Determination of chemical profile, antioxidant, DNA damage protection and antiamoebic activities of Teucrium polium and Stachys iberica Bektas Tepe a, ⁎, Serpil Degerli b , Serdal Arslan a , Erdogan Malatyali b , Cengiz Sarikurkcu c a Cumhuriyet University, Faculty of Science and Literature, Department of Molecular Biology and Genetics, TR-5814, Sivas, Turkey b Cumhuriyet University, School of Medicine, Department of Microbiology, TR-5814, Sivas, Turkey c Mugla University, Faculty of Science and Literature, Department of Chemistry, TR-48000, Mugla, Turkey article info abstract Article history: Received 29 July 2010 Accepted in revised form 28 September 2010 Available online 19 October 2010 This work deals with the evaluation of in vitro antioxidant, DNA preventing and antiamoebic activities of the water extracts of Teucrium polium and Stachys iberica. In all systems, T. polium extract exhibited excellent activity potential than that of S. iberica. The amount of total phenolics and flavonoids were high in this extract. In the presence of 40 mg/ml T. polium extract, a significant protection was observed for native super coiled DNA of pBR322 plasmid DNA. In the presence of 32 mg/ml of T. polium extract, no trophozoite was after the 24th hour. © 2010 Elsevier B.V. All rights reserved. Keywords: Teucrium polium Stachys iberica Antioxidant activity DNA damage protection Antiamoebic activity 1. Introduction Antioxidants are substances that when present in foods or body at low concentrations compared with that of an oxidizable substrate markedly delay or prevent the oxidation of that substrate. Antioxidants may help the body to protect itself against various types of oxidative damage caused by reactive oxygen species, which are linked to a variety of diseases including cancer, diabetes, shock, arthritis, and acceleration of the ageing process. Free radicals may also be involved in a number of diseases and tissue injuries [1]. Antioxidants may act by decreasing singlet oxygen concentration, intercepting singlet oxygen, preventing first chain initiation by scavenging initial radicals, binding metal ion catalysts, decomposing primary products to non-radical compounds, and chain- breaking to prevent continued hydrogen abstraction from substrates. In the last decade, it is recognized that the hydroxyl radicals derived from superoxide radicals and hydrogen peroxide is the most potent reactive oxygen radical which causes DNA damage by converting guanine into 8-hydroxyguanine [2]. In order to find new compounds to control oxidative DNA damage, which has been particularly implicated in carcinogenesis [3], the effects of extracts obtained from some medicinal and/or aromatic plants on DNA cleavage have been started to investigate. Antioxidants also provide protection against the hazard- ous effects of ultraviolet radiation. Ultraviolet radiation causes damage to the skin, which may result in both pre- cancerous and cancerous skin lesions and acceleration of skin ageing. Topical administration of enzymatic and non-enzy- matic antioxidants is an effective strategy for protecting the skin against UV-mediated oxidative damage. Amoebiasis is one of the major health problems in developing countries. An estimated 12% of the world's population harbor Entamoeba histolytica, and as a result amoebic dysentery is common in tropic and subtropic regions. The disease is generally associated with people living in areas of poor sanitation and socio-economic status than to the location and climate of countries. Poor life style, environmental conditions and the non-availability of guaranteed conventional medical cure are some complex etiological factors related to the disease [4,5]. Metronidazole is known to be highly effective Fitoterapia 82 (2011) 237–246 ⁎ Corresponding author. Tel.: + 90 505 840 85 77 (Mobile phone). E-mail address: bektastepe@yahoo.com (B. Tepe). 0367-326X/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.fitote.2010.10.006 Contents lists available at ScienceDirect Fitoterapia journal homepage: www.elsevier.com/locate/fitote A 17