Botany: Cinnamon (C. verum) is a medium-size evergreen tree that grows to about 10-20 m high. The bark is thin, smooth, and pinkish-brown, the leaves opposite, elliptic or oval to lanceolate-oval. Flowers are pale yellowish-green. All species are native to Southeast Asia.
Parts used are the dried bark, leaves and twigs.
Biochemistry: Cinnamon bark oil contains as its major component cinnamaldehyde (usually 60-75%). It contains also eugenol, eugenol acetate, cinnamyl alcohol, methyl eugenol, benzaldehyde, cuminaldehyde, benzyl benzoate, linalool, monoterpene hydrocarbons, carophyllene, safrole, and others.
Cinnamon leaf oil contains high concentrations of eugenol (Ceylon type 80-88%; Seychelles type 87-96%). It also contains cinnamaldehyde, cinnamyl acetate, eugenol acetate, benzaldehyde, and others. A cinnamon leaf oil of Chinese origin is reported to contain only about 3% eugenol but has a high content of safrole.
Products: Cinnamon bark oil is steam distilled from inner bark of certain species of cinnamon tree.
Cinnamon leaf essential oil (Cinnamomum zeylanicum essential oil, Cassia oil) is obtained by steam distillation of leaves and twigs of certain species of cinnamon tree.
Cassia, cinnamon, and their bark oils have been used either as flavours or tonic or counter-irritants in cosmetic preparations, including liniments, suntan lotions, nasal sprays, mouthwashes or gargles and toothpaste, among others.
Cinnamomum zeylanicum essential oil
Cinnamon bark oil is mostly used for fragrance and flavouring. The refreshing and cooling quality of the bark is due to the presence of methyl amyl ketone. Cinnamon oil (presumably bark oil) has anti-fungal, anti-viral, bactericidal and larvicidal properties.
Ceylon cinnamon leaf oil is used as a fragrance component in soaps, detergents, creams, lotions and perfumes.
Cinnamomum zeylanicum oil essential is not to be used in aromatherapy, as it may be harmful on the skin.
Allergic reactions to C. verum are common.
Cinnamaldehyde can cause dermatitis in humans and allergic reactions have occurred from contact with products containing either cinnamaldehyde or cinnamon oil. Cinnamon may cause allergic reactions in some people who are allergic to balsam of Peru. Cassia oil causes mucous membrane and dermal irritation, both effects being attributed to cinnamaldehyde.
An alcoholic extract of cinnamon, cinnamon oil and cassia oil have shown in vitro mutagenic activity. However, a recent test of the essential of C. cassia found no mutagenic activity in the Ames test.