The Olive (Olea europea L.) is an evergreen shrub or tree from the same family as olives (Oleaceae). The tree is branched and grows up to 10 meters in height, forming an irregular, knotty trunk with many branches and a wide, asymmetrical crown. The root is spindle-shaped, branched, and very developed. The bark is initially smooth and greyish but later becomes rough and cracks into dark scales. The buds are covered with greyish hairs. The leaves are opposite, evergreen, leathery, elongated, 3-10 cm long, and up to 2 cm wide, with a whole edge, pointed tip, silver-grey on the back, located on short petioles. The flowers are bisexual, monoecious, regular, small, and pleasant-smelling, gathered in loose panicle inflorescences and grow from the axils of the leaves. The perianth is double, consisting of a calyx and corolla. The calyx is made up of four lobes, and the corolla has four white petals.
It blooms in April and May. The ovary is superior and carries two seed embryos. Bees visit the flowers and collect pollen. The fruit is a fleshy, oval drupe, 1-3 cm long and up to 2 cm wide. Initially green, it becomes dark blue, black, or brownish-green when ripe. It ripens in September and October.
Olive trees grow wild in the Mediterranean region and are cultivated in Mediterranean countries and in regions with a similar climate in the USA.
TAXONOMY
KINGDOM: Plantae
ORDER: Lamiales
FAMILY: Oleaceae
GENUS: Olea
SPECIES: Olea europaea
COMMON NAME
Common olive, European Olive, Lady’s Oil, Sweet Oil Plant
FLOWERING TIME
IV – V month
Use for medicinal purposes
The leaves and fruits of the Olive (Olea europea L.) are used, both of which have a bitter taste. The leaves are harvested throughout the year, and the fruits when they ripen in late autumn. The leaf is used to reduce high blood pressure, as a diuretic, and to reduce blood sugar. The leaves of wild trees are believed to contain a higher concentration of active principles.
The fruits are used for the production of olive oil and as food, but they have to be processed first. In the Mediterranean region, 90% of olives are used to make olive oil.
Constituents
Olive leaves:
- oleoeuropine
- cholesterol
- leine
Olive fruit:
- oleuropein
- hydroxytyrosol
- tyrosol
- oleanolic acid
- quercetin
Olive oil:
- oleic acid, approximately 75%
- monounsaturated fatty acid
Action and application
Olive leaves lower blood pressure and help improve the circulatory system. They are also mildly diuretic and may be used to treat conditions such as cystitis. Possessing some ability to lower blood sugar levels, the leaves have been taken for diabetes.
The oil has been traditionally taken with lemon juice in teaspoonful doses to treat gallstones. The oil has a generally protective action on the digestive tract and is useful for dry skin.
Olives are very high in vitamin E and other powerful antioxidants. Studies show that they are good for the heart and may protect against osteoporosis and cancer. Oleic acid is linked to several health benefits, including decreased inflammation and a reduced risk of heart disease.
Olives are particularly rich in antioxidants, including oleuropein, hydroxytyrosol, tyrosol, oleanolic acid, and quercetin. Dietary antioxidants have been shown to reduce risk of chronic illnesses, such as heart disease.
Reference:
- Olive https://www.plantea.com.hr/maslina
- Andrew Chevallier Mnihm: The encyclopedia of medicinal plants, Dorling Kindersley Limited, London, 1996. ISBN 0 7513 03143
