Oregano or (Origanum vulgare) is a species of Origanum, native to Europe, the Mediterranean region and southern and central Asia. It is a perennial herb, growing to 20-80 cm tall, with opposite leaves 1-4 cm long. The flowers are purple, 3-4 mm long, produced in erect spikes. Its name derives from the Greek origanon oros "mountain" + the verb ganousthai "delight in". Oregano (seed) is also known as Ajwain (اجوائن) in Urdu.

Uses

Oregano is often used in tomato sauces, fried vegetables and grilled meat. Together with basil, it contributes much to the distinctive character of many Italian dishes.

Oregano combines nicely with pickled olives, capers, and lovage leaves. Unlike most Italian herbs,Fact: date=July 2007 oregano works with hot and spicy food, which is popular in southern Italy.

Oregano is an indispensable ingredient for Greek cuisine. Oregano adds flavour to Greek salad and is usually used separately or added to the lemon-olive oil sauce that accompanies many fish or meat barbecues and some casseroles.

The related species Origanum onites (Greece, Asia Minor) and O. heracleoticum (Italy, Balkan peninsula, West Asia) have similar flavours. A closely related plant is marjoram from Asia Minor, which, however, differs significantly in taste, because phenolic compounds are missing in its essential oil. Some breeds show a flavour intermediate between oregano and marjoram.

Pizza

The dish most commonly associated with oregano is pizza. Its variations have probably been eaten in Southern Italy for centuries. Oregano became popular in the US when returning WWII soldiers brought back with them a taste for the “pizza herb”.

Health benefits

Oregano is high in antioxidant activity, due to a high content of phenolic acids and flavonoids. Additionally, oregano has demonstrated antimicrobial activity against food-borne pathogens such as Listeria monocytogenes. Both of these characteristics may be useful in both health and food preservation. In the Philippines, oregano (Coleus aromaticus) is not commonly used for cooking but is rather considered as a primarily medicinal plant, useful for relieving children's coughs.

Main constituents include carvacrol, thymol, limonene, pinene, ocimene, and caryophyllene. The leaves and flowering stems are strongly antiseptic, antispasmodic, carminative, cholagogue, diaphoretic, emmenagogue, expectorant, stimulant, stomachic and mildly tonic. Oregano is taken by mouth for the treatment of colds, influenza, mild fevers, indigestion, stomach upsets and painful menstruation. It is strongly sedative and should not be taken in large doses, though mild teas have a soothing effect and aid restful sleep. Used topically, oregano is one of the best herbal antiseptics because of its high thymol content