Investigation of the Antimicrobial activity of essential oils of culinary and medicinal herbs and spices against selected gastrointestinal pathogens
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Investigation of the Antimicrobial activity of
essential oils of culinary and medicinal herbs
and spices against selected gastrointestinal
pathogens
Mike Chorlton,
Mike Chorlton, Eugene Rees,Eugene Rees,
Chris Phillips, Tim Claypole Chris Phillips,
Nidhika Berry and Paula Row
Tim Claypole, Nidhika Berry and Paula Row
Gastrointestinal micro-organisms cause
many deaths per year
Salmonella species cause food poisoning due to poorly
cooked chicken and eggs in the UK
There are thought to be 93.8 million cases of
gastroenteritis from non-typhoidal Salmonella
worldwide per year, and155, 000 deaths
(Majowicz SE et al. (2010) The global burden of non-typhoidal Salmonella gastroenteritis Clin Infect Dis. 50: 882- 889)
Irritable Bowel Syndrome...
Affects 10 - 22% of the UK population,
more women than men
Can persist for decades
Symptoms include:
• abdominal pain
• diarrhoea
• constipation
• bloating and
wind
Responsible for approximately half of al
out-patient visits to a gastroenterology
department
British Society for Gastroenterology (2006) Care of patients with gastrointestinal disorders in the United Kingdom. An
evidence - based strategy for the future. BSG, London. www.bsg.org.uk/pdf_word_docs/strategy06_final.pdf [accessed
25/08/09]
IBS has recently been linked to Small Intestinal
Bacterial Overgrowth, SIBO
Normally the small intestine
contains very few bacteria:
Terminal jejunum: 100-4 cfu/ml
Proximal ileum: 100-5 cfu/ml
Terminal ileum: 100-5 cfu/ml
In SIBO, bacterial numbers
can rise to 1011 cfu/ml
SIBO is currently defined as ≥105
colonic bacteria in the small
intestine*
*Posserud I et al. (2007) Small intestinal bacterial overgrowth
in patients with irritable bowel syndrome. Gut. 56: 802-808
Normally, easily digestible starch is completely digested and absorbed in the proximal small intestine. Poorly digestible starch is fermented in the colon, to give gas In SIBO, easily digestible starch meets bacteria in the small intestine and is fermented to produce gas Lin HC (2006) Small Intestinal Bacterial Overgrowth: a framework for understanding irritable bowel syndrome. JAMA 292: 852-858.
SIBO is diagnosed with a breath test
They breathe into a bag
Patients drink a glass
of water containing The sample is analysed for
an indigestible sugar the presence of hydrogen
eg lactulose and methane
Hydrogen is associated with diarrhoea-prone IBS
Methane is associated with constipation-prone IBS
IBS has been linked to intestinal dysbiosis
A change in the bacterial species present, not the numbers
Specifically, culture of the
faecal microbiota from
patients with IBS revealed:
• Decreased lactobacilli and
bifidobacteria
• increased facultative
anaerobes, mainly
streptococci and E. coli
• higher counts of anaerobes
such as Clostridium
Reviewed by Simren M et al. (2013) Intestinal microbiota in functional bowel disorders: a Rome Foundation report.
Gut 62: 159-176
Antibiotics can improve IBS symptoms In America, clinical trials have been conducted which showed that IBS can be treated with antibiotics such as: Metronidazole Neomycin The non-absorbed antibiotic (a non-absorbed antibiotic) Rifaximin (Xifaxan 200) However, IBS symptoms can return Rifaximin is in the rifamycin family, used to treat tuberculosis and C. diffici - there is concern about antibiotic resistance New treatments are urgently needed (Basseri RJ et al. (2011) Antibiotics for the treatment of irritable bowel syndrome. Gastroenterol. and Hepatol.455-493; Farrell DJ et al. (2013) Rifaximin in the treatment of irritable bowel syndrome: is there a high risk for the development of antimicrobial resistance?. [Review] J. Clin. Gastroenterol. 47: 205 -211)
Hypothesis: That essential oils of culinary herbs, and herbal medicines that have long been used to treat digestive disorders, have antibacterial activity, which would make them useful for treating infection with gastrointestinal pathogens and IBS
Peppermint is currently used to treat IBS
Colpermin and Mintec are enteric-
coated peppermint oil tablets.
