*Corresponding Author Address: Hassan Rammal, Doctoral School of Science and Technology, Research Platform for Environmental Science (PRASE), Faculty of Sciences, Lebanese University, Lebanon; E-mail: hasanrammal@hotmail.com World Journal of Pharmaceutical Sciences ISSN (Print): 2321-3310; ISSN (Online): 2321-3086 Published by Atom and Cell Publishers © All Rights Reserved Available online at: http://www.wjpsonline.org/ Original Article The antioxidant and anti-tumor activities of the Lebanese Centranthus Longiflorus L. Rawan Makki 1 , Hassan Rammal 1,2 *, Hussein Farhan 1 , Mohamad Nasser 1 , Zeinab El Dirani 1 , Akram Hijazi 1 , Bassam Badran 1 1 Doctoral School of Science and Technology, Research Platform for Environmental Science (PRASE), Faculty of Sciences, Lebanese University, Lebanon 2 Faculty of Agriculture and Veterinary Science, Lebanese University, Lebanon Received: 10-01-2015 / Revised: 28-01-2015 / Accepted: 30-01-2015 ABSTRACT This study aimed to examine both the impact of growth period on the chemical composition and the in vitro anti-oxidant and anti-proliferative properties for Centranthus longiflorus. Aqueous and ethanolic extracts from leaves and stems, collected from two harvests, were tested to diagnose their different secondary metabolites content. This was conducted through classical phytochemical screening tests. In addition, a test for their antioxidant (DPPH and H 2 O 2 radical scavenging) and for cell viability (Neutral red assay on HeLa cells), were conducted. The results have shown that both aqueous and ethanolic extracts from the different parts of the two C. longiflorus harvests contain alkaloid, coumarin, saponin, flavonoid, polyphenols, volatile oils and reducing sugars in different concentrations. Moreover, an antioxidant activity was observed by this plant where it inhibited the viability of HeLa cell line in a time-dependent (0–72 h) and dose-dependent (0–250 μM) manner. As such, the in vitro anti-oxidant and antiproliferative effects that were revealed from the two harvests of C. longiflorus reflect the significant potential use of this plant in the development of a new anti-cancer agent. Keywords: antioxidant activity, antiproliferative activity, Centranthus longiflorus, phytochemical screening INTRODUCTION Cancer is considered a leading cause of death worldwide, accounting for 8 million deaths in 2010 [1]. It is caused by numerous factors ranging from environmental factors to hereditary genetics. Current treatment of cancer can be done by surgery, chemotherapy, and radiation therapy [2-4]. In addition, there is widespread use of Complementary and Alternative Medicine (CAM) in developed countries [5, 6]. A recent study estimated the overall prevalence for the use of herbal products to be 13% to 63% among cancer patients [6]. In Canada, the investigators found that 67% of the respondents in a randomized survey reported using CAM [7]. Thus, many investigations are now being carried out to discover naturally occurring compounds that can be used to suppress or prevent the process of carcinogenesis [8, 9]. Lebanon is among the countries that are highly rich in medicinal plants in the Mediterranean region. In this study, we are interested in a Lebanese plant, Centranthus longiflorus L., an endemic plant to the Mediterranean (Lebanon, Syria, Turkey, Italy and Palestine). It is known as red valerian. In the literature, there is no study on the phytochemical screening, antioxidant and anti-tumor activities of this plant. For that, our study aimed, for the first time, to determine the phytochemical screening for aqueous and ethanolic extracts of two harvest periods of C. longiflorus leaves and stems, and to evaluate their antioxidant capacity using two in vitro tests, hydrogen peroxide radical and DPPH radicals and also to determine their anti- proliferative activity against cervical cancer cell line (HeLa) by using neutral red cytotoxicity assay. MATERIALS AND METHODS Plant Material: C. longiflorus plant was collected from Mount Lebanon during 2013. The collection process covered two different periods, the first was on May (premature plant) and the second was on June (mature plant). Preparation of Extracts: C. longiflorus leaves and stems were placed in the selected solvent (100 g of each part of the plant in 500 mL of distilled water or ethanol) after being well washed and divided into small pieces. Then, the paste was macerated