The plant which was chosen in this study sidr (Ziziphus spina-christi (L.) Desf.) has several important medicinal properties, allelopathic, antioxidant, and antimicrobial effect was investigated. Sidr leaves extract were studied for their allelopathic effect on wheat, barley, cress, and fenugreek. Different concentrations (0%, 2.5%, 5.0%, 7.5%, and 10%) of sidr aqueous and methanolic extracts (70% methanol) were used in vitro, and their effect on germination and seedling growth were noted. Screening with phytochemicals revealed that the leaves of sidr contain certain active compounds, such as tannins, saponins and flavonoids.
The antioxidant activity of the crude extracts was determined using the 2,2-Di(4-tertoctylphenyl)-1-picryl-hydrazyl (DPPH) assay, and the results revealed that the water extract had a moderate antioxidant activity while the methanolic extract had the highest activity along with the ascorbic acid that was used as a standard.
Antimicrobial activity against the tested microorganisms (Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Acinetobacter baumannii and Candida albicans) at different concentrations(1.5, 3.125, 6.25, 12.5, 25, 50, and 100 mg/mL), using dilution method that showed different results for the most effective plant extracts, as well as their minimum inhibitory concentration (MIC) values were determined.