Synthesis of Silver Nanoparticles Using Odontosoria chinensis (L.) J. Sm. and Evaluation of their Biological Potentials

Antibacterial and antioxidant potential analysis of Verbascum sinaiticum leaf extract and its synthesized silver nanoparticles

The potential applications of plant extract and nanoparticles in antibacterial and antioxidant studies have garnered significant interest in recent times. Despite being utilized in Ethiopian traditional medicine, Verbascum sinaiticum (qetetina) constituents and its usage in nanoparticle synthesis remain relatively unexplored. This study explores the potential of the plant extract and its nanoparticles for antibacterial and antioxidant applications, with a focus on the leaf extracts and its silver nanoparticles. The leaf extract was analyzed using LC-MS and GC-MS and found to contain over 70 compounds, including glycosides, phenolic compounds, flavonoids, and fatty acids. The synthesized nanoparticles had a maximum absorbance of 408 nm, with a size range of 2-40 nm and showed a spherical shape. Using the agar well diffusion method, the extract and nanoparticles were evaluated against Gram-positive (Staphylococcus aureus ATCC 2592, Streptococcus agalactia ATCC12386) and Gram-negative bacteria (Acinetobacter baumannii ATCC19606, Pseudomonas aeruginosa ATCC27853) bacterial strains. In terms of antibacterial effects, both the silver nanoparticles and leaf extract displayed a greater impact on gram-positive bacterial strains over gram-negative bacterial strains. Additionally, the tests for lowest inhibitory and bactericidal concentration indicated similar outcomes. Notably, the silver nanoparticles exhibited greater antibacterial activity compared to the leaf extract alone. The DPPH (2, 2-diphenylpicrylhydrazyl) assay was conducted to investigate antioxidant activity. The results showed that the plant extract had an IC50 value of 143 μg/ml, while the synthesized nanoparticle had an IC50 value of 216 μg/ml, indicating that the plant extract had greater antioxidant activity than the synthesized silver nanoparticles.

Green Synthesis of Novel Silver Nanoparticles Using Salvia blepharophylla and Salvia greggii: Antioxidant and Antidiabetic Potential and Effect on Foodborne Bacterial Pathogens

In the face of evolving healthcare challenges, the utilization of silver nanoparticles (AgNPs) has emerged as a compelling solution due to their unique properties and versatile applications. The aim of this study was the synthesis and characterization of novel AgNPs (SB-AgNPs and SG-AgNPs, respectively) using Salvia blepharophylla and Salvia greggii leaf extracts and the evaluation of their antimicrobial, antioxidant, and antidiabetic activities. Several analytical instrumental techniques were utilized for the characterization of SB-AgNPs and SG-AgNPs, including UV-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transmission infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). FTIR analysis identified various functional groups in the leaf extracts and nanoparticles, suggesting the involvement of phytochemicals as reducing and stabilizing agents. High-resolution TEM images displayed predominantly spherical nanoparticles with average sizes of 52.4 nm for SB-AgNPs and 62.5 nm for SG-AgNPs. Both SB-AgNPs and SG-AgNPs demonstrated remarkable antimicrobial activity against Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes and Gram-negative bacteria Salmonella typhimurium and Escherichia coli. SB-AgNPs and SG-AgNPs also exhibited 90.2 ± 1.34% and 89.5 ± 1.5% DPPH scavenging and 86.5 ± 1.7% and 80.5 ± 1.2% α-amylase inhibition, respectively, at a concentration of 100 μg mL-1. Overall, AgNPs synthesized using S. blepharophylla and Salvia greggii leaf extracts may serve as potential candidates for antibacterial, antioxidant, and antidiabetic agents. Consequently, this study provides viable solutions to mitigate the current crisis of antibiotic resistance and to efficiently combat antimicrobial infections and Type 2 diabetes.

Toxicological Aspects, Safety Assessment, and Green Toxicology of Silver Nanoparticles (AgNPs)—Critical Review: State of the Art

In recent years, research on silver nanoparticles (AgNPs) has attracted considerable interest among scientists because of, among other things, their alternative application to well-known medical agents with antibacterial properties. The size of the silver nanoparticles ranges from 1 to 100 nm. In this paper, we review the progress of research on AgNPs with respect to the synthesis, applications, and toxicological safety of AgNPs, and the issue of in vivo and in vitro research on silver nanoparticles. AgNPs’ synthesis methods include physical, chemical, and biological routes, as well as “green synthesis”. The content of this article covers issues related to the disadvantages of physical and chemical methods, which are expensive and can also have toxicity. This review pays special attention to AgNP biosafety concerns, such as potential toxicity to cells, tissues, and organs.

