Solaray Olive Leaf (Olea Europa) 400 mg. For the last 4,000 years, people in mediterranean countries have used Olive Leaves as a supplement to their diets. Olive is a small evergreen tree native to Mediterranean regions. The characteristic green to blue-black fruit of this tree yields a useful, edible oil. Both the oil and the dried green-grayish colored leaves are used medicinally. Historical or traditional use (may or may not be supported by scientific studies)The olive tree has been held in high esteem throughout history. Moses reportedly decreed that men who cultivated the leaf be exempt from serving in the army. The oil is symbolic of purity and goodness, while the olive branch represents peace and prosperity. Winners in the Greek Olympic games were crowned with a wreath of olive leaves. Historically, medicinal use of olive leaf has been for treatment of fevers and for the topical treatment of wounds or infection. As a poultice, it was also used by herbalists to treat skin rashes and boils. Active ConstituentsOlive leaf has a wide number of constituents, including oleuropein and several types of flavonoids (e.g., rutin, apigenin, luteolin). While olive leaf is traditionally associated with a wide number of medicinal claims, few of these have been verified by experimental study. In an animal study oleuropein (when given by injection or in intravenous form) was found to decrease blood pressure (e.g., systolic and diastolic) and dilate the coronary arteries surrounding the heart. This ability to lower blood pressure may justify the traditional use of olive leaf in the treatment of mild to moderate hypertension. However, human studies are needed to clearly establish olive leaf as a potential treatment for high blood pressure. In addition, a test tube study has revealed that oleuropein inhibits the oxidation of LDL ("bad") cholesterol. LDL oxidation is one part in a series of damaging events that, if left unchecked, can lead to the development of atherosclerosis.