growing.
Nature has always been a rich source of medicines. Many antibiotics we use today originated from natural sources. For example, potent antibiotics of last resort vancomycin – which is used to treat MRSA (methicillin-resistant Staphylococcus aureus) and C difficile infections – originated from soil microbes.
With antimicrobial resistance continuing to increase globally, new approaches and treatments are needed. Plants may be an underexplored source of both new antimicrobial compounds and compounds that make existing medicines more effective.
The story of tormentila shows how nature and traditional medicine can work hand in hand with modern science to address today’s challenges. He also highlights that solutions can be found in unexplored places – even in a small yellow wildflower growing in a peat bog.
