Green synthesis of silver nanoparticles using melissa officinalis extract and evaluation of their antimicrobial and cytotoxic properties

In this study, silver nanoparticles (AgNPs) were effectively synthesised using an aqueous extract of Melissa officinalis and characterised using UV-Vis spectroscopy, FTIR, SEM, XRD, DLS, and zeta potential studies. The antioxidant properties of these nanoparticles were evaluated using FRAP and DPPH tests, with the AgNPs outperforming the plant extract, registering a FRAP value of 2.23 Eq/mg vs 1.93 Eq/mg, and a DPPH scavenging efficiency of 86.72% versus 78.31% at a 1 mg/mL concentration. Their antibacterial ability was assessed against Staphylococcus aureus, Escherichia coli, and Proteus mirabilis, with a strong inhibitory effect reported only against S. aureus (14 mm zone of inhibition; MIC and MBC at 8 and 16 mg/mL, respectively). Cytotoxicity studies on MCF-7 breast cancer cells revealed that the plant extract had higher anticancer capabilities (IC?? = 32 mg/mL), whereas AgNPs had a more modest, dose-dependent response. Overall, these biosynthesized AgNPs displayed significant antioxidant and species-specific antibacterial properties, but their anticancer activity was lower compared to the original extract. The findings highlight their potential as ecologically friendly options for medical and pharmaceutical applications, with room for additional development to improve their therapeutic profile.

Dr Parichehr Hanachi completed her BS in biology (1984) from Teacher Training University, Tehran, MS in Biochemistry (1987) from Marmara University, Istanbul-Turkey, PhD in Clinical biochemistry (2002) from University Putra Malaysia (UPM) and Post doctoral (2003) from Faculty of Medical and Health Sciences (UPM). She after 10 years study and working in Faculty Medicine and Health Sciences, in UPM, Malaysia came back to Iran and working as ; Director of Research in Women Research Center, 2006-2009, Biomedical unite, Alzahra University and working as: Director of Physiology Dep, Faculty of Sport and Health Science, since 2012-2015. Currently she is appointed as : Director of international academic collaboration of Alzahra University since 2015. Her research are involved with, Human health impact and Microplastics pollution, Herbal medicine and disease.