Peppermint references  
 Mentha piperita 

    The bibliographic citations are derived from Medline databases through the National Library of Medicine.  

Nausea, dyspepsia, and Irritable Bowel Syndrome

Headaches

Oral bacteria

Effects on bacteria and fungi

Pain and inflammation

Uses in chemotherapy

Respiratory system

Effects on head lice

 

Nausea, dyspepsia, and Irritable Bowel Syndrome

Liu JH, Chen GH, Yeh HZ, Huang CK, Poon SK. (1997). Enteric-coated peppermint-oil capsules in the treatment of irritable
bowel syndrome: a prospective, randomized trial.  Journal of Gastroenterology,  32(6):765-8.  PMID: 9430014, UI: 98091849

Summary: This was a prospective, randomized, double-blind, placebo-controlled study of 110 outpatients with symptoms of irritable bowel
syndrome.  Symptom improvements were significantly better in the group taking peppermint oil capsules (Colpermin) than in
the group taking the placebo. Symptoms addressed were alleviation of abdominal pain, less abdominal distention, reduced
stool frequency, less intestinal rumbling, and less flatulence.  The researchers concluded that the peppermint capsules were
effective and well-tolerated.

May B, Kuntz HD, Kieser M, Kohler S.  (1996). Efficacy of a fixed peppermint oil/caraway combination in non-ulcer dyspepsia.
Arzneimettelforschung, 146(12):1149-53.  PMID: 9006790, UI: 97159451

Summary:  This was a double-blind, placebo-controlled trial using 45 patients with non-ulcer dyspepsia (poor digestion) to study the efficacy
and safety of Enteroplant, a standardized  preparation consisting of peppermint oil and caraway oil in an enteric coated capsule.
After four weeks of treatment, the peppermint/caraway capsule was significantly superior to the placebo in terms of relief of pain
severity and frequency. Similar favorable findings occurred with other gastrointestinal symptoms as well. The peppermint/caraway
combination was tolerated well.

Beesley, A., Hardcastle, J., Hardcastle, P.T., Taylor, C.J. (1996). Influenceof peppermint oil on absorptive and secretory processes
in rat small intestine. Gut, 39(2):214-9. PMID: 8991859, UI: 97131869

Summary: According to these authors, it is already established that peppermint oil relaxes intestinal smooth muscle by reducing the availability
of calcium to the tissue. This is one reason why it alleviates symptoms of irritable bowel syndrome. This study investigates the effect
of peppermint oil on processes of intestinal transport.

Tate, S.  (1997).  Peppermint oil: a treatment for postoperative nausea. Journal of Advanced Nursing, 26(3):543-9. 

Summary:  This study used control, placebo, and experimental groups of gynecological patients to test for post-operative nausea relief.
The experimental group required less nausea medication following surgery than the placebo group.  This difference was statistically
significant.  The cost of treatment with peppermint oil capsules was 48 pence (under $1).

Pittler MH,  Ernst E (1998). Peppermint oil for irritable bowel syndrome: a critical review and metaanalysis. American Journal of
Gastroenterology, 93(7):1131-5. PMID: 9672344, UI: 98336088

Summary: This is a review of clinical trials of peppermint extracts (Mentha x piperita) as a treatment for symptoms for irritable bowel syndrome
(IBS). Eight randomized, controlled trials were located. Together they indicated that peppermint oil seemed to help relieve symptoms
of IBS. These authors concluded that the efficacy of peppermint has not been established beyond a reasonable doubt. More carefully
designed and executed studies are needed for clarification. 

Oral bacteria

Shapiro S, Meier A, Guggenheim (1994).  The antimicrobial activity of essential oils and essential oil components towards oral
bacteria. Oral Microbiol Immunol, 9(4):202-8.

Summary: Minimal inhibitory concentrations and minimal bactericidal concentrations of essential oils were tested against anaerobic oral
bacteria. The most potent essential oils were Australian tea tree oil, peppermint oil, and sage oil. The most potent essential
oil components were thymol and eugenol.   

Pain and inflammation

NOTE: Both essential oil of peppermint and menthol, the primary active agent, are well-established as topical analgesics and
anti-inflammatories commonly used for muscle and joint pain. There is little recent clinical research testing these therapeutic
benefits.  Most of the current research focuses on specific applications of these properties other than muscle and joint pain,
such as headaches and gastro-intestinal conditions.

Atta, A.H., Alkofahi, A.  (1998).  Anti-nociceptive and anti-inflammatory effects of some Jordanian medicinal plant extracts.
J Ethnopharmacol, 60(2):117-24.  PMID: 9582001; UI: 98241157.

Summary:  Mentha piperita was found to have significant anti-inflammatory and analgesic effects when used against induced, localized
acute and chronic inflammation in rodents. The effects were dose-dependent. The authors concluded that the study affirmed
the traditional use of peppermint for these conditions of pain and inflammation.

Juergens UR, Stober M, Vetter H (1998).  The anti-inflammatory activity of L-menthol compared to mint oil in human monocytes
in vitro: a novel perspective for its therapeutic use in inflammatory diseases. Eur J Med Res, 3(12):539-45.

Summary: Using in-vitro (in a test tube) methods, L-menthol (a major component of mint oil) was found to significantly suppress the
inflammatory process. L-menthol was found to have preferable anti-inflammatory effects over mint oil.  The authors suggest this
data supports the use of clinical trials to investigate L-menthol for treatment of chronic inflammatory problems such as bronchial
asthma, colitis and allergic rhinitis. 

