Oregano has been used for a number of medicinal purposes throughout the centuries. The ancient Greeks were among the first to take advantage of oregano's curative qualities, and made compresses from the leaves to treat sores and aching muscles. They also used it to treat poisonous insect bites, coughs and digestive problems; meanwhile, the Chinese used it to relieve fever.
A comprehensive description of oregano and its uses can be found in the book De Historia Plantarum of Theophrastus (third century B.C.) the "Father of Botany," and in the De Materia Medica of Dioscorides (first century B.C.) a renowned physician and pharmacologist of his times. Prior to both of these, Hippocrates used oregano for curing various ailments such as stomach pain and respiratory diseases. Paracelsus recommended oregano in the 16th century for the medication of diarrhea, psoriasis and fungal infections.
Oregano has been cultivated in France since the Middle Ages and came to be an important herb in Mediterranean cooking. Although oregano is recognized today by every lover of pizza, it was hardly known in the United States until the early 20th century. GIs returning from Italy brought word of this fragrant and delicious herb back home after the war.
Oregano contains several constituents, including volatile oil (up to 3 percent), such as carvacrol thymol and borneol, plus flavonoids, rosmarinic acid, triterpenoids (e.g. ursolic and oleanolic acid), sterols, vitamin A, vitamin C and niacin. It's the carvacrol and thymol (which are thought to work synergistically) that are responsible for oregano's antimicrobial and antifungal effects. Research has shown that oil of oregano, and carvacrol in particular, inhibits the growth of Candida Albicans far more effectively than calcium magnesium caprylate, a well-known and commonly used antifungal agent.
In addition to its anti-fungal action, and according to the results of another test tube study from Australia, oil of oregano has a strong anti-microbial action against a wide number of bacteria including E. coli, Klebsiella pneumoniae, Salmonella enterica, and Staphylococcus aureus. Other test tube studies have shown that oil of oregano is more effective than the prescription medication Tinidazol in inhibiting the parasite Giardia (Giardia lamblia).
n a further study, volatile oils of oregano, thyme, cinnamon, and cumin were each able to stop the growth of another food-borne pathogen called Aspergillus parasiticus. Higher concentrations of these volatile oils were also able to stop the production of a potent poison from Aspergillus called aflatoxin. This research all confirms that the volatile oils found in oregano operate as one of nature's finest preservatives, and have an important role in preventing the spoilage of food and in reducing the risk of ingesting harmful bacteria, fungi and parasites.