Peppermint

Mentha Piperita (Family: Labitae)

Jennifer Baker and Allison Solomon

The above photograph is Mentha averensis, or Brook Mint.

Chemical Composition

• Menthol (28-29%)
• Menthone (20-31%)
• Menthyl acetate (3-10%)

Menthol is the primary constituent of peppermint oil. Menthol components contribute almost entirely to the pharmacology of peppermint. Peppermint oil is standardized to contain not less than 44% free menthol. Components are sensitive to climate, latitude (grown most in mid-western states of US where latitude range is 42-43(N) and maturity of plant.

Pharmacology

Carminative: The exact mechanism of this action is not know. However, one proposition is relaxation of the esophageal sphincter leading to released gas pressure in the stomach.

Antispasmodic: Inhibits contraction of smooth muscles by blocking the influx of Ca+2  into muscle cells.

Choleretic: Stimulates the flow of bile. May also improve the solubility of bile.

Analgesic: Stimulates nerves which perceive cold, while depressing those that perceive pain. The body reacts to this sensation quite strongly by increasing blood flow to the area of application, thus producing a period of warmth.

Clinical Applications

• Irritable Bowel Syndrome:  For many years peppermint has been used for IBS. A primaryproblem associated with IBS is the hypercontractility of intestinal smooth muscle. The antispasmodic property of peppermint allows these muscles to return to their proper tone, therefore reducing many of the abdominal pains and symptoms.

• Peppermint also reduces gas and nausea prevalent with IBS.
• Enteric-coated preparations should be used to allow delivery to the intestines and reduce possibility of heartburn. The dosage is 1-2 capsules (0.2mL/cap) TID between meals.

• Cholelithiasis: Peppermint is used for dissolving gallstones. This is an alternative to surgery and is safe when consumed for long periods of time (up to 4 yrs). Dosage is one enteric-coated capsule TID (0.2mL peppermint/cap) .
• External Analgesic: Peppermint is used in many OTC creams. The herbal extract aids in reducing pain associated with arthritis, fibromyositis, tendonitis and other inflammatory conditions involving the musculoskeletal system. Dosage is 1.26-16% cream applied 3 to 4 times per day. Additionally, diluted oil can be applied to gums of teething babies. Peppermint is also often used in throat lozenges to reduce pain of a sore throat.
• Common cold: Chest rub formulations can be applied on patients with colds to help make breathing easier. Benefit has not been proven in clinical studies, but this use is popular. Peppermint also demonstrates antiviral activity.
• Other uses: Ice cubes made out of mint tea can help soothe canker sores. Teas work gently to help colic. Nursing mothers who drink mint tea pass some to the baby. This helps to relax the baby's esophagus and, thus, eases burping. Drinking tea after vomiting helps to settle the stomach. Peppermint tea can also ease travel sickness.

Toxicology

• Heartburn (avoid tea/non capsulated preparations with GERD; take between meals)
• Contact dermatitis (enhanced with heating pad)
• Pure peppermint oil should not be ingested without dilution. 1-2 teaspoons of pure peppermint oil taken internally can be toxic.

Clinical Studies

1)  Rees WDW. Treating irritable bowel syndrome with peppermint oil. British Medical Journal, 1979 (Oct. 6), 835-6.

Sixteen patients with IRB were given either enteric-coated peppermint oil capsules or placebo three weeks and then crossed-over. Patients recorded daily severity of abdominal symptoms. Results showed a statistically significant advantage for the treatment period when peppermint capsules were used.

2)  Sparks MJW, O'Sullivan P, Herringtion AA, Morcos SK. Does peppermint oil relieve  spasm during barium enema? The British Journal of Radiology, 1995, 68, 841-843.

One hundred forty-one patients were randomized. 71 patients (control) were examined with standard barium enemas while 70 patients (treatment) were examined with a barium enema containing 16 mL of peppermint oil. The examinations were double blind. Spasms were absent in 64% of treatment group compared to 35% of control group (p<0.001). This technique is simple, cheap and may lessen the need for intravenous spasmolytic agents.

3)  May B, Kuntz H, Kieser M, Kohler S. Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia. Arzneim.-Forsch./Drug Res., 1996. 46(II), Nr. 12, 1449-53.

Thirty-nine patients with non-ulcer dyspepsia were evaluated in a double-blind, placebo-controlled multicenter trial. Treatment group (n=19) received one Enteroplant( (90 mg peppermint oil/50 mg caraway oil) capsule three times per day for four weeks. Control (n=20) group received placebo. The primary end-point was the improvement of pain intensity during the treatment period. After four weeks an improvement occurred in 89.5% of treatment group and 45% of control (p=0.015)

References

Beesley A, Hardcastle J, Hardcastle PT, Taylor CJ. Influence of peppermint oil on absorptive and secretory processes in rat small intestine. Gut 1996; 39: 214-19.

Chaopra D. Alternative Medicine: The Defomotove Guide. Future Medicine Publishing, Inc. Puyallup,WA. 1994.

Friedman, G. Treatment of the Irritable Bowel Syndrome. Gastroenterology Clinics of North America 1991; 20(2): 325-33.

May B, Kuntz H, Kieser M, Kohler S. Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia. Arzneim.-Forsh./Drug Res 1996; 46(II): 1149-53.

Pizzorno JE, Murray MT. A Textbook of Natural Medicine. Bastyr University Publications. Bothell, WA. 1993. V:Mentha 1-3.

Rees WDW. Treating irritable bowel syndrome with peppermint oil. British Medical Journal, 1979 (Oct. 6), 835-6.

Sparks MJW, O'Sullivan P, Herrington AA, Morcos SK. Does peppermint oil relieve spasm during barium enema? The British Journal of Radiology 1995; 68(812): 841-43.

Internet sites:

http://www.frontiesrherb.com/aromatherapy/aro.notes.no4.html

http://www.crop.cri.nz/broadshe/mints.htm

http://204.133.178.131/public/delicious/D!_backs/Dec_95/herb_king_mint.html