en <span style="font-size:10pt"><span style="background:white"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span cambria="" style="font-family:"><span style="color:black">Aims:</span></span></b> <span cambria="" lang="EN" style="font-family:"><span style="color:black">This study aimed to determine the biological activity test of the alcoholic extract of the leaves of </span></span><i><span cambria="" style="font-family:">Catharanthus roseus</span></i><span cambria="" lang="EN" style="font-family:"><span style="color:black">. </span></span></span></span></span></span><br> <span style="font-size:10pt"><span style="background:white"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span cambria="" lang="EN" style="font-family:">Materials & Methods:</span></b> <i><span cambria="" style="font-family:">Catharanthus roseus</span></i><span cambria="" lang="EN" style="font-family:"> was used in the implementation of the experiment and it included three factors: the first factor is watering the plants with three concentrations of sodium chloride salt (0, 50, and 100mmol) of sodium chloride, the second factor is three concentrations of nitrogen (urea) (0, 100 and 200mg.L^-1) and the third factor three concentrations of selenium (Na₂SeO₄; 0,25 and 50mg.L^-1), then tested the biological activity of plant leaf extracts from all treatments against Gram-positive <i>Staphylococcus aureus</i> and Gram-negative <i>Escherichia coli</i> bacteria through Measure the diameters of the areas of inhibition of bacterial growth. </span></span></span></span></span><br> <span style="font-size:10pt"><span style="background:white"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span cambria="" lang="EN" style="font-family:">Findings:</span></b><span cambria="" lang="EN" style="font-family:"> The results of the laboratory experiment showed that the extract of the leaves of triple combination plants (100mmol NaCl+200mg.L^-1 N+50mg.L^-1 Se) achieved the largest inhibition area for the growth of <i>E. coli</i> reaching 27.50mm compared to the control, which is 4.20mm, and plant leaf extract in the combination (100mmol NaCl+100mg.L^-1 N+50mg.L^-1Se) recorded the largest inhibition area in <i>S. aureus</i> reached 50.27mm compared to the control which <span style="color:black">recorded 9.10mm. </span></span></span></span></span></span><br> <span style="font-size:10pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span cambria="" lang="EN" style="font-family:"><span style="color:black">Conclusion:</span></span></b><span cambria="" lang="EN" style="font-family:"><span style="color:black"> The</span></span><span cambria="" style="font-family:"> plant leaf extract had an important role in inhibiting the growth of the bacteria studied, and the highest inhibition was observed in the interaction between the three factors salt, nitrogen, and selenium.</span></span></span></span> Alcoholic,Catharanthus,Sodium Chloride,Nitrogen,Selenium,Gram-Negative Bacteria, 59 64 http://ijwph.daneshafarand.org/browse.php?a_code=A-10-1859-1&slc_lang=en&sid=3 S.A.H. Sadoon Al-Ajeel 1003194753284600378289 1003194753284600378289 No Faculty of Education for Girls, University of Kufa, Kufa, Iraq K.K.A. Hassan 1003194753284600378288 1003194753284600378288 Yes Faculty of Education for Girls, University of Kufa, Kufa, Iraq