~ 89 ~ Journal of Pharmacognosy and Phytochemistry 2013; 2 (3): 89-94 ISSN 2278-4136 ISSN 2349-8234 JPP 2013; 2 (3): 89-94 © 2013 AkiNik Publications Received: 29-7-2013 Accepted: 13-8-2013 Hamdoon A. Mohammed Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt. Salmin K. Alshalmani Department of Pharmacognosy, Faculty of Pharmacy-University of Benghazi. Awad Giumma Abdellatif Department of Pharmacology, Faculty of Medicine- University of Benghazi. Antioxidant and Quantitative Estimation of Phenolic and Flavonoids of Three Halophytic Plants Growing in Libya Hamdoon A. Mohammed, Salmin K. Alshalmani and Awad Giumma Abdellatif ABSTRACT Halophytic plants are more susceptible for oxidative stress and damage due to high contents of salt and minerals inside these plants. Therefore, self defence against this oxidative stress appeared in the high phenolics particularly, flavonoids content are abundant in these plants. Mesembryanthemum crystallinum, Limoniastrum guyonianum and Anabasis articulate are three of halophytic plants growing in Mediterranean coast of Libya and most of North African countries, were taken as example for estimating the phenolic and flavonoids contents as well as antioxidant evaluation in order to understanding the effect of habitat of these plant imitation on the by-products production. Our present work suggested that, there are high relations between the qualitative and quantitative constituent of these halophytic plants which growing near to each other in the same environment. Keywords: Antioxidant activity; Phytochemical screening; Mesembryanthemum crystalline; Limoniastrum guyonianum; Anabasis articulate. 1. Introduction Oxidation is the transfer of electrons from one atom to another [1] . It represents an essential part of our metabolism and aerobic life in general, since oxygen is the ultimate electron acceptor in the electron flow systems that transport energy in the form of ATP [2] . Problems may arise however when the electron flow generates free radicals, such as O 2 -centred free radicals, known as reactive oxygen species (ROS), and including superoxide (O 2 ¯), peroxyl (ROO˙), Correspondence: Hamdoon A. Mohammed Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt. E-Mail: hamdoonhmdn@gmail.com, Tel: 00218916341356 alkoxyl (RO˙), hydroxyl (HO˙) and nitric oxide (NO˙) radicals [3] . ROS may be very damaging, since they can attack lipids in cell membranes, proteins in tissues or enzymes, carbohydrates and DNA to induce oxidative modifications, which cause membrane damage, loss of protein function and DNA damage [4] . This oxidative damage is considered to play a causative role in ageing and several degenerative diseases associated with it, such as heart disease, congestive dysfunction and cancer [5] . Humans have evolved antioxidant systems to protect against free radicals. These systems include some antioxidants produced in the body (endogenous antioxidants) and others obtained from the diet (exogenous antioxidants). Flavonoids are a group of naturally occurring polyphenolic compounds ubiquitously found in plants [6] . Flavonoids first appeared in green algae 500 million years ago, resulting from the fusion of two biogenetic pathways, namely the cinnamate and the ancient polyketide route and they have then become more and more complex with plant evolution [7] . flavonoids have long been recognized to possess anti-inflammatory, antioxidant, ant-allergic and hepato-protective properties. They are also believed to be antithrombotic, antibacterial, antifungal, antiviral, and cancer protective, and also to protect against cardiovascular disease [8-10] . Numerous publications have investigated the antioxidant activities of flavonoids and how they can contribute to the treatment of several diseases. Considering these publications, they indicate that biological and pharmacological effects of flavonoids may depend upon their behaviour as either antioxidants or as prooxidants [11] . Some flavonoids can behave as both antioxidants and prooxidants, depending on concentration and the redox environment present. For instance, certain flavonoids act as antioxidants against free radicals, yet demonstrate prooxidants activity when a transition metal such as Cu 2 +is present [12] .