Peppermint (Mentha peperita)
Historical note The written record of mint dates back to an ancient Greek
myth in which the Greek god Pluto was said to have affections for a beautiful
nymph named Minthe. His jealous wife Persephone cast a spell on the nymph,
transforming her into a plant. When Pluto could not reverse the spell, he gave
her a sweet scent that would emanate throughout the garden (Murray &
Pizzorno 1999). Peppermint has been used medicinally for generations as a
digestive aid and carminative. More recently, enteric-coated peppermint oil
capsules have been widely prescribed for the relief of IBS.
BOTANICAL NAME/FAMILY
Mentha x piperita (family [Labiatae] Lamiaceae)
PLANT PARTS USED
Leaf or stem— essential oil is distilled from the aerial parts.
CHEMICAL COMPONENTS
Peppermint leaves contain about 2.5% essential oil, 19% total polyphenolic compounds,
12% total flavonoid compounds (eriocitrin, luteolin-7-O-rutinoside,
hesperidoside) and 7% total hydroxycinnamic compounds (including rosmarinic acid)
(Duband et al 1992). The biochemistry, organisation, and regulation of essential oil
metabolism in the epidermal oil glands of peppermint have been defined and
research is underway to create ‘super’ transgenic peppermint plants with improved oil
composition and yield (Wildung & Croteau 2005).
Essential oil Over 100 constituents have been identified in peppermint oil. The
principal constituents are menthol (35–55%), menthones (10–35%), isomenthone,
menthyl acetate, menthofuran and cineole. To comply with the European
Pharmacopoeia, the oil must not contain more than 4% pulegone and not more than
1% carvone.
MAIN ACTIONS
The actions of the leaf as an infusion or liquid extract are largely dependent on the
essential oil content. Other compounds, such as the flavonoids, also contribute to the
overall activity, especially the antioxidant and anti-allergic activities. Peppermint oil is
relatively rapidly absorbed after oral administration and eliminated mainly via the bile
(Grigoleit & Grigoleit 2005a).