Antioxidant activity, total phenolic content and flavonoid concentrations of different plant parts of Teucrium polium L. subsp. polium

Recently, there is growing interest in finding naturally occurring antioxidants for use in foods or medicinal materials to replace synthetic antioxidants, which are being restricted due to their carcinogenicity [1]. Antioxidants are secondary constituents or metabolites found naturally in plants. They are mainly phenolics serving in plant defense mechanisms to counteract reactive oxygen species (ROS) in order to avoid oxidative damage. Their antioxidant activity is related to their redox properties, ability to scavenge a variety of reactive species such as superoxide, hydroxyl and peroxyl radicals and hypochlorous acid, singlet oxygen quenching, metal ion chelation [2,3]. It was reported that the antioxidant activity of plant materials was well correlated with the content of their phenolic compounds [4]. Teucrium polium L. subsp. polium (Felty germander) – belongs to the family Lamiaceae Lindely, subfamily Ajugoideae Kostel and section Polium (Miller) Schreber. T. polium is a wild-growing perennial herbaceous flowering plant with little branched stems up to 40 cm high. Leaves are without or with very short petiole, oval-elongated and slightly incised. Flowers are white to light pink, densely clustered at the top of the branch. Inhabit rocky limestones and dry mountain meadows in the Mediterranean region and Middle East [5]. T. polium is best popular species of this genus in the folk medicine, very often used for tea and tonic preparing during treatment of appetite loss, gastrointestinal ailments and as a spice plant. Numerous in vitro and in vivo tests of biological activity prove antibacterial, antifungal, antiinflammatory, antiproliferative, apoptotic, antinociceptive, antihypertensive, hepatoprotective and hypoglycemic properties [6]. Extracts from T. polium potentiates the cytotoxic and apoptotic effects of anticancer drugs: vincristine, vinblastine and doxorubicin, against a panel of cancerous cell lines [7]. The therapeutic benefits of T. polium extracts are usually attributed to their ability to suppress oxidative processes [8]. Numerous investigations showed the antioxidant activity of T. polium extracts, it was reported that the alcoholic extract of T. polium had a suppressing effect on hydrogen peroxide-induced lipid peroxidation in red blood cells [9], the ability of water extract to suppress Fe2+-induced lipid peroxidation in rat liver homogenates [10]. The objective of this study was to examine the distribution of phenolic compounds, as the carriers of antioxidant activity, in different vegetative parts of the plant, and what are the most suitable solvents for the production of extracts that are rich in phenolic compounds from T. polium. Separate examination of plant parts allows a significant contribution to medicinal plant study and their pharmaceutical applications [11]. Twenty Abstract