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

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‐N ₂ H ₄ ·H ₂ O). 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‐N ₂ H ₄ ·H ₂ O. The anti‐inflammatory ability of AgNPs was shown by the effective inhibition against 5‐lipoxygenase with IC ₅₀ values of 5.08 μg/mL for AgNPs‐LLJ and 59.12 μg/mL for AgNPs‐N ₂ H ₄ ·H ₂ O, 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‐N ₂ H ₄ ·H ₂ O 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.