Green Tea Polyphenol Active against Tuberculosis Bacteria | Medicine - Sci-News.com

Epigallocatechin gallate (EGCG), one of the principle polyphenolic compounds found in the leaves of the green tea plant (Camellia sinensis), is effective against Mycobacterium tuberculosis, a bacterium that causes tuberculosis in humans, according to new research from the Nanyang Technological University, Singapore.

Green tea leaves. Image credit: Highnesser.

“Though tuberculosis is curable, the success of current drugs on the market is increasingly being overshadowed by the bacteria’s clinical resistance,” said Nanyang Technological University’s Professor Gerhard Grüber, co-lead author of the study.

“Our discovery of the EGCG’s ability to inhibit the growth of Mycobacterium tuberculosis will allow us to look at how we can improve the potency of this compound in green tea, and other similar compounds, to develop new drugs to tackle this airborne disease.”

Tuberculosis is one of most important infectious diseases worldwide. One third of the world population is latently infected by Mycobacterium tuberculosis.

During infection, this pathogen undergoes a wide range of metabolic changes, which correlate with either growth or persistence.

Such forms of adaptation include the ability of mycobacteria to ‘breath’ and generate an enzyme called adenosine triphosphate (ATP) synthase.

“Cells require energy for vital processes such as cell wall formation to take place. They get their energy from an energy storage molecule made by ATP synthase,” the researchers explained.

To determine the factors affecting the production of this enzyme, Professor Grüber and colleagues studied Mycobacterium smegmatis and M. bovis.

“First, we found that alterations to the genetic code for ATP synthase resulted in an enzyme that produced fewer energy storage molecules in the bacterial cells, slower cell growth, and an altered colony shape,” they said.

“With these data, we then screened for and found 20 compounds that could possibly bind to ATP synthase and cause the same blocking effect, and then tested them for their efficacy.”

“Only EGCG showed it had the same crucial effect of reducing energy storage molecules in the bacterial cell.”

The results were published November 4, 2019 in the journal Scientific Reports.

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W. Saw et al. 2019. Disrupting coupling within mycobacterial F-ATP synthases subunit ε causes dysregulated energy production and cell wall biosynthesis. Sci Rep 9, 16759; doi: 10.1038/s41598-019-53107-3