Antimicrobial and lipid peroxidation inhibition potential of Ziziphus Spina-christi (Sedr), a Jordanian medicinal plant.

Background: Antimicrobial agents, specially antibiotics 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 Natural products such as plant extracts are emerging as possible replacement for the outdated antibiotics. Objective: The overall aims of this study were to evaluate the antimicrobial 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 antioxidant potential of the plant leaf extracts in linoleic acid model system. Methodology: Agar well diffusion and microtiter plate-based antibacterial assay incorporating resazurin as an indicator of cell growth were performed to determine the antimicrobial activities. Methanolic and ethanolic leaf extracts of Z.spina-christi were prepared and tested for their antioxidant activities against lipid peroxidation using ammonium thiocyanate method Results: Plant leaf extracts exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria. Gram-positive bacteria were found to be more susceptible to both extracts. However, no antifungal activity against C. albicans was detected for both extracts even at the highest working concentration of 70 mg/mL. Both extracts inhibited the peroxidation of linoleic acid significantly. Conclusion: Z. leaf extracts showed in vitro antimicrobial and antioxidant activities. Further purification of extracts and identification of the active component is necessary to enhance greater biological activities.