البناء الحيوي لجسيمات الفضة النانوية باستعمال مستخلصات اوراق نبات النعناع Mentha spicata ودراسة فعاليتها الحيوية

Biosynthesis of Silver Nanoparticles Using Plant Leaf Extracts of Mentha spicata and Study of Biological Activities

The present study described the rapid green synthesis of silver nanoparticles using three aqueous, ethanol and methanol leaf extracts of Mentha spicata as a reducing agent and stabilizing.

When a silver nitrate solution was exposed to leaf extract of Mentha spicata, led to reduce the Ag⁺ ions and produce change of colour that indicated the formation of silver nanoparticles.

Silver nanoparticles were characterized using UV-Visible spectroscopy which the peak showed between 450- 550 nm is the formation of plasmon of silver nanoparticles, spectrum of Fourier Transformation infera-red spectroscopy (FTIR) indicated that the presence of all the functional groups, Atomic Force Electronic Microscopic (AFM) showed the average diameter of silver nanoparticles which obtained 57.51, 76.40 and 91.87 nm, X-ray diffraction (XRD) technique revealed that the synthesis of silver nanoparticles.

Optimization studying for synthesis of silver nanoparticles such as concentration of silver nitrate, plant extract and effect of light (as inducer for biosynthesis of silver nanoparticles), previous studies showed that silver nitrate and plant extract  for biosynthesis of silver nanoparticles were 1 mM of silver nitrate and 5% volume of extract.

The antibacterial activity of silver nanoparticles was studied against multidruge resistance bacteria causing urinary tract infection, at concentration 5mg/ml with the average inhibition zone diameter were 16.33-18.67, 19.5-21.83, 16.83-23.33, 16.83-22.33 and 16.83-19.83 for Staphylococcus aureus, Escherichia coli, Enterococus faecalis, Proteus mirabilis and Acinetobacter baumannii, respectively.

The antifungal activity of silver nanoparticles was studied against Microsporum canis, Trichophyton mentagrophytes; at 5mg/ml the percentage of inhibition were 100, 84.97-87.27, respectively.

Silver nanoparticles were evaluted  as antioxidant and it had activity  which is antioxidant at 250, 275 and 300 µg/ml which was compared with antioxidant of aqueous, ethanolic and methanolic leaf extract of Mentha spicata that had efficient to reduction absorbance free radical ABTs to half (IC₅₀) at 1000, 1250 and 1250 µg/ml, respectively.

Effect of silver nanoparticles on human red blood cells hemolysis was investigated, In general silver nanoparticles showed that the low RBCs hemolysis percent at 50 µg/ ml were (2.80%), (3.39%) and (4.84%) with aqueous, ethanolic and methanolic, respectively. Whereas at 60 µg/ ml was ratio hemolysis reed blood cells (4.50%), (4.24%) and (6.03%) with aqueous, ethanolic and methanolic, respectively.