Green Synthesis of Silver Nanoparticles Using Spilanthes acmella Leaf Extract and its Antioxidant-Mediated Ameliorative Activity against Doxorubicin-Induced Toxicity in Dalton's Lymphoma Ascites (DLA)-Bearing Mice

Mikania micrantha silver nanoparticles exhibit anticancer activities against human lung adenocarcinoma via caspase-mediated apoptotic cell death

Green-mediated synthesis of nanoparticles has earned a promising role in the area of nanotechnology due to their biomedical applications. This study describes the synthesis of silver nanoparticles (AgNPs) using Mikania micrantha leaf extract and its functional activities against cancer. The synthesis of AgNPs was confirmed using Ultraviolet-Visible (UV-Vis) spectrum that exhibited an absorption band at 459 nm. The bioactive compounds of M. micrantha leaf extract that functioned as reducing and capping agents were confirmed by a shift in the absorption bands in Fourier Transform Infra-red Spectroscopy (FT-IR). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) studies validated the spherical shape and size of AgNPs, respectively. Energy Dispersive Spectroscopy (EDS) analysis revealed the presence of elemental silver. The crystalline nature of AgNPs was confirmed by the X-ray Diffraction Analysis (XRD). AgNPs effectively induced cytotoxicity and prevented A549 cell colony formation in a dose-dependent manner. Treatment of A549 cells with AgNPs also increased DNA damage, which was coupled with elevated lipid peroxidation and decreased antioxidant enzymes such as glutathione (GSH), glutathione-s-transferase (GST), and superoxide dismutase (SOD). Following AgNPs treatment, the mRNA expression levels of the pro-apoptotic genes as well as the activities of caspases were significantly elevated in A549 cells while the expression levels of anti-apoptotic genes were downregulated. Our study demonstrates the potential of the synthesised AgNPs for cancer therapy possibly targeting the apoptotic pathway.

Therapeutic potential of silver nanoparticles from Helianthemum lippii extract for mitigating cadmium-induced hepatotoxicity: liver function parameters, oxidative stress, and histopathology in wistar rats

Introduction: This study explores the therapeutic potential of silver nanoparticles (Ag NPs) synthesized using a Helianthemum lippii extract in mitigating cadmium-induced hepatotoxicity in Wistar rats. Given the increasing environmental and health concerns associated with cadmium exposure, novel and eco-friendly therapeutic strategies are essential. Methods: Ag NPs were characterized using X-ray diffraction, UV-Vis spectrometry, and energy-dispersive X-ray spectroscopy with scanning electron microscopy, confirming their formation with a cubic crystal structure and particle sizes ranging from 4.81 to 12.84 nm. A sub-acute toxicity study of Ag NPs (2 mg/kg and 10 mg/kg) was conducted, showing no significant difference compared to untreated control rats (n = 3 animals/group). Subsequently, adult Wistar rats (n = 5/group) were divided into a control group and three experimental groups: Ag NPs alone, exposure to 50 mg/kg CdCl2 in drinking water for 35 days, and CdCl2 exposure followed by 0.1 mg/kg/day Ag NPs intraperitoneally for 15 days. Results: In the CdCl2-exposed group, there was a significant decrease in body weight and increases in alanine and aspartate transaminase levels (p < 0.05 vs. control), indicating hepatotoxicity. Additionally, antioxidant defenses were decreased, and malondialdehyde levels were elevated. Liver histology revealed portal fibrosis, inflammation, necrosis, sinusoid and hepatic vein dilation, and cytoplasmic vacuolations. Treatment with Ag NPs post-CdCl2 exposure mitigated several adverse effects on liver function and architecture and improved body weight. Discussion: This study demonstrates the efficacy of Ag NPs synthesized via a green method in reducing cadmium-induced liver damage. These findings support the potential of Ag NPs in therapeutic applications and highlight the importance of sustainable and eco-friendly nanoparticle synthesis methods. By addressing both toxicity concerns and therapeutic efficacy, this research aligns with the growing emphasis on environmentally conscious practices in scientific research and healthcare.

