Terpenes are hydrocarbon compounds found in plants most commonly associated with essential oils and represent many pharmaceutical uses. These chemicals form the basis of some antiseptics, expectorants, gastrointestinal drugs, and pain relievers. Terpenes also show promise as an antioxidant.
More than 2,000 species of plants contain terpenes or their derivatives. The ancient Egyptians used essential oils in religious ceremonies, and more than 60 plant oils were mentioned in literature from the 1500s. With advances in organic chemistry, scientists identified a wide range of uses for terpenes worldwide.
The two most common terpenes studied include camphor and turpentine, but medicinal oils also appear in eucalyptus, lavender, thyme, mint, and hundreds of other plants. They appear in the leaves, bark, roots, and flowers of these plants. This chemical naturally wards off insects and herbivores, and aids in pollination.
Eucalyptus oil treats respiratory disease and is also used in dentistry. Its pungent scent is also added to fragrances and used in aromatherapy. As an expectorant, the chemical in eucalyptus stimulates the secretion of mucus. The oil might produce a diuretic effect, and can be taken orally to ease gastrointestinal spasms by increasing gastric juices in the gut.
Plant oils also produce an antiseptic effect against bacteria. It might be especially useful to fight toxins resistant to antibiotics, such as yeast and fungi. Other medicines contain these oils because of their anesthetic properties. Drug manufacturers add terpenes to creams and ointments to relieve pain and itching.
The chemical is found in greater quantities in plants containing ample chlorophyll, such as mint. The menthol in mint plants might reduce flatulence and indigestion when consumed as a tea. All varieties in the mint family, including peppermint and spearmint, contain chemical properties related to terpenes.
In addition to medicinal uses, the chemical is found in rubber and resins. It is also added to cleaning products and disinfectants, in the form of lemon oil or pine oil. If accidentally ingested in large quantities or high concentrations, the chemical might cause toxic effects.
Camphor and turpentine depress the central nervous system and can lead to respiratory disorder if aspirated. Nausea, vomiting, and seizures are typical symptoms of terpene poisoning. Children represent the most common victims of accidental ingestion. Certain plant oils have hallucinogenic effects and might lead to drug abuse.