Camphortree

The characteristic constituent that gives the tree its name. Camphor produces a cooling-then-warming counter-irritant sensation on skin by activating TRPV3 and TRPM8 receptors, and has mild topical analgesic, antipruritic and rubefacient actions. Systemically it is a CNS stimulant and proconvulsant, which underlies the well-documented toxicity of ingested or over-applied camphor.

An aromatic ether with expectorant, mucolytic and anti-inflammatory activity; it contributes the eucalyptus-like note of some camphor-laurel chemotypes and is the basis of their use in inhalant and chest-rub preparations.

A hepatocarcinogen and hepatotoxin whose use as a food/flavour additive is banned in most jurisdictions. Its presence is the main safety concern of safrole-chemotype camphor oil and a reason root-derived oils are avoided medicinally.

A floral-scented alcohol with sedative, anxiolytic and antimicrobial properties; the linalool chemotype of C. camphora is a major commercial source of natural linalool for perfumery and aromatherapy.

A reduced relative of camphor with mild analgesic and anti-inflammatory action; borneol is valued as a penetration enhancer that increases transdermal and blood-brain-barrier passage of co-administered agents.

A lilac-scented alcohol contributing antimicrobial and mild antioxidant activity to the whole oil.

A sesquiterpene alcohol with antimicrobial, antibiofilm and skin-penetration-enhancing properties, characteristic of one of the tree's less common chemical variants.

A citrus-scented hydrocarbon contributing to the aroma and providing minor antioxidant and solvent-like properties.

Camphor is used externally in chest rubs, balms and liniments as a counter-irritant for muscle aches, minor joint pain, itching and to relieve cough congestion. In the United States the FDA limits over-the-counter camphor products to a maximum of 11%. Warning: never apply to broken skin, do not use under occlusion over large areas, and do not apply to infants or the faces of young children (risk of laryngospasm and systemic absorption).

A few drops added to hot water for inhalation have traditionally been used to ease nasal and chest congestion. Keep away from the eyes; avoid in asthma where volatile oils may provoke bronchospasm; not for young children.

Linalool-rich 'ho' oils are used in diluted aromatherapy and perfumery. Safety: camphor essential oil must never be taken internally; camphorated oil, camphor oil and camphor liniment are banned oral products, and ingestion is potentially fatal. Avoid all camphor products in pregnancy and lactation. Safrole-rich root oils should not be used medicinally because safrole is a hepatocarcinogen.

GC-MS characterization of camphor-tree essential oils identified camphor, 1,8-cineole, terpinen-4-ol, limonene and safrole as principal volatiles and demonstrated contact and fumigant insecticidal activity against stored-product beetles, supporting traditional use of camphor as an insect repellent.

Reports in the poisoning literature document that ingestion of camphor-containing products causes rapid-onset seizures, with pediatric ingestions of 500-1000 mg associated with convulsions and death, informing the FDA restriction of over-the-counter products to <=11% camphor and the ban on camphorated oil.

Camphor (kafur) is described as a cooling, 'cold and dry' remedy used for fevers, headaches and as an antidote, reflecting its long standing in Arabic-Persian materia medica.

Camphor (karpura) is used in Ayurveda as a cooling, aromatic drug for respiratory complaints, skin conditions and ritual purposes, and remains an ingredient of many topical balms.

Camphor liniment and camphorated oil were official preparations used as rubefacients and 'stimulants'; their high poisoning rate later led to regulatory bans on the oral products.

Ladislas Meduna used injected camphor to induce therapeutic seizures in psychiatric patients, an early convulsive therapy that preceded and inspired electroconvulsive therapy - a striking historical illustration of camphor's proconvulsant action.