Background Viral and microbial infections constitute one of the most important life-threatening problems. The emergence of new viral and bacterial infectious diseases increases the demand for new therapeutic drugs. Purpose The objective of this study was to use the aqueous and hexane extracts of Lampranthus coccineus and Malephora lutea F. Aizoaceae for the synthesis of silver nanoparticles, and to investigate its possible antiviral activity. In addition to the investigation of the phytochemical composition of the crude methanolic extracts of the two plants through UPLC-MS metabolomic profiling, and it was followed by molecular docking in order to explore the chemical compounds that might contribute to the antiviral potential. Methods The formation of SNPs was further confirmed using a transmission electron microscope (TEM), UV-Visible spectroscopy and Fourier transform infrared spectroscopy. The antiviral activity of the synthesized nanoparticles was evaluated using MTT assay against HSV-1, HAV-10 virus and Coxsackie B4 virus. Metabolomics profiling was performed using UPLC-MS and molecular docking was performed via Autodock4 and visualization was done using the Discovery studio. Results The early signs of SNPs synthesis were detected by a color change from yellow to reddish brown color. The TEM analysis of SNPs showed spherical nanoparticles with mean size ranges between 10.12 nm to 27.89 nm, and 8.91 nm 14.48 nm for Lampranthus coccineus and Malephora lutea aqueous and hexane extracts respectively. The UV-Visible spectrophotometric analysis showed an absorption peak at λmax of 417 nm.The green synthesized SNPs of L. coccineus and M. lutea showed remarkable antiviral activity against HSV-1, HAV-10, and CoxB4 virus. Metabolomics profiling of the methanolic extract of L. coccineus and M. lutea resulted in identifying 12 compounds. The docking study predicted the patterns of interactions between the compounds of L. coccineus and M. lutea with herpes simplex thymidine kinase, hepatitis A 3c proteinase, and Coxsackievirus B4 3c protease, which was similar to those of the co-crystal inhibitors and this can provide a supposed explanation for the antiviral activity of the aqueous and nano extracts of L. coccineus and M. lutea . Conclusion These results highlight that SNPs of L. coccineus and M. lutea could have antiviral activity against HSV-1, HAV-10, and CoxB4 virus.

The green synthesis of silver nanoparticles (SNPs) using plant extracts is an eco-friendly method. It is a single step and offers several advantages such as time reducing, cost-effective and environmental non-toxic. Silver nanoparticles are a type of Noble metal nanoparticles and it has tremendous applications in the field of diagnostics, therapeutics, antimicrobial activity, anticancer and neurodegenerative diseases. In the present work, the aqueous extracts of aerial parts of Lampranthus coccineus and Malephora lutea F. Aizoaceae were successfully used for the synthesis of silver nanoparticles. The formation of silver nanoparticles was early detected by a color change from pale yellow to reddish-brown color and was further confirmed by transmission electron microscope (TEM), UV–visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and energy-dispersive X-ray diffraction (EDX). The TEM analysis of showed spherical nanoparticles with a mean size between 12.86 nm and 28.19 nm and the UV- visible spectroscopy showed λmax of 417 nm, which confirms the presence of nanoparticles. The neuroprotective potential of SNPs was evaluated by assessing the antioxidant and cholinesterase inhibitory activity. Metabolomic profiling was performed on methanolic extracts of L. coccineus and M. lutea and resulted in the identification of 12 compounds, then docking was performed to investigate the possible interaction between the identified compounds and human acetylcholinesterase, butyrylcholinesterase, and glutathione transferase receptor, which are associated with the progress of Alzheimer’s disease. Overall our SNPs highlighted its promising potential in terms of anticholinesterase and antioxidant activity as plant-based anti-Alzheimer drug and against oxidative stress.

Microbial resistance, oxidative stress, and inflammatory conditions are among the leading causes of death worldwide. In the current work, silver nanoparticles (AgNPs) were biosynthesized using the aqueous extracts of parsley, corn silk (CS), gum Arabic (GA) or combination of the three extracts. The formed nanoparticles were characterized using three techniques including transmission electron microscopy (TEM), UV-visible spectrophotometer and Fourier-transform infrared spectroscopy (FTIR). The antioxidant, anti-inflammatory, and antimicrobial activities were tested for the formed nanoparticles, the aqueous extracts of each of the three plants and their combination. Oxidative stress was induced by alloxan which promoted the development of diabetes mellitus in rats. Inflammation was induced by injecting carrageenan in rats' paws. Pathogenic microorganisms causing serious urinary tract infection (UTI) were selected for the antimicrobial assay. All aqueous extracts and the biosynthesized AgNPs showed variable degrees of antioxidant, anti-inflammatory and antimicrobial activities, however, the AgNPs biosynthesized by the combination of the three aqueous extracts was the most effective one. LC/MS was done to identify the compounds present in the crude extracts that may be responsible for the observed biological activities. LC/MS resulted in the identification of 13 compounds. Docking experiments on COX-1 (cyclooxygenase-1) and COX-2 (cyclooxygenase-2) were performed to determine the compounds responsible for the antiinflammatory activity of the extracts. The results showed that silver nanoparticles synthesized by the combination of the three aqueous extracts are considered promising candidates for the development of antioxidant, anti-inflammatory and antimicrobial agents. photochemical [10], electrochemical [7, 11], reverse micelle [12], thermal decomposition [13], radiation [7,14] and microwave-assisted [7] methods. Most of these methods require the use of hazardous chemicals and high energy for the preparation of nanoparticles. Biological synthesis of nanoparticles involves the use of natural materials such as plants, bacteria, fungi [1,5,15]. The use of plants for the synthesis of nanoparticles have an advantage over other biological methods as it does not involve the use of cell culture, and does not need longer incubation time required for the reduction of metal ions [16,17]. Plants are known to contain various secondary metabolites such as alkaloids, terpenoids, flavonoids and tannins which provide suitable reducing and surface agents for the nanoparticle synthesis and stabilization. Biopolymers such as cellulose, chitosan, alginate, dextran and tree gums are another family of natural sources which were used for the reduction and stabilization of nanoparticles [17,18].Recently, pathogenic bacteria and fungi such as Staphylococci spp., Enterococci spp., Klebsiella pneumoniae, and Pseudomonas spp. demonstrated resistance to commercially available antimicrobial agents at an increasing rate and has become a global thr...

The green synthesis of silver nanoparticles (SNPs) using plant extracts has gained great attention due to its unique properties. So, in this study, the aqueous and n-hexane extracts of Lampranthus coccineus F. Aizoaceae were used for the synthesis of silver nanoparticles. The early signs of SNPs synthesis were detected by a color change from yellow to reddish-brown color. The formation of SNPs was further confirmed using a transmission electron microscope (TEM), UV-Visible spectroscopy, and zeta potential. The TEM analysis of SNPs showed spherical nanoparticles with mean size ranges between 8.55 nm to 16.44 nm for Lampranthus coccineus aqueous and hexane extracts. The UV-Visible spectrophotometric analysis showed an absorption peak at λ max of 417 nm, which confirms the formation of SNPs. Zeta potential results indicated that the particles are negatively charged and fairly stable due to the electrostatic repulsion. The cytotoxic activity of the green synthesized SNPs as well as the four isolated compounds (β-Sitosterol-3-O-β-D-glucoside, P-methoxy benzoic acid, dibutyl phthalate, and dioctyl phthalate) was evaluated using MTT assay against MCF-7, HepG-2, and HCT-116 cell lines. Metabolic profiling of the annotated twelve compounds from the crude extract of L. coccineus. These compounds, along with the four isolated compounds were subjected to molecular docking study.

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