Facile phytosynthesis of gold nanoparticles using Nepeta bodeana Bunge: Evaluation of its therapeutics and potential catalytic activities

In the present study, the ethanol extract of leaves of Nepeta bodeana Bunge was utilized in environmentally friendly synthesis of gold nanoparticles (AuNPs) via an immediate, one-step, and cost-effective process. The biosynthesized AuNPs were characterized using a variety of techniques, including UV-visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and laser Doppler electrophoresis (zeta potential), among others. Pink in hue, the manufactured AuNPs were practically spherical and had < 20.5 nm in diameter. The peak of the localized surface plasmon resonance absorption band at 547 nm helped to explain the biogenic synthesis of AuNPs, which used the ethanolic extract of the Nepeta bodeana leaves. In addition to this, the biosynthesized AuNPs possessed the remarkable stability as a result of their zeta potential value of 22.3 mV. The green synthesized AuNPs demonstrated the excellent catalytic activity because they were able to catalytically degrade methylene blue (MB) at a variety of concentrations. The results indicated that 94.2% of MB were degraded after 10 min. They also showed a remarkable antibacterial activity against both Gram-nrgative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Bacillus cereus) bacteria. In addition, a proper antifungal activity with the minimum inhibitory concentration (MIC) values of 50 and 25 mu g/mL against Candida albicans and Aspergillus niger, respectively, were determined. The phytosynthesized AuNPs indicated a considerable antioxidant activity of 83% and 74% in the applied DPPH and ABTS radical scavenging activity tests, respectively. The anti-inflammatory properties of the synthesized AuNPs were established to be dose-dependent and varied from 11% to 76%. The green synthesized AuNPs also exhibited a concentration-dependent cytotoxicity on human liver (HepG2) and breast (MCF-7) cancer cells, which were around 77.4 and 71.2% at 300 mu g/mL, respectively. They showed as well a notable anti-diabetic activity with the 52% inhibition of a-amylase and the 62% glucose uptake activity by yeast cells at 300 mu g/mL. All these findings suggested that the produced AuNPs could be explored for developing many therapeutic as well as catalytic useful products.