Essential oils are a class of polyaromatic hydrocarbons extracted through steam distillation or cold pressed from the leaves, flowers, bark, wood, fruit, or peel of a single parent plant. The term "essential" refers to the essence of a plant, rather than an indispensible component of the oil or a vital biologic function. These organic compounds are a complex mixture of chemicals with structures that give the oil its aroma, therapeutic properties, and occasionally cause toxicity. More than 500 essential oils exist and can be categorized into five chemical groups: terpenes, quinines, substituted benzenes, aromatic/aliphatic esters, and phenols and aromatic/aliphatic alcohols.
Use of plant-derived essential oils in the practice of herbal medicine has a long and colorful history, dating back thousands of years. The virtues of these extracts have been mentioned in ancient Egyptian and Greek medical literature and throughout the Bible.
Essential oils were used to treat everything from asthma to snakebites until the early 20th century. In America "Indian doctors" frequently sold these products, claiming they learned medicinal secrets from local Native American tribes. These remedies were advertised at medicine shows and demonstrated by troupes such as the famous Kickapoo Indian Medicine Company. The purpose of these traveling caravans was to sell patent medicines, which typically contained substantial quantities of ethanol, in addition to other xenobiotics of uncertain therapeutic value. A bottle of Kickapoo Oil sold at the beginning of the 20th century purportedly contained "camphor, ether, capsicum, oil of cloves, oil of sassafras and myrrh." Needless to say, the risk-to-benefit ratio for this did not favor the patient, and the "doctors" who sold them quite rightly earned a reputation for quackery.86
With the ascent of scientific research, many essential oil remedies fell from use. More recently, however, trends in globalization and natural healing have led to a popular resurgence in the use of essential oils in developed countries. Essential oils currently are marketed for use in aromatherapy and certain complementary medicines. The reintroduction of these xenobiotics into mainstream society has highlighted the need for research and toxicity studies to ensure that appropriate decision making and care can be provided to exposed patients.
Absinthe; Oil of Wormwood
Absinthe is an emerald green liqueur made from the extract of the wormwood plant Artemisia absinthium. The earliest references to wormwood date to 1500 B.C., when its antihelminthic properties were described. It is thought that Napoleon's soldiers popularized the drink upon their return from Algeria, where they had added wormwood extract to their wine to avoid helminthic infections during the war.43
Absinthe achieved exceptional popularity in the late 19th century in Europe. Famous artists and authors including Lautrec, Van Gogh, Baudelaire, and Wilde sat for hours in the cafes of Paris, drinking the green liqueur and romanticizing its aphrodisiac effects. However, recognition of ...