Green synthesis of silver nanoparticles by using Allium sativum extract and evaluation of their electrical activities in bio-electrochemical cell

Phytochemical profiling and fractionation of Helianthemum lippii extract versus silver nanoparticle-modified extract: assessment of photoprotective, anti-hemolytic, antibacterial, and anti-inflammatory properties

Introduction

This study investigates the synthesis of silver nanoparticles (Ag NPs) using Helianthemum lippii extract and evaluates their photoprotective, anti-hemolytic, antibacterial, and anti-inflammatory properties compared to various extract fractions, including total aqueous extract (AE), flavonoid monoglycosides (FMG), flavonoid diglycosides/triglycosides (FDG/FTG), tannins (TN), and anthocyanins (AC). Helianthemum lippii is rich in bioactive compounds such as caffeic acid, p-coumaric acid, and gallic acid, known for their therapeutic potential. This study aims to determine whether embedding these phytochemicals into Ag NPs enhances their biomedical applications compared to the natural extract fractions.

Methods

Ag NPs were synthesized using Helianthemum lippii extract through a green synthesis approach, and their physicochemical properties, including size and morphology, were characterized. High-performance liquid chromatography (HPLC) was used to identify key phytochemicals in the various extract fractions. Biological assays were conducted to assess photoprotective efficacy (sun protection factor, SPF), antibacterial activity (minimum inhibitory concentration, MIC), anti-inflammatory potential (percentage inhibition), and hemolytic properties, with sodium dodecyl sulfate (SDS) serving as a control.

Results

HPLC analysis confirmed the presence of bioactive compounds, including caffeic acid, p-coumaric acid, and gallic acid, in the AE extract. The Ag NPs were spherical with an average diameter of 35 nm and had phytochemicals adsorbed on their surface. The AC fraction demonstrated the highest SPF (28.27), followed by TN (27.99), AE (23.20), and Ag NPs (22.50), while FMG exhibited a moderate SPF (19.39) compared to the commercial sunscreen Avene® (40.00). Ag NPs exhibited superior antibacterial activity with MIC values of 0.2 mg/mL against Pseudomonas aeruginosa and 0.4 mg/mL against Bacillus subtilis, outperforming AE, which had a MIC of 2.81 mg/mL. Anti-inflammatory assays showed that Ag NPs achieved 79.8% inhibition at 400 μg/mL, surpassing AE (71.75%) and TN (67.9%), and were comparable to diclofenac (72.63%). Hemolysis assays revealed that Ag NPs induced only 1.35% hemolysis, lower than AE (1.91%) and significantly below SDS (90.48%).

Discussion

The findings demonstrate that Helianthemum lippii-derived Ag NPs exhibit enhanced antibacterial, anti-inflammatory, and anti-hemolytic properties compared to the extract fractions. While the SPF of Ag NPs was slightly lower than the AC and TN fractions, their superior multifunctional bioactivities underscore their potential for various biomedical applications. The integration of phytochemicals into Ag NPs significantly enhances their therapeutic efficacy, making them promising candidates for advanced pharmaceutical formulations and topical protective agents.

Biosynthesis and characterizations of silver nanoparticles by using green banana peel extract: Evaluation of their antibacterial and electrical performances

Biosynthesized silver nanoparticles (Ag NPs) hold tremendous promise in nano-bioscience, with applications spanning engineering, science, and industry. This study delves into their fabrication process, crystallographic characteristics, and nanostructures. Employing green banana peel extract (GBPE), Ag NPs were synthesized. Various analytical techniques, such as UV-Vis absorption spectrophotometry (UV), X-ray diffraction (XRD), Gas chromatography-mass spectrometry (GC-MS), Field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR), and Transmission electron microscopy (TEM) elucidate their attributes. UV-visible analysis reveals a 413 nm absorption band due to surface plasmon resonance. The Ag NPs exhibit a face-centered cubic structure with an average crystallite size of 45.87 nm. Lattice parameters and dislocation density are also determined. When tested against harmful bacteria, such as E. coli and S. epidermidis, advanced microscopy reveals a median size of particles of 55.12 nm and demonstrates their antibacterial characteristics. These environmentally benign Ag NPs also improve the efficiency of bio-electrochemical cells (BECs), opening the door to large-scale manufacturing at a reasonable cost and broadening the range of possible uses.

Biosynthesis of silver nanoparticles by banana pulp extract: Characterizations, antibacterial activity, and bioelectricity generation

Here, green banana pulp extract (PE) has been used as a bio-reducing agent for the reduction of silver ions to silver nanoparticles (AgNPs). Bio-synthesized AgNPs were characterized by using UV, XRD, FEEM, TEM, and FTIR analysis. The face-centered cubic structures of AgNPs were formed with an average crystallite size of 31.26 nm and an average particle size of 42.97 nm. In this report, the electrical activities of green synthesized AgNPs have been evaluated along with the antibacterial activities. The antibacterial activities of AgNPs were evaluated against two pathogenic bacteria: Escherichia coli (gram-negative) and Staphylococcus epidermidis (gram-positive). AgNPs were added to the electrochemical cell and results demonstrated the improvement of power of the electrochemical cell. Green synthesized AgNPs showed excellent antibacterial activities against both gram-positive and negative bacteria and most importantly the NPs played an important role as an effective catalyst to enhance the electrical performance of bio-electrochemical cells. These significant findings may help in the advancement of nanotechnology in biomedical applications as well as in the creation of cheap and eco-friendly power generation devices.