مضادات الميكروبات ومثبطات بيروكسيد الدهون في نبات Ziziphus Spina-christi (Sedr) ، وهو نبات طبي أردني.

Background and Objective: Anti-microbial agents, specially anti-biotics are becoming less potent against microbial infections due to the development of resistance. The need to find new agents never been more pressing. Natural products such as plant extracts are emerging as possible replacement for the outdated anti-biotics. The overall aims of this study were to evaluate the anti-microbial activities of crude methanolic and ethanolic leaf extracts of Ziziphus spina-christi (sedr), collected from Jordan Valley, against Gram-negative bacteria represented by E. coli and P. aeruginosa, Gram-positive bacteria represented by S. aureus and yeast represented by C. albicans and to assess the lipid anti-oxidant potential of the plant leaf extracts in linoleic acid model system. Materials and Methods: Methanolic and ethanolic leaf extracts of Z. spina-christi were prepared and tested for their anti-oxidant activities against lipid peroxidation using ammonium thiocyanate method. Agar well diffusion and microtiter plate-based anti-bacterial assay incorporating resazurin as an indicator of cell growth were performed to determine the anti-microbial activities. Results: Plant leaf extracts exhibited anti-bacterial activity against both Gram-positive and Gram-negative bacteria. Gram-positive bacteria were found to be more susceptible to both extracts. However, no anti-fungal activity against C. albicans was detected for both extracts even at the highest working concentration of 70 mg mL?1. Both extracts inhibited the peroxidation of linoleic acid significantly. Conclusion: Ziziphus leaf extracts showed in vitro anti-microbial and anti-oxidant activities. Further purification of extracts and identification of the active component is necessary to enhance greater biological activities.