Bay

Botanical Description & Habitat

Laurus nobilis

Family
Lauraceae

Common Names

Bay laurel	Bay tree
Grecian laurel	Indian bay
Roman laurel	Sweet bay

Habitat
Grows wild and is cultivated near the Mediterranean Sea

Description
Bay is a small evergreen bush or tree. The stem has smooth, gray bark and grows up to 2 feet in height. The leaves are dark green and leathery, with a lighter underside; the upper surface is glossy, and the leaves are pointed at both ends. Whitish male and female flowers grow on different plants, appearing in clusters on the upper leaf axil during April and May.

The fruits are small berries ripening from a greenish hue to a glossy black, and they each contain a single seed.

Medicinal Parts
Flowers, leaves - dried, collected in summer

Historical Properties & Uses

Bay leaf contains a volatile oil accounting for most of its common uses. As a carminative, digestive aid, stomachic, stimulant, and aperitive, its applications are those of most aromatic herbs. It is applied as a liniment and ointment to treat rheumatism; it also has an astringent action, and has been used as a diuretic and cholagogue. Bay possesses proven antibiotic and sedative properties.

Method of Action

Bay leaf has good antibiotic properties
The oils of bay have shown antibiotic activity ranging from moderate to good.

Bay has also exhibited good antitubercular activity, even at dilutions of 1:160 to 1:320. Incubated at 37 degrees C. for seven days with the H37Rv strain of Mycobacterium tuberculosis, bay leaf extract inhibited growth at dilutions of 1:60-1:320. This makes it one of the best plants among those that have such activity.

Bay has sedative properties
A primary constituent of bay, methyl eugenol, has been shown to have sedative and narcotic properties. In mice, the effect is sedative at low doses, becoming narcotic at extremely high levels. The oil also helps prevent death and convulsions due to strychnine.

Drug Interactions & Precautions

Possible Interactions
The tannin in bay leaves may potentiate the antibiotic activity of echinacea. The tannin in tea made from may may be inactivated by the addition of milk or cream.

Comments
Due to the presence of eugenol, bay leaves may inhibit certain liver microsomal hydroxylating systems, thereby producing toxic effects from drugs which are normally metabolized by those systems.

Safety Factors & Toxicity

Bay is generally regarded as safe by the FDA, and possesses no known toxicity.

Contact dermatitis has been reported by sensitive individuals.

Preparation & Administration

Three times a day

Essential oil of leaf
0.05-0.2 ml, watch for contact dermatitis

Note: This Herbal Preparation information is a summary of data from books and articles by various authors. It is not intended to replace the advice or attention of health care professionals.

References

Am Hospital Formulary Service. Am Soc of Hosp Pharm. Wash, D.C.

Blacow, N.W. Martindale: The Extra Pharmacopoeia. The Pharmaceutical Press: London, England, 1973.

Bressler, R., M.D. Bogdonoff & G.J. Subak-Sharpe. 1981. The Physicians Drug Manual. Doubleday & Co, Inc. Garden City, NY. 1213 pp.

Fitzpatrick, F.K. Plant substances active against mycobacterium tuberculosis. Antibiotics And Chemotherapy, 4(5), 528-536, 1954.

Goodman, L.S. & A. Gilman. 1975. Pharm Basis of Thera. MacMillan, NY.

Hansten, P.D. 1979. Drug Interactions, 4th ed. Lea & Febiger, Phila.

Jaffe, H., et.al. 1968. In vivo inhibition of mouse liver microsomal hydroxylating systems by methylenedioxyphenyl insecticide synergists and related compounds. Life Sciences, 7. pp. 1051-1052.

Kastrup, E.K., ed. 1981. Drug Facts and Comparisons, 1982 edition. Facts and Comparisions Division, J.P. Lippincott Co, Phila(St. Louis).

List, P. & L. Hoerhammer. 1969-1976. Hagers Hanbuch der Pharmazeutischen Praxis, vols. 2-5. Springer-Verlag, Berlin.

Lust, John B. 1980. The Herb Book. Benedict, Lust Publications. CA.

Macgregor, J.T., et. al., J. Of Agri. And Food Chem., 22, 777, 1974.

Martin, E.W. 1978. Drug Interactions Index, 1978/79. J.B. Lippincott Company, Philadelphia.

Maruzzella, J.C. & Sircurella, N.A. Antibacterial activity of essential oil vapors. J Of The Am Pharm Assoc, 49(11), 692-694, 1960.

Maruzzela, J.C. & Lichtenstein, M.B. The in vitro antibacterial activity of oils. J. Of The Am. Pharm. Ass., 45(6), 378-381, 1956.

Mowrey, Daniel B., Ph.D. Exper. Psych., Brigham Young University. Director of Nebo Institute of Herbal Sciences. Director of Behavior Change Agent Training Institute. Director of Research, Nova Corp.

Nishikawa, H. Screening tests for antibiotic action of plant extracts. Japanese J Of Experimental Medicine, 20, 337-349, 1949.

Opdyke, D.L.J. Food Cosmetics And Toxicology, 13(Supplement), 713,, 1975.

Scientific Committee, British Herbal Pharmocopaeia, British Herbal Med Assoc, Lane House, Cowling, Na Keighley, West Yorks, Bd Bd220lx, l983

Thomas, C. L. 1985. Taber's Cyclopedic Medical Dictionary. F.A. Davis Co. Pub., Philadelphia. 2170 pp.

Vincent, D. & G. Segonzac. 1953. Comptes Rendus des Seances de la Societe de Biologie et de ses Filiales, 147. pp. 1776-1779.