Green Synthesis of Silver Nanoparticles by Hypericum perforatum extract and Berberine and Evaluation of Their Antibacterial Effects

Bacterial infections are a major cause of chronic infections and mortality, and antibiotics are the preferred treatment for bacterial infections. However, studies show that widespread use of antibiotics has led to the emergence of multidrug-resistant bacterial strains. Hence, the need to develop new and alternative strategies for the production of effective drugs has become an important issue. Recently, the use of nanotechnology has been widely common in various fields. Materials in the nanoscale have unique physical and chemical properties. Silver nanoparticles have different applications and their antimicrobial properties have been confirmed in several studies. This study aimed to investigate the antibacterial properties of silver nanoparticles synthesized by berberine and Hypericum perforatum extract.

In this experimental study, the antibacterial effects of synthesized nanoparticles on standard strains of Escherichia coli [ATCC 25922], Pseudomonas aeruginosa [ATCC 27853], Klebsiella pneumoniae [ATCC 9997], and Staphylococcus aureus [ATCC 29212] were investigated. The MIC content of silver nanoparticles alone and in combination with berberine and Hypericum perforatum extract was investigated for the studied bacteria using the broth microdilution method.

The results of the evaluation of the minimum inhibitory concentration [MIC] of the synthesized compounds on the studied bacteria showed that the nanoparticles synthesized by berberine and Hypericum perforatum extract had the highest antibacterial effects. However, each of the compounds Berberine and Hypericum perforatum extract alone did not show significant antibacterial properties. The results of this study also showed that the highest inhibitory concentration of nanoparticles synthesized by berberine and Hypericum perforatum extract was related to Pseudomonas aeruginosa [0.0375 mg / ml] and the lowest inhibitory concentration was related to Enterococcus faecalis [0.185 mg/ml].

The results of the present study showed that silver nanoparticles synthesized with berberine and Hypericum perforatum extract have significant antibacterial effects. As a result, nanoparticles, including silver nanoparticles, can become one of the most important alternatives to antibiotics due to their unique properties in targeting bacteria. However, achieving definitive results requires further studies in this area.