Respiratory system

Morice AH, Marshall AE, Higgins KS, Grattan TJ (1994).  Effect of inhaled menthol on citric acid induced cough in normal
subjects. Thorax 49(10):1024-6.

Summary: In this randomized, controlled clinical trial, 20 healthy subjects inhaled 75% menthol in eucalyptus oil or one of two placebos
prior to having a cough induced. Results showed that menthol inhalation caused a significant reduction in induced cough, and
can be considered an effective antitussive agent for induced cough. (Essentics note: There is no menthol in eucalyptus oil.
Peppermint oil usually has between 28-46% menthol).

Zanker KS, Tolle W, Blumel G, Probst J. (1980).  Evaluation of surfactant-like effects of commonly used remedies for colds.
Respiration
, 39(3):150-7.

Summary: Surfactant effects of eucalyptol, eucalyptus oil, camphor, and menthol were studied by spreading them on DPL films.  Eucalyptol
was inhaled by rabbits and changes in lung compliance was tested. All of the substances acted as surfactants, decreasing surface
tension between water and air. Lung compliance values in rabbits improved. 

Burrow A, Eccles R, Jones AS. (1983).  The effects of camphor, eucalyptus and menthol vapour on nasal resistance to airflow
and nasal sensation.
Acta Otolaryngol, 96(1-2):157-61.

Summary: Individuals were exposed to 5 minutes of camphor, eucalyptus, or menthol vapor. No effect on nasal resistance to airflow was
reported, but a majority of subjects reported a cold sensation in the nose and a feeling of improved airflow. 

Headaches

Gobel H, Fresenius J, Heinze A, Dworschak M, Soyka D (1996). Effectiveness of Oleum mentha piperitae and paracetamol in
therapy of headache of the tension type. Nervenarzt, 67(8):672-81.  PMID: 8805113, UI: 96398274

Summary:   This was a randomized, placebo-controlled double-blind study using a locally applied, diluted peppermint oil preparation on 41
patients. The peppermint oil preparation was applied across the forehead three times at 15 minute intervals. It showed a significant
reduction in headache compared with the placebo, and a similar reduction in pain intensity when compared to 1,000 mg acetomeniphen.
No adverse effects were reported. The researchers concluded that the peppermint oil preparation is efficient at alleviating tension-type
headaches, and is well-tolerated and cost-effective.   

Gobel, H., Schmidt, G., Soyka, D. (1994).  Effect of peppermint and eucalyptus oil preparations on neurophysiological and
experimental algesimetric headache parameters. Cephalalgia, 14(3): 228-34.

Summary: 32 healthy subjects were involved in this double-blind, placebo-controlled, randomized cross-over study. Four test preparations
were applied to large areas of the forehead and temples. A reduction in sensitivity to headache with a significant analgesic effect
was found with a combination of peppermint oil and ethanol. The researchers conclude that essential oil preparations can have
significant effects on the pathophysiology of headache. 

Effects on bacteria and fungi

Pattnaik S, Subramanyam VR, Kole C (1996).  Antibacterial and antifungal activity of ten essential oils in vitro. Microbios,
86(349):237-46.

Summary:  The essential oils were tested against 22 bacterial strains and twelve fungi strains by the disc diffusion method. Peppermint oil
was effective against all 22 bacterial strains and 11 fungi strains.   

Sow AI, Koyalta D, Boye CS, Diedhiou/Badiane D, Bassene E (1995).  Antibacterial activity of essential oils from mint in
Senegal. Dakar Med, 40(2):193-5.

Summary: The essential oils of three species of mint (Mentha spp.) showed strong anti-bacterial and anti-fungal activity against ten
bacterial strains and a fungus, Candida albicans.  

Pattnaik S, Subramanyam VR, Rath CC (1998).  Effect of essential oils on the viability and morphology of Escherichia coli
(SP-11). Microbios, 84(340):195-9.

Summary: Essential oils from eucalyptus, lemongrass, peppermint and palmarosa were tested against a strain of E.coli.  All four oils
killed the strain at very low dilutions.

Pattnaik S, Rath C, Subramanyam VR (1995). Characterization of resistance to essential oils in a strain of Pseudomonas
aeruginosa (VR-6). Microbios, 81(326):29-31.

Summary: These researchers found a strain of Pseudomonas aeruginosa harboring a plasmid. This strain was not inhibited by large
concentrations of essential oils of eucalyptus, lemongrass, palmarosa, or peppermint. Resistance to the bactericidal effects
of the oils was demonstrated.

Uses in chemotherapy

Abdullah D, Ping QN, Liu GJ (1996).  Enhancing effect of essential oils on the penetration of 5-fluorouracil through rat skin.
Yao Hsueh Hsueh Pao, 31(3):214-21.

Summary: In this study on excised rat skin, eucalyptus oil caused a 60-fold increase in the penetration of 5-fluorouracil (a chemotherapy agent)
through the skin.  Peppermint oils caused a 48-fold increase in penetration. Modes of action are discussed.  

Effects on head lice

Veal L (1996).  The potential effectiveness of essential oils as a treatment for headlice, Pediculus humanus capitis. 
Complement Ther Nurs Midwifery
2(4):97-101.

Summary:  Essential oils of aniseed, cinnamon leaf, red thyme, tea tree, peppermint, nutmeg, rosemary, and pine were tested in the lab
against lice, Pediculus humanus.  All the oils except for rosemary and pine were found to be effective in the laboratory.  Phenols,
phenolic ethers, ketones, and oxides (1,8-cineole) appear to be the major toxic components of these essential oils when used on lice.

Last updated 04.14.05

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