Mentha pulegium, commonly (European) pennyroyal, or pennyrile, also called mosquito plant and pudding grass,Keville, Kathi (1994). Herbs: An Illustrated Encyclopedia. New York City: Friedman/Fairfax Publishers. pp. 128. is a species of flowering plant in the Mentha family, Lamiaceae, native to Europe, North Africa, and the Middle East. Kew World Checklist of Selected Plant Families Crushed pennyroyal leaves emit a very strong fragrance similar to spearmint. Pennyroyal is a traditional folk remedy, emmenagogue, abortifacient, and culinary herb, but is toxic to the liver and has caused some deaths. European pennyroyal is related to an American species, Hedeoma pulegioides. Though they differ in genera, they share similar chemical properties.
The flowering period starts in June and continues into mid-summer, although in northern countries it flowers rather later, sometimes as late as September, when it can fail to set seed.
Its Ploidy is 2n = 20.
In California, where it is considered an invasive species, it occupies a similar niche, in seeps, streamsides, vernal pools and swales, marshes, and ditches. There is some speculation that it may displace native species in these areas.
Few animals eat pennyroyal. In Britain, the only insect known to feed on it is the bug Heterogaster artemisiae Schilling, which is a seed bug that normally feeds on Thymus praecox.
It is considered an axiophyte in many British counties, because low-intensity pasture is a rare habitat, although it has been spreading in recent decades. Its Indicator value in Britain are L = 8, F = 7, R = 5, N = 7, and S = 0.
Records from Greek and Roman physicians and scholars contain information pertaining to pennyroyal's medicinal properties, as well as recipes used to prepare it. Pliny the Elder, in his encyclopedia Naturalis Historia ( Natural History), described the plant as an emmenagogue, and that it also expelled a dead fetus. Galen only listed pennyroyal as an emmenagogue, as did Oribasius. Roman and Greek writers Quintus Serenus Sammonicus and Aspasia the Physician however both agreed that pennyroyal, when served in tepid water, was an effective abortive method. A medical text on gynecology attributed to Cleopatra (though it was actually written by a female Greek physician Metrodora) recommends the use of pennyroyal with wine to induce abortions.
In regard to its contraceptive properties, it was referred to in a joking manner in Aristophanes' play Peace (421 BCE). The god Hermes provides the male character Trygaios a female companion; when Trygaios asks if there would be a problem if she became pregnant, Hermes responds, "Not if you add a dose of pennyroyal." In a similar manner, in Aristophanes' comedy Lysistrata, after a pregnant female character on stage is told to withhold her body sexually from her husband, a slender female character, in comparison to the pregnant woman, is described as "a very lovely land Well croppy, and trimmed and spruced with pennyroyal."
Early settlers in colonial Virginia used dried pennyroyal to eradicate pests. Pennyroyal was such a popular herb that the Royal Society published an article on its use against rattlesnakes in the first volume of its Philosophical Transactions in 1665. 17th-century apothecary and physician Nicholas Culpeper mentions pennyroyal in his medical text The English Physitian, published in 1652. In addition to its abortive properties, Culpeper recommends its use for gastrointestinal ailments, such as constipation and hemorrhoids, as well as itching and blemishes to the skin, and even toothaches.
Pennyroyal is an essential ingredient in the North African dish, which is still eaten to this day, called .
Pennyroyal continues to be used up through the 20th and 21st centuries. Its oil is still commercially available today, though little is known about the appropriate dosages for humans. Scientists therefore likely consider it unsafe for use, as it is potentially toxic.
Pennyroyal has historically also been used as a mint flavoring in herbal teas and foods. It is recommended that pennyroyal tea should not be drunk on a regular basis. Consumption of pennyroyal tea can be fatal to infants and children.
In Italy the fresh leaves of this plant, which in Rome and the surrounding area is called menta romana, are used in Roman cuisine to flavour lamb and tripe. In culinary use it should not be confused with lesser calamint ( Clinopodium nepeta), which in Rome is used to prepare artichokes.
The pennyroyal plant has also been used as an emmenagogue and an abortifacient. Rennie's 1833 supplement to the pharmacopeias admitted its use as an "expectorant, diuretic, and emmenagogue" in doses of 10 grains to 1 scruple (0.6–1.3g) of the powdered dried herb, but dismissed the use of the Pennyroyal Water (Aqua Pulegii) as "popularly but erroneously supposed" to be an abortifacient no. Chemicals in the pennyroyal plant cause the uterine lining to contract, causing a woman's uterine lining to shed. Since the U.S. Congress passed the Dietary Supplement Health and Education Act in October 1994, all manufactured forms of pennyroyal in the United States have carried a warning label against its use by pregnant women, but pennyroyal is not regulated by the U.S. Food and Drug Administration.
At least one study has shown pennyroyal oil to have potent acaricidal activity against house dust mites.
Symptoms that may persist after ingesting a small dose (<10 mL) of pennyroyal oil are nausea, vomiting, abdominal pain and dizziness. Larger volumes may result in multiorgan failure that could lead to death. There are no current toxicokinetics studies performed on humans for the effects of pulegone, but there are some studies performed on other mammals. When pulegone is ingested, it is broken down by the liver and reacts to form multiple toxic metabolites that can wreak havoc in the body. Some identified metabolites are menthofuran, piperitenone, piperitone, and menthone.
The exocyclic double bond found in pulegone is vital to the activation and binding mechanism of the molecule and causes it to be an effective hepatotoxin. When ingested, pulegone targets the liver and kidneys, among other organs. Studies conducted on rats show that one of the main effects is the inhibition of contractile activity in the myometrium and death by kidney failure. The studies also found that long-term exposure to pennyroyal increased incidences of urinary bladder tumors.
The exact pathway by which pulegone is converted to menthofuran is unknown, but one study strongly suggested it included allylic oxidation of a methyl group (from CYP450), intramolecular cyclization to form a hemiketal, and subsequent dehydration to form the furan. Pthofuran may deplete glutathione levels, leaving hepatocytes vulnerable to free radical damage.
A study testing pulegone toxicity found inhibitors of cytochrome P450, such as cobaltous chloride or piperonyl butoxide, blocked toxicity. Such testing has not been expanded to humans, however, as the pennyroyal mechanism of toxicity is still not entirely understood.
|
|