Comparative Bio-Potential Effects of Fresh and Boiled Mountain Vegetable (Fern) Extract Mediated Silver Nanoparticles

This current investigation was designed to synthesize Ag nanoparticles (AgNPs) using both the fresh (Fbf) and boiled (Bbf) Korean mountain vegetable fern (named Gosari) extracts and make a comparative evaluation of its multi-therapeutic potentials. The screening of phytochemicals in the fern extract was undertaken. The synthesized fern-mediated silver nanoparticles are characterized and investigated for their bio-potential like α-glucosidase inhibition, antioxidant, and cytotoxicity prospects. The obtained AgNPs were characterized by the UV-Vis Spectra, SEM, EDS, XRD, FTIR, DLS, Zeta potential analysis, etc. The synthesis of the Fbf-AgNPs was very fast and started within 1 h of the reaction whereas the synthesis of the Bbf-AgNPs synthesis was slow and it started around 18 h of incubation. The UV-Vis spectra displayed the absorption maxima of 424 nm for Fbf-AgNPs and in the case of Bbf-AgNPs, it was shown at 436 nm. The current research results demonstrated that both Fbf-AgNPs and Bbf-AgNPs displayed a strong α-glucosidase inhibition effect with more than 96% effect at 1 µg/mL concentration, but the Bbf-AgNPs displayed a slightly higher effect with IC₅₀ value slightly lower than the Fbf-AgNPs. Both Fbf-AgNPs and Bbf-AgNPs displayed good antioxidant effects concerning the in vitro antioxidant assays. In the case of the cytotoxicity potential assay also, among both the investigated Fbf-AgNPs and Bbf-AgNPs nanoparticles, the Bbf-AgNPs showed stronger effects with lower IC₅₀ value as compared to the Fbf-AgNPs. In conclusion, both the fern-mediated AgNPs displayed promising multi-therapeutic potential and could be beneficial in the cosmetics and pharmaceutical sectors. Though the synthesis process is rapid in Fbf-AgNPs, but it is concluded from the results of all the tested bio-potential assays, Bbf-AgNPs is slightly better than Fbf-AgNPs.

Recent update on nano-phytopharmaceuticals in the management of diabetes

Due to changed lifestyle and other reasons, diabetes has become one of the common metabolic disorder of the globe. Numerous therapeutic options are available, which controls the plasma glucose levels. However, most of the drugs are associated with some undesired side effects. Owing to the side effects and enhanced understanding of the phytochemicals, an inclination toward herbal medicine is seen in the population. These herbal products are also associated with concerns like poor aqueous solubility, compromised permeation, and a low degree of bioavailability. So, the emergence of nanotechnology in the herbal medicine is required to nullify the associated concerns of conventional antidiabetic drugs. The present review aims to compile the literature available for the nano-interventions pertinent to herbal products for diabetes management.

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

The significance of silver nanostructures has been growing considerably, thanks to their ubiquitous presence in numerous applications, including but not limited to renewable energy, electronics, biosensors, wastewater treatment, medicine, and clinical equipment. The properties of silver nanostructures, such as size, size distribution, and morphology, are strongly dependent on synthesis process conditions such as the process type, equipment type, reagent type, precursor concentration, temperature, process duration, and pH. Physical and chemical methods have been among the most common methods to synthesize silver nanostructures; however, they possess substantial disadvantages and short-comings, especially compared to green synthesis methods. On the contrary, the number of green synthesis techniques has been increasing during the last decade and they have emerged as alternative routes towards facile and effective synthesis of silver nanostructures with different morphologies. In this review, we have initially outlined the most common and popular chemical and physical methodologies and reviewed their advantages and disadvantages. Green synthesis methodologies are then discussed in detail and their advantages over chemical and physical methods have been noted. Recent studies are then reviewed in detail and the effects of essential reaction parameters, such as temperature, pH, precursor, and reagent concentration, on silver nanostructure size and morphology are discussed. Also, green synthesis techniques used for the synthesis of one-dimensional (1D) silver nanostructures have been reviewed, and the potential of alternative green reagents for their synthesis has been discussed. Furthermore, current challenges regarding the green synthesis of 1D silver nanostructures and future direction are outlined. To sum up, we aim to show the real potential of green nanotechnology towards the synthesis of silver nanostructures with various morphologies (especially 1D ones) and the possibility of altering current techniques towards more environmentally friendly, more energy-efficient, less hazardous, simpler, and cheaper procedures.

