NTU Undergraduates' research April 2014 - Biosciences | Page 24

Investigation Into The Effects Of Natural Products On Microbial
Pathogens
Sophie Brown

Nottingham Trent University

Antibiotic resistance is on the rise and the production of new antibiotics is slowing. This is in
addition to the high costs of treatment failure due to resistant infections. These reasons call for an
acceleration in the discovery of alternative methods to treat infection. Natural products such a
foodstuffs and plant extracts have been used for thousands of years to treat minor ailments and in
light of this, this study aimed to investigate the effectiveness of some of these products on
inhibiting the growth of twenty-one bacterial pathogens found in human wounds. Eight products
were screened: manuka honey, tea tree oil, aloe vera, cranberry juice, garlic, red chilli peppers,
ginger and green tea. Cranberry juice, ginger and tea tree oil were discarded from the
investigation after preliminary tests due to poor effectiveness leaving the remainder to be assessed
for a minimum inhibitory concentration and minimum bactericidal concentration. All products,
with the exception of chilli, demonstrated the ability to inhibit growth of the organisms; manuka
honey being the strongest inhibitor overall, acting as a bactericide in 19/21 cases. Using the
fractional inhibitory concentration index it was found that manuka honey/garlic, aloe vera/garlic
and garlic/green tea were synergistic compounds in selected organisms; however none were able to
reproduce the bactericidal effects seen when used individually.