Green synthesis of silver nanoparticles from Lonicera japonica leaf extract and their anti‐inflammatory and antibacterial effects

Abstract

A green synthesis of silver nanoparticles (AgNPs) using aqueous Lonicera japonica leaf extract (AgNPs-LLJ) was reported and their anti-inflammatory and antibacterial effects were investigated. In comparison, AgNPs were also synthesised using the liquid phase chemical reduction method (AgNPs-N2H4·H2O). The synthesised AgNPs were identified using multiple analytical techniques. The results showed that both AgNPs were spherical particles with an average particle size of 20–30 nm for AgNPs-LLJ and 10–20 nm for AgNPs-N2H4·H2O. The anti-inflammatory ability of AgNPs was shown by the effective inhibition against 5-lipoxygenase with IC50 values of 5.08 μg/mL for AgNPs-LLJ and 59.12 μg/mL for AgNPs-N2H4·H2O, indicating that AgNPs-LLJ had much more obvious anti-inflammatory effect. Furthermore, the cytotoxicity research on RAW264.7 mouse macrophages showed that AgNPs-LLJ had no cytotoxicity at the concentration of 40 μg/mL compared with control. Their antibacterial effects on Escherichia coli (EC) and Staphlococcus aureus (SA) were studied by agar well diffusion method. The maximum antibacterial circles of AgNPs-N2H4·H2O on EC and SA were 15 and 14 mm, respectively, whereas it was 5.0 and 5.0 mm for AgNPs-LLJ, respectively. The authors conclude that AgNPs-LLJs have a potential to be a nanomedicine for nanobiomedical applications.