Aqueous extract of Myrtus communis L.was mixed with 2 mM AgNO3 solution and heated at 70 °C for 3 min. The fresh suspension of aqueous M. communis was reddish brown in colour, after addition of 2mM AgNO3 and heated at 70 °C for 3 min, the suspension turned t o dark green. The UV-Vis spectral analysis showed silver surface Plasmon resonance band at 370 nm, while High Resolution-TEM investigation reveal that silver nanoparticles of size 100nm was obtained; FTIR was indicated on the active functional groups carboxylic group at 2930 cm−1, metal carboxylic acid and esters groups at1718 cm−1, primary amines at 1623 cm−1, NO2 group at1380 cm−1 and carboxylic group at 1224 cm−1. Also, Total phenolic content of aqueous extract was 318µg/mL, which is more than its sliver nanoparticles solution which was 307 µg/ mL In this work, antimicrobial activity of silver nanoparticles synthesized from aqueous extract of Myrtus communis was investigated on standard bacteria, yeast and clinical MRSA isolate by well diffusion method. Synthesized silver nanoparticles showed good antimicrobial activity against used strains and isolates. Serial dilutions (0.025-50 mg/ml) were made from AgNp solutions; result showed that the MIC of AgNp solutions was 0.0175mg/ml. S.aureus cells were grown in incubator shaker at 37 °C for 24 h. in the presence of 0.0175mg/ml of AgNp solutions and were investigated by TEM to appear vertically more oblong than untreated cells. Some of antioxidant parameters were investigated e.g.: DPPH radical scavenging activity, Ferric reducing power and Hydrogen peroxid e radical scavenging activity, the obtained results indicated that the silver nanoparticles has highest values of these assays. Cytotoxicity was done in vivo via hepatic, kidney enzymes and in vitro via MTT assay. All results were indicated that all tested solutions gave normal ranges, while by using MTT assay; the obtained result showed that Hep-2 cells proliferation was significantly inhibited by aqueous extract with an IC50 value of 166.9µg/ml while in case of AgNPs with an IC50value of 40.5µg/ml of the concentration