Total accepted phenolic, tannin, triterpenoid, flavonoid and sterol contents, anti-diabetic, anti-inflammatory and cytotoxic activities of Tectaria paradoxa (Fee.) Sledge

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The results of the present study revealed the phytochemical composition and bio potentials of Tectaria paradoxa (Fee.) Sledge.

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The extracts of T. paradoxa demonstrated dose dependent anti-inflammatory, anti-diabetic and cytotoxic activities.

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The anti-inflammatory activity of the Tectarai paradoxa were as follows methanol > chloroform > acetone > petroleum ether.

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The anti-diabetic properties of the Tectarai paradoxa were as follows methanol > acetone > chloroform > petroleum ether.•The cytotoxcity of the Tectarai paradoxa were as follows chloroform > petroleum ether > methanol > acetone.

The present study was aimed to reveal the phytochemical composition and bio potentials of Tectaria paradoxa (Fee.) Sledge. The total phenolic, tannin, flavonoid, terpenoids, sterols content were determined. RBC membrane stabilization against heat induced haemolysis, In-vitro Alpha-amylase inhibitory assay and Brine Shrimp lethality bioassay was performed to determine the anti-inflammatory, anti-diabetic and cytotoxic activity. Among the tested extracts, methanolic extracts of T. paradoxa showed high amount of phenolics 351.43 ± 14.5 mg GAE/g, tannin 34.38 ± 1.02 mg GAE/g, flavonoids 1384.44 ± 50.92 mg QE/g, triterpenoids 130.5 ± 2.77 mg/g and acetone extracts of T. paradoxa displayed maximum amount of sterols 3.2 ± 0.2 mg/g. The extracts of T. paradoxa demonstrated dose dependent anti-inflammatory, anti-diabetic and cytotoxic activities. The anti-inflammatory activity of the T. paradoxa were as follows methanol > chloroform > acetone > petroleum ether. The anti-diabetic properties of the T. paradoxa were as follows methanol > acetone > chloroform > petroleum ether. The cytotoxicity of the T. paradoxa were as follows chloroform (LC₅₀ = 25.52 μg/mL) > petroleum ether (LC₅₀ = 36.99 μg/mL) > methanol (LC₅₀ = 44.26 μg/mL) > acetone (LC₅₀ = 55.9 μg/mL). The existence of phenolics, tannin, flavonoids, sterols and triterpenoids may be responsible for the observed biological activities. The results of the present study identified the pool of medicinal properties existence in T. paradoxa. Further studies on the isolation of active principles may bring out an alternative source for anti-inflammatory and anti-cancer drugs from T. paradoxa.

In Vitro Toxicity, Antioxidant, Anti-Inflammatory, and Antidiabetic Potential of Sphaerostephanos unitus (L.) Holttum

Pteridophytes have been widely used in several systems of medicine. Several reports have increasingly assessed their bioactive effects, but for Sphaerostephanos unitus (L.) Holttum, only its antibacterial potential has been assessed. In this sense, the present study was carried out to reveal the phytochemical profile and to determine the toxicity, antioxidant, antidiabetic, and anti-inflammatory potential of S. unitus. Brine shrimp lethality, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, phosphomolybdenum assay, superoxide radical scavenging activity, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assay (ABTS), and in vitro α-amylase inhibitory and membrane stabilization assays were applied. S. unitus extract toxicity showed variable mortality percentages, with LC50 values ranging from 4 to 30 mg/mL. DPPH radical scavenging effects of S. unitus extracts were as follows: methanol > acetone > petroleum ether > chloroform. S. unitus acetone extract displayed the strongest phosphomolybdenum reduction (10 ± 2 mg Ascorbic Acid Equivalent/g). The studied extracts also revealed efficient, superoxide scavenging effects in a dose-dependent manner. In S. unitus, the highest ABTS radical scavenging rate was observed in the chloroform extract (3000 ± 40 µmol/g). The S. unitus anti-inflammatory effect was as follows: petroleum ether > chloroform > methanol > acetone. In S. unitus extract, the highest percentage of α-amylase activity (80%) was observed for the petroleum ether extract (25 µg/mL). Faced with these findings, further studies should be performed to isolate and identify the S. unitus compounds responsible for their antioxidant, antidiabetic and anti-inflammatory effects.