Interest in the olive leaf and its chemical constituents has recently been increasing. Its benefits, however, have been known for centuries, and it has been traditionally used to prevent and treat diseases. The main constituent of the olive leaves is oleuropeine one of iridoide monoterpenes, which is thought to be responsible for pharmacological effects. Furthermore, the olive leaves contain triterpenes including oleanolic and maslinic acid, flavonoides (luteolin, apigenine, rutin...), and chalcones (olivin, olivin-diglucoside). Its chemical content makes olive leaf one of the most potent natural antioxidant. Olive leaf is used to enhance the immune system, as an antimicrobial and in heart disease. Folk medicine uses also include hypertonia, arteriosclerosis, rheumatism, gout, diabetes mellitus, and fever. Recently, experimental animal studies have demonstrated hypoglycemic, hypotensive, antiarrhythmic, and vasodilator effects, as well as spasmolytic effect on the intestinal smooth muscle. Antibacterial, antiviral and antiinflammatory activity were also confirmed. The beneficial properties of olive leaf are further enhanced by the bioavailability of its polyphenolic constituents, which are readily absorbed through the gastrointestinal tract, resulting in significant levels in the circulation. Clinical studies to confirm experimental results are needed

Despite progress in conventional pharmacology in producing effective drugs, the plant kingdom might provide a useful source of new anti-ulcer compounds for development pharmaceutical entities or, alternatively, as simple dietary adjuncts to existing therapies. Botanical compounds with anti-ulcer activity include flavonoids(i.e.quercetin, naringin, silymarin, anthocyanosides, sophoradin derivatives) saponins (i.e. from Panax japonicus and Kochia scoparia), tannins (i.e. from Linderae umbellatae), gums and mucilages (i.e. gum guar and myrrh). This article reviews the gastro-protective and anti-ulcer properties of the most commonly employed herbal medicines and their identified active constituents. Among herbal drugs, liquorice, aloe gel and capsicum (chilli) have been used extensively and their clinical efficacy documented, but тhe documented literature has centred primarily on pharmacological action in experimental animals.