This genus is closely related to Cinnamomum, and many species produce essential oil. The most significant members of the genus Aniba are A. duckei, A. parviflora and A. rosaeodora, all of which yield rosewood, or bois de rose, essential oil.
The most common species, from the aromatherapy essential oil trade perspective, would appear to be A. rosaeodora from Brazil. The essential oil is obtained from the wood chips from the tropical evergreen. There are environmental issues associated with its production: there are major concerns over deforestation (Santana et al. 1997), and rosewood was included on the endangered species list, leading to the preparation of sustainable management plans; however, Burfield (2004) commented that there was no independent audit of the bio-resources and cast doubt on the actual relevance of such initiatives. The essential oil is a colourless mobile liquid with a mild, sweet, woody, floral odour (Lawless 1995).
According to Bowles, rosewood contains linalool as its major component at 85.3 per cent, followed by α-terpineol at 3.5 per cent and cis-linalool oxide at 1.5 per cent. According to Burfield (2004) the linalool content is usually in the region of 84–93 per cent and is a racemic mix of d- and l-linalool. Price and Price (2007) highlight rosewood’s applications as an antifungal for candida and as an
‘anti-infectious’ agent for respiratory infections; also for its stimulating and tonic qualities, which can aid in cases of general debility, overwork, sexual debility, nervous depression and stress-related headaches. For some uses of rosewood in aromatherapy, please see Table 8.22.
Table 8.22 Rosewood essential oil in aromatherapy
System Rosewood with
Nervous (stress, debility, etc.) Lavender, bergamot, clary sage,
geranium, lemon, palmarosa, lemongrass, jasmine
Integumentary (including infections) Lemongrass, lavender, palmarosa, geranium
Respiratory Sandalwood, ginger, benzoin, lemon
G
enusC
innamOmumThis genus contains around 200 species. Several of these are significant from an essential oil and aromatherapy perspective. These are Cinnamomum camphora, the botanical source of camphor essential oils, and also ravintsara (also inaccurately described as ravensara) essential oil; C. cassia yielding cassia or Chinese cinnamon,
and C. verum (previously C. zeylanicum), which is the source of cinnamon bark and leaf oils.
Cinnamomum camphora – camphor and ravintsara
The Japanese C. camphora is known as hon-sho is considered to be the true camphor tree, and the botanical source of camphor essential oil. Crude camphor exudes from the wood of the tall evergreen, via the fissures in the bark; the roots also contain the volatile oil (Weiss 1997).
The essential oil is steam distilled from the crude camphor, rectified under vacuum, producing three fractions – white (lightest), brown and yellow camphor.
Because of this they are not classed as true essential oils, as they are incomplete.
Only the white camphor has use in aromatherapy, as the safrole content of the other fractions is high, in brown camphor at 80 per cent and 20 per cent in yellow.
Safrole is a very toxic compound, associated with genotoxicity and carcinogenicity (Tisserand and Balacs 1995). White camphor is dominated by the ketone known as ‘camphor’ at 30–50 per cent, and the oxide 1,8-cineole at 50 per cent (Tisserand and Balacs 1995). Its camphor content confers potential convulsant and neurotoxic hazards, so white camphor essential oil is contraindicated in epilepsy, fever, pregnancy and children under two (Tisserand and Balacs 1995). White camphor is rarely used in aromatherapy, and if it is used it should be with caution.
C. camphora was introduced to Madagascar in the middle of the nineteenth century, and now grows wild in the central eastern region. This species is known to produce subspecies and four distinct chemotypes. The cineole type contains around 76 per cent 1,8-cineole, and also 20 per cent α-pinene and α-terpinene.
The linalool type is dominated by linalool at around 80 per cent with 10 per cent monoterpenes – this is available as ho oil. The safrole type contains 80 per cent safrole and 10 per cent monoterpenols. Finally, the nerolidol type contains 40–60 per cent nerolidol with 20 per cent each of monoterpenoids and sesquiterpenoids (Behra, Rakotoarison and Harris 2001).
