Green Synthesis of Gold and Silver Nanoparticles Using Leaf Extract of Clerodendrum inerme; Characterization, Antimicrobial, and Antioxidant Activities

Abstract

Due to their versatile applications, gold (Au) and silver (Ag) nanoparticles (NPs) have been synthesized by many approaches, including green processes using plant extracts for reducing metal ions. In this work, we propose to use plant extract with active biomedical components for NPs synthesis, aiming to obtain NPs inheriting the biomedical functions of the plants. By using leaves extract of Clerodendrum inerme (C. inerme) as both a reducing agent and a capping agent, we have synthesized gold (CI-Au) and silver (CI-Ag) NPs covered with biomedically active functional groups from C. inerme. The synthesized NPs were evaluated for different biological activities such as antibacterial and antimycotic against different pathogenic microbes (B. subtilis, S. aureus, Klebsiella, and E. coli) and (A. niger, T. harzianum, and A. flavus), respectively, using agar well diffusion assays. The antimicrobial propensity of NPs further assessed by reactive oxygen species (ROS) glutathione (GSH) and FTIR analysis. Biofilm inhibition activity was also carried out using colorimetric assays. The antioxidant and cytotoxic potential of CI-Au and CI-Ag NPs was determined using DPPH free radical scavenging and MTT assay, respectively. The CI-Au and CI-Ag NPs were demonstrated to have much better antioxidant in terms of %DPPH scavenging (75.85% ± 0.67% and 78.87% ± 0.19%), respectively. They exhibited excellent antibacterial, antimycotic, biofilm inhibition and cytotoxic performance against pathogenic microbes and MCF-7 cells compared to commercial Au and Ag NPs functionalized with dodecanethiol and PVP, respectively. The biocompatibility test further corroborated that CI-Ag and CI-Au NPs are more biocompatible at the concentration level of 1–50 µM. Hence, this work opens a new environmentally-friendly path for synthesizing nanomaterials inherited with enhanced and/or additional biomedical functionalities inherited from their herbal sources.

Green Synthesis of Chromium Oxide Nanoparticles for Antibacterial, Antioxidant Anticancer, and Biocompatibility Activities

“…These peaks are matched with the FTIR signals of the leaf extracts with slight shifting. These results suggest that many biologically active phytomolecules are left adsorbed on the surface of the Cr 2 O 3 nanoparticle [ 9 , 10 ]. Moreover, the FTIR signal at 612 cm −1 , corresponding to Cr-O, further validated the metal-oxygen bond formation [ 2 , 7 , 18 ].…”

“…The carbon peak could be attributed to the presence of phytomolecules (polyphenols, alkaloids, flavonoids, etc.) of leaf extract of A. indicum (L.) Sweet adsorbed on Cr 2 O 3 nanoparticle’s surface [ 9 , 10 ].…”

“…The antibacterial propensity of the green synthesized Cr 2 O 3 nanoparticles was determined using agar well diffusion assay against four different bacterial strains ( Staphylococcus aureus ATCC ® 23235™, Bacillus subtilis ATCC ® 6051™, Escherichia coli ATCC ® 25922™, and Bordetella bronchiseptica ATCC ® 4617™), following the protocol previously reported by [ 9 ]. The antibiotic drug (Leflox) and dimethyl sulfoxide (DMSO) were used as a positive and negative control, respectively.…”

“…The poisonous effects of Cr 2 O 3 nanoparticles can be reduced by coating or functionalization their surfaces with biogenic materials. One of the most promising ways of achieving this, is surface coating Cr 2 O 3 with plants’ biogenic phytomolecules [ 9 ].…”

“…properties. So, green synthesis using plants enhances the nanoparticle’s biocompatibility and is responsible for the synergetic effect [ 9 , 10 ].…”