Green tea has long been praised for its health-boosting properties, with new research suggesting a compound in the popular drink may also ward off coronavirus complications.
The UK's unprecedented vaccination programme means coronavirus death rates have plummeted, with four fatalities within 28 days of a positive test on 6 June – a 99.6% reduction from 8 January's 1,325 peak.
Case numbers have risen by 49% over the past seven days, however, which many experts blame on the emergence of the more transmissible Delta variant, first identified in India.
With coronavirus drugs still limited, scientists from Swansea University have screened more than 100 compounds that have previously shown promise against other strains within the coronavirus class.
Results suggest gallocatechin, a chemical compound in green tea, could be effective against coronavirus complications.
While the research is still in its infancy, the scientists believe gallocatechin may one day be a "readily available, accessible and affordable" treatment.
"Nature's oldest pharmacy has always been a treasure of potential novel drugs and we questioned if any of these compounds could assist us in battling the COVID-19 [the disease caused by the coronavirus] pandemic," said study author Dr Suresh Mohankumar.
“We screened and sorted a library of natural compounds already know to be active against other coronaviruses using an artificial intelligence-aided computer programme."
The circulating coronavirus is one of seven pathogens of the same viral class that are known to infect humans. Others include the virus that causes severe acute respiratory syndrome (Sars), which killed 774 people during its 2002/3 outbreak.
“Our findings suggested one of the compounds in green tea could combat the coronavirus behind COVID-19," said Dr Mohankumar.
While the research is still in an early stage, gallocatechin is thought to have potential benefits when administered via a drug, rather than by drinking green tea.
Watch: The health benefits of green tea
The Swansea scientists screened 132 phytochemicals – compounds produced by plants – that were previously tested against Sars or fellow coronavirus Middle East respiratory syndrome (Mers), which killed 858 people during its 2012 outbreak.
Gallocatechin was then further tested for its potential to inhibit the coronavirus's activity.
Writing in the journal RSC Advances, the scientists said gallocatechin "has shown potential to inhibit multiple targets of" the coronavirus.
"The compound our model predicts to be most active is gallocatechin, which is present in green tea and could be readily available, accessible and affordable," said Dr Mohankumar.
"There now needs to be further investigation to show if it can be proven clinically effective and safe for preventing or treating COVID-19."
The scientists are looking for potential partners that could continue their research via laboratory, animal and human studies.
"This is fascinating research and demonstrates natural products remain an important source of lead compounds in the fight against infectious diseases," said Professor Andrew Morris, head of pharmacy at Swansea University.
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