Green tea can boost the potential of antibiotics to battle superbugs and other bacterial strains and even make previously antibiotic-resistant bacteria susceptible to treatment, according to "surprised" Egyptian scientists.

Speaking at the Society for General Microbiology's 162nd meeting in Edinburgh yesterday, Scotland, Dr Mervat Kassem said the research she led demonstrated antibiotics were more effective when taken in conjunction with green tea in fighting more than 28 disease-causing micro-organisms.


Green and mean

Because green tea is such a popular beverage in Egypt, the researchers sought to determine if it had any positive or negative effect on the effectiveness of antibiotics to fight disease. They were surprised at how strong were the positive affects of the in vitro study that is under peer-review.

Dr Kassem told NutraIngrients.com the 12-month study that will be published in the European Journal of Clinical Microbiology and Infectious Diseases showed the potential of green tea to reduce antibiotic dosage

Different classes of antibiotics were tested separately and in combination with green tea against strains from the bacterial family Staphylococcus spp, gram negative isolates and three standard strains using the disc agar diffusion technique.

Green tea enhanced the bactericidal activity of all tested antibiotics especially when green tea-chloramphenicol [an antimicrobial bacterium] combination was tested.

"In every case green tea enhanced the bacteria-killing activity of the antibiotics," said Dr Kassem who is from the Faculty of Pharmacy at Alexandria University in Egypt. "For example, the killing effect of chloramphenicol was 99.99 per cent better when taken with green tea than when taken on its own in some circumstances."

Method

Green tea made 20 per cent of the drug-resistant bacteria susceptible to one of the cephalosporin antibiotics used in the study. Cephalosporin is a widely used antibiotic that some strains of bacteria have evolved to resist.

Green tea also demonstrated an ability to break down the resistance of one out of the five tested isolates to the antibiotic cefuroxime.

The effect of green tea on direct inhibition of β-lactamases production was conducted using the nitrocefin method. β-lactamases are produced by some bacteria and are responsible for their resistance to certain antibiotics.

The effect of omeprazole, a proton pump inhibitor, and sub-inhibitory concentration of green tea on the antimicrobial activity of the antibiotic tetracycline HCl was also studied.

In conclusion, beneficial outcomes of concomitant administration of green tea with tetracycline, chloramphenicol as well as β-lactam antibiotics were observed.

The researchers called for further enquiry into other botanicals.

"In the future, we will be looking at other natural herb products such as marjoram and thyme to see whether they also contain active compounds which can help in the battle against drug-resistant bacteria," said Dr Kassem.

Source

Unpublished
'Influence of green tea on the antimicrobial activity of some antibiotics against multiresistant clinical isolates'
Alexandria University, Alexandria, Egypt, Dept of Microbiology, Faculty of Pharmacy
Authors: Mervat A. Kassem, Nourhan H. Fanaki, Mohamed A. Fawzi and Fatma S.E. Dabbous