A review of microbes mediated biosynthesis of silver nanoparticles and their enhanced antimicrobial activities

In recent decades, biosynthesis of metal and (or) metal oxide nanoparticles using microbes is accepted as one of the most sustainable, cost-effective, robust, and green processes as it does not encompass the usage of largely hazardous chemicals. Accordingly, numerous simple, inexpensive, and environmentally friendly approaches for the biosynthesis of silver nanoparticles (AgNPs) were reported using microbes avoiding conventional (chemical) methods. This comprehensive review detailed an advance made in recent years in the microbes-mediated biosynthesis of AgNPs and evaluation of their antimicrobial activities covering the literature from 2015-till date. It also aimed at elaborating the possible effect of the different phytochemicals, their concentrations, extraction temperature, extraction solvent, pH, reaction time, reaction temperature, and concentration of precursor on the shape, size, and stability of the synthesized AgNPs. In addition, while trying to understand the antimicrobial activities against targeted pathogenic microbes the probable mechanism of the interaction of produced AgNPs with the cell wall of targeted microbes that led to the cell's reputed and death have also been detailed. Lastly, this review detailed the shape and size-dependent antimicrobial activities of the microbes-mediated AgNPs and their enhanced antimicrobial activities by synergetic interaction with known commercially available antibiotic drugs.

Comparative life cycle cost analysis of bio-valorized magnetite nanocatalyst for biodiesel production: Modeling, optimization, kinetics and thermodynamic study

An active, high surface area, recyclable, magnetic, basic, iron oxide-based nanocatalyst was developed from banana leaves waste and used for microwave-assisted transesterification of soybean oil to biodiesel. According to the Hammett indicator, the catalyst has a high total basicity of 15 < H < 18.4. After optimization through the response surface methodology, the reaction allows 96.5 % biodiesel yield in the presence of 24:1 methanol to soybean oil molar ratio, 6 wt% BLW@Fe3O4, 0.5 h at 65 °C. The magnetic nature of the catalyst improves reusability for up to 6 cycles. Thermodynamic analyses showed that transesterification of soybean oil to biodiesel is an endothermic reaction. Moreover, the catalyst has the potential to reduce biodiesel production costs by utilizing abundant biomass waste materials. The calculated cost for 1 kg of catalyst is $1.14, while the biodiesel's cost per kg produced in this work is merely $1.05, showing high commercial viability.

A highly selective Hg2+ colorimetric sensor and antimicrobial agent based on green synthesized silver nanoparticles using Equisetum diffusum extract

Plasmonic nanoparticles such as Ag have gained great interest in the biomedical domain and chemical analysis due to their unique optical properties. Herein, we report a simple, cost-effective, and highly selective colorimetric sensor of mercury(ii) based on E. diffusum (horsetail) extract-functionalized Ag nanoparticles (ED-AgNPs). The ED-AgNPs were synthesized by exploiting the coordination of Ag+ with the various functional groups of ED extract under sunlight exposure for only tens of seconds. ED-AgNPs (63 nm) were characterized using various techniques such as UV-vis, FTIR, DLS, SEM and EDX. FTIR spectra suggested the successful encapsulation of the AgNPs surface with ED extract and XRD confirmed its crystalline nature. This ED-AgNPs colorimetric sensor revealed remarkable selectivity towards Hg2+ in aqueous solution among other transition metal ions through a redox reaction mechanism. Besides, the sensor exhibited high sensitivity with rapid response and a detection limit of 70 nM. The sensor demonstrated feasibility for Hg(ii) detection in spiked tap and river water samples. In addition, the synthesized ED-AgNPs revealed enhanced antimicrobial activity with higher efficacy against the Gram-positive bacterium (L. monocytogenes with an inhibition zone of 18 mm) than the Gram-negative bacterium (E. coli with an inhibition zone of 10 mm). The simplicity and adaptability of this colorimetric sensor render it a promising candidate for on-site and point-of-care detection of heavy metal ions in diverse conditions.