Antibacterial activity of extracts and silver nanoparticles from Vitex Agnus castus against bacteria isolated from Hospital wastewater

Abstract

The plants extract and silver nanoparticles are gaining popularity and are being used in medical technologies due to their antibacterial activity. This study aimed to evaluate the potential antimicrobial properties of an aqueous leaves extract of Vitex agnus-castus and biosynthesized Ag NP particles. The extract was made using three distinct methods, and silver nanoparticles were formed by adding 0.2 grams of silver nitrate to the extract. UV-Vis Spectroscopy, scanning electron microscopy (SEM), Energy-Dispersive X-ray spectroscopy (XRD), Fourier transform infrared (FTIR) spectroscopy, and Gas chromatography-mass spectrometry (GC-MS) were used to determine the characteristics of the silver nanoparticles. The results indicated that the Soxhlet extraction method produced the highest percentage of silver nanoparticles, measuring 56.13%. The antibacterial activity of both the extracts and the silver nanoparticles was tested against Gram-positive and Gram-negative bacteria isolated from hospital wastewater at three different concentrations: 25, 35, and 50 mg/mL. The extracts exhibited the strongest inhibition of 25 mm against Enterobacter cloacae strain NCTC 9394 (FP929040) when using an aqueous Soxhlet extract at a concentration of 35 mg/mL. Conversely, the lowest inhibition recorded was 11 mm against Pseudomonas aeruginosa strain WPB098 (CP031876) with an acetone Soxhlet extract at a concentration of 50 mg/mL. In addition, at a concentration of 35 mg/mL, the cold soak extract did not affect Citrobacter sedlakii strain NWPK (MW720666). The antibacterial activity of biosynthesized silver nanoparticles showed inhibition against Pseudomonas aeruginosa strain WPB098 (CP031876) reached 25 mm from the aqueous Soxhlet extract at a concentration of 50 mg/mL was combined with biosynthesized silver nanoparticles from the hot soaking extract at 50°C at a concentration of 50 mg/ml. Meanwhile, the lowest inhibitory against Escherichia coli strain S51 (CP015995) was 15 mm, which was achieved by using biosynthesized silver nanoparticles from aqueous Soxhlet extract at a concentration of 35 mg/mL. Biosynthesized silver nanoparticles from Vitex agnus-castus exhibited strong antibacterial activity against both Gram-positive and Gram-negative bacteria, as promising antibacterial agents.