They uncoat in the later part of the
ileum - so would probably bypass SIBO
The useful activity of peppermint in
these tablets is most likely
peppermint’s antispasmodic effectDisc Diffusion Assay
2) Add 10 µl essential 3) Grow the bacteria
1) Plate out a lawn
oil to a small disc
of bacteria, or yeast
and place it on the
lawn of bacteria
+
(Disc diffusion: Dilruba Meah)Effect of Essential oils on E. coli NC07360 Aniseed, asafoetida, cinnamon, clove, garlic, lemon balm, lemon grass, May Chang, oregano, peppermint, rosemary, thyme and winter savory were all strongly antibacterial against the E. coli type strain
Effect of Essential oils on E. coli NC09001 Cinnamon and winter savory were strongly antibacterial Aniseed, asafoetida, caraway, clove, coriander, lemon balm, May Chang, oregano, rosemary, tea tree and thyme were also effective
Effect of oils on Salmonella enterica Cinnamon and winter savory were strongly antibacterial Aniseed, asafoetida clove, lavender, lemon balm, May Chang, oregano, tea tree, and thyme were also effective
Effect of oils on Clostridium difficile Many essential oils inhibited the growth of C.difficile Cinnamon, clove, garlic, lemon balm, lemon grass, May Chang, oregano, peppermint, thyme and winter savory were the most potent
Effect of Essential oils on Candida albicans
Many essential oils were antimicrobial towards C.
albicans
The most effective were asafoetida, garlic, lemon balm,
lemongrass, May Chang, thyme and winter savoryAntibacterial activity against S. enterica under aerobic and anaerobic conditions The upper GI tract is an aerobic environment; the colon is anaerobic The best essential oils were effective against S. enterica under aerobic and anaerobic conditions, although there were slight differences
Batch Testing Wine buyers know that different wines have different characters The vintage and the terroir affect the taste, the compounds present The potential for batch to batch variation of herbal medicines is often ignored We have seen evidence of batch variation in antibacterial activity of the essential oils We have analysed some of the oils by Gas chromatography mass spectrometry
Variation in cinnamon oil composition
Cinnamon A Cinnamaldehyde
Cinnamon B m-Eugenol
Clove A m-Eugenol
Clove B m-Eugenol
Cinnamon A, the more active one, has cinnamaldehyde as expected
Cinnamon B (probably leaf oil) has Eugenol and is more like clove oil.Oregano, Thyme and Winter savory oil
share common components
Oregano p-Cymene
Thymol
Thyme A m-Cymene
Cyclo- Thymol
fenchene
Thyme B m-Cymene Thymol
* more potent
Winter savoryCarvacrol Thymol
p-Cymene
They all contain thymol and cymene. Winter savory has carvacrol tooVariation in Aniseed Essential oils
Aniseed A Anethole
Estragole
Himachalene
Aniseed B α-cedrene
Aniseed A and Aniseed B are totally different
Aniseed A has the expected composition;
B is the more active oneVariation in Lemon Balm Essential oils
Citronellal
Lemon Balm A Citronellol
D-Limonene Carene
Lemon Balm B
Lemon balm A had higher activity against E. coli
Lemon balm essential oil can be very variable, depending upon
harvest time. Citral becomes converted to citronellal.Summary of Results
Cinnamon and Winter savory were strongly
Cinnamon bark antibacterial against all of the organisms.
Aniseed, asafoetida, clove, oregano and thym
were also effective against all the organisms.
Batch variation was seen in antimicrobial
activity and chemical composition of the
Asafoetida
essential oils
We have identified the main compounds
present in these oils; we aim to test these
in the assay singly
Winter savoryWhat about toxicity? Herbs have long
been used to treat digestive disorders
In her 1932 book, A Modern
Herbal, Grieve refers to
Aqua mirabilis:
“used on the continent as an
aromatic water for the
treatment of internal pains”
It consisted of 1 part each of
cinnamon, fennel, lavender,
peppermint, rosemary and sage
essential oils, 350 parts spirit
(alcohol) and 644 parts
distilled waterIn the 1700s, William Lewis wrote the
New London Dispensatory...
The New Dispensatory containing
I) the elements of pharmacy, and
II) the materia medica
It also refers to Aqua mirabilis:
This one contained:
“celandine leaves, melilot flowers,
cardamum seeds, cubebs,
galingale, nutmegs, cloves, mace,
ginger…”You can also read