Ravintsara essential oil is obtained from the Madagascan C. camphora leaf;
this is the cineole chemotype. It has a fresh, clean, cineolic scent, and the main components are 1,8-cineole at 53–68 per cent, sabinene at 12–15 per cent, α- and β-pinenes at up to 10 per cent, and myrcene at around 1–2 per cent. It has very low camphor content (if any), so the above contraindications do not apply to ravintsara oil. It appears to be strongly antiviral and antimicrobial and an excellent nerve tonic (Behra et al. 2001).
Jeannot et al. (2007) give a similar list of constituents; they also note an α-terpineol content of up to 8.7 per cent and terpinen-4-ol at up to 3.6 per cent. This is similar to the figures given by Price and Price (1997) for Ravensara aromatica essential oil. Its therapeutic properties have been described in relation to its constituents. It is indicated as an anti-inflammatory for bronchial asthma, and
is also a bronchodilator – it has been suggested that 1,8-cineole inhibits cytokine and prostaglandin production by stimulating monocytes in vitro (Juergens, Stöber and Vetter 1998, cited in Jeannot et al. 2007).
The aromatherapy literature does give indications for ravintsara, under the guise of ‘ravensara’. Price and Price (1997) highlight its anti-infectious applications – for glandular fever, bronchitis, flu, sinusitis and whooping cough. Here it is also cited as an antiviral, useful for chicken pox, dendrites, herpes zoster, viral enteritis and viral hepatitis. Schnaubelt (1995, 1999) suggests that it is a central nervous system tonic with uplifting qualities, making it a good choice in cases of flu. He also states that it is helpful for insomnia. Ravintsara can be used with the fixed oil of Calophylum inophyllum (also from Madagascar) to alleviate the pain of shingles.
For its uses according to Schnaubelt, see Table 8.23.
Table 8.23 Ravintsara essential oil (adapted from Schnaubelt 1995, 1999)
System Ravintsara with
Immune/Respiratory (viral infections) Asthma
Eucalyptus radiata (50:50 topical application over thorax, and inhalation) Inhalation, with lavender
Immune/Herpes zoster (shingles) 50:50 with tamanu fixed oil (Calophylum inophyllum) applied to lesions
Nervous (insomnia) Osmanthus absolute
Cinnamomum cassia – Chinese cassie (or cassia)
This essential oil is not used in aromatherapy because it is a strong dermal sensitizer and mucous membrane irritant. It contains very large amounts of cinnamaldehyde, in the region of 75–90 per cent (Tisserand and Balacs 1995).
Cinnamomum verum (zeylanicum) – cinnamon bark and leaf Two cinnamon oils are available – one from the inner bark and one from the leaves. The tree is native to wet tropical regions of Sri Lanka, India and Southeast Asia (Weiss 1997). Cinnamon bark oil is not used in aromatherapy as it is a dermal irritant, a strong dermal sensitizer and a mucous membrane irritant. This is mainly due to the eugenol content of up to 18 per cent and cinnamaldehyde content of up to 75 per cent (Tisserand and Balacs 1995).
Cinnamon leaf oil can be used in aromatherapy, although the suggested maximum concentration is 3 per cent. Tisserand and Balacs cite numerous oral contraindications related to the eugenol content. Eugenol is hepatotoxic and inhibits blood clotting. The leaf oil contains 70–90 per cent eugenol and traces
of safrole (<1%). Cinnamon leaf essential oil is a light yellow/brownish, mobile liquid with a somewhat harsh, warm, spicy odour. It is used in perfumery and confectionary. Because of its eugenol content, cinnamon leaf oil is rubefacient and antimicrobial. In aromatherapy, Lawless (1995) suggests that it can be used to improve circulation, aid the digestive system, support the immune system and ease conditions such as debility and stress. See Table 8.24 for some uses of cinnamon leaf oil in aromatherapy.
Table 8.24 Cinnamon leaf essential oil in aromatherapy
System Cinnamon leaf with
Cardiovascular (poor peripheral circulation)
Musculoskeletal (aches and pains, rheumatism)
Lavender, nutmeg, lemongrass, citrus oils, e.g. grapefruit, lemon
Digestive Coriander seed, cardamom, palmarosa,
sweet orange, mandarin, lime Nervous/Immune (debility, stress-related
conditions, susceptibility to infection)
Lavender, lemon, bay laurel, ravintsara, rosewood, ylang ylang, lime