Mentha pulegium

Mentha pulegium

Synonyms

Hedeoma pulegioides

Vernacular Name

Pudding Grass, True pennyroyal, Fleabane, Pennyroyal

Description

Mentha pulegium is a perennial from the mint genus.  Growing to a height of 25cm, the stems of the plant are prostrate, and are square upon a cross-section, a common trait of the mint family.  The heavily branched stems are covered in a downy pubescence, so too, is the majority of the rest of the plant.  The leaves of M. pulegium are elliptical, pubscent, and have a scent similar to spearmint.  The plant is similar in many respects to American Pennyroyal (Hedeoma pulegioides), M. pulegium can be identified by its smaller leaves, which are often, though not always, toothed.  The hermaphroditic flowers are small, and grow into whorl-like patterns to form their calyxes.  Blooming from August to October, each 1cm long flower is two-lipped, often bluish-lilac or lavender in color.  In contrast to H. pelugioides, the flower has four stamens, as opposed to two.

Origin / Habitat

M. pulegium plant originated in Europe and Asia and is thought to be naturalized in the United States via European colonists. It is often found growing near water, such as streams, pools and lakes.  M. pulegium flourishes in nutrient-rich, sandy, moist soil and sunny conditions.

Chemical Constituents

Pugelone, alpha-pinene, beta pinene, limonene, 3-octanone, p-cymene, 3-octylactate, 3-octanol, 1-octen-3-ol, 3-methylcyclohexanone, menthone, isomenthone, isopulegone, piperitone, lauric acid, myristic acid, palmitic acid among others.(2)

Plant Part Used

Whole plant

Traditional Use

M. pulegium has been ingested as an infusion for gastrointestinal complaints by several Native American tribes including the Delaware, Ojibwa and Oklahoma  while the Mohegan tribe thought that it warmed the digestive tract. Other reported uses include its use as an analgesic poultice by the Cherokees and as an infusion for pain by Shinnecock and Iroquois.(3)

One of the most popular traditional uses is for promoting menstruation.  Because of this effect, this plant, an abortifacient, is used to unblock menses.  M. pulegium has been used to induce labor and strengthen menstrual flow.(1),(3)

M. pulegium has also been used as an insecticide and as an insect repellant.(3)

Dosage

Tincture: 2- 10 drops daily.  Tea: 1 teaspoon in one cup boiling water.(1)

Pharmacology

Pre-clinical

Abortfacient activity

The most reported and yet controversial use of M. pulegium is as an abortifacient. The constituents of M. pulegium (mainly pulegone) are reported to have emmenagogic properties, stimulating uterine contraction and promoting menstrual flow.(4) Although the essential oil has been used for centuries to induce abortion, there is no scientific proof to support this use. Therefore, the use of M. pulegium as an abortifacient cannot be substantiated by clinical evidence at this time.(5)

Antibacterial activity

The use of M. pulegium as an antibacterial agent and insect repellent is supported by laboratory studies.(6) The essential oils, including pulegone, are the components that are responsible for the antimicrobial and insecticidal activity.(7)

Clinical

No documentation

Interaction and Depletions

Interaction with other Herbs

No documentation

Interaction with Drugs

No documentation

Precautions and Contraindications

Side effects

M. pulegium oil ingestion has been associated with severe hepatotoxicity and death.(8) The primary constituent, R-(+)-pulegone, is metabolized via hepatic cytochrome P450 to toxic intermediates.

Do not use in individuals with liver or kidney problems.

M. pulegium may cause allergic reactions such as contact dermatitis. Do not use if allergic to M. pulegium or the essential oils of M. pulegium.(11)

Pregnancy

Based on historical use, M. pulegium should not be used in pregnancy due to the potential for abortifacient effects.(10)

Age limitation

No documentation

Adverse reaction

Death has been reported after consumption of half an ounce (15mL) of the oil.(9) If ingestion of M. pulegium is suspected there will be a characteristic strong, minty smell on the patient’s breath. The healthcare personnel can determine if M. pulegium ingestion is the cause of toxicity by using gas chromatography to test for the active metabolite menthofuran in urine, blood, or other tissues. The overdose management includes lavage, and/or administration of activated charcoal. The symptoms of M. pulegium toxicity may mimic that of acetaminophen.

Read More

  1) Essential Oil

  2) Western Herbs

References

1. Hutchens AR. Indian Herbalogy of North America. Boston MA: Shambhala Publications;1991.215.
2. Duke, JA. Handbook of Medicinal Herbs. Florida:CRC Press; 1985.
3. Moerman DE.  Native American Ethnobotany. Portland OR: Timber Press; 2009.353.
4. Black DR. Pregnancy unaffected by pennyroyal usage. J Am Osteopath Assoc. May1985;85(5):282.
5. Soares PM, Assreuy AM, Souza EP, et l. Inhibitory effects of the essential oil of Mentha pulegium on the isolated rat myometrium. Planta Med. Mar2005;71(3):214-218.
6. Mahboubi M, Haghi G. Antimicrobial activity and chemical composition of Mentha pulegium L. essential oil.J Ethnopharmacol. 26Sep2008;119(2):325-327.
7. Martins HM, Martins ML, Dias MI, et al. Evaluation of microbiological quality of medicinal plants used in natural infusions. Int J Food Microbiol 15August2001;68(1-2):149-153.
8. Carmichael PG. Pennyroyal metabolites in human poisoning. Ann Intern Med. 1Feb 1997;126(3):250-251.
9. Bakerink JA, Gospe SM Jr, Dimand RJ, Eldridge MW. Multiple organ failure after ingestion of pennyroyal oil from herbal tea in two infants. Pediatrics.1996;98(5):944-947.
10. Anderson, Ilene B.; Sidney D. Nelson and Paul D. Blanc. Pennyroyal Metabolites in Human Poisoning. Annals of Internal Medicine. 1997; 126(3):250–251.
11. Pérez-Calderón R, Gonzalo-Garijo A, Bartolomé-Zavala B, et al. Occupational contact urticaria due to pennyroyal (Mentha pulegium). Contact Dermatitis. Oct2007;57(4):285-286.