Comparative study on the effects of silver nanoparticles and methanolic extracts of Calendula officinalis on pathogenic bacteria Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa under laboratory conditions

In recent years, the drug resistance and side effects of antimicrobial drugs have increased in the treatment of infections. Therefore, the use of new herbal medicines with less side effects and nanotechnology in the medical arena can be a great help in treating these types of infections. The purpose of this study is to compare the effects of silver nanoparticles and methanolic extracts of Calendula officinalis on four strains of pathogens bacterial . In this descriptive-laboratory study, the plant was identified as a plant of C.officinalis, based on herbological characteristics in the Herbarium section of Azad University, Ahar Branch. In this study, the antimicrobial effects of methanolic extract of C.officinalis were studied by Soxhlet extractor method at concentrations of 20 mg / ml to 400 mg / ml of methanolic extract and 10 to 80 μg / ml concentrations of silver nanoparticles. Then, their antibacterial effects were investigated using well-diffusion and dilution methods. The findings showed that methanolic extract of C.officinalis prevents the growth of S.aureus, B.cereus and E.coli. While the inhibitory effect of silver nanoparticles on P.aeruginosa and E.coli bacteria is more than gram-positive bacteria. The effect of the combination of C.officinalis extract and silver nanoparticles was much greater than the effect of each of them. The results showed that the flower extract of the C.officinalis has an antibacterial effect. Therefore, this extract can be a good option for future studies in In Vivo to provide antibacterial drugs.