International Journal of Pharmacy and Medical Sciences 5 (2): 54-60, 2015 ISSN 2222-5854 © IDOSI Publications, 2015 DOI: 10.5829/idosi.ijpms.2015.5.2.1118 Corresponding Author: Dr. Idress Hamad Attitalla, Department of Microbiology, Faculty of Science, Omar Al-Mukhtar University, P.O. Box: 919, Al-Bayda, Libya. E-mail: idressattitalla2004@yahoo.com. 54 Antibacterial Screening of Essential Oil from Seeds of Nigella sativa and Nigella orientalis Idress Hamad Attitalla, Ilham O.A. Abdraba and Marei A. Altayar 1 2 3 Department of Microbiology, Faculty of Science, Omar Al-Mukhtar University, Al-Bayda, Libya 1 Department of Microbiology and Immunology, Faculty of Medicine, 2 Omar Al-Mukhtar University, P.O. Box: 919, Al-Bayda, Libya Department of Medical Microbiology and Parasitology, 3 Faculty of Medicine, Benghazi University, Benghazi, Libya Abstract: The antioxidant activity of essential oil extracted from the dry seeds of Nigella sativa and Nigella orientalis were evaluated by the scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and the reducing power assay, total phenolic and flavonoids are also detected. The essential oil extracted from Nigella sativa and Nigella orientalis were screened for antimicrobial activities against some pathogens viz., Escherichia coli, Pseudomonas aeruginosa Staphylococcus aureus, Acinetobacter sp. and Klebsiella pneumonia. The result obtained from the in vitro antioxidant screened showed that oils from Nigella sativa and Nigella orientalis have considerable amounts of polyphenolic and flavonoids compounds which are responsible for the antioxidant properties. And also they give the higher reductive potential due to reducing capacity and DPPH free radical scavenging activity which serves as strong indicator of antioxidant activities. The essential oils from Nigella sativa and Nigella orientalis were found to produce significant inhibition against all the pathogens. In conclusion, the present study suggests that oil extracted from Nigella sativa and Nigella orientalis have potential activity as source of natural antioxidant. Key words: Nigella sativa Nigella orientalis Antioxidant activity DPPH Free radical and Antibacterial INTRODUCTION induced by either disease or chemicals [1]. It would Nigella sativa (NS) and Nigella Orientalis (NO) has thymoquinone might be related to their cytoprotective been used as a natural healing aid for thousands of years and antioxidant actions and to their effect on some by various cultures and civilizations around the world, as mediator of inflammation [5]. well as a supplement to help maintaining good health. El-Kadi and Kandil [6] investigated the effect of NS It is most famous for the saying of the holy prophet on immune system and reported that the administration of Muhammad P.B.U.H. "Hold on to use of the Black seed, 1 g twice daily in human volunteers enhanced immune for it has a remedy for every illness except death." The functions as manifested by improve helper T cells and word "hold on to" indicates a long term use. The seeds of natural killer cell activity. However, Fararh [7] NS (Ranunculaceae) are commonly used in folk (herbal) demonstrated that NS seeds and its purified proteins medicine all over the world for treatment and prevention enhanced the production of interleukin-3 by human of a number of skin diseases and conditions [1, 2]. lymphocytes and have an effect on macrophages as well. The seeds contain both fixed and essential oils, proteins, In other study Hanafi [8] observed that NS promote alkaloids and saponins [3, 4]. Much of the biological stimulatory and suppressive effects depending upon activities of the seeds have been shown to be due to the the donor and concentration used. In the same root of thymoquinone, in which the major component of the study, it was reported that the ethanolic extract of NS essential oils and volatile oil, that have been reported has been shown to potentiate cellular immune responses include protection against neuro and hepatotoxicity [9]. appear that the beneficial effects of the use of seeds and