Leung's Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics

1. S. D. Sastry et al.,Phytochemistry, 11 ,
   453 (1972).


2. A. O. Tucker and S. S. Tucker,Econ. Bot.,
   42 , 214 (1988).


3. R. Baranauskiene et al.,J. Agric Food
   Chem., 51 , 3840 (2003).


4. M. E. Ibrahim and A. A. Ezz El-Din,
   Egypt. J. Hortic., 26 , 281 (1999).


5. F. Murai et al.,Chem. Pharm. Bull., 32 ,
   2809 (1984).


6. M. Tagawa and F. Murai,Planta Med., 47 ,
   109 (1983).


7. G. R. Waller et al.,Science, 164 , 1281
   (1969).


8. C. O. Mossoco et al.,Vet. Hum. Toxicol.,
   37 , 530 (1995).


9. A. Nostro et al., Int. J. Antimicrob.
   Agents, 18 , 583 (2001).


10. C. Bourrel et al.,J. Essent. Oil Res., 5 , 159
    (1993).


11. T. Eisner,Science, 146 , 1318 (1964).


12. C. J. Peterson and J. Ems-Wilson,J. Econ.
    Entomol., 96 , 1275 (2003).


13. C. J. Peterson et al.,J. Econ. Entomol., 95 ,
    377 (2002).


14. M. M. Bernardi et al.,Toxicon, 36 , 1261
    (1998).


15. K. C. Osterhoudt et al., Vet. Hum.
    Toxicol., 39 , 373 (1997).


16. M. A. Birkett and J. A. Pickett,
    Phytochemistry, 62 , 651 (2003).

CEDAR LEAF OIL

Source: Thuja occidentalis L. (Family
Cupressaceae).

Common/vernacular names:American arbor-
vitae, cedar leaf, eastern white cedar, northern
white cedar, thuja, and white cedar oils.

GENERAL DESCRIPTION

Thuja occidentalisis a small- to medium-size
tree belonging to the cypress family and grows
up to about 20 m high; native to northeastern
North America (Nova Scotia south to North
Carolina and west to Illinois). There are many
cultivated varieties. Parts used are the fresh
leaves and twigs, from which cedar leaf oil is
obtained by steam distillation. Major produ-
cers of the oil are Canada and the United
States.

CHEMICAL COMPOSITION

Contains mainly thujone, isothujone,l-fench-
one, borneol,l-bornyl acetate,dl-limonene,

d-sabinene,d-terpinen-4-ol, pinene, camphor,

myrcene, and l-a-thujene, among others,

with thujone in major concentration and

accounting for up to 65% (w/w) of the oil

(KARRER).1–5

PHARMACOLOGY AND BIOLOGICAL

ACTIVITIES

Oil is believed to have expectorant, uterine

stimulant, emmenagogue, anthelmintic, and

counterirritant properties.

Antiviral activity has been demonstrated

in vitro.^6 Leaf extract stimulates phagocytosis

(erythrocytes) through Kupffer’s cells in iso-

lated rat liver.^7

TOXICOLOGY

The oil is reported to be nontoxic when applied

externally.^4 Due to its high thujone content, the

oil is poisonous when ingested in large quanti-

ties, producing symptoms such as hypotension

and convulsions and eventually death (see

absinthium)(MERCK).

Cedar leaf oil 161