~ 242 ~  Journal of Pharmacognosy and Phytochemistry 2015; 4(4): 242-249 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2015; 4(4): 242-249 Received: 07-09-2015 Accepted: 10-10-2015 Mouna Kchaou Laboratory of Chemistry of Natural Substances, University of Sfax, Faculty of Sciences of Sfax, 3000, P.B“1171”, 3000, Sfax, Tunisia. Hichem Ben Salah Laboratory of Chemistry of Natural Substances, University of Sfax, Faculty of Sciences of Sfax, 3000, P.B“1171”, 3000, Sfax, Tunisia. Raed Abdennabi Laboratory of Plant Biotechnology Applied to Crop Improvement, Faculty of Science, Sfax University, BP 1171, 3000 Sfax, Tunisia Ameni Walha Laboratory of Chemistry of Natural Substances, University of Sfax, Faculty of Sciences of Sfax, 3000, P.B“1171”, 3000, Sfax, Tunisia. Noureddine Allouche Laboratory of Chemistry of Natural Substances, University of Sfax, Faculty of Sciences of Sfax, 3000, P.B“1171”, 3000, Sfax, Tunisia. Correspondence: Noureddine Allouche Laboratory of Chemistry of Natural Substances, University of Sfax, Faculty of Sciences of Sfax, 3000, P.B“1171”, 3000, Sfax, Tunisia. Antioxidant, antibacterial and antiacetylcholinesterase activities of Phalaris canariensis from Tunisia Mouna Kchaou, Hichem Ben Salah, Raed Abdennabi, Ameni Walha, Noureddine Allouche Abstract This study evaluates the antioxidant, antibacterial and antiacetylcholinesterase activities as well as phenolic contents of various extracts from Phalaris canariensis. The results showed that the methanol extract is endowed with the highest antiacetylcholinesterase activity (PI = 65.0%) and the best radical scavenging property with IC50=0.12 mg/mL. Meanwhile, this extract was found to have the highest phenolic content (190.58 mg gallic acid equivalents/g extract). Moreover, the ethyl acetate extract exhibited the best reducing power effect and the highest total antioxidant capacity (330.9 mg vitamin E/mg extract). In addition, the best antibacterial effect was observed for the methanolic extract against Micrococcus luteus. It was noticed that the extents of antiacetylcholinesterase, antibacterial and antioxidant activities of Phalaris canariensis extracts are in accordance with their phenolic compounds. Keywords: Phalaris canariensis, antioxidant, antibacterial, antiacetylcholinesterase, polyphenols, flavonoids. Introduction Medicinal plants are good sources of active natural products that differ widely in terms of structure and biological properties, so they can be used for various applications, especially as food additives and health promoting ingredients. For the reason, during last few decades, they have been become a subject for study of bioactive compounds [1] . Many of these plants and their products are also excellent sources for phytochemicals and have been found to possess a variety of biological activities including antioxidant, antibacterial and antiacetylcholinesterase activities [2] . However, the oxidative stress which involves the production of reactive oxygen species (ROS), is the basis for chronic diseases and aging is being reexamined. Accumulating evidence suggests that ROS exert essential metabolic functions and that removal of too many ROS can upset cell signaling pathways and actually increase the risk of chronic disease [3] . In recent decades, there has been growing interest in finding natural antioxidants in plants because they inhibit oxidative damage and may consequently prevent aging and neurodegenerative diseases [4] . Antioxidants are widely used in the food industry as potential inhibitors of lipid peroxidation [5] . However, many synthetic antioxidants used in foods, such as butylated hydroxyanisole and butylated hydroxytoluene, may be accumulated in the body resulting in liver damage and carcinogenesis [6] . For this reason, more attention has been paid to natural non-toxic antioxidants in an effort to protect the human body from free radicals and retard the progress of many chronic diseases. Neurodegenerative diseases are nowadays also one of the major concerns due to the increase in life expectations. Among these include Parkinson's disease (PD), Huntington's disease (HD) and Alzheimer's disease (AD). Alzheimer’s disease (AD) is a devastating neurological disorder characterized by a profound degradation of cognitive function and a progressive loss of memory [7] . Medical researchers have generally confirmed that the loss of acetylcholine in brain ultimately leads to the appearance of AD [8] . One of the most promising approaches for treating this latter disease is to improve the acetylcholine level in the brain using acetylcholinesterase (AChE) inhibitors [9] . Inhibition of acetylcholinesterase (AChE), the key enzyme in the breakdown of Acetylcholine (ACh), is considered to be a promising for the treatment of Alzheimer's disease (AD). However, only tacrine, donepezil and rivastigmine were used for treatment of AD and have been approved by the food and drug administration in the United States [10] , but this synthetically drugs have been reported to cause problems associated with bioavailability and gastrointestinal disturbances [11] . Therefore, the search for new AChE inhibitors, particularly from natural products, with higher efficacy continues.