143 Mosad Ahmed Ghareeb. et al. / International Journal of Phytopharmacology, 5(2), 2014, 143-157. e- ISSN 0975 – 9328 Print ISSN 2229 – 7472 International Journal of Phytopharmacology Journal homepage: www.onlineijp.com ANTIOXIDANT AND CYTOTOXIC ACTIVITIES OF TECTONA GRANDIS LINN. LEAVES Mosad Ahmed Ghareeb 1* , Hussein Ahmed Shoeb 1 , Hassan Mohamed Fawzy Madkour 2 , Laila Abdel-Ghany Refaey 1 , Mona Abdel-Motagaly Mohamed 1 , Amal Mohamed Saad 1 1 Laboratory of Medicinal Chemistry, Theodor Bilharz Research Institute, Giza, Egypt. 2 Department of Chemistry, Faculty of Science, Ain-Shams University, Cairo, Egypt. ABSTRACT Cancer prevention and treatment have attracted increasing interest. Leaves of Tectona grandis Linn. (Verbenaceae) are widely used in the folklore to treat various types of diseases. This study characterizes the antioxidant activity, total phenolic content (TPC) and cytotoxic activity of different methanolic extracts as well as the derived subfractions (Pet. ether; CHCl 3 , EtOAc and n-BuOH) from the 90% methanolic extract of T. grandis. The antioxidant activity was evaluated via three assays; 1,1'-diphenyl-2-picraylhydrazyl free radical (DPPH), phosphomolybdenum method (total antioxidant capacity; TAC and reducing power antioxidant assay (RPAA). Due to the high antioxidant activity of the tested fractions, their cytotoxic activity was evaluated via using preliminary brine shrimp lethality test and toward liver cancer cell line; HepG2 using Sulphorhodamine-B assay. The DPPH activity was ranged from (15.78, 10.63 and 19.58 μg/ml); TAC was ranged from (477.58, 589.50 and 400.30; mg AAE /g extract); RPAA (OD value) was ranged from (0.699, 0.783 and 0.423; 200 mg/ml) and TPC was ranged from (208.32, 400.56 and 295.67; mg GAE/g extract) all respectively for defatted 90% methanol, n- BuOH and EtOAc fractions. A positive linear relationship existed between antioxidant activity and TPC (all R 2 values > 0.91). The mortality of brine shrimp larvae (LC 50 ) against different dosage of defatted 90% methanol, n-BuOH and EtOAc respectively was (100, 15.84 and 125.89). The HepG2 results showed that defatted 90% MeOH and n-BuOH fractions have cytotoxic activity with IC 50 ≤ 20μg/ml which falls within the American Cancer Institute criteria. It was concluded that T. grandis extracts possess a powerful antioxidant and cytotoxic activities. Key words: Tectona grandis, Antioxidant activity, Cytotoxic activity, Total phenolic content. INTRODUCTION Free radicals are highly reactive unstable chemical compounds, containing an unpaired electron; the presence of unpaired electrons usually confers a considerable degree of reactivity cause damage to other molecules by extracting electrons from them in order to reach a stable form (Lee et al., 2003; Valko et al., 2007). These reactive species can be classified into; reactive oxygen species (ROS) namely (oxygen-centered radicals) such as superoxide anion (O2 •- ), hydroxyl (HO • ), alkoxyl (RO • ) and peroxyl (ROO • ) radicals or reactive nitrogen Corresponding Author Mosad Ahmed Ghareeb Email: mosad_tbri@hotmail.com species (RNS which include agents like peroxynitrite anion (ONOO - ) and nitric oxide (NO • ) radical, among other; in addition, there are non-free radical species (oxygen-centered nonradical derivatives) such as hydrogen peroxide (H 2 O 2 ), singlet oxygen 1 O 2 (O-O:), nitric oxide (NO) and hypochlorous acid (HClO) (Golden et al., 2002). The continuous production of such species in human body due to exposure to exogenous oxidizing agents from environmental pollutants (cigarette smoke, pesticides and UV radiation), life style and to endogenous ones produced by metabolism, lead to harmful destructive changes in structures of all human cells and tissues including; cellular membranes, nucleotides in DNA and critical sulfhydryl bonds in proteins, these all aspects are consider as an introduction to the up normal cell growth and finally leading to cancer (Machlin and Bendich, IJP