Green tea is an
orally ingested beverage popular in Asian and Western communities. The tea is
derived from an herbal plant Camellia
sinensis. Some studies have shown that green tea has several medical
benefits, some of which include reduction in cholesterol level, protection
against cardio-vascular diseases, cancer, etc. And its leaves contain many
polyphenolic compounds such as (-)-epicatechin (EC), (-)-epicatechin-3-gallate
(ECG), (-)-epigallocatechin (EGC), and (-)epigallocatechin-3-gallate
(EGCG). These polyphenol compounds have been implicated to have distinct
properties that combat the harmful effects of cell proliferation. They contain
certain anti-viral and antibacterial properties that inhibit growth.
In this study, 1%
green tea and modified lipophilic green tea polyphenols (GTP and LTP) were used
in combination with the most commonly prescribed antibiotics to study their
effects on gram-positive, gram-negative, and acid-fast bacteria. Six
microorganisms in stock were constantly maintained and utilized in the
experiment: the gram positive bacteria were Staphylococcus
epidermidis, Bacillus megaterium;
the gram negative bacteria were Escherichia
coli, Serratia marcescens, Enterobacter aerogenes; and the
acid-fast bacterium was Mycobacterium
smegmatis.
The results
indicated that 1% GTP and 1% LTP provided different synergistic effects on
several antibiotics in various bacteria. It was found that 1% GTP works the
best synergistically against Enterobacter aerogenes, making
the resistant strainsusceptible to 8 out of 12 antibiotics used. 1% LTP worked
the best on Escherichia coli and was able to convert 7
antibiotic resistant categories to susceptible. In addition, 1% LTP was also
able to inhibit the growth of Serratia marcescens synergistically
with 3 antibiotics.
In conclusion, these
results suggested that 1% GTP and 1% LTP provided beneficial effects on
selected antibiotics against microbial growth and are able to reverse the
antibiotic resistance to susceptible. And green tea polyphenols could serve as
natural alternatives to combat against antibiotic resistance pathogens. In
addition, pure hydrophilic green tea polyphenol (GTP) such as EGCG and pure
lipophilic tea compound EGCG-stearate should be used to further evaluate the
efficacy of the synergism of these polyphenols on different antibiotics.
Article by Bobak
Haghjoo, et al, from USA.
Full access: http://mrw.so/1UZ3tR
Image by Kayleigh Karr, from Flickr-cc.
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