Olive Leaf

Olea europea

Olive is a small evergreen tree native to Mediterranean regions. The tree has distinctive silver-green leaves. The fleshy, eliptical fruit of the olive tree yields a widely popular and nutritious edible oil that has also been used traditionally for healing. Both the oil and the dried leaves are employed medicinally. (1,2)

The olive tree has been revered throughout history. The early Greeks and Romans utilized olive to maintain good health. The the olive branch is a universal symbol of peace. Victors in the early Olympic games were crowned with a wreath of olive leaves. 1,3

Olive leaf has been used in folk medicine to treat constipation, diabetes, hypertension, obesity, rheumatism, and excess water retention, fevers, (2,3) and for the topical treatment of wounds or infection. 4

Phytochemicals and Activities

Olive leaf has a wide number of constituents, including oleuropein and several types of flavonoids including rutin, apigenin and luteolin. The leaf also contains choline, and the antimalarials cinchonidine and cinchonine. 4, 5

In one animal study oleuropein given by injection decreased blood pressure and dilated the coronary arteries surrounding the heart. 6 This blood pressure lowering activity may support the traditional use of olive leaf for mild to moderate hypertension. 7

An In vitro study showed that oleuropein inhibits the oxidation of LDL cholesterol. LDL oxidation can lead to the development of atherosclerosis. Olive leaf extract offers beneficial antioxidant activity to humans. 7

Oleuropein from olives may also have antibacterial properties. When unheated olives are brined to preserve them, oleuropein is converted into another chemical called elenolic acid. Elenolic acid has shown antibacterial actions against several species of Lactobacilli and Staphylococcus aureus and Bacillus subtilus in a test tube study. 8

Olive leaf extracts have been employed experimentally to lower elevated blood-sugar levels in animals with diabetes. But these results have not been reproduced in human clinical trials, thus no conclusions can be made regarding the treatment of human diabetes. 3

References

1. Hmamouchi, Mohamed, Les Plantes Medicinales Et Aromatiques Marocaines CNCPRST Morocco 1999.

2. Bellakhdar, Jamal, Plantes Medicinales au Maghreb at soins de base Editions Le Fennec, Morocco.

3. Sijelmassi, Abdelhai Les Plantes Medicinales du Maroc, Editions Le Fennec, Morocco 2005.

4. Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris, France: Technique & Documentation-Lavoisier, 1995, 487–9.

5. Dr Duke’s Phytochemical and Ethnobotanical Databases: http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl

6. Petkov V, Manolov P. Pharmacological analysis of the iridoid oleuropein. Arzneim Forsch/Drug Research 1972;22:1476–86.

7. Visioli F, Galli C. Oleuropein protects low density lipoprotein from oxidation. Life Sciences 1994;55:1965–71.

8. Fleming HP, Walter WM, Etchells JL. Antimicrobial properties of oleuropein and products of its hydrolysis from green olives. Applied Microbiol 1973;26:777–82.