Phytochemical Screening and Antimicrobial Activity of Ziziphus mauritiana Lam. And Ziziphus mucronate Lam. Extracts

The objective of this study was to determine the phytochemical profile and antimicrobial activity of leaf and bark extracts of Ziziphus mauritiana and Ziziphus mucronata. For this purpose, an extraction by maceration using ethanol was carried out and the extracts were subjected to antibacterial activity assessment through qualitative and quantitative approaches. The qualitative tests were performed using agar well diffusion method while for quantitative tests minimal inhibitory, bactericidal and fungicidal concentration (MIC, MBC or MFC) were used determined through microdilution in microplates method. The antimicrobial mechanisms such as cell lysis and action on the proton pump of the extracts were also studied. The highest extraction yield was obtained with the Z. mauritiana leaf extract (28.8%). In addition, the highest contents of polyphenols (256.6 mg GEA/g DM) and flavonoids (165.2 mg CE/g DM) were obtained with the bark of Z. mucronata. The bark extracts of Z. mauritiana exhibited highest antibacterial activity (36.7 mm on Staphylococcus aureus) while, Z. mucronata extracts are more active on fungi, with the highest activity on Candida albicans (26.7 mm). The antimicrobial activity of the extract increases with the concentration and, regarding the MBC/MIC and MFC/MIC ratio, the extracts showed bacteriostatic activity on the different bacteria and fungi and the possible mechanism included an activity on the proton pump. The bark and leaf extracts of Z. mauritiana and Z. mucronata could be used in traditional medicine to treat infections due to these multiple pathogens.