African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5210

Full Length Research Paper

Antioxidant and anti-listerial activities of selected Egyptian medicinal plants

  Riham O. Bakr1, El-Sayed A. Omer2, Khaled A. Abd EL-Razik3*, Azza S. M. Abu elnaga4, Enas N. Danial5,6 and Abd El-Naser G. Elgindy2
  1Department of Pharmacognosy, Faculty of Pharmacy, October University For ModernSciences and Arts (MSA), Egypt. 2Department of Medicinal and Aromatic Plants, National Research Center (NRC), Dokki, Giza, Egypt. 3Animal Reproduction Department, National Research Center (NRC), Dokki, Giza, Egypt. 4Department of Microbiology, National Research Center (NRC), Dokki, Giza, Egypt. 5Department of Biochemistry, Faculty of Girls Science, King Abdulaziz University, Jeddah, Saudi Arabia. 6Department of Chemistry of Natural and Microbial Products, National Research Center (NRC), Dokki, Giza, Egypt.
Email: [email protected]

  •  Accepted: 25 June 2013
  •  Published: 13 September 2013

Abstract

 

This work investigates the phenolic, antioxidant capacity of crude extracts of eight Egyptian medicinal plants (Syrian oregano, marjoram, rosemary, lemongrass, thyme, yarrow, marigold and sweet wormwood) and estimates their activity against Listeria monocytogenes, one of the most virulent food borne pathogens. Antioxidant activity of Rosemary (70.6±1.65%) and thyme (70.8±1.72%) based on TBA assay was significantly higher compared to other plants and ascorbic acid. Rosemary was found to possess the best antilisterial activity with lowest MBC (8 µl/ml); while its total phenolic content (TPC) represented 69.73 ± 0.47 mg/g GAE. Thyme showed MBC of 46 µl/ml with TPC 96.85±0.56 mg/g GAE. Lemon grass and marigold showed considerable antilisterial activity (MBC 31, 46 µl/ml respectively), although they had lower phenolic contents and low thiobarbituric acid inhibition. Sweet wormwood, marjoram and yarrow were inactive against listeria. Rosemary and thyme appeared as possible alternatives for synthetic food additives and preservatives.

 

Key words: Medicinal plants, anti-listerial, antioxidant, rosemary, thyme.